u-boot/drivers/i2c/exynos_hs_i2c.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

560 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2016, Google Inc
*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, d.mueller@elsoft.ch
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <asm/arch/clk.h>
#include <asm/arch/cpu.h>
#include <asm/arch/pinmux.h>
#include "s3c24x0_i2c.h"
DECLARE_GLOBAL_DATA_PTR;
/* HSI2C-specific register description */
/* I2C_CTL Register bits */
#define HSI2C_FUNC_MODE_I2C (1u << 0)
#define HSI2C_MASTER (1u << 3)
#define HSI2C_RXCHON (1u << 6) /* Write/Send */
#define HSI2C_TXCHON (1u << 7) /* Read/Receive */
#define HSI2C_SW_RST (1u << 31)
/* I2C_FIFO_CTL Register bits */
#define HSI2C_RXFIFO_EN (1u << 0)
#define HSI2C_TXFIFO_EN (1u << 1)
#define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16)
#define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4)
/* I2C_TRAILING_CTL Register bits */
#define HSI2C_TRAILING_COUNT (0xff)
/* I2C_INT_EN Register bits */
#define HSI2C_TX_UNDERRUN_EN (1u << 2)
#define HSI2C_TX_OVERRUN_EN (1u << 3)
#define HSI2C_RX_UNDERRUN_EN (1u << 4)
#define HSI2C_RX_OVERRUN_EN (1u << 5)
#define HSI2C_INT_TRAILING_EN (1u << 6)
#define HSI2C_INT_I2C_EN (1u << 9)
#define HSI2C_INT_ERROR_MASK (HSI2C_TX_UNDERRUN_EN |\
HSI2C_TX_OVERRUN_EN |\
HSI2C_RX_UNDERRUN_EN |\
HSI2C_RX_OVERRUN_EN |\
HSI2C_INT_TRAILING_EN)
/* I2C_CONF Register bits */
#define HSI2C_AUTO_MODE (1u << 31)
#define HSI2C_10BIT_ADDR_MODE (1u << 30)
#define HSI2C_HS_MODE (1u << 29)
/* I2C_AUTO_CONF Register bits */
#define HSI2C_READ_WRITE (1u << 16)
#define HSI2C_STOP_AFTER_TRANS (1u << 17)
#define HSI2C_MASTER_RUN (1u << 31)
/* I2C_TIMEOUT Register bits */
#define HSI2C_TIMEOUT_EN (1u << 31)
/* I2C_TRANS_STATUS register bits */
#define HSI2C_MASTER_BUSY (1u << 17)
#define HSI2C_SLAVE_BUSY (1u << 16)
#define HSI2C_TIMEOUT_AUTO (1u << 4)
#define HSI2C_NO_DEV (1u << 3)
#define HSI2C_NO_DEV_ACK (1u << 2)
#define HSI2C_TRANS_ABORT (1u << 1)
#define HSI2C_TRANS_SUCCESS (1u << 0)
#define HSI2C_TRANS_ERROR_MASK (HSI2C_TIMEOUT_AUTO |\
HSI2C_NO_DEV | HSI2C_NO_DEV_ACK |\
HSI2C_TRANS_ABORT)
#define HSI2C_TRANS_FINISHED_MASK (HSI2C_TRANS_ERROR_MASK | HSI2C_TRANS_SUCCESS)
/* I2C_FIFO_STAT Register bits */
#define HSI2C_RX_FIFO_EMPTY (1u << 24)
#define HSI2C_RX_FIFO_FULL (1u << 23)
#define HSI2C_TX_FIFO_EMPTY (1u << 8)
#define HSI2C_TX_FIFO_FULL (1u << 7)
#define HSI2C_RX_FIFO_LEVEL(x) (((x) >> 16) & 0x7f)
#define HSI2C_TX_FIFO_LEVEL(x) ((x) & 0x7f)
#define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
#define HSI2C_TIMEOUT_US 10000 /* 10 ms, finer granularity */
/*
* Wait for transfer completion.
*
* This function reads the interrupt status register waiting for the INT_I2C
* bit to be set, which indicates copletion of a transaction.
*
* @param i2c: pointer to the appropriate register bank
*
* @return: I2C_OK in case of successful completion, I2C_NOK_TIMEOUT in case
* the status bits do not get set in time, or an approrpiate error
* value in case of transfer errors.
*/
static int hsi2c_wait_for_trx(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (i-- > 0) {
u32 int_status = readl(&i2c->usi_int_stat);
if (int_status & HSI2C_INT_I2C_EN) {
u32 trans_status = readl(&i2c->usi_trans_status);
/* Deassert pending interrupt. */
writel(int_status, &i2c->usi_int_stat);
if (trans_status & HSI2C_NO_DEV_ACK) {
debug("%s: no ACK from device\n", __func__);
return I2C_NACK;
}
if (trans_status & HSI2C_NO_DEV) {
debug("%s: no device\n", __func__);
return I2C_NOK;
}
if (trans_status & HSI2C_TRANS_ABORT) {
debug("%s: arbitration lost\n", __func__);
return I2C_NOK_LA;
}
if (trans_status & HSI2C_TIMEOUT_AUTO) {
debug("%s: device timed out\n", __func__);
return I2C_NOK_TOUT;
}
return I2C_OK;
}
udelay(1);
}
debug("%s: transaction timeout!\n", __func__);
return I2C_NOK_TOUT;
}
static int hsi2c_get_clk_details(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
ulong clkin;
unsigned int op_clk = i2c_bus->clock_frequency;
unsigned int i = 0, utemp0 = 0, utemp1 = 0;
unsigned int t_ftl_cycle;
#if (defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
clkin = get_i2c_clk();
#else
clkin = get_PCLK();
#endif
/* FPCLK / FI2C =
* (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
* uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
* uTemp1 = (TSCLK_L + TSCLK_H + 2)
* uTemp2 = TSCLK_L + TSCLK_H
*/
t_ftl_cycle = (readl(&hsregs->usi_conf) >> 16) & 0x7;
utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
/* CLK_DIV max is 256 */
for (i = 0; i < 256; i++) {
utemp1 = utemp0 / (i + 1);
if ((utemp1 < 512) && (utemp1 > 4)) {
i2c_bus->clk_cycle = utemp1 - 2;
i2c_bus->clk_div = i;
return 0;
}
}
return -EINVAL;
}
static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
unsigned int t_sr_release;
unsigned int n_clkdiv;
unsigned int t_start_su, t_start_hd;
unsigned int t_stop_su;
unsigned int t_data_su, t_data_hd;
unsigned int t_scl_l, t_scl_h;
u32 i2c_timing_s1;
u32 i2c_timing_s2;
u32 i2c_timing_s3;
u32 i2c_timing_sla;
n_clkdiv = i2c_bus->clk_div;
t_scl_l = i2c_bus->clk_cycle / 2;
t_scl_h = i2c_bus->clk_cycle / 2;
t_start_su = t_scl_l;
t_start_hd = t_scl_l;
t_stop_su = t_scl_l;
t_data_su = t_scl_l / 2;
t_data_hd = t_scl_l / 2;
t_sr_release = i2c_bus->clk_cycle;
i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0;
i2c_timing_sla = t_data_hd << 0;
writel(HSI2C_TRAILING_COUNT, &hsregs->usi_trailing_ctl);
/* Clear to enable Timeout */
clrsetbits_le32(&hsregs->usi_timeout, HSI2C_TIMEOUT_EN, 0);
/* set AUTO mode */
writel(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf);
/* Enable completion conditions' reporting. */
writel(HSI2C_INT_I2C_EN, &hsregs->usi_int_en);
/* Enable FIFOs */
writel(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl);
/* Currently operating in Fast speed mode. */
writel(i2c_timing_s1, &hsregs->usi_timing_fs1);
writel(i2c_timing_s2, &hsregs->usi_timing_fs2);
writel(i2c_timing_s3, &hsregs->usi_timing_fs3);
writel(i2c_timing_sla, &hsregs->usi_timing_sla);
}
/* SW reset for the high speed bus */
static void exynos5_i2c_reset(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *i2c = i2c_bus->hsregs;
u32 i2c_ctl;
/* Set and clear the bit for reset */
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl |= HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl &= ~HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
/* Initialize the configure registers */
hsi2c_ch_init(i2c_bus);
}
/*
* Poll the appropriate bit of the fifo status register until the interface is
* ready to process the next byte or timeout expires.
*
* In addition to the FIFO status register this function also polls the
* interrupt status register to be able to detect unexpected transaction
* completion.
*
* When FIFO is ready to process the next byte, this function returns I2C_OK.
* If in course of polling the INT_I2C assertion is detected, the function
* returns I2C_NOK. If timeout happens before any of the above conditions is
* met - the function returns I2C_NOK_TOUT;
* @param i2c: pointer to the appropriate i2c register bank.
* @param rx_transfer: set to True if the receive transaction is in progress.
* @return: as described above.
*/
static unsigned hsi2c_poll_fifo(struct exynos5_hsi2c *i2c, bool rx_transfer)
{
u32 fifo_bit = rx_transfer ? HSI2C_RX_FIFO_EMPTY : HSI2C_TX_FIFO_FULL;
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_fifo_stat) & fifo_bit) {
if (readl(&i2c->usi_int_stat) & HSI2C_INT_I2C_EN) {
/*
* There is a chance that assertion of
* HSI2C_INT_I2C_EN and deassertion of
* HSI2C_RX_FIFO_EMPTY happen simultaneously. Let's
* give FIFO status priority and check it one more
* time before reporting interrupt. The interrupt will
* be reported next time this function is called.
*/
if (rx_transfer &&
!(readl(&i2c->usi_fifo_stat) & fifo_bit))
break;
return I2C_NOK;
}
if (!i--) {
debug("%s: FIFO polling timeout!\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
/*
* Preapre hsi2c transaction, either read or write.
*
* Set up transfer as described in section 27.5.1.2 'I2C Channel Auto Mode' of
* the 5420 UM.
*
* @param i2c: pointer to the appropriate i2c register bank.
* @param chip: slave address on the i2c bus (with read/write bit exlcuded)
* @param len: number of bytes expected to be sent or received
* @param rx_transfer: set to true for receive transactions
* @param: issue_stop: set to true if i2c stop condition should be generated
* after this transaction.
* @return: I2C_NOK_TOUT in case the bus remained busy for HSI2C_TIMEOUT_US,
* I2C_OK otherwise.
*/
static int hsi2c_prepare_transaction(struct exynos5_hsi2c *i2c,
u8 chip,
u16 len,
bool rx_transfer,
bool issue_stop)
{
u32 conf;
conf = len | HSI2C_MASTER_RUN;
if (issue_stop)
conf |= HSI2C_STOP_AFTER_TRANS;
/* Clear to enable Timeout */
writel(readl(&i2c->usi_timeout) & ~HSI2C_TIMEOUT_EN, &i2c->usi_timeout);
/* Set slave address */
writel(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr);
if (rx_transfer) {
/* i2c master, read transaction */
writel((HSI2C_RXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* read up to len bytes, stop after transaction is finished */
writel(conf | HSI2C_READ_WRITE, &i2c->usi_auto_conf);
} else {
/* i2c master, write transaction */
writel((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* write up to len bytes, stop after transaction is finished */
writel(conf, &i2c->usi_auto_conf);
}
/* Reset all pending interrupt status bits we care about, if any */
writel(HSI2C_INT_I2C_EN, &i2c->usi_int_stat);
return I2C_OK;
}
/*
* Wait while i2c bus is settling down (mostly stop gets completed).
*/
static int hsi2c_wait_while_busy(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_trans_status) & HSI2C_MASTER_BUSY) {
if (!i--) {
debug("%s: bus busy\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
static int hsi2c_write(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len,
bool issue_stop)
{
int i, rv = 0;
if (!(len + alen)) {
/* Writes of zero length not supported in auto mode. */
debug("%s: zero length writes not supported\n", __func__);
return I2C_NOK;
}
rv = hsi2c_prepare_transaction
(i2c, chip, len + alen, false, issue_stop);
if (rv != I2C_OK)
return rv;
/* Move address, if any, and the data, if any, into the FIFO. */
for (i = 0; i < alen; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: address write failed\n", __func__);
goto write_error;
}
writel(addr[i], &i2c->usi_txdata);
}
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: data write failed\n", __func__);
goto write_error;
}
writel(data[i], &i2c->usi_txdata);
}
rv = hsi2c_wait_for_trx(i2c);
write_error:
if (issue_stop) {
int tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
}
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
static int hsi2c_read(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len)
{
int i, rv, tmp_ret;
bool drop_data = false;
if (!len) {
/* Reads of zero length not supported in auto mode. */
debug("%s: zero length read adjusted\n", __func__);
drop_data = true;
len = 1;
}
if (alen) {
/* Internal register adress needs to be written first. */
rv = hsi2c_write(i2c, chip, addr, alen, NULL, 0, false);
if (rv != I2C_OK)
return rv;
}
rv = hsi2c_prepare_transaction(i2c, chip, len, true, true);
if (rv != I2C_OK)
return rv;
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, true);
if (rv != I2C_OK)
goto read_err;
if (drop_data)
continue;
data[i] = readl(&i2c->usi_rxdata);
}
rv = hsi2c_wait_for_trx(i2c);
read_err:
tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
static int exynos_hs_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
int ret;
for (; nmsgs > 0; nmsgs--, msg++) {
if (msg->flags & I2C_M_RD) {
ret = hsi2c_read(hsregs, msg->addr, 0, 0, msg->buf,
msg->len);
} else {
ret = hsi2c_write(hsregs, msg->addr, 0, 0, msg->buf,
msg->len, true);
}
if (ret) {
exynos5_i2c_reset(i2c_bus);
return -EREMOTEIO;
}
}
return 0;
}
static int s3c24x0_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
i2c_bus->clock_frequency = speed;
if (hsi2c_get_clk_details(i2c_bus))
return -EFAULT;
hsi2c_ch_init(i2c_bus);
return 0;
}
static int s3c24x0_i2c_probe(struct udevice *dev, uint chip, uint chip_flags)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
uchar buf[1];
int ret;
buf[0] = 0;
/*
* What is needed is to send the chip address and verify that the
* address was <ACK>ed (i.e. there was a chip at that address which
* drove the data line low).
*/
ret = hsi2c_read(i2c_bus->hsregs, chip, 0, 0, buf, 1);
return ret != I2C_OK;
}
static int s3c_i2c_ofdata_to_platdata(struct udevice *dev)
{
const void *blob = gd->fdt_blob;
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
int node;
node = dev_of_offset(dev);
i2c_bus->hsregs = (struct exynos5_hsi2c *)devfdt_get_addr(dev);
i2c_bus->id = pinmux_decode_periph_id(blob, node);
i2c_bus->clock_frequency = fdtdec_get_int(blob, node,
"clock-frequency", 100000);
i2c_bus->node = node;
i2c_bus->bus_num = dev->seq;
exynos_pinmux_config(i2c_bus->id, PINMUX_FLAG_HS_MODE);
i2c_bus->active = true;
return 0;
}
static const struct dm_i2c_ops exynos_hs_i2c_ops = {
.xfer = exynos_hs_i2c_xfer,
.probe_chip = s3c24x0_i2c_probe,
.set_bus_speed = s3c24x0_i2c_set_bus_speed,
};
static const struct udevice_id exynos_hs_i2c_ids[] = {
{ .compatible = "samsung,exynos5-hsi2c" },
{ }
};
U_BOOT_DRIVER(hs_i2c) = {
.name = "i2c_s3c_hs",
.id = UCLASS_I2C,
.of_match = exynos_hs_i2c_ids,
.ofdata_to_platdata = s3c_i2c_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct s3c24x0_i2c_bus),
.ops = &exynos_hs_i2c_ops,
};