/* * Copyright (c) 2006-2023, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2020-01-09 shelton first version */ #include #include "drv_soft_i2c.h" #ifdef RT_USING_I2C #define LOG_TAG "drv.i2c" #include #if !defined(BSP_USING_I2C1) && !defined(BSP_USING_I2C2) && !defined(BSP_USING_I2C3) && !defined(BSP_USING_I2C4) #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 n32_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 #ifdef BSP_USING_I2C4 I2C4_BUS_CONFIG, #endif }; static struct n32_i2c i2c_obj[sizeof(soft_i2c_config) / sizeof(soft_i2c_config[0])]; /** * This function initializes the i2c pin. * * @param n32 i2c dirver class. */ static void n32_i2c_gpio_init(struct n32_i2c *i2c) { struct n32_soft_i2c_config *cfg = (struct n32_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 n32 config class. * @param The sda pin state. */ static void n32_set_sda(void *data, rt_int32_t state) { struct n32_soft_i2c_config *cfg = (struct n32_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 n32 config class. * @param The scl pin state. */ static void n32_set_scl(void *data, rt_int32_t state) { struct n32_soft_i2c_config *cfg = (struct n32_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 n32_get_sda(void *data) { struct n32_soft_i2c_config *cfg = (struct n32_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 n32_get_scl(void *data) { struct n32_soft_i2c_config *cfg = (struct n32_soft_i2c_config *)data; return rt_pin_read(cfg->scl); } /** * The time delay function. * * @param microseconds. */ static void n32_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 n32_bit_ops_default = { .data = RT_NULL, .set_sda = n32_set_sda, .set_scl = n32_set_scl, .get_sda = n32_get_sda, .get_scl = n32_get_scl, .udelay = n32_udelay, .delay_us = 1, .timeout = 100 }; /** * if i2c is locked, this function will unlock it * * @param n32 config class * * @return RT_EOK indicates successful unlock. */ static rt_err_t n32_i2c_bus_unlock(const struct n32_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); n32_udelay(100); rt_pin_write(cfg->scl, PIN_LOW); n32_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 n32_i2c); rt_err_t result; for (int i = 0; i < obj_num; i++) { i2c_obj[i].ops = n32_bit_ops_default; i2c_obj[i].ops.data = (void *)&soft_i2c_config[i]; i2c_obj[i].i2c_bus.priv = &i2c_obj[i].ops; n32_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); n32_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 */