zephyr/drivers/i2c/i2c_mchp_xec.c

672 lines
15 KiB
C

/*
* Copyright (c) 2019 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT microchip_xec_i2c
#include <drivers/clock_control.h>
#include <kernel.h>
#include <soc.h>
#include <errno.h>
#include <drivers/i2c.h>
#include <logging/log.h>
LOG_MODULE_REGISTER(i2c_mchp, CONFIG_I2C_LOG_LEVEL);
#define SPEED_100KHZ_BUS 0
#define SPEED_400KHZ_BUS 1
#define SPEED_1MHZ_BUS 2
#define EC_OWN_I2C_ADDR 0x7F
#define RESET_WAIT_US 20
/* I2C timeout is 10 ms (WAIT_INTERVAL * WAIT_COUNT) */
#define WAIT_INTERVAL 50
#define WAIT_COUNT 200
/* I2C Read/Write bit pos */
#define I2C_READ_WRITE_POS 0
struct xec_speed_cfg {
uint32_t bus_clk;
uint32_t data_timing;
uint32_t start_hold_time;
uint32_t config;
uint32_t timeout_scale;
};
struct i2c_xec_config {
uint32_t port_sel;
uint32_t base_addr;
uint8_t girq_id;
uint8_t girq_bit;
void (*irq_config_func)(void);
};
struct i2c_xec_data {
uint32_t pending_stop;
uint32_t speed_id;
struct i2c_slave_config *slave_cfg;
bool slave_attached;
bool slave_read;
};
/* Recommended programming values based on 16MHz
* i2c_baud_clk_period/bus_clk_period - 2 = (low_period + hi_period)
* bus_clk_reg (16MHz/100KHz -2) = 0x4F + 0x4F
* (16MHz/400KHz -2) = 0x0F + 0x17
* (16MHz/1MHz -2) = 0x05 + 0x09
*/
static const struct xec_speed_cfg xec_cfg_params[] = {
[SPEED_100KHZ_BUS] = {
.bus_clk = 0x00004F4F,
.data_timing = 0x0C4D5006,
.start_hold_time = 0x0000004D,
.config = 0x01FC01ED,
.timeout_scale = 0x4B9CC2C7,
},
[SPEED_400KHZ_BUS] = {
.bus_clk = 0x00000F17,
.data_timing = 0x040A0A06,
.start_hold_time = 0x0000000A,
.config = 0x01000050,
.timeout_scale = 0x159CC2C7,
},
[SPEED_1MHZ_BUS] = {
.bus_clk = 0x00000509,
.data_timing = 0x04060601,
.start_hold_time = 0x00000006,
.config = 0x10000050,
.timeout_scale = 0x089CC2C7,
},
};
static void i2c_xec_reset_config(const struct device *dev)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
struct i2c_xec_data *data =
(struct i2c_xec_data *const) (dev->data);
uint32_t ba = config->base_addr;
/* Assert RESET and clr others */
MCHP_I2C_SMB_CFG(ba) = MCHP_I2C_SMB_CFG_RESET;
k_busy_wait(RESET_WAIT_US);
/* Bus reset */
MCHP_I2C_SMB_CFG(ba) = 0;
/* Write 0x80. i.e Assert PIN bit, ESO = 0 and Interrupts
* disabled (ENI)
*/
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_PIN;
/* Enable controller and I2C filters */
MCHP_I2C_SMB_CFG(ba) = MCHP_I2C_SMB_CFG_GC_EN |
MCHP_I2C_SMB_CFG_ENAB |
MCHP_I2C_SMB_CFG_FEN |
(config->port_sel &
MCHP_I2C_SMB_CFG_PORT_SEL_MASK);
/* Configure bus clock register, Data Timing register,
* Repeated Start Hold Time register,
* and Timeout Scaling register
*/
MCHP_I2C_SMB_BUS_CLK(ba) = xec_cfg_params[data->speed_id].bus_clk;
MCHP_I2C_SMB_DATA_TM(ba) = xec_cfg_params[data->speed_id].data_timing;
MCHP_I2C_SMB_RSHT(ba) =
xec_cfg_params[data->speed_id].start_hold_time;
MCHP_I2C_SMB_TMTSC(ba) = xec_cfg_params[data->speed_id].timeout_scale;
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_PIN |
MCHP_I2C_SMB_CTRL_ESO |
MCHP_I2C_SMB_CTRL_ACK;
k_busy_wait(RESET_WAIT_US);
}
static int xec_spin_yield(int *counter)
{
*counter = *counter + 1;
if (*counter > WAIT_COUNT) {
return -ETIMEDOUT;
}
k_busy_wait(WAIT_INTERVAL);
return 0;
}
static void cleanup_registers(uint32_t ba)
{
uint32_t cfg = MCHP_I2C_SMB_CFG(ba);
cfg |= MCHP_I2C_SMB_CFG_FLUSH_MXBUF_WO;
MCHP_I2C_SMB_CFG(ba) = cfg;
cfg &= ~MCHP_I2C_SMB_CFG_FLUSH_MXBUF_WO;
cfg |= MCHP_I2C_SMB_CFG_FLUSH_MRBUF_WO;
MCHP_I2C_SMB_CFG(ba) = cfg;
cfg &= ~MCHP_I2C_SMB_CFG_FLUSH_MRBUF_WO;
cfg |= MCHP_I2C_SMB_CFG_FLUSH_SXBUF_WO;
MCHP_I2C_SMB_CFG(ba) = cfg;
cfg &= ~MCHP_I2C_SMB_CFG_FLUSH_SXBUF_WO;
cfg |= MCHP_I2C_SMB_CFG_FLUSH_SRBUF_WO;
MCHP_I2C_SMB_CFG(ba) = cfg;
cfg &= ~MCHP_I2C_SMB_CFG_FLUSH_SRBUF_WO;
}
#ifdef CONFIG_I2C_SLAVE
static void restart_slave(uint32_t ba)
{
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_PIN |
MCHP_I2C_SMB_CTRL_ESO |
MCHP_I2C_SMB_CTRL_ACK |
MCHP_I2C_SMB_CTRL_ENI;
}
#endif
static void recover_from_error(const struct device *dev)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
uint32_t ba = config->base_addr;
cleanup_registers(ba);
i2c_xec_reset_config(dev);
}
static int wait_bus_free(const struct device *dev)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
int ret;
int counter = 0;
uint32_t ba = config->base_addr;
while (!(MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_NBB)) {
ret = xec_spin_yield(&counter);
if (ret < 0) {
return ret;
}
}
/* Check for bus error */
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_BER) {
recover_from_error(dev);
return -EBUSY;
}
return 0;
}
static int wait_completion(const struct device *dev)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
int ret;
int counter = 0;
uint32_t ba = config->base_addr;
/* Wait for transaction to be completed */
while (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_PIN) {
ret = xec_spin_yield(&counter);
if (ret < 0) {
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_PIN) {
recover_from_error(dev);
return ret;
}
}
}
/* Check if Slave send ACK/NACK */
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_LRB_AD0) {
recover_from_error(dev);
return -EIO;
}
/* Check for bus error */
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_BER) {
recover_from_error(dev);
return -EBUSY;
}
return 0;
}
static bool check_lines(uint32_t ba)
{
return ((!(MCHP_I2C_SMB_BB_CTRL(ba) & MCHP_I2C_SMB_BB_CLKI_RO)) ||
(!(MCHP_I2C_SMB_BB_CTRL(ba) & MCHP_I2C_SMB_BB_DATI_RO)));
}
static int i2c_xec_configure(const struct device *dev,
uint32_t dev_config_raw)
{
struct i2c_xec_data *data =
(struct i2c_xec_data *const) (dev->data);
if (!(dev_config_raw & I2C_MODE_MASTER)) {
return -ENOTSUP;
}
if (dev_config_raw & I2C_ADDR_10_BITS) {
return -ENOTSUP;
}
switch (I2C_SPEED_GET(dev_config_raw)) {
case I2C_SPEED_STANDARD:
data->speed_id = SPEED_100KHZ_BUS;
break;
case I2C_SPEED_FAST:
data->speed_id = SPEED_400KHZ_BUS;
break;
case I2C_SPEED_FAST_PLUS:
data->speed_id = SPEED_1MHZ_BUS;
break;
default:
return -EINVAL;
}
i2c_xec_reset_config(dev);
return 0;
}
static int i2c_xec_poll_write(const struct device *dev, struct i2c_msg msg,
uint16_t addr)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
struct i2c_xec_data *data =
(struct i2c_xec_data *const) (dev->data);
uint32_t ba = config->base_addr;
int ret;
if (data->pending_stop == 0) {
/* Check clock and data lines */
if (check_lines(ba)) {
return -EBUSY;
}
/* Wait until bus is free */
ret = wait_bus_free(dev);
if (ret) {
return ret;
}
/* Send slave address */
MCHP_I2C_SMB_DATA(ba) = (addr & ~BIT(0));
/* Send start and ack bits */
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_PIN |
MCHP_I2C_SMB_CTRL_ESO | MCHP_I2C_SMB_CTRL_STA |
MCHP_I2C_SMB_CTRL_ACK;
ret = wait_completion(dev);
if (ret) {
return ret;
}
}
/* Send bytes */
for (int i = 0U; i < msg.len; i++) {
MCHP_I2C_SMB_DATA(ba) = msg.buf[i];
ret = wait_completion(dev);
if (ret) {
return ret;
}
/* Handle stop bit for last byte to write */
if (i == (msg.len - 1)) {
if (msg.flags & I2C_MSG_STOP) {
/* Send stop and ack bits */
MCHP_I2C_SMB_CTRL_WO(ba) =
MCHP_I2C_SMB_CTRL_PIN |
MCHP_I2C_SMB_CTRL_ESO |
MCHP_I2C_SMB_CTRL_STO |
MCHP_I2C_SMB_CTRL_ACK;
data->pending_stop = 0;
} else {
data->pending_stop = 1;
}
}
}
return 0;
}
static int i2c_xec_poll_read(const struct device *dev, struct i2c_msg msg,
uint16_t addr)
{
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
struct i2c_xec_data *data =
(struct i2c_xec_data *const) (dev->data);
uint32_t ba = config->base_addr;
uint8_t byte, ctrl;
int ret;
if (!(msg.flags & I2C_MSG_RESTART)) {
/* Check clock and data lines */
if (check_lines(ba)) {
return -EBUSY;
}
/* Wait until bus is free */
ret = wait_bus_free(dev);
if (ret) {
return ret;
}
}
/* MCHP I2C spec recommends that for repeated start to write to control
* register before writing to data register
*/
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_ESO |
MCHP_I2C_SMB_CTRL_STA | MCHP_I2C_SMB_CTRL_ACK;
/* Send slave address */
MCHP_I2C_SMB_DATA(ba) = (addr | BIT(0));
ret = wait_completion(dev);
if (ret) {
return ret;
}
if (msg.len == 1) {
/* Send NACK for last transaction */
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_ESO;
}
/* Read dummy byte */
byte = MCHP_I2C_SMB_DATA(ba);
ret = wait_completion(dev);
if (ret) {
return ret;
}
for (int i = 0U; i < msg.len; i++) {
while (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_PIN) {
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_BER) {
recover_from_error(dev);
return -EBUSY;
}
}
if (i == (msg.len - 1)) {
if (msg.flags & I2C_MSG_STOP) {
/* Send stop and ack bits */
ctrl = (MCHP_I2C_SMB_CTRL_PIN |
MCHP_I2C_SMB_CTRL_ESO |
MCHP_I2C_SMB_CTRL_STO |
MCHP_I2C_SMB_CTRL_ACK);
MCHP_I2C_SMB_CTRL_WO(ba) = ctrl;
data->pending_stop = 0;
}
} else if (i == (msg.len - 2)) {
/* Send NACK for last transaction */
MCHP_I2C_SMB_CTRL_WO(ba) = MCHP_I2C_SMB_CTRL_ESO;
}
msg.buf[i] = MCHP_I2C_SMB_DATA(ba);
}
return 0;
}
static int i2c_xec_transfer(const struct device *dev, struct i2c_msg *msgs,
uint8_t num_msgs, uint16_t addr)
{
int ret = 0;
#ifdef CONFIG_I2C_SLAVE
struct i2c_xec_data *data = dev->data;
if (data->slave_attached) {
LOG_ERR("Device is registered as slave");
return -EBUSY;
}
#endif
addr <<= 1;
for (int i = 0U; i < num_msgs; i++) {
if ((msgs[i].flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) {
ret = i2c_xec_poll_write(dev, msgs[i], addr);
if (ret) {
LOG_ERR("Write error: %d", ret);
return ret;
}
} else {
ret = i2c_xec_poll_read(dev, msgs[i], addr);
if (ret) {
LOG_ERR("Read error: %d", ret);
return ret;
}
}
}
return 0;
}
static void i2c_xec_bus_isr(void *arg)
{
#ifdef CONFIG_I2C_SLAVE
struct device *dev = (struct device *)arg;
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
struct i2c_xec_data *data = dev->data;
const struct i2c_slave_callbacks *slave_cb = data->slave_cfg->callbacks;
uint32_t ba = config->base_addr;
uint32_t status;
uint8_t val;
uint8_t dummy = 0U;
if (!data->slave_attached) {
return;
}
/* Get current status */
status = MCHP_I2C_SMB_STS_RO(ba);
/* Bus Error */
if (status & MCHP_I2C_SMB_STS_BER) {
if (slave_cb->stop) {
slave_cb->stop(data->slave_cfg);
}
restart_slave(ba);
goto clear_iag;
}
/* External stop */
if (status & MCHP_I2C_SMB_STS_EXT_STOP) {
if (slave_cb->stop) {
slave_cb->stop(data->slave_cfg);
}
dummy = MCHP_I2C_SMB_DATA(ba);
restart_slave(ba);
goto clear_iag;
}
/* Address byte handling */
if (status & MCHP_I2C_SMB_STS_AAS) {
uint8_t slv_data = MCHP_I2C_SMB_DATA(ba);
if (!(slv_data & BIT(I2C_READ_WRITE_POS))) {
/* Slave receive */
data->slave_read = false;
if (slave_cb->write_requested) {
slave_cb->write_requested(data->slave_cfg);
}
goto clear_iag;
} else {
/* Slave transmit */
data->slave_read = true;
if (slave_cb->read_requested) {
slave_cb->read_requested(data->slave_cfg, &val);
}
MCHP_I2C_SMB_DATA(ba) = val;
goto clear_iag;
}
}
/* Slave transmit */
if (data->slave_read) {
/* Master has Nacked, then just write a dummy byte */
if (MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_LRB_AD0) {
MCHP_I2C_SMB_DATA(ba) = dummy;
} else {
if (slave_cb->read_processed) {
slave_cb->read_processed(data->slave_cfg, &val);
}
MCHP_I2C_SMB_DATA(ba) = val;
}
} else {
val = MCHP_I2C_SMB_DATA(ba);
/* TODO NACK Master */
if (slave_cb->write_received) {
slave_cb->write_received(data->slave_cfg, val);
}
}
clear_iag:
MCHP_GIRQ_SRC(config->girq_id) = BIT(config->girq_bit);
#endif
}
#ifdef CONFIG_I2C_SLAVE
static int i2c_xec_slave_register(const struct device *dev,
struct i2c_slave_config *config)
{
const struct i2c_xec_config *cfg = dev->config;
struct i2c_xec_data *data = dev->data;
uint32_t ba = cfg->base_addr;
int ret;
int counter = 0;
if (!config) {
return -EINVAL;
}
if (data->slave_attached) {
return -EBUSY;
}
/* Wait for any outstanding transactions to complete so that
* the bus is free
*/
while (!(MCHP_I2C_SMB_STS_RO(ba) & MCHP_I2C_SMB_STS_NBB)) {
ret = xec_spin_yield(&counter);
if (ret < 0) {
return ret;
}
}
data->slave_cfg = config;
/* Set own address */
MCHP_I2C_SMB_OWN_ADDR(ba) = data->slave_cfg->address;
restart_slave(ba);
data->slave_attached = true;
/* Clear before enabling girq bit */
MCHP_GIRQ_SRC(cfg->girq_id) = BIT(cfg->girq_bit);
MCHP_GIRQ_ENSET(cfg->girq_id) = BIT(cfg->girq_bit);
return 0;
}
static int i2c_xec_slave_unregister(const struct device *dev,
struct i2c_slave_config *config)
{
const struct i2c_xec_config *cfg = dev->config;
struct i2c_xec_data *data = dev->data;
if (!data->slave_attached) {
return -EINVAL;
}
data->slave_attached = false;
MCHP_GIRQ_ENCLR(cfg->girq_id) = BIT(cfg->girq_bit);
return 0;
}
#endif
static const struct i2c_driver_api i2c_xec_driver_api = {
.configure = i2c_xec_configure,
.transfer = i2c_xec_transfer,
#ifdef CONFIG_I2C_SLAVE
.slave_register = i2c_xec_slave_register,
.slave_unregister = i2c_xec_slave_unregister,
#endif
};
static int i2c_xec_init(const struct device *dev)
{
struct i2c_xec_data *data =
(struct i2c_xec_data *const) (dev->data);
int ret;
data->pending_stop = 0;
data->slave_attached = false;
/* Default configuration */
ret = i2c_xec_configure(dev,
I2C_MODE_MASTER |
I2C_SPEED_SET(I2C_SPEED_STANDARD));
if (ret) {
LOG_ERR("i2c configure failed %d", ret);
return ret;
}
#ifdef CONFIG_I2C_SLAVE
const struct i2c_xec_config *config =
(const struct i2c_xec_config *const) (dev->config);
config->irq_config_func();
#endif
return 0;
}
#define I2C_XEC_DEVICE(n) \
static void i2c_xec_irq_config_func_##n(void); \
\
static struct i2c_xec_data i2c_xec_data_##n; \
static const struct i2c_xec_config i2c_xec_config_##n = { \
.base_addr = \
DT_INST_REG_ADDR(n), \
.port_sel = DT_INST_PROP(n, port_sel), \
.girq_id = DT_INST_PROP(n, girq), \
.girq_bit = DT_INST_PROP(n, girq_bit), \
.irq_config_func = i2c_xec_irq_config_func_##n, \
}; \
DEVICE_DT_INST_DEFINE(n, &i2c_xec_init, NULL, \
&i2c_xec_data_##n, &i2c_xec_config_##n, \
POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, \
&i2c_xec_driver_api); \
\
static void i2c_xec_irq_config_func_##n(void) \
{ \
IRQ_CONNECT(DT_INST_IRQN(n), \
DT_INST_IRQ(n, priority), \
i2c_xec_bus_isr, \
DEVICE_DT_INST_GET(n), 0); \
irq_enable(DT_INST_IRQN(n)); \
}
DT_INST_FOREACH_STATUS_OKAY(I2C_XEC_DEVICE)