zephyr/drivers/i2c/i2c_nrf5.c

383 lines
9.1 KiB
C

/*
* Copyright (c) 2016-2017 ARM Ltd.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <i2c.h>
#include <soc.h>
#include <nrf.h>
#include <misc/util.h>
#include <gpio.h>
#define SYS_LOG_LEVEL CONFIG_SYS_LOG_I2C_LEVEL
#include <logging/sys_log.h>
/* @todo
*
* Only one instance of twi0 and spi0 may be active at any point in time.
* Only one instance of twi1, spi1 and spis1 may be active at a time.
*/
#define NRF5_TWI_INT_STOPPED \
(TWI_INTENSET_STOPPED_Set << TWI_INTENSET_STOPPED_Pos)
#define NRF5_TWI_INT_RXDREADY \
(TWI_INTENSET_RXDREADY_Set << TWI_INTENSET_RXDREADY_Pos)
#define NRF5_TWI_INT_TXDSENT \
(TWI_INTENSET_TXDSENT_Set << TWI_INTENSET_TXDSENT_Pos)
#define NRF5_TWI_INT_ERROR \
(TWI_INTENSET_ERROR_Set << TWI_INTENSET_ERROR_Pos)
struct i2c_nrf5_config {
volatile NRF_TWI_Type *base;
void (*irq_config_func)(struct device *dev);
union dev_config default_cfg;
};
struct i2c_nrf5_data {
struct k_sem sem;
u32_t rxd:1;
u32_t txd:1;
u32_t err:1;
u32_t stopped:1;
struct device *gpio;
};
static int i2c_nrf5_configure(struct device *dev, u32_t dev_config_raw)
{
const struct i2c_nrf5_config *config = dev->config->config_info;
union dev_config dev_config = (union dev_config)dev_config_raw;
volatile NRF_TWI_Type *twi = config->base;
SYS_LOG_DBG("");
if (dev_config.bits.is_slave_read) {
return -EINVAL;
}
if (dev_config.bits.use_10_bit_addr) {
return -EINVAL;
}
switch (dev_config.bits.speed) {
case I2C_SPEED_STANDARD:
twi->FREQUENCY = TWI_FREQUENCY_FREQUENCY_K100;
break;
case I2C_SPEED_FAST:
twi->FREQUENCY = TWI_FREQUENCY_FREQUENCY_K400;
break;
default:
SYS_LOG_ERR("unsupported speed");
return -EINVAL;
}
return 0;
}
static int i2c_nrf5_read(struct device *dev, struct i2c_msg *msg)
{
const struct i2c_nrf5_config *config = dev->config->config_info;
struct i2c_nrf5_data *data = dev->driver_data;
volatile NRF_TWI_Type *twi = config->base;
__ASSERT_NO_MSG(msg->len);
if (msg->flags & I2C_MSG_RESTART) {
/* No special behaviour required for
* repeated start.
*/
}
for (int offset = 0; offset < msg->len; offset++) {
if (offset == msg->len-1) {
SYS_LOG_DBG("SHORTS=2");
twi->SHORTS = 2; /* BB->STOP */
} else {
SYS_LOG_DBG("SHORTS=1");
twi->SHORTS = 1; /* BB->SUSPEND */
}
if (offset == 0) {
SYS_LOG_DBG("STARTRX");
twi->TASKS_STARTRX = 1;
} else {
SYS_LOG_DBG("RESUME");
twi->TASKS_RESUME = 1;
}
k_sem_take(&data->sem, K_FOREVER);
if (data->err) {
data->err = 0;
SYS_LOG_DBG("rx error 0x%x", twi->ERRORSRC);
twi->TASKS_STOP = 1;
twi->ENABLE = TWI_ENABLE_ENABLE_Disabled;
return -EIO;
}
__ASSERT_NO_MSG(data->rxd);
SYS_LOG_DBG("RXD");
data->rxd = 0;
msg->buf[offset] = twi->RXD;
}
if (msg->flags & I2C_MSG_STOP) {
SYS_LOG_DBG("TASK_STOP");
k_sem_take(&data->sem, K_FOREVER);
SYS_LOG_DBG("err=%d txd=%d rxd=%d stopped=%d errsrc=0x%x",
data->err, data->txd, data->rxd,
data->stopped, twi->ERRORSRC);
__ASSERT_NO_MSG(data->stopped);
data->stopped = 0;
}
return 0;
}
static int i2c_nrf5_write(struct device *dev,
struct i2c_msg *msg)
{
const struct i2c_nrf5_config *config = dev->config->config_info;
struct i2c_nrf5_data *data = dev->driver_data;
volatile NRF_TWI_Type *twi = config->base;
__ASSERT_NO_MSG(msg->len);
SYS_LOG_DBG("");
data->stopped = 0;
data->txd = 0;
twi->EVENTS_TXDSENT = 0;
twi->SHORTS = 0;
for (int offset = 0; offset < msg->len; offset++) {
SYS_LOG_DBG("txd=0x%x", msg->buf[offset]);
twi->TXD = msg->buf[offset];
if (offset == 0) {
SYS_LOG_DBG("STARTTX");
twi->TASKS_STARTTX = 1;
}
SYS_LOG_DBG("wait for sync");
k_sem_take(&data->sem, K_FOREVER);
SYS_LOG_DBG("err=%d txd=%d stopped=%d errsrc=0x%x",
data->err, data->txd,
data->stopped, twi->ERRORSRC);
if (data->err) {
data->err = 0;
SYS_LOG_ERR("tx error 0x%x",
twi->ERRORSRC);
twi->ERRORSRC = twi->ERRORSRC;
twi->TASKS_STOP = 1;
return -EIO;
}
__ASSERT_NO_MSG(data->txd);
data->txd = 0;
SYS_LOG_DBG("txdsent arrived");
}
if (msg->flags & I2C_MSG_STOP) {
SYS_LOG_DBG("TASK_STOP");
twi->TASKS_STOP = 1;
k_sem_take(&data->sem, K_FOREVER);
SYS_LOG_DBG("err=%d txd=%d rxd=%d stopped=%d errsrc=0x%x",
data->err, data->txd, data->rxd,
data->stopped, twi->ERRORSRC);
data->stopped = 0;
}
return 0;
}
static int i2c_nrf5_transfer(struct device *dev, struct i2c_msg *msgs,
u8_t num_msgs, u16_t addr)
{
const struct i2c_nrf5_config *config = dev->config->config_info;
volatile NRF_TWI_Type *twi = config->base;
SYS_LOG_DBG("transaction-start addr=0x%x", addr);
/* @todo The NRF5 imposes constraints on which peripherals can
* be simultaneously active. We should take steps here to
* enforce appropriate mutual exclusion between SPI, TWI and
* SPIS drivers.
*/
twi->ENABLE = TWI_ENABLE_ENABLE_Enabled;
twi->ADDRESS = addr;
for (int i = 0; i < num_msgs; i++) {
int r;
SYS_LOG_DBG("msg len=%d %s%s%s", msgs[i].len,
(msgs[i].flags & I2C_MSG_READ) ? "R":"W",
(msgs[i].flags & I2C_MSG_STOP) ? "S":"-",
(msgs[i].flags & I2C_MSG_RESTART) ? "+":"-");
if (msgs[i].flags & I2C_MSG_READ) {
twi->EVENTS_RXDREADY = 0;
twi->INTENSET = (NRF5_TWI_INT_TXDSENT
| NRF5_TWI_INT_RXDREADY
| NRF5_TWI_INT_ERROR
| NRF5_TWI_INT_STOPPED);
r = i2c_nrf5_read(dev, msgs + i);
} else {
r = i2c_nrf5_write(dev, msgs + i);
}
if (r != 0) {
twi->ENABLE = TWI_ENABLE_ENABLE_Disabled;
return r;
}
}
twi->ENABLE = TWI_ENABLE_ENABLE_Disabled;
return 0;
}
static void i2c_nrf5_isr(void *arg)
{
struct device *dev = (struct device *)arg;
const struct i2c_nrf5_config *config = dev->config->config_info;
struct i2c_nrf5_data *data = dev->driver_data;
volatile NRF_TWI_Type *twi = config->base;
if (twi->EVENTS_RXDREADY) {
data->rxd = 1;
twi->EVENTS_RXDREADY = 0;
k_sem_give(&data->sem);
}
if (twi->EVENTS_TXDSENT) {
data->txd = 1;
twi->EVENTS_TXDSENT = 0;
k_sem_give(&data->sem);
}
if (twi->EVENTS_ERROR) {
data->err = 1;
twi->EVENTS_ERROR = 0;
k_sem_give(&data->sem);
}
if (twi->EVENTS_STOPPED) {
data->stopped = 1;
twi->EVENTS_STOPPED = 0;
k_sem_give(&data->sem);
}
}
static int i2c_nrf5_init(struct device *dev)
{
const struct i2c_nrf5_config *config = dev->config->config_info;
struct i2c_nrf5_data *data = dev->driver_data;
volatile NRF_TWI_Type *twi = config->base;
int status;
SYS_LOG_DBG("");
data->gpio = device_get_binding(CONFIG_GPIO_NRF5_P0_DEV_NAME);
k_sem_init(&data->sem, 0, UINT_MAX);
config->irq_config_func(dev);
twi->ENABLE = TWI_ENABLE_ENABLE_Disabled;
status = gpio_pin_configure(data->gpio, CONFIG_I2C_NRF5_GPIO_SCL_PIN,
GPIO_DIR_IN
| GPIO_PUD_PULL_UP
| GPIO_DS_DISCONNECT_HIGH);
__ASSERT_NO_MSG(status == 0);
status = gpio_pin_configure(data->gpio, CONFIG_I2C_NRF5_GPIO_SCA_PIN,
GPIO_DIR_IN
| GPIO_PUD_PULL_UP
| GPIO_DS_DISCONNECT_HIGH);
__ASSERT_NO_MSG(status == 0);
twi->PSELSCL = CONFIG_I2C_NRF5_GPIO_SCL_PIN;
twi->PSELSDA = CONFIG_I2C_NRF5_GPIO_SCA_PIN;
twi->ERRORSRC = twi->ERRORSRC;
twi->EVENTS_TXDSENT = 0;
twi->EVENTS_RXDREADY = 0;
twi->EVENTS_ERROR = 0;
twi->INTENSET = (NRF5_TWI_INT_TXDSENT
| NRF5_TWI_INT_RXDREADY
| NRF5_TWI_INT_ERROR
| NRF5_TWI_INT_STOPPED);
status = i2c_nrf5_configure(dev, config->default_cfg.raw);
if (status) {
return status;
}
return 0;
}
static const struct i2c_driver_api i2c_nrf5_driver_api = {
.configure = i2c_nrf5_configure,
.transfer = i2c_nrf5_transfer,
};
/* i2c & spi instance with the same id (e.g. I2C_0 and SPI_0) can NOT be used
* at the same time on nRF5x chip family.
*/
#if defined(CONFIG_I2C_0) && !defined(CONFIG_SPI_0)
static void i2c_nrf5_config_func_0(struct device *dev);
static const struct i2c_nrf5_config i2c_nrf5_config_0 = {
.base = NRF_TWI0,
.irq_config_func = i2c_nrf5_config_func_0,
.default_cfg.raw = CONFIG_I2C_0_DEFAULT_CFG,
};
static struct i2c_nrf5_data i2c_nrf5_data_0;
DEVICE_AND_API_INIT(i2c_nrf5_0, CONFIG_I2C_0_NAME, i2c_nrf5_init,
&i2c_nrf5_data_0, &i2c_nrf5_config_0,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_nrf5_driver_api);
static void i2c_nrf5_config_func_0(struct device *dev)
{
IRQ_CONNECT(NRF5_IRQ_SPI0_TWI0_IRQn, CONFIG_I2C_0_IRQ_PRI,
i2c_nrf5_isr, DEVICE_GET(i2c_nrf5_0), 0);
irq_enable(NRF5_IRQ_SPI0_TWI0_IRQn);
}
#endif /* CONFIG_I2C_0 && !CONFIG_SPI_0 */
#if defined(CONFIG_I2C_1) && !defined(CONFIG_SPI_1)
static void i2c_nrf5_config_func_1(struct device *dev);
static const struct i2c_nrf5_config i2c_nrf5_config_1 = {
.base = NRF_TWI1,
.irq_config_func = i2c_nrf5_config_func_1,
.default_cfg.raw = CONFIG_I2C_1_DEFAULT_CFG,
};
static struct i2c_nrf5_data i2c_nrf5_data_1;
DEVICE_AND_API_INIT(i2c_nrf5_1, CONFIG_I2C_1_NAME, i2c_nrf5_init,
&i2c_nrf5_data_1, &i2c_nrf5_config_1,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_nrf5_driver_api);
static void i2c_nrf5_config_func_1(struct device *dev)
{
IRQ_CONNECT(NRF5_IRQ_SPI1_TWI1_IRQn, CONFIG_I2C_1_IRQ_PRI,
i2c_nrf5_isr, DEVICE_GET(i2c_nrf5_1), 0);
irq_enable(NRF5_IRQ_SPI1_TWI1_IRQn);
}
#endif /* CONFIG_I2C_1 && !CONFIG_SPI_1 */