zephyr/drivers/i2c/i2c_nrfx_twi.c

289 lines
7.6 KiB
C

/*
* Copyright (c) 2018, Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/i2c.h>
#include <dt-bindings/i2c/i2c.h>
#include <nrfx_twi.h>
#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
#include <logging/log.h>
LOG_MODULE_REGISTER(i2c_nrfx_twi);
struct i2c_nrfx_twi_data {
struct k_sem transfer_sync;
struct k_sem completion_sync;
volatile nrfx_err_t res;
u32_t dev_config;
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
u32_t pm_state;
#endif
};
struct i2c_nrfx_twi_config {
nrfx_twi_t twi;
nrfx_twi_config_t config;
};
static inline struct i2c_nrfx_twi_data *get_dev_data(struct device *dev)
{
return dev->driver_data;
}
static inline
const struct i2c_nrfx_twi_config *get_dev_config(struct device *dev)
{
return dev->config->config_info;
}
static int i2c_nrfx_twi_transfer(struct device *dev, struct i2c_msg *msgs,
u8_t num_msgs, u16_t addr)
{
int ret = 0;
k_sem_take(&(get_dev_data(dev)->transfer_sync), K_FOREVER);
nrfx_twi_enable(&get_dev_config(dev)->twi);
for (size_t i = 0; i < num_msgs; i++) {
if (I2C_MSG_ADDR_10_BITS & msgs[i].flags) {
ret = -ENOTSUP;
break;
}
nrfx_twi_xfer_desc_t cur_xfer = {
.p_primary_buf = msgs[i].buf,
.primary_length = msgs[i].len,
.address = addr,
.type = (msgs[i].flags & I2C_MSG_READ) ?
NRFX_TWI_XFER_RX : NRFX_TWI_XFER_TX
};
u32_t xfer_flags = 0;
nrfx_err_t res;
/* In case the STOP condition is not supposed to appear after
* the current message, check what is requested further:
*/
if (!(msgs[i].flags & I2C_MSG_STOP)) {
/* - if the transfer consists of more messages
* and the I2C repeated START is not requested
* to appear before the next message, suspend
* the transfer after the current message,
* so that it can be resumed with the next one,
* resulting in the two messages merged into
* a continuous transfer on the bus
*/
if ((i < (num_msgs - 1)) &&
!(msgs[i + 1].flags & I2C_MSG_RESTART)) {
xfer_flags |= NRFX_TWI_FLAG_SUSPEND;
/* - otherwise, just finish the transfer without
* generating the STOP condition, unless the current
* message is an RX request, for which such feature
* is not supported
*/
} else if (msgs[i].flags & I2C_MSG_READ) {
ret = -ENOTSUP;
break;
} else {
xfer_flags |= NRFX_TWI_FLAG_TX_NO_STOP;
}
}
res = nrfx_twi_xfer(&get_dev_config(dev)->twi,
&cur_xfer,
xfer_flags);
if (res != NRFX_SUCCESS) {
if (res == NRFX_ERROR_BUSY) {
ret = -EBUSY;
break;
} else {
ret = -EIO;
break;
}
}
k_sem_take(&(get_dev_data(dev)->completion_sync), K_FOREVER);
res = get_dev_data(dev)->res;
if (res != NRFX_SUCCESS) {
LOG_ERR("Error %d occurred for message %d", res, i);
ret = -EIO;
break;
}
}
nrfx_twi_disable(&get_dev_config(dev)->twi);
k_sem_give(&(get_dev_data(dev)->transfer_sync));
return ret;
}
static void event_handler(nrfx_twi_evt_t const *p_event, void *p_context)
{
struct device *dev = p_context;
struct i2c_nrfx_twi_data *dev_data = get_dev_data(dev);
switch (p_event->type) {
case NRFX_TWI_EVT_DONE:
dev_data->res = NRFX_SUCCESS;
break;
case NRFX_TWI_EVT_ADDRESS_NACK:
dev_data->res = NRFX_ERROR_DRV_TWI_ERR_ANACK;
break;
case NRFX_TWI_EVT_DATA_NACK:
dev_data->res = NRFX_ERROR_DRV_TWI_ERR_DNACK;
break;
default:
dev_data->res = NRFX_ERROR_INTERNAL;
break;
}
k_sem_give(&dev_data->completion_sync);
}
static int i2c_nrfx_twi_configure(struct device *dev, u32_t dev_config)
{
nrfx_twi_t const *inst = &(get_dev_config(dev)->twi);
if (I2C_ADDR_10_BITS & dev_config) {
return -EINVAL;
}
switch (I2C_SPEED_GET(dev_config)) {
case I2C_SPEED_STANDARD:
nrf_twi_frequency_set(inst->p_twi, NRF_TWI_FREQ_100K);
break;
case I2C_SPEED_FAST:
nrf_twi_frequency_set(inst->p_twi, NRF_TWI_FREQ_400K);
break;
default:
LOG_ERR("unsupported speed");
return -EINVAL;
}
get_dev_data(dev)->dev_config = dev_config;
return 0;
}
static const struct i2c_driver_api i2c_nrfx_twi_driver_api = {
.configure = i2c_nrfx_twi_configure,
.transfer = i2c_nrfx_twi_transfer,
};
static int init_twi(struct device *dev)
{
nrfx_err_t result = nrfx_twi_init(&get_dev_config(dev)->twi,
&get_dev_config(dev)->config,
event_handler, dev);
if (result != NRFX_SUCCESS) {
LOG_ERR("Failed to initialize device: %s",
dev->config->name);
return -EBUSY;
}
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
get_dev_data(dev)->pm_state = DEVICE_PM_ACTIVE_STATE;
#endif
return 0;
}
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
static int twi_nrfx_pm_control(struct device *dev, u32_t ctrl_command,
void *context, device_pm_cb cb, void *arg)
{
int ret = 0;
if (ctrl_command == DEVICE_PM_SET_POWER_STATE) {
u32_t new_state = *((const u32_t *)context);
if (new_state != get_dev_data(dev)->pm_state) {
switch (new_state) {
case DEVICE_PM_ACTIVE_STATE:
init_twi(dev);
if (get_dev_data(dev)->dev_config) {
i2c_nrfx_twi_configure(
dev,
get_dev_data(dev)->dev_config);
}
break;
case DEVICE_PM_LOW_POWER_STATE:
case DEVICE_PM_SUSPEND_STATE:
case DEVICE_PM_OFF_STATE:
nrfx_twi_uninit(&get_dev_config(dev)->twi);
break;
default:
ret = -ENOTSUP;
}
if (!ret) {
get_dev_data(dev)->pm_state = new_state;
}
}
} else {
assert(ctrl_command == DEVICE_PM_GET_POWER_STATE);
*((u32_t *)context) = get_dev_data(dev)->pm_state;
}
if (cb) {
cb(dev, ret, context, arg);
}
return ret;
}
#endif /* CONFIG_DEVICE_POWER_MANAGEMENT */
#define I2C_NRFX_TWI_INVALID_FREQUENCY ((nrf_twi_frequency_t)-1)
#define I2C_NRFX_TWI_FREQUENCY(bitrate) \
(bitrate == I2C_BITRATE_STANDARD ? NRF_TWI_FREQ_100K \
: bitrate == 250000 ? NRF_TWI_FREQ_250K \
: bitrate == I2C_BITRATE_FAST ? NRF_TWI_FREQ_400K \
: I2C_NRFX_TWI_INVALID_FREQUENCY)
#define I2C_NRFX_TWI_DEVICE(idx) \
BUILD_ASSERT_MSG( \
I2C_NRFX_TWI_FREQUENCY( \
DT_NORDIC_NRF_TWI_I2C_##idx##_CLOCK_FREQUENCY) \
!= I2C_NRFX_TWI_INVALID_FREQUENCY, \
"Wrong I2C " #idx " frequency setting in dts"); \
static int twi_##idx##_init(struct device *dev) \
{ \
IRQ_CONNECT(DT_NORDIC_NRF_TWI_I2C_##idx##_IRQ_0, \
DT_NORDIC_NRF_TWI_I2C_##idx##_IRQ_0_PRIORITY, \
nrfx_isr, nrfx_twi_##idx##_irq_handler, 0); \
return init_twi(dev); \
} \
static struct i2c_nrfx_twi_data twi_##idx##_data = { \
.transfer_sync = Z_SEM_INITIALIZER( \
twi_##idx##_data.transfer_sync, 1, 1), \
.completion_sync = Z_SEM_INITIALIZER( \
twi_##idx##_data.completion_sync, 0, 1) \
}; \
static const struct i2c_nrfx_twi_config twi_##idx##z_config = { \
.twi = NRFX_TWI_INSTANCE(idx), \
.config = { \
.scl = DT_NORDIC_NRF_TWI_I2C_##idx##_SCL_PIN, \
.sda = DT_NORDIC_NRF_TWI_I2C_##idx##_SDA_PIN, \
.frequency = I2C_NRFX_TWI_FREQUENCY( \
DT_NORDIC_NRF_TWI_I2C_##idx##_CLOCK_FREQUENCY) \
} \
}; \
DEVICE_DEFINE(twi_##idx, \
DT_NORDIC_NRF_TWI_I2C_##idx##_LABEL, \
twi_##idx##_init, \
twi_nrfx_pm_control, \
&twi_##idx##_data, \
&twi_##idx##z_config, \
POST_KERNEL, \
CONFIG_I2C_INIT_PRIORITY, \
&i2c_nrfx_twi_driver_api)
#ifdef CONFIG_I2C_0_NRF_TWI
I2C_NRFX_TWI_DEVICE(0);
#endif
#ifdef CONFIG_I2C_1_NRF_TWI
I2C_NRFX_TWI_DEVICE(1);
#endif