u-boot/drivers/i2c/mvtwsi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for the TWSI (i2c) controller found on the Marvell
* orion5x and kirkwood SoC families.
*
* Author: Albert Aribaud <albert.u.boot@aribaud.net>
* Copyright (c) 2010 Albert Aribaud.
*/
#include <common.h>
#include <i2c.h>
#include <log.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <linux/bitops.h>
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
#include <linux/compat.h>
#ifdef CONFIG_DM_I2C
#include <dm.h>
#endif
DECLARE_GLOBAL_DATA_PTR;
/*
* Include a file that will provide CONFIG_I2C_MVTWSI_BASE*, and possibly other
* settings
*/
#ifndef CONFIG_DM_I2C
#if defined(CONFIG_ARCH_ORION5X)
#include <asm/arch/orion5x.h>
#elif (defined(CONFIG_ARCH_KIRKWOOD) || defined(CONFIG_ARCH_MVEBU))
#include <asm/arch/soc.h>
#elif defined(CONFIG_ARCH_SUNXI)
#include <asm/arch/i2c.h>
#else
#error Driver mvtwsi not supported by SoC or board
#endif
#endif /* CONFIG_DM_I2C */
/*
* On SUNXI, we get CONFIG_SYS_TCLK from this include, so we want to
* always have it.
*/
#if defined(CONFIG_DM_I2C) && defined(CONFIG_ARCH_SUNXI)
#include <asm/arch/i2c.h>
#endif
/*
* TWSI register structure
*/
#ifdef CONFIG_ARCH_SUNXI
struct mvtwsi_registers {
u32 slave_address;
u32 xtnd_slave_addr;
u32 data;
u32 control;
u32 status;
u32 baudrate;
u32 soft_reset;
u32 debug; /* Dummy field for build compatibility with mvebu */
};
#else
struct mvtwsi_registers {
u32 slave_address;
u32 data;
u32 control;
union {
u32 status; /* When reading */
u32 baudrate; /* When writing */
};
u32 xtnd_slave_addr;
u32 reserved0[2];
u32 soft_reset;
u32 reserved1[27];
u32 debug;
};
#endif
#ifdef CONFIG_DM_I2C
struct mvtwsi_i2c_dev {
/* TWSI Register base for the device */
struct mvtwsi_registers *base;
/* Number of the device (determined from cell-index property) */
int index;
/* The I2C slave address for the device */
u8 slaveadd;
/* The configured I2C speed in Hz */
uint speed;
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
/* The current length of a clock period (depending on speed) */
uint tick;
};
#endif /* CONFIG_DM_I2C */
/*
* enum mvtwsi_ctrl_register_fields - Bit masks for flags in the control
* register
*/
enum mvtwsi_ctrl_register_fields {
/* Acknowledge bit */
MVTWSI_CONTROL_ACK = 0x00000004,
/* Interrupt flag */
MVTWSI_CONTROL_IFLG = 0x00000008,
/* Stop bit */
MVTWSI_CONTROL_STOP = 0x00000010,
/* Start bit */
MVTWSI_CONTROL_START = 0x00000020,
/* I2C enable */
MVTWSI_CONTROL_TWSIEN = 0x00000040,
/* Interrupt enable */
MVTWSI_CONTROL_INTEN = 0x00000080,
};
/*
* On sun6i and newer, IFLG is a write-clear bit, which is cleared by writing 1;
* on other platforms, it is a normal r/w bit, which is cleared by writing 0.
*/
#ifdef CONFIG_SUNXI_GEN_SUN6I
#define MVTWSI_CONTROL_CLEAR_IFLG 0x00000008
#else
#define MVTWSI_CONTROL_CLEAR_IFLG 0x00000000
#endif
/*
* enum mvstwsi_status_values - Possible values of I2C controller's status
* register
*
* Only those statuses expected in normal master operation on
* non-10-bit-address devices are specified.
*
* Every status that's unexpected during normal operation (bus errors,
* arbitration losses, missing ACKs...) is passed back to the caller as an error
* code.
*/
enum mvstwsi_status_values {
/* START condition transmitted */
MVTWSI_STATUS_START = 0x08,
/* Repeated START condition transmitted */
MVTWSI_STATUS_REPEATED_START = 0x10,
/* Address + write bit transmitted, ACK received */
MVTWSI_STATUS_ADDR_W_ACK = 0x18,
/* Data transmitted, ACK received */
MVTWSI_STATUS_DATA_W_ACK = 0x28,
/* Address + read bit transmitted, ACK received */
MVTWSI_STATUS_ADDR_R_ACK = 0x40,
/* Address + read bit transmitted, ACK not received */
MVTWSI_STATUS_ADDR_R_NAK = 0x48,
/* Data received, ACK transmitted */
MVTWSI_STATUS_DATA_R_ACK = 0x50,
/* Data received, ACK not transmitted */
MVTWSI_STATUS_DATA_R_NAK = 0x58,
/* No relevant status */
MVTWSI_STATUS_IDLE = 0xF8,
};
/*
* enum mvstwsi_ack_flags - Determine whether a read byte should be
* acknowledged or not.
*/
enum mvtwsi_ack_flags {
/* Send NAK after received byte */
MVTWSI_READ_NAK = 0,
/* Send ACK after received byte */
MVTWSI_READ_ACK = 1,
};
/*
* calc_tick() - Calculate the duration of a clock cycle from the I2C speed
*
* @speed: The speed in Hz to calculate the clock cycle duration for.
* @return The duration of a clock cycle in ns.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
inline uint calc_tick(uint speed)
{
/* One tick = the duration of a period at the specified speed in ns (we
* add 100 ns to be on the safe side) */
return (1000000000u / speed) + 100;
}
#ifndef CONFIG_DM_I2C
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
/*
* twsi_get_base() - Get controller register base for specified adapter
*
* @adap: Adapter to get the register base for.
* @return Register base for the specified adapter.
*/
static struct mvtwsi_registers *twsi_get_base(struct i2c_adapter *adap)
{
switch (adap->hwadapnr) {
#ifdef CONFIG_I2C_MVTWSI_BASE0
case 0:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE0;
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE1
case 1:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE1;
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE2
case 2:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE2;
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE3
case 3:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE3;
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE4
case 4:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE4;
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE5
case 5:
return (struct mvtwsi_registers *)CONFIG_I2C_MVTWSI_BASE5;
#endif
default:
printf("Missing mvtwsi controller %d base\n", adap->hwadapnr);
break;
}
return NULL;
}
#endif
/*
* enum mvtwsi_error_class - types of I2C errors
*/
enum mvtwsi_error_class {
/* The controller returned a different status than expected */
MVTWSI_ERROR_WRONG_STATUS = 0x01,
/* The controller timed out */
MVTWSI_ERROR_TIMEOUT = 0x02,
};
/*
* mvtwsi_error() - Build I2C return code from error information
*
* For debugging purposes, this function packs some information of an occurred
* error into a return code. These error codes are returned from I2C API
* functions (i2c_{read,write}, dm_i2c_{read,write}, etc.).
*
* @ec: The error class of the error (enum mvtwsi_error_class).
* @lc: The last value of the control register.
* @ls: The last value of the status register.
* @es: The expected value of the status register.
* @return The generated error code.
*/
inline uint mvtwsi_error(uint ec, uint lc, uint ls, uint es)
{
return ((ec << 24) & 0xFF000000)
| ((lc << 16) & 0x00FF0000)
| ((ls << 8) & 0x0000FF00)
| (es & 0xFF);
}
/*
* twsi_wait() - Wait for I2C bus interrupt flag and check status, or time out.
*
* @return Zero if status is as expected, or a non-zero code if either a time
* out occurred, or the status was not the expected one.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status,
uint tick)
{
int control, status;
int timeout = 1000;
do {
control = readl(&twsi->control);
if (control & MVTWSI_CONTROL_IFLG) {
/*
* On Armada 38x it seems that the controller works as
* if it first set the MVTWSI_CONTROL_IFLAG in the
* control register and only after that it changed the
* status register.
* This sometimes caused weird bugs which only appeared
* on selected I2C speeds and even then only sometimes.
* We therefore add here a simple ndealy(100), which
* seems to fix this weird bug.
*/
ndelay(100);
status = readl(&twsi->status);
if (status == expected_status)
return 0;
else
return mvtwsi_error(
MVTWSI_ERROR_WRONG_STATUS,
control, status, expected_status);
}
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
ndelay(tick); /* One clock cycle */
} while (timeout--);
status = readl(&twsi->status);
return mvtwsi_error(MVTWSI_ERROR_TIMEOUT, control, status,
expected_status);
}
/*
* twsi_start() - Assert a START condition on the bus.
*
* This function is used in both single I2C transactions and inside
* back-to-back transactions (repeated starts).
*
* @twsi: The MVTWSI register structure to use.
* @expected_status: The I2C bus status expected to be asserted after the
* operation completion.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if status is as expected, or a non-zero code if either a time
* out occurred or the status was not the expected one.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
static int twsi_start(struct mvtwsi_registers *twsi, int expected_status,
uint tick)
{
/* Assert START */
writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_START |
MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* Wait for controller to process START */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return twsi_wait(twsi, expected_status, tick);
}
/*
* twsi_send() - Send a byte on the I2C bus.
*
* The byte may be part of an address byte or data.
*
* @twsi: The MVTWSI register structure to use.
* @byte: The byte to send.
* @expected_status: The I2C bus status expected to be asserted after the
* operation completion.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if status is as expected, or a non-zero code if either a time
* out occurred or the status was not the expected one.
*/
static int twsi_send(struct mvtwsi_registers *twsi, u8 byte,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
int expected_status, uint tick)
{
/* Write byte to data register for sending */
writel(byte, &twsi->data);
/* Clear any pending interrupt -- that will cause sending */
writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_CLEAR_IFLG,
&twsi->control);
/* Wait for controller to receive byte, and check ACK */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return twsi_wait(twsi, expected_status, tick);
}
/*
* twsi_recv() - Receive a byte on the I2C bus.
*
* The static variable mvtwsi_control_flags controls whether we ack or nak.
*
* @twsi: The MVTWSI register structure to use.
* @byte: The byte to send.
* @ack_flag: Flag that determines whether the received byte should
* be acknowledged by the controller or not (sent ACK/NAK).
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if status is as expected, or a non-zero code if either a time
* out occurred or the status was not the expected one.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag,
uint tick)
{
int expected_status, status, control;
/* Compute expected status based on passed ACK flag */
expected_status = ack_flag ? MVTWSI_STATUS_DATA_R_ACK :
MVTWSI_STATUS_DATA_R_NAK;
/* Acknowledge *previous state*, and launch receive */
control = MVTWSI_CONTROL_TWSIEN;
control |= ack_flag == MVTWSI_READ_ACK ? MVTWSI_CONTROL_ACK : 0;
writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* Wait for controller to receive byte, and assert ACK or NAK */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = twsi_wait(twsi, expected_status, tick);
/* If we did receive the expected byte, store it */
if (status == 0)
*byte = readl(&twsi->data);
return status;
}
/*
* twsi_stop() - Assert a STOP condition on the bus.
*
* This function is also used to force the bus back to idle state (SDA =
* SCL = 1).
*
* @twsi: The MVTWSI register structure to use.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if the operation succeeded, or a non-zero code if a time out
* occurred.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
static int twsi_stop(struct mvtwsi_registers *twsi, uint tick)
{
int control, stop_status;
int status = 0;
int timeout = 1000;
/* Assert STOP */
control = MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_STOP;
writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* Wait for IDLE; IFLG won't rise, so we can't use twsi_wait() */
do {
stop_status = readl(&twsi->status);
if (stop_status == MVTWSI_STATUS_IDLE)
break;
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
ndelay(tick); /* One clock cycle */
} while (timeout--);
control = readl(&twsi->control);
if (stop_status != MVTWSI_STATUS_IDLE)
status = mvtwsi_error(MVTWSI_ERROR_TIMEOUT,
control, status, MVTWSI_STATUS_IDLE);
return status;
}
/*
* twsi_calc_freq() - Compute I2C frequency depending on m and n parameters.
*
* @n: Parameter 'n' for the frequency calculation algorithm.
* @m: Parameter 'm' for the frequency calculation algorithm.
* @return The I2C frequency corresponding to the passed m and n parameters.
*/
static uint twsi_calc_freq(const int n, const int m)
{
#ifdef CONFIG_ARCH_SUNXI
return CONFIG_SYS_TCLK / (10 * (m + 1) * (1 << n));
#else
return CONFIG_SYS_TCLK / (10 * (m + 1) * (2 << n));
#endif
}
/*
* twsi_reset() - Reset the I2C controller.
*
* Resetting the controller also resets the baud rate and slave address, hence
* they must be re-established after the reset.
*
* @twsi: The MVTWSI register structure to use.
*/
static void twsi_reset(struct mvtwsi_registers *twsi)
{
/* Reset controller */
writel(0, &twsi->soft_reset);
/* Wait 2 ms -- this is what the Marvell LSP does */
udelay(20000);
}
/*
* __twsi_i2c_set_bus_speed() - Set the speed of the I2C controller.
*
* This function sets baud rate to the highest possible value that does not
* exceed the requested rate.
*
* @twsi: The MVTWSI register structure to use.
* @requested_speed: The desired frequency the controller should run at
* in Hz.
* @return The actual frequency the controller was configured to.
*/
static uint __twsi_i2c_set_bus_speed(struct mvtwsi_registers *twsi,
uint requested_speed)
{
uint tmp_speed, highest_speed, n, m;
uint baud = 0x44; /* Baud rate after controller reset */
highest_speed = 0;
/* Successively try m, n combinations, and use the combination
* resulting in the largest speed that's not above the requested
* speed */
for (n = 0; n < 8; n++) {
for (m = 0; m < 16; m++) {
tmp_speed = twsi_calc_freq(n, m);
if ((tmp_speed <= requested_speed) &&
(tmp_speed > highest_speed)) {
highest_speed = tmp_speed;
baud = (m << 3) | n;
}
}
}
writel(baud, &twsi->baudrate);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
/* Wait for controller for one tick */
#ifdef CONFIG_DM_I2C
ndelay(calc_tick(highest_speed));
#else
ndelay(10000);
#endif
return highest_speed;
}
/*
* __twsi_i2c_init() - Initialize the I2C controller.
*
* @twsi: The MVTWSI register structure to use.
* @speed: The initial frequency the controller should run at
* in Hz.
* @slaveadd: The I2C address to be set for the I2C master.
* @actual_speed: A output parameter that receives the actual frequency
* in Hz the controller was set to by the function.
* @return Zero if the operation succeeded, or a non-zero code if a time out
* occurred.
*/
static void __twsi_i2c_init(struct mvtwsi_registers *twsi, int speed,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
int slaveadd, uint *actual_speed)
{
uint tmp_speed;
/* Reset controller */
twsi_reset(twsi);
/* Set speed */
tmp_speed = __twsi_i2c_set_bus_speed(twsi, speed);
if (actual_speed)
*actual_speed = tmp_speed;
/* Set slave address; even though we don't use it */
writel(slaveadd, &twsi->slave_address);
writel(0, &twsi->xtnd_slave_addr);
/* Assert STOP, but don't care for the result */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
#ifdef CONFIG_DM_I2C
(void) twsi_stop(twsi, calc_tick(*actual_speed));
#else
(void) twsi_stop(twsi, 10000);
#endif
}
/*
* i2c_begin() - Start a I2C transaction.
*
* Begin a I2C transaction with a given expected start status and chip address.
* A START is asserted, and the address byte is sent to the I2C controller. The
* expected address status will be derived from the direction bit (bit 0) of
* the address byte.
*
* @twsi: The MVTWSI register structure to use.
* @expected_start_status: The I2C status the controller is expected to
* assert after the address byte was sent.
* @addr: The address byte to be sent.
* @tick: The duration of a clock cycle at the current
* I2C speed.
* @return Zero if the operation succeeded, or a non-zero code if a time out or
* unexpected I2C status occurred.
*/
static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
u8 addr, uint tick)
{
int status, expected_addr_status;
/* Compute the expected address status from the direction bit in
* the address byte */
if (addr & 1) /* Reading */
expected_addr_status = MVTWSI_STATUS_ADDR_R_ACK;
else /* Writing */
expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK;
/* Assert START */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = twsi_start(twsi, expected_start_status, tick);
/* Send out the address if the start went well */
if (status == 0)
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = twsi_send(twsi, addr, expected_addr_status, tick);
/* Return 0, or the status of the first failure */
return status;
}
/*
* __twsi_i2c_probe_chip() - Probe the given I2C chip address.
*
* This function begins a I2C read transaction, does a dummy read and NAKs; if
* the procedure succeeds, the chip is considered to be present.
*
* @twsi: The MVTWSI register structure to use.
* @chip: The chip address to probe.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if the operation succeeded, or a non-zero code if a time out or
* unexpected I2C status occurred.
*/
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip,
uint tick)
{
u8 dummy_byte;
int status;
/* Begin i2c read */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1) | 1, tick);
/* Dummy read was accepted: receive byte, but NAK it. */
if (status == 0)
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = twsi_recv(twsi, &dummy_byte, MVTWSI_READ_NAK, tick);
/* Stop transaction */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status;
}
/*
* __twsi_i2c_read() - Read data from a I2C chip.
*
* This function begins a I2C write transaction, and transmits the address
* bytes; then begins a I2C read transaction, and receives the data bytes.
*
* NOTE: Some devices want a stop right before the second start, while some
* will choke if it is there. Since deciding this is not yet supported in
* higher level APIs, we need to make a decision here, and for the moment that
* will be a repeated start without a preceding stop.
*
* @twsi: The MVTWSI register structure to use.
* @chip: The chip address to read from.
* @addr: The address bytes to send.
* @alen: The length of the address bytes in bytes.
* @data: The buffer to receive the data read from the chip (has to have
* a size of at least 'length' bytes).
* @length: The amount of data to be read from the chip in bytes.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if the operation succeeded, or a non-zero code if a time out or
* unexpected I2C status occurred.
*/
static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
u8 *addr, int alen, uchar *data, int length,
uint tick)
{
int status = 0;
int stop_status;
int expected_start = MVTWSI_STATUS_START;
if (alen > 0) {
/* Begin i2c write to send the address bytes */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = i2c_begin(twsi, expected_start, (chip << 1), tick);
/* Send address bytes */
while ((status == 0) && alen--)
status = twsi_send(twsi, addr[alen],
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
MVTWSI_STATUS_DATA_W_ACK, tick);
/* Send repeated STARTs after the initial START */
expected_start = MVTWSI_STATUS_REPEATED_START;
}
/* Begin i2c read to receive data bytes */
if (status == 0)
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = i2c_begin(twsi, expected_start, (chip << 1) | 1, tick);
/* Receive actual data bytes; set NAK if we if we have nothing more to
* read */
while ((status == 0) && length--)
status = twsi_recv(twsi, data++,
length > 0 ?
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
MVTWSI_READ_ACK : MVTWSI_READ_NAK, tick);
/* Stop transaction */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
stop_status = twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status != 0 ? status : stop_status;
}
/*
* __twsi_i2c_write() - Send data to a I2C chip.
*
* This function begins a I2C write transaction, and transmits the address
* bytes; then begins a new I2C write transaction, and sends the data bytes.
*
* @twsi: The MVTWSI register structure to use.
* @chip: The chip address to read from.
* @addr: The address bytes to send.
* @alen: The length of the address bytes in bytes.
* @data: The buffer containing the data to be sent to the chip.
* @length: The length of data to be sent to the chip in bytes.
* @tick: The duration of a clock cycle at the current I2C speed.
* @return Zero if the operation succeeded, or a non-zero code if a time out or
* unexpected I2C status occurred.
*/
static int __twsi_i2c_write(struct mvtwsi_registers *twsi, uchar chip,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
u8 *addr, int alen, uchar *data, int length,
uint tick)
{
int status, stop_status;
/* Begin i2c write to send first the address bytes, then the
* data bytes */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1), tick);
/* Send address bytes */
while ((status == 0) && (alen-- > 0))
status = twsi_send(twsi, addr[alen], MVTWSI_STATUS_DATA_W_ACK,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
tick);
/* Send data bytes */
while ((status == 0) && (length-- > 0))
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
status = twsi_send(twsi, *(data++), MVTWSI_STATUS_DATA_W_ACK,
tick);
/* Stop transaction */
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
stop_status = twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status != 0 ? status : stop_status;
}
#ifndef CONFIG_DM_I2C
static void twsi_i2c_init(struct i2c_adapter *adap, int speed,
int slaveadd)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
__twsi_i2c_init(twsi, speed, slaveadd, NULL);
}
static uint twsi_i2c_set_bus_speed(struct i2c_adapter *adap,
uint requested_speed)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
__twsi_i2c_set_bus_speed(twsi, requested_speed);
return 0;
}
static int twsi_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return __twsi_i2c_probe_chip(twsi, chip, 10000);
}
static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *data, int length)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
u8 addr_bytes[4];
addr_bytes[0] = (addr >> 0) & 0xFF;
addr_bytes[1] = (addr >> 8) & 0xFF;
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return __twsi_i2c_read(twsi, chip, addr_bytes, alen, data, length,
10000);
}
static int twsi_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *data, int length)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
u8 addr_bytes[4];
addr_bytes[0] = (addr >> 0) & 0xFF;
addr_bytes[1] = (addr >> 8) & 0xFF;
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length,
10000);
}
#ifdef CONFIG_I2C_MVTWSI_BASE0
U_BOOT_I2C_ADAP_COMPLETE(twsi0, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0)
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE1
U_BOOT_I2C_ADAP_COMPLETE(twsi1, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 1)
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE2
U_BOOT_I2C_ADAP_COMPLETE(twsi2, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 2)
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE3
U_BOOT_I2C_ADAP_COMPLETE(twsi3, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 3)
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE4
U_BOOT_I2C_ADAP_COMPLETE(twsi4, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 4)
#endif
#ifdef CONFIG_I2C_MVTWSI_BASE5
U_BOOT_I2C_ADAP_COMPLETE(twsi5, twsi_i2c_init, twsi_i2c_probe,
twsi_i2c_read, twsi_i2c_write,
twsi_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 5)
#endif
#else /* CONFIG_DM_I2C */
static int mvtwsi_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
u32 chip_flags)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
return __twsi_i2c_probe_chip(dev->base, chip_addr, dev->tick);
}
static int mvtwsi_i2c_set_bus_speed(struct udevice *bus, uint speed)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
dev->speed = __twsi_i2c_set_bus_speed(dev->base, speed);
dev->tick = calc_tick(dev->speed);
return 0;
}
static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
dev->base = devfdt_get_addr_ptr(bus);
if (!dev->base)
return -ENOMEM;
dev->index = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
"cell-index", -1);
dev->slaveadd = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
"u-boot,i2c-slave-addr", 0x0);
dev->speed = dev_read_u32_default(bus, "clock-frequency",
I2C_SPEED_STANDARD_RATE);
return 0;
}
static void twsi_disable_i2c_slave(struct mvtwsi_registers *twsi)
{
clrbits_le32(&twsi->debug, BIT(18));
}
static int mvtwsi_i2c_bind(struct udevice *bus)
{
struct mvtwsi_registers *twsi = devfdt_get_addr_ptr(bus);
/* Disable the hidden slave in i2c0 of these platforms */
if ((IS_ENABLED(CONFIG_ARMADA_38X) || IS_ENABLED(CONFIG_ARCH_KIRKWOOD))
&& bus->req_seq == 0)
twsi_disable_i2c_slave(twsi);
return 0;
}
static int mvtwsi_i2c_probe(struct udevice *bus)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
uint actual_speed;
__twsi_i2c_init(dev->base, dev->speed, dev->slaveadd, &actual_speed);
dev->speed = actual_speed;
dev->tick = calc_tick(dev->speed);
return 0;
}
static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
struct i2c_msg *dmsg, *omsg, dummy;
memset(&dummy, 0, sizeof(struct i2c_msg));
/* We expect either two messages (one with an offset and one with the
* actual data) or one message (just data or offset/data combined) */
if (nmsgs > 2 || nmsgs == 0) {
debug("%s: Only one or two messages are supported.", __func__);
return -1;
}
omsg = nmsgs == 1 ? &dummy : msg;
dmsg = nmsgs == 1 ? msg : msg + 1;
if (dmsg->flags & I2C_M_RD)
return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
omsg->len, dmsg->buf, dmsg->len,
dev->tick);
else
return __twsi_i2c_write(dev->base, dmsg->addr, omsg->buf,
i2c: mvtwsi: Make delay times frequency-dependent Some devices using the MVTWSI driver have the option to run at speeds faster than Standard Mode (100kHZ). On the Armada 38x controllers, this is actually necessary, since due to erratum FE-8471889, a timing violation concerning repeated starts prevents the controller from working correctly in Standard Mode. One of the workarounds recommended in the erratum is to set the bus to Fast Mode (400kHZ) operation and ensure all connected devices are set to Fast Mode. In the current version of the driver, however, the delay times are hard-coded to 10ms, corresponding to Standard Mode operation. To take full advantage of the faster modes, we would need to either keep the currently configured I2C speed in a globally accessible variable, or pass it to the necessary functions as a parameter. For DM, the first option is not a problem, and we can simply keep the speed in the private data of the driver. For the legacy interface, however, we would need to introduce a static variable, which would cause problems with boots from NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate twsi_control_flags." As to not clutter the interface with yet another parameter, we therefore keep the default 10ms delays for the legacy functions. In DM mode, we make the delay time dependant on the frequency to allow taking full advantage of faster modes of operation (tested with up to 1MHZ frequency on Armada MV88F6820). Signed-off-by: Mario Six <mario.six@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
2016-07-21 09:57:12 +00:00
omsg->len, dmsg->buf, dmsg->len,
dev->tick);
}
static const struct dm_i2c_ops mvtwsi_i2c_ops = {
.xfer = mvtwsi_i2c_xfer,
.probe_chip = mvtwsi_i2c_probe_chip,
.set_bus_speed = mvtwsi_i2c_set_bus_speed,
};
static const struct udevice_id mvtwsi_i2c_ids[] = {
{ .compatible = "marvell,mv64xxx-i2c", },
{ .compatible = "marvell,mv78230-i2c", },
{ .compatible = "allwinner,sun6i-a31-i2c", },
{ /* sentinel */ }
};
U_BOOT_DRIVER(i2c_mvtwsi) = {
.name = "i2c_mvtwsi",
.id = UCLASS_I2C,
.of_match = mvtwsi_i2c_ids,
.bind = mvtwsi_i2c_bind,
.probe = mvtwsi_i2c_probe,
.ofdata_to_platdata = mvtwsi_i2c_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct mvtwsi_i2c_dev),
.ops = &mvtwsi_i2c_ops,
};
#endif /* CONFIG_DM_I2C */