blob: d84600491591dd6099999f521deb15d30c5fdbe5 [file] [log] [blame]
/*
* Copyright (c) 2022 ITE Corporation. All Rights Reserved.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ite_enhance_i2c
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/pinctrl.h>
#include <errno.h>
#include <soc.h>
#include <soc_dt.h>
#include <zephyr/sys/util.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(i2c_ite_enhance, CONFIG_I2C_LOG_LEVEL);
#include "i2c-priv.h"
/* Start smbus session from idle state */
#define I2C_MSG_START BIT(5)
#define I2C_LINE_SCL_HIGH BIT(0)
#define I2C_LINE_SDA_HIGH BIT(1)
#define I2C_LINE_IDLE (I2C_LINE_SCL_HIGH | I2C_LINE_SDA_HIGH)
struct i2c_enhance_config {
void (*irq_config_func)(void);
uint32_t bitrate;
uint8_t *base;
uint8_t i2c_irq_base;
uint8_t port;
/* SCL GPIO cells */
struct gpio_dt_spec scl_gpios;
/* SDA GPIO cells */
struct gpio_dt_spec sda_gpios;
/* I2C alternate configuration */
const struct pinctrl_dev_config *pcfg;
uint8_t prescale_scl_low;
uint32_t clock_gate_offset;
};
enum i2c_pin_fun {
SCL = 0,
SDA,
};
enum i2c_ch_status {
I2C_CH_NORMAL = 0,
I2C_CH_REPEAT_START,
I2C_CH_WAIT_READ,
I2C_CH_WAIT_NEXT_XFER,
};
struct i2c_enhance_data {
enum i2c_ch_status i2ccs;
struct i2c_msg *msgs;
struct k_mutex mutex;
struct k_sem device_sync_sem;
/* Index into output data */
size_t widx;
/* Index into input data */
size_t ridx;
/* operation freq of i2c */
uint32_t bus_freq;
/* Error code, if any */
uint32_t err;
/* address of device */
uint16_t addr_16bit;
/* wait for stop bit interrupt */
uint8_t stop;
};
enum enhanced_i2c_transfer_direct {
TX_DIRECT,
RX_DIRECT,
};
enum enhanced_i2c_ctl {
/* Hardware reset */
E_HW_RST = 0x01,
/* Stop */
E_STOP = 0x02,
/* Start & Repeat start */
E_START = 0x04,
/* Acknowledge */
E_ACK = 0x08,
/* State reset */
E_STS_RST = 0x10,
/* Mode select */
E_MODE_SEL = 0x20,
/* I2C interrupt enable */
E_INT_EN = 0x40,
/* 0 : Standard mode , 1 : Receive mode */
E_RX_MODE = 0x80,
/* State reset and hardware reset */
E_STS_AND_HW_RST = (E_STS_RST | E_HW_RST),
/* Generate start condition and transmit slave address */
E_START_ID = (E_INT_EN | E_MODE_SEL | E_ACK | E_START | E_HW_RST),
/* Generate stop condition */
E_FINISH = (E_INT_EN | E_MODE_SEL | E_ACK | E_STOP | E_HW_RST),
};
enum enhanced_i2c_host_status {
/* ACK receive */
E_HOSTA_ACK = 0x01,
/* Interrupt pending */
E_HOSTA_INTP = 0x02,
/* Read/Write */
E_HOSTA_RW = 0x04,
/* Time out error */
E_HOSTA_TMOE = 0x08,
/* Arbitration lost */
E_HOSTA_ARB = 0x10,
/* Bus busy */
E_HOSTA_BB = 0x20,
/* Address match */
E_HOSTA_AM = 0x40,
/* Byte done status */
E_HOSTA_BDS = 0x80,
/* time out or lost arbitration */
E_HOSTA_ANY_ERROR = (E_HOSTA_TMOE | E_HOSTA_ARB),
/* Byte transfer done and ACK receive */
E_HOSTA_BDS_AND_ACK = (E_HOSTA_BDS | E_HOSTA_ACK),
};
enum i2c_reset_cause {
I2C_RC_NO_IDLE_FOR_START = 1,
I2C_RC_TIMEOUT,
};
static int i2c_parsing_return_value(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
if (!data->err) {
return 0;
}
/* Connection timed out */
if (data->err == ETIMEDOUT) {
return -ETIMEDOUT;
}
/* The device does not respond ACK */
if (data->err == E_HOSTA_ACK) {
return -ENXIO;
} else {
return -EIO;
}
}
static int i2c_get_line_levels(const struct device *dev)
{
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
int pin_sts = 0;
if (IT8XXX2_I2C_TOS(base) & IT8XXX2_I2C_SCL_IN) {
pin_sts |= I2C_LINE_SCL_HIGH;
}
if (IT8XXX2_I2C_TOS(base) & IT8XXX2_I2C_SDA_IN) {
pin_sts |= I2C_LINE_SDA_HIGH;
}
return pin_sts;
}
static int i2c_is_busy(const struct device *dev)
{
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
return (IT8XXX2_I2C_STR(base) & E_HOSTA_BB);
}
static int i2c_bus_not_available(const struct device *dev)
{
if (i2c_is_busy(dev) ||
(i2c_get_line_levels(dev) != I2C_LINE_IDLE)) {
return -EIO;
}
return 0;
}
static void i2c_reset(const struct device *dev)
{
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
/* State reset and hardware reset */
IT8XXX2_I2C_CTR(base) = E_STS_AND_HW_RST;
}
/* Set clock frequency for i2c port D, E , or F */
static void i2c_enhanced_port_set_frequency(const struct device *dev,
int freq_hz)
{
const struct i2c_enhance_config *config = dev->config;
uint32_t clk_div, psr, pll_clock;
uint8_t *base = config->base;
pll_clock = chip_get_pll_freq();
/*
* Let psr(Prescale) = IT8XXX2_I2C_PSR(p_ch)
* Then, 1 SCL cycle = 2 x (psr + 2) x SMBus clock cycle
* SMBus clock = pll_clock / clk_div
* SMBus clock cycle = 1 / SMBus clock
* 1 SCL cycle = 1 / freq
* 1 / freq = 2 x (psr + 2) x (1 / (pll_clock / clk_div))
* psr = ((pll_clock / clk_div) x (1 / freq) x (1 / 2)) - 2
*/
if (freq_hz) {
/* Get SMBus clock divide value */
clk_div = (IT8XXX2_ECPM_SCDCR2 & 0x0F) + 1U;
/* Calculate PSR value */
psr = (pll_clock / (clk_div * (2U * freq_hz))) - 2U;
/* Set psr value under 0xFD */
if (psr > 0xFD) {
psr = 0xFD;
}
/* Adjust SCL low period prescale */
psr += config->prescale_scl_low;
/* Set I2C Speed */
IT8XXX2_I2C_PSR(base) = psr & 0xFF;
IT8XXX2_I2C_HSPR(base) = psr & 0xFF;
}
}
static int i2c_enhance_configure(const struct device *dev,
uint32_t dev_config_raw)
{
const struct i2c_enhance_config *config = dev->config;
struct i2c_enhance_data *const data = dev->data;
if (!(I2C_MODE_MASTER & dev_config_raw)) {
return -EINVAL;
}
if (I2C_ADDR_10_BITS & dev_config_raw) {
return -EINVAL;
}
data->bus_freq = I2C_SPEED_GET(dev_config_raw);
i2c_enhanced_port_set_frequency(dev, config->bitrate);
return 0;
}
static int i2c_enhance_get_config(const struct device *dev, uint32_t *dev_config)
{
struct i2c_enhance_data *const data = dev->data;
uint32_t speed;
if (!data->bus_freq) {
LOG_ERR("The bus frequency is not initially configured.");
return -EIO;
}
switch (data->bus_freq) {
case I2C_SPEED_DT:
case I2C_SPEED_STANDARD:
case I2C_SPEED_FAST:
case I2C_SPEED_FAST_PLUS:
speed = I2C_SPEED_SET(data->bus_freq);
break;
default:
return -ERANGE;
}
*dev_config = (I2C_MODE_MASTER | speed);
return 0;
}
static int enhanced_i2c_error(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
uint32_t i2c_str = IT8XXX2_I2C_STR(base);
if (i2c_str & E_HOSTA_ANY_ERROR) {
data->err = i2c_str & E_HOSTA_ANY_ERROR;
/* device does not respond ACK */
} else if ((i2c_str & E_HOSTA_BDS_AND_ACK) == E_HOSTA_BDS) {
if (IT8XXX2_I2C_CTR(base) & E_ACK)
data->err = E_HOSTA_ACK;
}
return data->err;
}
static void enhanced_i2c_start(const struct device *dev)
{
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
/* reset i2c port */
i2c_reset(dev);
/* Set i2c frequency */
i2c_enhanced_port_set_frequency(dev, config->bitrate);
/*
* Set time out register.
* I2C D/E/F clock/data low timeout.
*/
IT8XXX2_I2C_TOR(base) = I2C_CLK_LOW_TIMEOUT;
/* bit1: Enable enhanced i2c module */
IT8XXX2_I2C_CTR1(base) = IT8XXX2_I2C_MDL_EN;
}
static void i2c_pio_trans_data(const struct device *dev,
enum enhanced_i2c_transfer_direct direct,
uint16_t trans_data, int first_byte)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
uint32_t nack = 0;
if (first_byte) {
/* First byte must be slave address. */
IT8XXX2_I2C_DTR(base) = trans_data |
(direct == RX_DIRECT ? BIT(0) : 0);
/* start or repeat start signal. */
IT8XXX2_I2C_CTR(base) = E_START_ID;
} else {
if (direct == TX_DIRECT) {
/* Transmit data */
IT8XXX2_I2C_DTR(base) = (uint8_t)trans_data;
} else {
/*
* Receive data.
* Last byte should be NACK in the end of read cycle
*/
if (((data->ridx + 1) == data->msgs->len) &&
(data->msgs->flags & I2C_MSG_STOP)) {
nack = 1;
}
}
/* Set hardware reset to start next transmission */
IT8XXX2_I2C_CTR(base) = E_INT_EN | E_MODE_SEL |
E_HW_RST | (nack ? 0 : E_ACK);
}
}
static int enhanced_i2c_tran_read(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
uint8_t in_data = 0;
if (data->msgs->flags & I2C_MSG_START) {
/* clear start flag */
data->msgs->flags &= ~I2C_MSG_START;
enhanced_i2c_start(dev);
/* Direct read */
data->i2ccs = I2C_CH_WAIT_READ;
/* Send ID */
i2c_pio_trans_data(dev, RX_DIRECT, data->addr_16bit << 1, 1);
} else {
if (data->i2ccs) {
if (data->i2ccs == I2C_CH_WAIT_READ) {
data->i2ccs = I2C_CH_NORMAL;
/* Receive data */
i2c_pio_trans_data(dev, RX_DIRECT, in_data, 0);
/* data->msgs->flags == I2C_MSG_RESTART */
} else {
/* Write to read */
data->i2ccs = I2C_CH_WAIT_READ;
/* Send ID */
i2c_pio_trans_data(dev, RX_DIRECT,
data->addr_16bit << 1, 1);
}
} else {
if (data->ridx < data->msgs->len) {
/* read data */
*(data->msgs->buf++) = IT8XXX2_I2C_DRR(base);
data->ridx++;
/* done */
if (data->ridx == data->msgs->len) {
data->msgs->len = 0;
if (data->msgs->flags & I2C_MSG_STOP) {
data->i2ccs = I2C_CH_NORMAL;
IT8XXX2_I2C_CTR(base) = E_FINISH;
/* wait for stop bit interrupt */
data->stop = 1;
return 1;
}
/* End the transaction */
data->i2ccs = I2C_CH_WAIT_READ;
return 0;
}
/* read next byte */
i2c_pio_trans_data(dev, RX_DIRECT, in_data, 0);
}
}
}
return 1;
}
static int enhanced_i2c_tran_write(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
uint8_t out_data;
if (data->msgs->flags & I2C_MSG_START) {
/* Clear start bit */
data->msgs->flags &= ~I2C_MSG_START;
enhanced_i2c_start(dev);
/* Send ID */
i2c_pio_trans_data(dev, TX_DIRECT, data->addr_16bit << 1, 1);
} else {
/* Host has completed the transmission of a byte */
if (data->widx < data->msgs->len) {
out_data = *(data->msgs->buf++);
data->widx++;
/* Send Byte */
i2c_pio_trans_data(dev, TX_DIRECT, out_data, 0);
if (data->i2ccs == I2C_CH_WAIT_NEXT_XFER) {
data->i2ccs = I2C_CH_NORMAL;
}
} else {
/* done */
data->msgs->len = 0;
if (data->msgs->flags & I2C_MSG_STOP) {
IT8XXX2_I2C_CTR(base) = E_FINISH;
/* wait for stop bit interrupt */
data->stop = 1;
} else {
/* Direct write with direct read */
data->i2ccs = I2C_CH_WAIT_NEXT_XFER;
return 0;
}
}
}
return 1;
}
static int i2c_transaction(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
/* no error */
if (!(enhanced_i2c_error(dev))) {
if (!data->stop) {
/*
* The return value indicates if there is more data
* to be read or written. If the return value = 1,
* it means that the interrupt cannot be disable and
* continue to transmit data.
*/
if (data->msgs->flags & I2C_MSG_READ) {
return enhanced_i2c_tran_read(dev);
} else {
return enhanced_i2c_tran_write(dev);
}
}
}
/* reset i2c port */
i2c_reset(dev);
IT8XXX2_I2C_CTR1(base) = 0;
data->stop = 0;
/* done doing work */
return 0;
}
static int i2c_enhance_transfer(const struct device *dev, struct i2c_msg *msgs,
uint8_t num_msgs, uint16_t addr)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
int res;
/* Lock mutex of i2c controller */
k_mutex_lock(&data->mutex, K_FOREVER);
/*
* If the transaction of write to read is divided into two
* transfers, the repeat start transfer uses this flag to
* exclude checking bus busy.
*/
if (data->i2ccs == I2C_CH_NORMAL) {
/* Make sure we're in a good state to start */
if (i2c_bus_not_available(dev)) {
/* Recovery I2C bus */
i2c_recover_bus(dev);
/*
* After resetting I2C bus, if I2C bus is not available
* (No external pull-up), drop the transaction.
*/
if (i2c_bus_not_available(dev)) {
/* Unlock mutex of i2c controller */
k_mutex_unlock(&data->mutex);
return -EIO;
}
}
msgs->flags |= I2C_MSG_START;
}
for (int i = 0; i < num_msgs; i++) {
data->widx = 0;
data->ridx = 0;
data->err = 0;
data->msgs = &(msgs[i]);
data->addr_16bit = addr;
if (msgs->flags & I2C_MSG_START) {
data->i2ccs = I2C_CH_NORMAL;
}
/*
* Start transaction.
* The return value indicates if the initial configuration
* of I2C transaction for read or write has been completed.
*/
if (i2c_transaction(dev)) {
/* Enable I2C interrupt. */
irq_enable(config->i2c_irq_base);
}
/* Wait for the transfer to complete */
/* TODO: the timeout should be adjustable */
res = k_sem_take(&data->device_sync_sem, K_MSEC(100));
/*
* The irq will be enabled at the condition of start or
* repeat start of I2C. If timeout occurs without being
* wake up during suspend(ex: interrupt is not fired),
* the irq should be disabled immediately.
*/
irq_disable(config->i2c_irq_base);
/*
* The transaction is dropped on any error(timeout, NACK, fail,
* bus error, device error).
*/
if (data->err) {
break;
}
if (res != 0) {
data->err = ETIMEDOUT;
/* reset i2c port */
i2c_reset(dev);
LOG_ERR("I2C ch%d:0x%X reset cause %d",
config->port, data->addr_16bit, I2C_RC_TIMEOUT);
/* If this message is sent fail, drop the transaction. */
break;
}
}
/* reset i2c channel status */
if (data->err || (msgs->flags & I2C_MSG_STOP)) {
data->i2ccs = I2C_CH_NORMAL;
}
/* Unlock mutex of i2c controller */
k_mutex_unlock(&data->mutex);
return i2c_parsing_return_value(dev);
}
static void i2c_enhance_isr(void *arg)
{
struct device *dev = (struct device *)arg;
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
/* If done doing work, wake up the task waiting for the transfer */
if (!i2c_transaction(dev)) {
irq_disable(config->i2c_irq_base);
k_sem_give(&data->device_sync_sem);
}
}
static int i2c_enhance_init(const struct device *dev)
{
struct i2c_enhance_data *data = dev->data;
const struct i2c_enhance_config *config = dev->config;
uint8_t *base = config->base;
uint32_t bitrate_cfg;
int error, status;
/* Initialize mutex and semaphore */
k_mutex_init(&data->mutex);
k_sem_init(&data->device_sync_sem, 0, K_SEM_MAX_LIMIT);
/* Enable clock to specified peripheral */
volatile uint8_t *reg = (volatile uint8_t *)
(IT8XXX2_ECPM_BASE + (config->clock_gate_offset >> 8));
uint8_t reg_mask = config->clock_gate_offset & 0xff;
*reg &= ~reg_mask;
/* Enable I2C function */
/* Software reset */
IT8XXX2_I2C_DHTR(base) |= IT8XXX2_I2C_SOFT_RST;
IT8XXX2_I2C_DHTR(base) &= ~IT8XXX2_I2C_SOFT_RST;
/* reset i2c port */
i2c_reset(dev);
/* bit1, Module enable */
IT8XXX2_I2C_CTR1(base) = 0;
/* Set clock frequency for I2C ports */
if (config->bitrate == I2C_BITRATE_STANDARD ||
config->bitrate == I2C_BITRATE_FAST ||
config->bitrate == I2C_BITRATE_FAST_PLUS) {
bitrate_cfg = i2c_map_dt_bitrate(config->bitrate);
} else {
/* Device tree specified speed */
bitrate_cfg = I2C_SPEED_DT << I2C_SPEED_SHIFT;
}
error = i2c_enhance_configure(dev, I2C_MODE_MASTER | bitrate_cfg);
data->i2ccs = I2C_CH_NORMAL;
if (error) {
LOG_ERR("i2c: failure initializing");
return error;
}
/* Set the pin to I2C alternate function. */
status = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (status < 0) {
LOG_ERR("Failed to configure I2C pins");
return status;
}
return 0;
}
static int i2c_enhance_recover_bus(const struct device *dev)
{
const struct i2c_enhance_config *config = dev->config;
int i, status;
/* Set SCL of I2C as GPIO pin */
gpio_pin_configure_dt(&config->scl_gpios, GPIO_OUTPUT);
/* Set SDA of I2C as GPIO pin */
gpio_pin_configure_dt(&config->sda_gpios, GPIO_OUTPUT);
/*
* In I2C recovery bus, 1ms sleep interval for bitbanging i2c
* is mainly to ensure that gpio has enough time to go from
* low to high or high to low.
*/
/* Pull SCL and SDA pin to high */
gpio_pin_set_dt(&config->scl_gpios, 1);
gpio_pin_set_dt(&config->sda_gpios, 1);
k_msleep(1);
/* Start condition */
gpio_pin_set_dt(&config->sda_gpios, 0);
k_msleep(1);
gpio_pin_set_dt(&config->scl_gpios, 0);
k_msleep(1);
/* 9 cycles of SCL with SDA held high */
for (i = 0; i < 9; i++) {
/* SDA */
gpio_pin_set_dt(&config->sda_gpios, 1);
/* SCL */
gpio_pin_set_dt(&config->scl_gpios, 1);
k_msleep(1);
/* SCL */
gpio_pin_set_dt(&config->scl_gpios, 0);
k_msleep(1);
}
/* SDA */
gpio_pin_set_dt(&config->sda_gpios, 0);
k_msleep(1);
/* Stop condition */
gpio_pin_set_dt(&config->scl_gpios, 1);
k_msleep(1);
gpio_pin_set_dt(&config->sda_gpios, 1);
k_msleep(1);
/* Set GPIO back to I2C alternate function */
status = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (status < 0) {
LOG_ERR("Failed to configure I2C pins");
return status;
}
/* reset i2c port */
i2c_reset(dev);
LOG_ERR("I2C ch%d reset cause %d", config->port,
I2C_RC_NO_IDLE_FOR_START);
return 0;
}
static const struct i2c_driver_api i2c_enhance_driver_api = {
.configure = i2c_enhance_configure,
.get_config = i2c_enhance_get_config,
.transfer = i2c_enhance_transfer,
.recover_bus = i2c_enhance_recover_bus,
};
#define I2C_ITE_ENHANCE_INIT(inst) \
PINCTRL_DT_INST_DEFINE(inst); \
BUILD_ASSERT((DT_INST_PROP(inst, clock_frequency) == \
50000) || \
(DT_INST_PROP(inst, clock_frequency) == \
I2C_BITRATE_STANDARD) || \
(DT_INST_PROP(inst, clock_frequency) == \
I2C_BITRATE_FAST) || \
(DT_INST_PROP(inst, clock_frequency) == \
I2C_BITRATE_FAST_PLUS), "Not support I2C bit rate value"); \
static void i2c_enhance_config_func_##inst(void); \
\
static const struct i2c_enhance_config i2c_enhance_cfg_##inst = { \
.base = (uint8_t *)(DT_INST_REG_ADDR(inst)), \
.irq_config_func = i2c_enhance_config_func_##inst, \
.bitrate = DT_INST_PROP(inst, clock_frequency), \
.i2c_irq_base = DT_INST_IRQN(inst), \
.port = DT_INST_PROP(inst, port_num), \
.scl_gpios = GPIO_DT_SPEC_INST_GET(inst, scl_gpios), \
.sda_gpios = GPIO_DT_SPEC_INST_GET(inst, sda_gpios), \
.prescale_scl_low = DT_INST_PROP_OR(inst, prescale_scl_low, 0), \
.clock_gate_offset = DT_INST_PROP(inst, clock_gate_offset), \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst), \
}; \
\
static struct i2c_enhance_data i2c_enhance_data_##inst; \
\
I2C_DEVICE_DT_INST_DEFINE(inst, i2c_enhance_init, \
NULL, \
&i2c_enhance_data_##inst, \
&i2c_enhance_cfg_##inst, \
POST_KERNEL, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&i2c_enhance_driver_api); \
\
static void i2c_enhance_config_func_##inst(void) \
{ \
IRQ_CONNECT(DT_INST_IRQN(inst), \
0, \
i2c_enhance_isr, \
DEVICE_DT_INST_GET(inst), 0); \
}
DT_INST_FOREACH_STATUS_OKAY(I2C_ITE_ENHANCE_INIT)