blob: e8c1623d41fdd9ecd73c6e433808d432bf02f807 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2009
* Vipin Kumar, STMicroelectronics, vipin.kumar@st.com.
*/
#include <clk.h>
#include <dm.h>
#include <i2c.h>
#include <log.h>
#include <malloc.h>
#include <pci.h>
#include <reset.h>
#include <asm/io.h>
#include <linux/delay.h>
#include "designware_i2c.h"
#include <dm/device_compat.h>
#include <linux/err.h>
/*
* This assigned unique hex value is constant and is derived from the two ASCII
* letters 'DW' followed by a 16-bit unsigned number
*/
#define DW_I2C_COMP_TYPE 0x44570140
/*
* This constant is used to calculate when during the clock high phase the data
* bit shall be read. The value was copied from the Linux v6.5 function
* i2c_dw_scl_hcnt() which provides the following explanation:
*
* "This is just an experimental rule: the tHD;STA period turned out to be
* proportinal to (_HCNT + 3). With this setting, we could meet both tHIGH and
* tHD;STA timing specs."
*/
#define T_HD_STA_OFFSET 3
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;
}
/* High and low times in different speed modes (in ns) */
enum {
/* SDA Hold Time */
DEFAULT_SDA_HOLD_TIME = 300,
};
/**
* calc_counts() - Convert a period to a number of IC clk cycles
*
* @ic_clk: Input clock in Hz
* @period_ns: Period to represent, in ns
* Return: calculated count
*/
static uint calc_counts(uint ic_clk, uint period_ns)
{
return DIV_ROUND_UP(ic_clk / 1000 * period_ns, NANO_TO_KILO);
}
/**
* struct i2c_mode_info - Information about an I2C speed mode
*
* Each speed mode has its own characteristics. This struct holds these to aid
* calculations in dw_i2c_calc_timing().
*
* @speed: Speed in Hz
* @min_scl_lowtime_ns: Minimum value for SCL low period in ns
* @min_scl_hightime_ns: Minimum value for SCL high period in ns
* @def_rise_time_ns: Default rise time in ns
* @def_fall_time_ns: Default fall time in ns
*/
struct i2c_mode_info {
int speed;
int min_scl_hightime_ns;
int min_scl_lowtime_ns;
int def_rise_time_ns;
int def_fall_time_ns;
};
static const struct i2c_mode_info info_for_mode[] = {
[IC_SPEED_MODE_STANDARD] = {
I2C_SPEED_STANDARD_RATE,
MIN_SS_SCL_HIGHTIME,
MIN_SS_SCL_LOWTIME,
1000,
300,
},
[IC_SPEED_MODE_FAST] = {
I2C_SPEED_FAST_RATE,
MIN_FS_SCL_HIGHTIME,
MIN_FS_SCL_LOWTIME,
300,
300,
},
[IC_SPEED_MODE_FAST_PLUS] = {
I2C_SPEED_FAST_PLUS_RATE,
MIN_FP_SCL_HIGHTIME,
MIN_FP_SCL_LOWTIME,
260,
500,
},
[IC_SPEED_MODE_HIGH] = {
I2C_SPEED_HIGH_RATE,
MIN_HS_SCL_HIGHTIME,
MIN_HS_SCL_LOWTIME,
120,
120,
},
};
/**
* dw_i2c_calc_timing() - Calculate the timings to use for a bus
*
* @priv: Bus private information (NULL if not using driver model)
* @mode: Speed mode to use
* @ic_clk: IC clock speed in Hz
* @spk_cnt: Spike-suppression count
* @config: Returns value to use
* Return: 0 if OK, -EINVAL if the calculation failed due to invalid data
*/
static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode,
int ic_clk, int spk_cnt,
struct dw_i2c_speed_config *config)
{
int fall_cnt, rise_cnt, min_tlow_cnt, min_thigh_cnt;
int hcnt, lcnt, period_cnt, diff, tot;
int sda_hold_time_ns, scl_rise_time_ns, scl_fall_time_ns;
const struct i2c_mode_info *info;
/*
* Find the period, rise, fall, min tlow, and min thigh in terms of
* counts of the IC clock
*/
info = &info_for_mode[mode];
period_cnt = ic_clk / info->speed;
scl_rise_time_ns = priv && priv->scl_rise_time_ns ?
priv->scl_rise_time_ns : info->def_rise_time_ns;
scl_fall_time_ns = priv && priv->scl_fall_time_ns ?
priv->scl_fall_time_ns : info->def_fall_time_ns;
rise_cnt = calc_counts(ic_clk, scl_rise_time_ns);
fall_cnt = calc_counts(ic_clk, scl_fall_time_ns);
min_tlow_cnt = calc_counts(ic_clk, info->min_scl_lowtime_ns);
min_thigh_cnt = calc_counts(ic_clk, info->min_scl_hightime_ns);
debug("dw_i2c: mode %d, ic_clk %d, speed %d, period %d rise %d fall %d tlow %d thigh %d spk %d\n",
mode, ic_clk, info->speed, period_cnt, rise_cnt, fall_cnt,
min_tlow_cnt, min_thigh_cnt, spk_cnt);
/*
* Back-solve for hcnt and lcnt according to the following equations:
* SCL_High_time = [(HCNT + IC_*_SPKLEN + T_HD_STA_OFFSET) * ic_clk] + SCL_Fall_time
* SCL_Low_time = [(LCNT + 1) * ic_clk] - SCL_Fall_time + SCL_Rise_time
*/
hcnt = min_thigh_cnt - fall_cnt - T_HD_STA_OFFSET - spk_cnt;
lcnt = min_tlow_cnt - rise_cnt + fall_cnt - 1;
if (hcnt < 0 || lcnt < 0) {
debug("dw_i2c: bad counts. hcnt = %d lcnt = %d\n", hcnt, lcnt);
return log_msg_ret("counts", -EINVAL);
}
/*
* Now add things back up to ensure the period is hit. If it is off,
* split the difference and bias to lcnt for remainder
*/
tot = hcnt + lcnt + T_HD_STA_OFFSET + spk_cnt + rise_cnt + 1;
if (tot < period_cnt) {
diff = (period_cnt - tot) / 2;
hcnt += diff;
lcnt += diff;
tot = hcnt + lcnt + T_HD_STA_OFFSET + spk_cnt + rise_cnt + 1;
lcnt += period_cnt - tot;
}
config->scl_lcnt = lcnt;
config->scl_hcnt = hcnt;
/* Use internal default unless other value is specified */
sda_hold_time_ns = priv && priv->sda_hold_time_ns ?
priv->sda_hold_time_ns : DEFAULT_SDA_HOLD_TIME;
config->sda_hold = calc_counts(ic_clk, sda_hold_time_ns);
debug("dw_i2c: hcnt = %d lcnt = %d sda hold = %d\n", hcnt, lcnt,
config->sda_hold);
return 0;
}
/**
* calc_bus_speed() - Calculate the config to use for a particular i2c speed
*
* @priv: Private information for the driver (NULL if not using driver model)
* @i2c_base: Registers for the I2C controller
* @speed: Required i2c speed in Hz
* @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
* @config: Returns the config to use for this speed
* Return: 0 if OK, -ve on error
*/
static int calc_bus_speed(struct dw_i2c *priv, struct i2c_regs *regs, int speed,
ulong bus_clk, struct dw_i2c_speed_config *config)
{
const struct dw_scl_sda_cfg *scl_sda_cfg = NULL;
enum i2c_speed_mode i2c_spd;
int spk_cnt;
int ret;
if (priv)
scl_sda_cfg = priv->scl_sda_cfg;
/* Allow high speed if there is no config, or the config allows it */
if (speed >= I2C_SPEED_HIGH_RATE)
i2c_spd = IC_SPEED_MODE_HIGH;
else if (speed >= I2C_SPEED_FAST_PLUS_RATE)
i2c_spd = IC_SPEED_MODE_FAST_PLUS;
else if (speed >= I2C_SPEED_FAST_RATE)
i2c_spd = IC_SPEED_MODE_FAST;
else
i2c_spd = IC_SPEED_MODE_STANDARD;
/* Check is high speed possible and fall back to fast mode if not */
if (i2c_spd == IC_SPEED_MODE_HIGH) {
u32 comp_param1;
comp_param1 = readl(&regs->comp_param1);
if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH)
i2c_spd = IC_SPEED_MODE_FAST;
}
/* Get the proper spike-suppression count based on target speed */
if (!priv || !priv->has_spk_cnt)
spk_cnt = 0;
else if (i2c_spd >= IC_SPEED_MODE_HIGH)
spk_cnt = readl(&regs->hs_spklen);
else
spk_cnt = readl(&regs->fs_spklen);
if (scl_sda_cfg) {
config->sda_hold = scl_sda_cfg->sda_hold;
if (i2c_spd == IC_SPEED_MODE_STANDARD) {
config->scl_hcnt = scl_sda_cfg->ss_hcnt;
config->scl_lcnt = scl_sda_cfg->ss_lcnt;
} else if (i2c_spd == IC_SPEED_MODE_HIGH) {
config->scl_hcnt = scl_sda_cfg->hs_hcnt;
config->scl_lcnt = scl_sda_cfg->hs_lcnt;
} else {
config->scl_hcnt = scl_sda_cfg->fs_hcnt;
config->scl_lcnt = scl_sda_cfg->fs_lcnt;
}
} else {
ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, spk_cnt,
config);
if (ret)
return log_msg_ret("gen_confg", ret);
}
config->speed_mode = i2c_spd;
return 0;
}
/**
* _dw_i2c_set_bus_speed() - Set the i2c speed
*
* @priv: Private information for the driver (NULL if not using driver model)
* @i2c_base: Registers for the I2C controller
* @speed: Required i2c speed in Hz
* @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
* Return: 0 if OK, -ve on error
*/
static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base,
unsigned int speed, unsigned int bus_clk)
{
struct dw_i2c_speed_config config;
unsigned int cntl;
unsigned int ena;
int ret;
ret = calc_bus_speed(priv, i2c_base, speed, bus_clk, &config);
if (ret)
return ret;
/* Get enable setting for restore later */
ena = readl(&i2c_base->ic_enable) & IC_ENABLE_0B;
/* to set speed cltr must be disabled */
dw_i2c_enable(i2c_base, false);
cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
switch (config.speed_mode) {
case IC_SPEED_MODE_HIGH:
cntl |= IC_CON_SPD_HS;
writel(config.scl_hcnt, &i2c_base->ic_hs_scl_hcnt);
writel(config.scl_lcnt, &i2c_base->ic_hs_scl_lcnt);
break;
case IC_SPEED_MODE_STANDARD:
cntl |= IC_CON_SPD_SS;
writel(config.scl_hcnt, &i2c_base->ic_ss_scl_hcnt);
writel(config.scl_lcnt, &i2c_base->ic_ss_scl_lcnt);
break;
case IC_SPEED_MODE_FAST_PLUS:
case IC_SPEED_MODE_FAST:
default:
cntl |= IC_CON_SPD_FS;
writel(config.scl_hcnt, &i2c_base->ic_fs_scl_hcnt);
writel(config.scl_lcnt, &i2c_base->ic_fs_scl_lcnt);
break;
}
writel(cntl, &i2c_base->ic_con);
/* Configure SDA Hold Time if required */
if (config.sda_hold)
writel(config.sda_hold, &i2c_base->ic_sda_hold);
/* Restore back i2c now speed set */
if (ena == IC_ENABLE_0B)
dw_i2c_enable(i2c_base, true);
if (priv)
priv->config = config;
return 0;
}
int dw_i2c_gen_speed_config(const struct udevice *dev, int speed_hz,
struct dw_i2c_speed_config *config)
{
struct dw_i2c *priv = dev_get_priv(dev);
ulong rate;
int ret;
#if CONFIG_IS_ENABLED(CLK)
rate = clk_get_rate(&priv->clk);
if (IS_ERR_VALUE(rate))
return log_msg_ret("clk", -EINVAL);
#else
rate = IC_CLK;
#endif
ret = calc_bus_speed(priv, priv->regs, speed_hz, rate, config);
if (ret)
printf("%s: ret=%d\n", __func__, ret);
if (ret)
return log_msg_ret("calc_bus_speed", ret);
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);
#if !CONFIG_IS_ENABLED(DM_I2C)
_dw_i2c_set_bus_speed(NULL, i2c_base, speed, IC_CLK);
writel(slaveaddr, &i2c_base->ic_sar);
#endif
/* Enable i2c */
ret = dw_i2c_enable(i2c_base, true);
if (ret)
return ret;
return 0;
}
#if !CONFIG_IS_ENABLED(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(NULL, i2c_get_base(adap), speed, IC_CLK);
}
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)
#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);
ulong rate;
#if CONFIG_IS_ENABLED(CLK)
rate = clk_get_rate(&i2c->clk);
if (IS_ERR_VALUE(rate))
return log_ret(-EINVAL);
#else
rate = IC_CLK;
#endif
return _dw_i2c_set_bus_speed(i2c, i2c->regs, speed, rate);
}
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;
}
int designware_i2c_of_to_plat(struct udevice *bus)
{
struct dw_i2c *priv = dev_get_priv(bus);
int ret;
if (!priv->regs)
priv->regs = dev_read_addr_ptr(bus);
dev_read_u32(bus, "i2c-scl-rising-time-ns", &priv->scl_rise_time_ns);
dev_read_u32(bus, "i2c-scl-falling-time-ns", &priv->scl_fall_time_ns);
dev_read_u32(bus, "i2c-sda-hold-time-ns", &priv->sda_hold_time_ns);
ret = reset_get_bulk(bus, &priv->resets);
if (ret) {
if (ret != -ENOTSUPP)
dev_warn(bus, "Can't get reset: %d\n", ret);
} else {
reset_deassert_bulk(&priv->resets);
}
#if CONFIG_IS_ENABLED(CLK)
ret = clk_get_by_index(bus, 0, &priv->clk);
if (ret)
return ret;
ret = clk_enable(&priv->clk);
if (ret && ret != -ENOSYS && ret != -ENOTSUPP) {
dev_err(bus, "failed to enable clock\n");
return ret;
}
#endif
return 0;
}
int designware_i2c_probe(struct udevice *bus)
{
struct dw_i2c *priv = dev_get_priv(bus);
uint comp_type;
comp_type = readl(&priv->regs->comp_type);
if (comp_type != DW_I2C_COMP_TYPE) {
log_err("I2C bus %s has unknown type %#x\n", bus->name,
comp_type);
return -ENXIO;
}
log_debug("I2C bus %s version %#x\n", bus->name,
readl(&priv->regs->comp_version));
return __dw_i2c_init(priv->regs, 0, 0);
}
int designware_i2c_remove(struct udevice *dev)
{
struct dw_i2c *priv = dev_get_priv(dev);
#if CONFIG_IS_ENABLED(CLK)
clk_disable(&priv->clk);
#endif
return reset_release_bulk(&priv->resets);
}
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,
.of_to_plat = designware_i2c_of_to_plat,
.probe = designware_i2c_probe,
.priv_auto = sizeof(struct dw_i2c),
.remove = designware_i2c_remove,
.flags = DM_FLAG_OS_PREPARE,
.ops = &designware_i2c_ops,
};
#endif /* CONFIG_DM_I2C */