espressif/ESP8266_RTOS_SDK
1
0
Fork 0
mirror of https://github.com/espressif/ESP8266_RTOS_SDK.git synced 2025-05-22 17:47:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'feature/i2c_clk_stretch' into 'master'

Browse Source 
feature(i2c): add i2c clock stretch

See merge request sdk/ESP8266_RTOS_SDK!916
This commit is contained in:
Wu Jian Gang
2019-08-26 14:08:25 +08:00
parent 7d06edf258 d673e2836a
commit dbded69dd5
3 changed files with 15 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
components/esp8266/driver/i2c.c
View File

@ -109,14 +109,21 @@ static i2c_obj_t *p_i2c_obj[I2C_NUM_MAX] = {0};
static i2c_config_t *i2c_config[I2C_NUM_MAX] = {NULL};
static i2c_last_state_t *i2c_last_state[I2C_NUM_MAX] = {NULL};
static void i2c_master_set_dc(i2c_port_t i2c_num, uint8_t sda, uint8_t scl)
static inline void i2c_master_set_dc(i2c_port_t i2c_num, uint8_t sda, uint8_t scl)
{
uint32_t i = 0;
uint32_t clk_stretch_tick = i2c_config[i2c_num]->clk_stretch_tick;
gpio_set_level(i2c_config[i2c_num]->sda_io_num, sda & 0x1);
gpio_set_level(i2c_config[i2c_num]->scl_io_num, scl & 0x1);
if ((i2c_last_state[i2c_num]->scl == 0) && ((scl & 0x1) == 1)) {
// An I2C slave is allowed to hold down the clock if it needs to reduce the bus speed. The master, on the other hand, is required to read back the clock signal after releasing it to the high state and wait until the line has actually gone high.
while (gpio_get_level(i2c_config[i2c_num]->scl_io_num) == 0 && (i++) < clk_stretch_tick); // Clock stretching
}
i2c_last_state[i2c_num]->val = ((sda & 0x1) << 1) | (scl & 0x1);
gpio_set_level(i2c_config[i2c_num]->sda_io_num, i2c_last_state[i2c_num]->sda);
gpio_set_level(i2c_config[i2c_num]->scl_io_num, i2c_last_state[i2c_num]->scl);
}
static uint8_t i2c_master_get_dc(i2c_port_t i2c_num)
static inline uint8_t i2c_master_get_dc(i2c_port_t i2c_num)
{
uint8_t sda_out;
sda_out = gpio_get_level(i2c_config[i2c_num]->sda_io_num);

1
components/esp8266/include/driver/i2c.h
View File

@ -64,6 +64,7 @@ typedef struct {
gpio_pullup_t sda_pullup_en; /*!< Internal GPIO pull mode for I2C sda signal*/
gpio_num_t scl_io_num; /*!< GPIO number for I2C scl signal */
gpio_pullup_t scl_pullup_en; /*!< Internal GPIO pull mode for I2C scl signal*/
uint32_t clk_stretch_tick; /*!< Clock Stretch time, depending on CPU frequency*/
} i2c_config_t;
typedef void *i2c_cmd_handle_t; /*!< I2C command handle */