zephyr/drivers/i2c/i2c_imx.c

457 lines
11 KiB
C

/*
* Copyright (c) 2018 Diego Sueiro, <diego.sueiro@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <i2c.h>
#include <soc.h>
#include <i2c_imx.h>
#include <misc/util.h>
#include "i2c-priv.h"
#define DEV_CFG(dev) \
((const struct i2c_imx_config * const)(dev)->config->config_info)
#define DEV_DATA(dev) \
((struct i2c_imx_data * const)(dev)->driver_data)
#define DEV_BASE(dev) \
((I2C_Type *)(DEV_CFG(dev))->base)
struct i2c_imx_config {
I2C_Type *base;
void (*irq_config_func)(struct device *dev);
u32_t bitrate;
};
struct i2c_master_transfer {
const u8_t *txBuff;
volatile u8_t *rxBuff;
volatile u32_t cmdSize;
volatile u32_t txSize;
volatile u32_t rxSize;
volatile bool isBusy;
volatile u32_t currentDir;
volatile u32_t currentMode;
volatile bool ack;
};
struct i2c_imx_data {
struct i2c_master_transfer transfer;
struct k_sem device_sync_sem;
};
static bool i2c_imx_write(struct device *dev, u8_t *txBuffer, u8_t txSize)
{
I2C_Type *base = DEV_BASE(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
struct i2c_master_transfer *transfer = &data->transfer;
transfer->isBusy = true;
/* Clear I2C interrupt flag to avoid spurious interrupt */
I2C_ClearStatusFlag(base, i2cStatusInterrupt);
/* Set I2C work under Tx mode */
I2C_SetDirMode(base, i2cDirectionTransmit);
transfer->currentDir = i2cDirectionTransmit;
transfer->txBuff = txBuffer;
transfer->txSize = txSize;
I2C_WriteByte(base, *transfer->txBuff);
transfer->txBuff++;
transfer->txSize--;
/* Enable I2C interrupt, subsequent data transfer will be handled
* in ISR.
*/
I2C_SetIntCmd(base, true);
/* Wait for the transfer to complete */
k_sem_take(&data->device_sync_sem, K_FOREVER);
return transfer->ack;
}
static void i2c_imx_read(struct device *dev, u8_t *rxBuffer, u8_t rxSize)
{
I2C_Type *base = DEV_BASE(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
struct i2c_master_transfer *transfer = &data->transfer;
transfer->isBusy = true;
/* Clear I2C interrupt flag to avoid spurious interrupt */
I2C_ClearStatusFlag(base, i2cStatusInterrupt);
/* Change to receive state. */
I2C_SetDirMode(base, i2cDirectionReceive);
transfer->currentDir = i2cDirectionReceive;
transfer->rxBuff = rxBuffer;
transfer->rxSize = rxSize;
if (transfer->rxSize == 1) {
/* Send Nack */
I2C_SetAckBit(base, false);
} else {
/* Send Ack */
I2C_SetAckBit(base, true);
}
/* dummy read to clock in 1st byte */
I2C_ReadByte(base);
/* Enable I2C interrupt, subsequent data transfer will be handled
* in ISR.
*/
I2C_SetIntCmd(base, true);
/* Wait for the transfer to complete */
k_sem_take(&data->device_sync_sem, K_FOREVER);
}
static int i2c_imx_configure(struct device *dev, u32_t dev_config_raw)
{
I2C_Type *base = DEV_BASE(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
struct i2c_master_transfer *transfer = &data->transfer;
u32_t baudrate;
if (!(I2C_MODE_MASTER & dev_config_raw)) {
return -EINVAL;
}
if (I2C_ADDR_10_BITS & dev_config_raw) {
return -EINVAL;
}
/* Initialize I2C state structure content. */
transfer->txBuff = 0;
transfer->rxBuff = 0;
transfer->cmdSize = 0;
transfer->txSize = 0;
transfer->rxSize = 0;
transfer->isBusy = false;
transfer->currentDir = i2cDirectionReceive;
transfer->currentMode = i2cModeSlave;
switch (I2C_SPEED_GET(dev_config_raw)) {
case I2C_SPEED_STANDARD:
baudrate = KHZ(100);
break;
case I2C_SPEED_FAST:
baudrate = MHZ(1);
break;
default:
return -EINVAL;
}
/* Setup I2C init structure. */
i2c_init_config_t i2cInitConfig = {
.baudRate = baudrate,
.slaveAddress = 0x00
};
i2cInitConfig.clockRate = get_i2c_clock_freq(base);
I2C_Init(base, &i2cInitConfig);
I2C_Enable(base);
return 0;
}
static int i2c_imx_send_addr(struct device *dev, u16_t addr, u8_t flags)
{
u8_t byte0 = addr << 1;
byte0 |= (flags & I2C_MSG_RW_MASK) == I2C_MSG_READ;
return i2c_imx_write(dev, &byte0, 1);
}
static int i2c_imx_transfer(struct device *dev, struct i2c_msg *msgs,
u8_t num_msgs, u16_t addr)
{
I2C_Type *base = DEV_BASE(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
struct i2c_master_transfer *transfer = &data->transfer;
u8_t *buf, *buf_end;
u16_t timeout = UINT16_MAX;
int result = -EIO;
if (!num_msgs) {
return 0;
}
/* Wait until bus not busy */
while ((I2C_I2SR_REG(base) & i2cStatusBusBusy) && (--timeout)) {
}
if (timeout == 0) {
return result;
}
/* Make sure we're in a good state so slave recognises the Start */
I2C_SetWorkMode(base, i2cModeSlave);
transfer->currentMode = i2cModeSlave;
/* Switch back to Rx direction. */
I2C_SetDirMode(base, i2cDirectionReceive);
transfer->currentDir = i2cDirectionReceive;
/* Start condition */
I2C_SetDirMode(base, i2cDirectionTransmit);
transfer->currentDir = i2cDirectionTransmit;
I2C_SetWorkMode(base, i2cModeMaster);
transfer->currentMode = i2cModeMaster;
/* Send address after any Start condition */
if (!i2c_imx_send_addr(dev, addr, msgs->flags)) {
goto finish; /* No ACK received */
}
do {
if (msgs->flags & I2C_MSG_RESTART) {
I2C_SendRepeatStart(base);
if (!i2c_imx_send_addr(dev, addr, msgs->flags)) {
goto finish; /* No ACK received */
}
}
/* Transfer data */
buf = msgs->buf;
buf_end = buf + msgs->len;
if ((msgs->flags & I2C_MSG_RW_MASK) == I2C_MSG_READ) {
i2c_imx_read(dev, msgs->buf, msgs->len);
} else {
if (!i2c_imx_write(dev, msgs->buf, msgs->len)) {
goto finish; /* No ACK received */
}
}
if (msgs->flags & I2C_MSG_STOP) {
I2C_SetWorkMode(base, i2cModeSlave);
transfer->currentMode = i2cModeSlave;
I2C_SetDirMode(base, i2cDirectionReceive);
transfer->currentDir = i2cDirectionReceive;
}
/* Next message */
msgs++;
num_msgs--;
} while (num_msgs);
/* Complete without error */
result = 0;
return result;
finish:
I2C_SetWorkMode(base, i2cModeSlave);
transfer->currentMode = i2cModeSlave;
I2C_SetDirMode(base, i2cDirectionReceive);
transfer->currentDir = i2cDirectionReceive;
return result;
}
static void i2c_imx_isr(void *arg)
{
struct device *dev = (struct device *)arg;
I2C_Type *base = DEV_BASE(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
struct i2c_master_transfer *transfer = &data->transfer;
/* Clear interrupt flag. */
I2C_ClearStatusFlag(base, i2cStatusInterrupt);
/* Exit the ISR if no transfer is happening for this instance. */
if (!transfer->isBusy)
return;
if (i2cModeMaster == transfer->currentMode) {
if (i2cDirectionTransmit == transfer->currentDir) {
/* Normal write operation. */
transfer->ack =
!(I2C_GetStatusFlag(base, i2cStatusReceivedAck));
if (transfer->txSize == 0) {
/* Close I2C interrupt. */
I2C_SetIntCmd(base, false);
/* Release I2C Bus. */
transfer->isBusy = false;
k_sem_give(&data->device_sync_sem);
} else {
I2C_WriteByte(base, *transfer->txBuff);
transfer->txBuff++;
transfer->txSize--;
}
} else {
/* Normal read operation. */
if (transfer->rxSize == 2) {
/* Send Nack */
I2C_SetAckBit(base, false);
} else {
/* Send Ack */
I2C_SetAckBit(base, true);
}
if (transfer->rxSize == 1) {
/* Switch back to Tx direction to avoid
* additional I2C bus read.
*/
I2C_SetDirMode(base, i2cDirectionTransmit);
transfer->currentDir = i2cDirectionTransmit;
}
*transfer->rxBuff = I2C_ReadByte(base);
transfer->rxBuff++;
transfer->rxSize--;
/* receive finished. */
if (transfer->rxSize == 0) {
/* Close I2C interrupt. */
I2C_SetIntCmd(base, false);
/* Release I2C Bus. */
transfer->isBusy = false;
k_sem_give(&data->device_sync_sem);
}
}
}
}
static int i2c_imx_init(struct device *dev)
{
const struct i2c_imx_config *config = DEV_CFG(dev);
struct i2c_imx_data *data = DEV_DATA(dev);
u32_t bitrate_cfg;
int error;
k_sem_init(&data->device_sync_sem, 0, UINT_MAX);
bitrate_cfg = _i2c_map_dt_bitrate(config->bitrate);
error = i2c_imx_configure(dev, I2C_MODE_MASTER | bitrate_cfg);
if (error) {
return error;
}
config->irq_config_func(dev);
return 0;
}
static const struct i2c_driver_api i2c_imx_driver_api = {
.configure = i2c_imx_configure,
.transfer = i2c_imx_transfer,
};
#ifdef CONFIG_I2C_1
static void i2c_imx_config_func_1(struct device *dev);
static const struct i2c_imx_config i2c_imx_config_1 = {
.base = (I2C_Type *)I2C_1_BASE_ADDRESS,
.irq_config_func = i2c_imx_config_func_1,
.bitrate = I2C_1_CLOCK_FREQUENCY,
};
static struct i2c_imx_data i2c_imx_data_1;
DEVICE_AND_API_INIT(i2c_imx_1, I2C_1_LABEL, &i2c_imx_init,
&i2c_imx_data_1, &i2c_imx_config_1,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_imx_driver_api);
static void i2c_imx_config_func_1(struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(I2C_1_IRQ, I2C_1_IRQ_PRIORITY,
i2c_imx_isr, DEVICE_GET(i2c_imx_1), 0);
irq_enable(I2C_1_IRQ);
}
#endif /* CONFIG_I2C_1 */
#ifdef CONFIG_I2C_2
static void i2c_imx_config_func_2(struct device *dev);
static const struct i2c_imx_config i2c_imx_config_2 = {
.base = (I2C_Type *)I2C_2_BASE_ADDRESS,
.irq_config_func = i2c_imx_config_func_2,
.bitrate = I2C_2_CLOCK_FREQUENCY,
};
static struct i2c_imx_data i2c_imx_data_2;
DEVICE_AND_API_INIT(i2c_imx_2, I2C_2_LABEL, &i2c_imx_init,
&i2c_imx_data_2, &i2c_imx_config_2,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_imx_driver_api);
static void i2c_imx_config_func_2(struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(I2C_2_IRQ, I2C_2_IRQ_PRIORITY,
i2c_imx_isr, DEVICE_GET(i2c_imx_2), 0);
irq_enable(I2C_2_IRQ);
}
#endif /* CONFIG_I2C_2 */
#ifdef CONFIG_I2C_3
static void i2c_imx_config_func_3(struct device *dev);
static const struct i2c_imx_config i2c_imx_config_3 = {
.base = (I2C_Type *)I2C_3_BASE_ADDRESS,
.irq_config_func = i2c_imx_config_func_3,
.bitrate = I2C_3_CLOCK_FREQUENCY,
};
static struct i2c_imx_data i2c_imx_data_3;
DEVICE_AND_API_INIT(i2c_imx_3, I2C_3_LABEL, &i2c_imx_init,
&i2c_imx_data_3, &i2c_imx_config_3,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_imx_driver_api);
static void i2c_imx_config_func_3(struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(I2C_3_IRQ, I2C_3_IRQ_PRIORITY,
i2c_imx_isr, DEVICE_GET(i2c_imx_3), 0);
irq_enable(I2C_3_IRQ);
}
#endif /* CONFIG_I2C_3 */
#ifdef CONFIG_I2C_4
static void i2c_imx_config_func_4(struct device *dev);
static const struct i2c_imx_config i2c_imx_config_4 = {
.base = (I2C_Type *)I2C_4_BASE_ADDRESS,
.irq_config_func = i2c_imx_config_func_4,
.bitrate = I2C_4_CLOCK_FREQUENCY,
};
static struct i2c_imx_data i2c_imx_data_4;
DEVICE_AND_API_INIT(i2c_imx_4, I2C_4_LABEL, &i2c_imx_init,
&i2c_imx_data_4, &i2c_imx_config_4,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&i2c_imx_driver_api);
static void i2c_imx_config_func_4(struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(I2C_4_IRQ, I2C_4_IRQ_PRIORITY,
i2c_imx_isr, DEVICE_GET(i2c_imx_4), 0);
irq_enable(I2C_4_IRQ);
}
#endif /* CONFIG_I2C_4 */