u-boot/drivers/i2c/designware_i2c.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2009
* Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <pci.h>
#include <reset.h>
#include <asm/io.h>
#include "designware_i2c.h"
struct dw_scl_sda_cfg {
u32 ss_hcnt;
u32 fs_hcnt;
u32 ss_lcnt;
u32 fs_lcnt;
u32 sda_hold;
};
#ifdef CONFIG_X86
/* BayTrail HCNT/LCNT/SDA hold time */
static struct dw_scl_sda_cfg byt_config = {
.ss_hcnt = 0x200,
.fs_hcnt = 0x55,
.ss_lcnt = 0x200,
.fs_lcnt = 0x99,
.sda_hold = 0x6,
};
#endif
struct dw_i2c {
struct i2c_regs *regs;
struct dw_scl_sda_cfg *scl_sda_cfg;
struct reset_ctl reset_ctl;
};
#ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED
static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
{
u32 ena = enable ? IC_ENABLE_0B : 0;
writel(ena, &i2c_base->ic_enable);
return 0;
}
#else
static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
{
u32 ena = enable ? IC_ENABLE_0B : 0;
int timeout = 100;
do {
writel(ena, &i2c_base->ic_enable);
if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
return 0;
/*
* Wait 10 times the signaling period of the highest I2C
* transfer supported by the driver (for 400KHz this is
* 25us) as described in the DesignWare I2C databook.
*/
udelay(25);
} while (timeout--);
printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
return -ETIMEDOUT;
}
#endif
/*
* i2c_set_bus_speed - Set the i2c speed
* @speed: required i2c speed
*
* Set the i2c speed.
*/
static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
struct dw_scl_sda_cfg *scl_sda_cfg,
unsigned int speed)
{
unsigned int cntl;
unsigned int hcnt, lcnt;
int i2c_spd;
if (speed >= I2C_MAX_SPEED)
i2c_spd = IC_SPEED_MODE_MAX;
else if (speed >= I2C_FAST_SPEED)
i2c_spd = IC_SPEED_MODE_FAST;
else
i2c_spd = IC_SPEED_MODE_STANDARD;
/* to set speed cltr must be disabled */
dw_i2c_enable(i2c_base, false);
cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
switch (i2c_spd) {
#ifndef CONFIG_X86 /* No High-speed for BayTrail yet */
case IC_SPEED_MODE_MAX:
cntl |= IC_CON_SPD_SS;
if (scl_sda_cfg) {
hcnt = scl_sda_cfg->fs_hcnt;
lcnt = scl_sda_cfg->fs_lcnt;
} else {
hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
}
writel(hcnt, &i2c_base->ic_hs_scl_hcnt);
writel(lcnt, &i2c_base->ic_hs_scl_lcnt);
break;
#endif
case IC_SPEED_MODE_STANDARD:
cntl |= IC_CON_SPD_SS;
if (scl_sda_cfg) {
hcnt = scl_sda_cfg->ss_hcnt;
lcnt = scl_sda_cfg->ss_lcnt;
} else {
hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
}
writel(hcnt, &i2c_base->ic_ss_scl_hcnt);
writel(lcnt, &i2c_base->ic_ss_scl_lcnt);
break;
case IC_SPEED_MODE_FAST:
default:
cntl |= IC_CON_SPD_FS;
if (scl_sda_cfg) {
hcnt = scl_sda_cfg->fs_hcnt;
lcnt = scl_sda_cfg->fs_lcnt;
} else {
hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
}
writel(hcnt, &i2c_base->ic_fs_scl_hcnt);
writel(lcnt, &i2c_base->ic_fs_scl_lcnt);
break;
}
writel(cntl, &i2c_base->ic_con);
/* Configure SDA Hold Time if required */
if (scl_sda_cfg)
writel(scl_sda_cfg->sda_hold, &i2c_base->ic_sda_hold);
/* Enable back i2c now speed set */
dw_i2c_enable(i2c_base, true);
return 0;
}
/*
* i2c_setaddress - Sets the target slave address
* @i2c_addr: target i2c address
*
* Sets the target slave address.
*/
static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr)
{
/* Disable i2c */
dw_i2c_enable(i2c_base, false);
writel(i2c_addr, &i2c_base->ic_tar);
/* Enable i2c */
dw_i2c_enable(i2c_base, true);
}
/*
* i2c_flush_rxfifo - Flushes the i2c RX FIFO
*
* Flushes the i2c RX FIFO
*/
static void i2c_flush_rxfifo(struct i2c_regs *i2c_base)
{
while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE)
readl(&i2c_base->ic_cmd_data);
}
/*
* i2c_wait_for_bb - Waits for bus busy
*
* Waits for bus busy
*/
static int i2c_wait_for_bb(struct i2c_regs *i2c_base)
{
unsigned long start_time_bb = get_timer(0);
while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) ||
!(readl(&i2c_base->ic_status) & IC_STATUS_TFE)) {
/* Evaluate timeout */
if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
return 1;
}
return 0;
}
static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr,
int alen)
{
if (i2c_wait_for_bb(i2c_base))
return 1;
i2c_setaddress(i2c_base, chip);
while (alen) {
alen--;
/* high byte address going out first */
writel((addr >> (alen * 8)) & 0xff,
&i2c_base->ic_cmd_data);
}
return 0;
}
static int i2c_xfer_finish(struct i2c_regs *i2c_base)
{
ulong start_stop_det = get_timer(0);
while (1) {
if ((readl(&i2c_base->ic_raw_intr_stat) & IC_STOP_DET)) {
readl(&i2c_base->ic_clr_stop_det);
break;
} else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
break;
}
}
if (i2c_wait_for_bb(i2c_base)) {
printf("Timed out waiting for bus\n");
return 1;
}
i2c_flush_rxfifo(i2c_base);
return 0;
}
/*
* i2c_read - Read from i2c memory
* @chip: target i2c address
* @addr: address to read from
* @alen:
* @buffer: buffer for read data
* @len: no of bytes to be read
*
* Read from i2c memory.
*/
static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr,
int alen, u8 *buffer, int len)
{
unsigned long start_time_rx;
unsigned int active = 0;
#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
/*
* EEPROM chips that implement "address overflow" are ones
* like Catalyst 24WC04/08/16 which has 9/10/11 bits of
* address and the extra bits end up in the "chip address"
* bit slots. This makes a 24WC08 (1Kbyte) chip look like
* four 256 byte chips.
*
* Note that we consider the length of the address field to
* still be one byte because the extra address bits are
* hidden in the chip address.
*/
dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
addr);
#endif
if (i2c_xfer_init(i2c_base, dev, addr, alen))
return 1;
start_time_rx = get_timer(0);
while (len) {
if (!active) {
/*
* Avoid writing to ic_cmd_data multiple times
* in case this loop spins too quickly and the
* ic_status RFNE bit isn't set after the first
* write. Subsequent writes to ic_cmd_data can
* trigger spurious i2c transfer.
*/
if (len == 1)
writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
else
writel(IC_CMD, &i2c_base->ic_cmd_data);
active = 1;
}
if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) {
*buffer++ = (uchar)readl(&i2c_base->ic_cmd_data);
len--;
start_time_rx = get_timer(0);
active = 0;
} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
return 1;
}
}
return i2c_xfer_finish(i2c_base);
}
/*
* i2c_write - Write to i2c memory
* @chip: target i2c address
* @addr: address to read from
* @alen:
* @buffer: buffer for read data
* @len: no of bytes to be read
*
* Write to i2c memory.
*/
static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
int alen, u8 *buffer, int len)
{
int nb = len;
unsigned long start_time_tx;
#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
/*
* EEPROM chips that implement "address overflow" are ones
* like Catalyst 24WC04/08/16 which has 9/10/11 bits of
* address and the extra bits end up in the "chip address"
* bit slots. This makes a 24WC08 (1Kbyte) chip look like
* four 256 byte chips.
*
* Note that we consider the length of the address field to
* still be one byte because the extra address bits are
* hidden in the chip address.
*/
dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
addr);
#endif
if (i2c_xfer_init(i2c_base, dev, addr, alen))
return 1;
start_time_tx = get_timer(0);
while (len) {
if (readl(&i2c_base->ic_status) & IC_STATUS_TFNF) {
if (--len == 0) {
writel(*buffer | IC_STOP,
&i2c_base->ic_cmd_data);
} else {
writel(*buffer, &i2c_base->ic_cmd_data);
}
buffer++;
start_time_tx = get_timer(0);
} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
printf("Timed out. i2c write Failed\n");
return 1;
}
}
return i2c_xfer_finish(i2c_base);
}
/*
* __dw_i2c_init - Init function
* @speed: required i2c speed
* @slaveaddr: slave address for the device
*
* Initialization function.
*/
static int __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr)
{
int ret;
/* Disable i2c */
ret = dw_i2c_enable(i2c_base, false);
if (ret)
return ret;
writel(IC_CON_SD | IC_CON_RE | IC_CON_SPD_FS | IC_CON_MM,
&i2c_base->ic_con);
writel(IC_RX_TL, &i2c_base->ic_rx_tl);
writel(IC_TX_TL, &i2c_base->ic_tx_tl);
writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
#ifndef CONFIG_DM_I2C
__dw_i2c_set_bus_speed(i2c_base, NULL, speed);
writel(slaveaddr, &i2c_base->ic_sar);
#endif
/* Enable i2c */
ret = dw_i2c_enable(i2c_base, true);
if (ret)
return ret;
return 0;
}
#ifndef CONFIG_DM_I2C
/*
* The legacy I2C functions. These need to get removed once
* all users of this driver are converted to DM.
*/
static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
{
switch (adap->hwadapnr) {
#if CONFIG_SYS_I2C_BUS_MAX >= 4
case 3:
return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
#endif
#if CONFIG_SYS_I2C_BUS_MAX >= 3
case 2:
return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
#endif
#if CONFIG_SYS_I2C_BUS_MAX >= 2
case 1:
return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
#endif
case 0:
return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
default:
printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
}
return NULL;
}
static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
adap->speed = speed;
return __dw_i2c_set_bus_speed(i2c_get_base(adap), NULL, speed);
}
static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
{
__dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
}
static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *buffer, int len)
{
return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len);
}
static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *buffer, int len)
{
return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len);
}
/* dw_i2c_probe - Probe the i2c chip */
static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev)
{
struct i2c_regs *i2c_base = i2c_get_base(adap);
u32 tmp;
int ret;
/*
* Try to read the first location of the chip.
*/
ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1);
if (ret)
dw_i2c_init(adap, adap->speed, adap->slaveaddr);
return ret;
}
U_BOOT_I2C_ADAP_COMPLETE(dw_0, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
dw_i2c_write, dw_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0)
#if CONFIG_SYS_I2C_BUS_MAX >= 2
U_BOOT_I2C_ADAP_COMPLETE(dw_1, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
dw_i2c_write, dw_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED1, CONFIG_SYS_I2C_SLAVE1, 1)
#endif
#if CONFIG_SYS_I2C_BUS_MAX >= 3
U_BOOT_I2C_ADAP_COMPLETE(dw_2, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
dw_i2c_write, dw_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED2, CONFIG_SYS_I2C_SLAVE2, 2)
#endif
#if CONFIG_SYS_I2C_BUS_MAX >= 4
U_BOOT_I2C_ADAP_COMPLETE(dw_3, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
dw_i2c_write, dw_i2c_set_bus_speed,
CONFIG_SYS_I2C_SPEED3, CONFIG_SYS_I2C_SLAVE3, 3)
#endif
#else /* CONFIG_DM_I2C */
/* The DM I2C functions */
static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
int nmsgs)
{
struct dw_i2c *i2c = dev_get_priv(bus);
int ret;
debug("i2c_xfer: %d messages\n", nmsgs);
for (; nmsgs > 0; nmsgs--, msg++) {
debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
if (msg->flags & I2C_M_RD) {
ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0,
msg->buf, msg->len);
} else {
ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0,
msg->buf, msg->len);
}
if (ret) {
debug("i2c_write: error sending\n");
return -EREMOTEIO;
}
}
return 0;
}
static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct dw_i2c *i2c = dev_get_priv(bus);
return __dw_i2c_set_bus_speed(i2c->regs, i2c->scl_sda_cfg, speed);
}
static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr,
uint chip_flags)
{
struct dw_i2c *i2c = dev_get_priv(bus);
struct i2c_regs *i2c_base = i2c->regs;
u32 tmp;
int ret;
/* Try to read the first location of the chip */
ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1);
if (ret)
__dw_i2c_init(i2c_base, 0, 0);
return ret;
}
static int designware_i2c_probe(struct udevice *bus)
{
struct dw_i2c *priv = dev_get_priv(bus);
int ret;
if (device_is_on_pci_bus(bus)) {
#ifdef CONFIG_DM_PCI
/* Save base address from PCI BAR */
priv->regs = (struct i2c_regs *)
dm_pci_map_bar(bus, PCI_BASE_ADDRESS_0, PCI_REGION_MEM);
#ifdef CONFIG_X86
/* Use BayTrail specific timing values */
priv->scl_sda_cfg = &byt_config;
#endif
#endif
} else {
priv->regs = (struct i2c_regs *)devfdt_get_addr_ptr(bus);
}
ret = reset_get_by_name(bus, "i2c", &priv->reset_ctl);
if (ret)
pr_info("reset_get_by_name() failed: %d\n", ret);
if (&priv->reset_ctl)
reset_deassert(&priv->reset_ctl);
return __dw_i2c_init(priv->regs, 0, 0);
}
static int designware_i2c_bind(struct udevice *dev)
{
static int num_cards;
char name[20];
/* Create a unique device name for PCI type devices */
if (device_is_on_pci_bus(dev)) {
/*
* ToDo:
* Setting req_seq in the driver is probably not recommended.
* But without a DT alias the number is not configured. And
* using this driver is impossible for PCIe I2C devices.
* This can be removed, once a better (correct) way for this
* is found and implemented.
*/
dev->req_seq = num_cards;
sprintf(name, "i2c_designware#%u", num_cards++);
device_set_name(dev, name);
}
return 0;
}
static const struct dm_i2c_ops designware_i2c_ops = {
.xfer = designware_i2c_xfer,
.probe_chip = designware_i2c_probe_chip,
.set_bus_speed = designware_i2c_set_bus_speed,
};
static const struct udevice_id designware_i2c_ids[] = {
{ .compatible = "snps,designware-i2c" },
{ }
};
U_BOOT_DRIVER(i2c_designware) = {
.name = "i2c_designware",
.id = UCLASS_I2C,
.of_match = designware_i2c_ids,
.bind = designware_i2c_bind,
.probe = designware_i2c_probe,
.priv_auto_alloc_size = sizeof(struct dw_i2c),
.ops = &designware_i2c_ops,
};
#ifdef CONFIG_X86
static struct pci_device_id designware_pci_supported[] = {
/* Intel BayTrail has 7 I2C controller located on the PCI bus */
{ PCI_VDEVICE(INTEL, 0x0f41) },
{ PCI_VDEVICE(INTEL, 0x0f42) },
{ PCI_VDEVICE(INTEL, 0x0f43) },
{ PCI_VDEVICE(INTEL, 0x0f44) },
{ PCI_VDEVICE(INTEL, 0x0f45) },
{ PCI_VDEVICE(INTEL, 0x0f46) },
{ PCI_VDEVICE(INTEL, 0x0f47) },
{},
};
U_BOOT_PCI_DEVICE(i2c_designware, designware_pci_supported);
#endif
#endif /* CONFIG_DM_I2C */