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/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-05-16 shelton first version
*/
#include "drv_common.h"
#include "drv_soft_i2c.h"
#ifdef RT_USING_I2C
#define LOG_TAG "drv.i2c"
#include <drv_log.h>
#if !defined(BSP_USING_I2C1) && !defined(BSP_USING_I2C2) && \
!defined(BSP_USING_I2C3)
#error "Please define at least one BSP_USING_I2Cx"
/* this driver can be disabled at menuconfig RT-Thread Components Device Drivers */
#endif
static const struct at32_soft_i2c_config soft_i2c_config[] =
{
#ifdef BSP_USING_I2C1
I2C1_BUS_CONFIG,
#endif
#ifdef BSP_USING_I2C2
I2C2_BUS_CONFIG,
#endif
#ifdef BSP_USING_I2C3
I2C3_BUS_CONFIG,
#endif
};
static struct at32_i2c i2c_obj[sizeof(soft_i2c_config) / sizeof(soft_i2c_config[0])];
/**
* this function initializes the i2c pin.
*
* @param at32 i2c dirver class.
*/
static void at32_i2c_gpio_init(struct at32_i2c *i2c)
{
struct at32_soft_i2c_config* cfg = (struct at32_soft_i2c_config*)i2c->ops.data;
rt_pin_mode(cfg->scl, PIN_MODE_OUTPUT_OD);
rt_pin_mode(cfg->sda, PIN_MODE_OUTPUT_OD);
rt_pin_write(cfg->scl, PIN_HIGH);
rt_pin_write(cfg->sda, PIN_HIGH);
}
/**
* this function sets the sda pin.
*
* @param at32 config class.
* @param the sda pin state.
*/
static void at32_set_sda(void *data, rt_int32_t state)
{
struct at32_soft_i2c_config* cfg = (struct at32_soft_i2c_config*)data;
if (state)
{
rt_pin_write(cfg->sda, PIN_HIGH);
}
else
{
rt_pin_write(cfg->sda, PIN_LOW);
}
}
/**
* this function sets the scl pin.
*
* @param at32 config class.
* @param the scl pin state.
*/
static void at32_set_scl(void *data, rt_int32_t state)
{
struct at32_soft_i2c_config* cfg = (struct at32_soft_i2c_config*)data;
if (state)
{
rt_pin_write(cfg->scl, PIN_HIGH);
}
else
{
rt_pin_write(cfg->scl, PIN_LOW);
}
}
/**
* this function gets the sda pin state.
*
* @param the sda pin state.
*/
static rt_int32_t at32_get_sda(void *data)
{
struct at32_soft_i2c_config* cfg = (struct at32_soft_i2c_config*)data;
return rt_pin_read(cfg->sda);
}
/**
* this function gets the scl pin state.
*
* @param the scl pin state.
*/
static rt_int32_t at32_get_scl(void *data)
{
struct at32_soft_i2c_config* cfg = (struct at32_soft_i2c_config*)data;
return rt_pin_read(cfg->scl);
}
/**
* the time delay function.
*
* @param microseconds.
*/
static void at32_udelay(rt_uint32_t us)
{
rt_uint32_t ticks;
rt_uint32_t told, tnow, tcnt = 0;
rt_uint32_t reload = SysTick->LOAD;
ticks = us * reload / (1000000 / RT_TICK_PER_SECOND);
told = SysTick->VAL;
while (1)
{
tnow = SysTick->VAL;
if (tnow != told)
{
if (tnow < told)
{
tcnt += told - tnow;
}
else
{
tcnt += reload - tnow + told;
}
told = tnow;
if (tcnt >= ticks)
{
break;
}
}
}
}
static const struct rt_i2c_bit_ops at32_bit_ops_default =
{
.data = RT_NULL,
.set_sda = at32_set_sda,
.set_scl = at32_set_scl,
.get_sda = at32_get_sda,
.get_scl = at32_get_scl,
.udelay = at32_udelay,
.delay_us = 1,
.timeout = 100
};
/**
* if i2c is locked, this function will unlock it
*
* @param at32 config class
*
* @return RT_EOK indicates successful unlock.
*/
static rt_err_t at32_i2c_bus_unlock(const struct at32_soft_i2c_config *cfg)
{
rt_int32_t i = 0;
if (PIN_LOW == rt_pin_read(cfg->sda))
{
while (i++ < 9)
{
rt_pin_write(cfg->scl, PIN_HIGH);
at32_udelay(100);
rt_pin_write(cfg->scl, PIN_LOW);
at32_udelay(100);
}
}
if (PIN_LOW == rt_pin_read(cfg->sda))
{
return -RT_ERROR;
}
return RT_EOK;
}
/* i2c initialization function */
int rt_hw_i2c_init(void)
{
rt_size_t obj_num = sizeof(i2c_obj) / sizeof(struct at32_i2c);
rt_err_t result;
for (int i = 0; i < obj_num; i++)
{
i2c_obj[i].ops = at32_bit_ops_default;
i2c_obj[i].ops.data = (void*)&soft_i2c_config[i];
i2c_obj[i].i2c_bus.priv = &i2c_obj[i].ops;
at32_i2c_gpio_init(&i2c_obj[i]);
result = rt_i2c_bit_add_bus(&i2c_obj[i].i2c_bus, soft_i2c_config[i].bus_name);
RT_ASSERT(result == RT_EOK);
at32_i2c_bus_unlock(&soft_i2c_config[i]);
LOG_D("software simulation %s init done, pin scl: %d, pin sda %d",
soft_i2c_config[i].bus_name,
soft_i2c_config[i].scl,
soft_i2c_config[i].sda);
}
return RT_EOK;
}
INIT_BOARD_EXPORT(rt_hw_i2c_init);
#endif /* RT_USING_I2C */
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