drivers/i2c/i2c_ll_stm32.c

/*
 * Copyright (c) 2016 BayLibre, SAS
 * Copyright (c) 2017 Linaro Ltd
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <clock_control/stm32_clock_control.h>
#include <clock_control.h>
#include <misc/util.h>
#include <kernel.h>
#include <board.h>
#include <errno.h>
#include <i2c.h>
#include "i2c-priv.h"
#include "i2c_ll_stm32.h"

#define SYS_LOG_LEVEL CONFIG_SYS_LOG_I2C_LEVEL
#include <logging/sys_log.h>

static int i2c_stm32_runtime_configure(struct device *dev, u32_t config)
{
	const struct i2c_stm32_config *cfg = DEV_CFG(dev);
	struct i2c_stm32_data *data = DEV_DATA(dev);
	I2C_TypeDef *i2c = cfg->i2c;
	u32_t clock = 0;

#if defined(CONFIG_SOC_SERIES_STM32F3X) || defined(CONFIG_SOC_SERIES_STM32F0X)
	LL_RCC_ClocksTypeDef rcc_clocks;

	/*
	 * STM32F0/3 I2C's independent clock source supports only
	 * HSI and SYSCLK, not APB1. We force clock variable to
	 * SYSCLK frequency.
	 */
	LL_RCC_GetSystemClocksFreq(&rcc_clocks);
	clock = rcc_clocks.SYSCLK_Frequency;
#else
	clock_control_get_rate(device_get_binding(STM32_CLOCK_CONTROL_NAME),
			(clock_control_subsys_t *) &cfg->pclken, &clock);
#endif /* CONFIG_SOC_SERIES_STM32F3X) || CONFIG_SOC_SERIES_STM32F0X */

	data->dev_config = config;

	LL_I2C_Disable(i2c);
	LL_I2C_SetMode(i2c, LL_I2C_MODE_I2C);

	return stm32_i2c_configure_timing(dev, clock);
}

#define OPERATION(msg) (((struct i2c_msg *) msg)->flags & I2C_MSG_RW_MASK)

static int i2c_stm32_transfer(struct device *dev, struct i2c_msg *msg,
			      u8_t num_msgs, u16_t slave)
{
	const struct i2c_stm32_config *cfg = DEV_CFG(dev);
	struct i2c_msg *current, *next;
	I2C_TypeDef *i2c = cfg->i2c;
	int ret = 0;

	LL_I2C_Enable(i2c);

	current = msg;
	/*
	 * Set I2C_MSG_RESTART flag on first message in order to send start
	 * condition
	 */
	current->flags |= I2C_MSG_RESTART;
	while (num_msgs > 0) {
		u8_t *next_msg_flags = NULL;

		if (num_msgs > 1) {
			next = current + 1;
			next_msg_flags = &(next->flags);

			/*
			 * Stop or restart condition between messages
			 * of different directions is required
			 */
			if (OPERATION(current) != OPERATION(next)) {
				if (!(next->flags & I2C_MSG_RESTART)) {
					ret = -EINVAL;
					break;
				}
			}
		}

		if (current->len > 255) {
			ret = -EINVAL;
			break;
		}

		/* Stop condition is required for the last message */
		if ((num_msgs == 1) && !(current->flags & I2C_MSG_STOP)) {
			ret = -EINVAL;
			break;
		}

		if ((current->flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) {
			ret = stm32_i2c_msg_write(dev, current, next_msg_flags,
						  slave);
		} else {
			ret = stm32_i2c_msg_read(dev, current, next_msg_flags,
						 slave);
		}

		if (ret < 0) {
			break;
		}

		current++;
		num_msgs--;
	};

	LL_I2C_Disable(i2c);

	return ret;
}

static const struct i2c_driver_api api_funcs = {
	.configure = i2c_stm32_runtime_configure,
	.transfer = i2c_stm32_transfer,
};

static int i2c_stm32_init(struct device *dev)
{
	struct device *clock = device_get_binding(STM32_CLOCK_CONTROL_NAME);
	const struct i2c_stm32_config *cfg = DEV_CFG(dev);
	u32_t bitrate_cfg;
	int ret;
#ifdef CONFIG_I2C_STM32_INTERRUPT
	struct i2c_stm32_data *data = DEV_DATA(dev);

	k_sem_init(&data->device_sync_sem, 0, UINT_MAX);
	cfg->irq_config_func(dev);
#endif

	__ASSERT_NO_MSG(clock);
	clock_control_on(clock, (clock_control_subsys_t *) &cfg->pclken);

#if defined(CONFIG_SOC_SERIES_STM32F3X) || defined(CONFIG_SOC_SERIES_STM32F0X)
	/*
	 * STM32F0/3 I2C's independent clock source supports only
	 * HSI and SYSCLK, not APB1. We force I2C clock source to SYSCLK.
	 * I2C2 on STM32F0 uses APB1 clock as I2C clock source
	 */

	switch ((u32_t)cfg->i2c) {
#ifdef CONFIG_I2C_1
	case CONFIG_I2C_1_BASE_ADDRESS:
		LL_RCC_SetI2CClockSource(LL_RCC_I2C1_CLKSOURCE_SYSCLK);
		break;
#endif /* CONFIG_I2C_1 */

#if defined(CONFIG_SOC_SERIES_STM32F3X) && defined(CONFIG_I2C_2)
	case CONFIG_I2C_2_BASE_ADDRESS:
		LL_RCC_SetI2CClockSource(LL_RCC_I2C2_CLKSOURCE_SYSCLK);
		break;
#endif /* CONFIG_SOC_SERIES_STM32F3X && CONFIG_I2C_2 */

#ifdef CONFIG_I2C_3
	case CONFIG_I2C_3_BASE_ADDRESS:
		LL_RCC_SetI2CClockSource(LL_RCC_I2C3_CLKSOURCE_SYSCLK);
		break;
#endif /* CONFIG_I2C_3 */
	}
#endif /* CONFIG_SOC_SERIES_STM32F3X) || CONFIG_SOC_SERIES_STM32F0X */

	bitrate_cfg = _i2c_map_dt_bitrate(cfg->bitrate);

	ret = i2c_stm32_runtime_configure(dev, I2C_MODE_MASTER | bitrate_cfg);
	if (ret < 0) {
		SYS_LOG_ERR("i2c: failure initializing");
		return ret;
	}

	return 0;
}

#ifdef CONFIG_I2C_1

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_1(struct device *port);
#endif

static const struct i2c_stm32_config i2c_stm32_cfg_1 = {
	.i2c = (I2C_TypeDef *)CONFIG_I2C_1_BASE_ADDRESS,
	.pclken = {
		.enr = LL_APB1_GRP1_PERIPH_I2C1,
		.bus = STM32_CLOCK_BUS_APB1,
	},
#ifdef CONFIG_I2C_STM32_INTERRUPT
	.irq_config_func = i2c_stm32_irq_config_func_1,
#endif
	.bitrate = CONFIG_I2C_1_BITRATE,
};

static struct i2c_stm32_data i2c_stm32_dev_data_1;

DEVICE_AND_API_INIT(i2c_stm32_1, CONFIG_I2C_1_NAME, &i2c_stm32_init,
		    &i2c_stm32_dev_data_1, &i2c_stm32_cfg_1,
		    POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
		    &api_funcs);

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_1(struct device *dev)
{
#ifdef CONFIG_I2C_STM32_COMBINED_INTERRUPT
	IRQ_CONNECT(CONFIG_I2C_1_COMBINED_IRQ, CONFIG_I2C_1_COMBINED_IRQ_PRI,
		   stm32_i2c_combined_isr, DEVICE_GET(i2c_stm32_1), 0);
	irq_enable(CONFIG_I2C_1_COMBINED_IRQ);
#else
	IRQ_CONNECT(CONFIG_I2C_1_EVENT_IRQ, CONFIG_I2C_1_EVENT_IRQ_PRI,
		   stm32_i2c_event_isr, DEVICE_GET(i2c_stm32_1), 0);
	irq_enable(CONFIG_I2C_1_EVENT_IRQ);

	IRQ_CONNECT(CONFIG_I2C_1_ERROR_IRQ, CONFIG_I2C_1_ERROR_IRQ_PRI,
		   stm32_i2c_error_isr, DEVICE_GET(i2c_stm32_1), 0);
	irq_enable(CONFIG_I2C_1_ERROR_IRQ);
#endif
}
#endif

#endif /* CONFIG_I2C_1 */

#ifdef CONFIG_I2C_2

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_2(struct device *port);
#endif

static const struct i2c_stm32_config i2c_stm32_cfg_2 = {
	.i2c = (I2C_TypeDef *)CONFIG_I2C_2_BASE_ADDRESS,
	.pclken = {
		.enr = LL_APB1_GRP1_PERIPH_I2C2,
		.bus = STM32_CLOCK_BUS_APB1,
	},
#ifdef CONFIG_I2C_STM32_INTERRUPT
	.irq_config_func = i2c_stm32_irq_config_func_2,
#endif
	.bitrate = CONFIG_I2C_2_BITRATE,
};

static struct i2c_stm32_data i2c_stm32_dev_data_2;

DEVICE_AND_API_INIT(i2c_stm32_2, CONFIG_I2C_2_NAME, &i2c_stm32_init,
		    &i2c_stm32_dev_data_2, &i2c_stm32_cfg_2,
		    POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
		    &api_funcs);

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_2(struct device *dev)
{
#ifdef CONFIG_I2C_STM32_COMBINED_INTERRUPT
	IRQ_CONNECT(CONFIG_I2C_2_COMBINED_IRQ, CONFIG_I2C_2_COMBINED_IRQ_PRI,
		   stm32_i2c_combined_isr, DEVICE_GET(i2c_stm32_2), 0);
	irq_enable(CONFIG_I2C_2_COMBINED_IRQ);
#else
	IRQ_CONNECT(CONFIG_I2C_2_EVENT_IRQ, CONFIG_I2C_2_EVENT_IRQ_PRI,
		   stm32_i2c_event_isr, DEVICE_GET(i2c_stm32_2), 0);
	irq_enable(CONFIG_I2C_2_EVENT_IRQ);

	IRQ_CONNECT(CONFIG_I2C_2_ERROR_IRQ, CONFIG_I2C_2_ERROR_IRQ_PRI,
		   stm32_i2c_error_isr, DEVICE_GET(i2c_stm32_2), 0);
	irq_enable(CONFIG_I2C_2_ERROR_IRQ);
#endif
}
#endif

#endif /* CONFIG_I2C_2 */

#ifdef CONFIG_I2C_3

#ifndef I2C3_BASE
#error "I2C_3 is not available on the platform that you selected"
#endif /* I2C3_BASE */

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_3(struct device *port);
#endif

static const struct i2c_stm32_config i2c_stm32_cfg_3 = {
	.i2c = (I2C_TypeDef *)CONFIG_I2C_3_BASE_ADDRESS,
	.pclken = {
		.enr = LL_APB1_GRP1_PERIPH_I2C3,
		.bus = STM32_CLOCK_BUS_APB1,
	},
#ifdef CONFIG_I2C_STM32_INTERRUPT
	.irq_config_func = i2c_stm32_irq_config_func_3,
#endif
	.bitrate = CONFIG_I2C_3_BITRATE,
};

static struct i2c_stm32_data i2c_stm32_dev_data_3;

DEVICE_AND_API_INIT(i2c_stm32_3, CONFIG_I2C_3_NAME, &i2c_stm32_init,
		    &i2c_stm32_dev_data_3, &i2c_stm32_cfg_3,
		    POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
		    &api_funcs);

#ifdef CONFIG_I2C_STM32_INTERRUPT
static void i2c_stm32_irq_config_func_3(struct device *dev)
{
	IRQ_CONNECT(CONFIG_I2C_3_EVENT_IRQ, CONFIG_I2C_3_EVENT_IRQ_PRI,
		   stm32_i2c_event_isr, DEVICE_GET(i2c_stm32_3), 0);
	irq_enable(CONFIG_I2C_3_EVENT_IRQ);

	IRQ_CONNECT(CONFIG_I2C_3_ERROR_IRQ, CONFIG_I2C_3_ERROR_IRQ_PRI,
		   stm32_i2c_error_isr, DEVICE_GET(i2c_stm32_3), 0);
	irq_enable(CONFIG_I2C_3_ERROR_IRQ);
}
#endif

#endif /* CONFIG_I2C_3 */