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/*
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* SPDX - FileCopyrightText : 2022 - 2023 Espressif Systems ( Shanghai ) CO LTD
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*
* SPDX - License - Identifier : Apache - 2.0
*/
# include "ulp_riscv_i2c.h"
# include "esp_check.h"
# include "soc/rtc_i2c_reg.h"
# include "soc/rtc_i2c_struct.h"
# include "soc/rtc_io_struct.h"
# include "soc/sens_reg.h"
# include "soc/clk_tree_defs.h"
# include "hal/i2c_ll.h"
# include "driver/rtc_io.h"
# include "freertos/FreeRTOS.h"
# include "freertos/task.h"
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# include "sdkconfig.h"
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static const char * RTCI2C_TAG = " ulp_riscv_i2c " ;
# define I2C_CTRL_SLAVE_ADDR_MASK (0xFF << 0)
# define I2C_CTRL_SLAVE_REG_ADDR_MASK (0xFF << 11)
# define I2C_CTRL_MASTER_TX_DATA_MASK (0xFF << 19)
# if CONFIG_IDF_TARGET_ESP32S3
# define ULP_I2C_CMD_RESTART 0 /*!<I2C restart command */
# define ULP_I2C_CMD_WRITE 1 /*!<I2C write command */
# define ULP_I2C_CMD_READ 2 /*!<I2C read command */
# define ULP_I2C_CMD_STOP 3 /*!<I2C stop command */
# define ULP_I2C_CMD_END 4 /*!<I2C end command */
# else
# define ULP_I2C_CMD_RESTART I2C_LL_CMD_RESTART /*!<I2C restart command */
# define ULP_I2C_CMD_WRITE I2C_LL_CMD_WRITE /*!<I2C write command */
# define ULP_I2C_CMD_READ I2C_LL_CMD_READ /*!<I2C read command */
# define ULP_I2C_CMD_STOP I2C_LL_CMD_STOP /*!<I2C stop command */
# define ULP_I2C_CMD_END I2C_LL_CMD_END /*!<I2C end command */
# endif // CONFIG_IDF_TARGET_ESP32S3
/* Use the register structure to access RTC_I2C and RTCIO module registers */
rtc_i2c_dev_t * i2c_dev = & RTC_I2C ;
rtc_io_dev_t * rtc_io_dev = & RTCIO ;
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# define MICROSEC_TO_RTC_FAST_CLK(period) (period) * ((float)(SOC_CLK_RC_FAST_FREQ_APPROX) / (1000000.0))
/* Read/Write timeout (number of iterations)*/
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# define ULP_RISCV_I2C_RW_TIMEOUT CONFIG_ULP_RISCV_I2C_RW_TIMEOUT
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static esp_err_t i2c_gpio_is_cfg_valid ( gpio_num_t sda_io_num , gpio_num_t scl_io_num )
{
/* Verify that the SDA and SCL GPIOs are valid RTC I2C io pins */
ESP_RETURN_ON_ERROR ( ! rtc_gpio_is_valid_gpio ( sda_io_num ) , RTCI2C_TAG , " RTC I2C SDA GPIO invalid " ) ;
ESP_RETURN_ON_ERROR ( ! rtc_gpio_is_valid_gpio ( scl_io_num ) , RTCI2C_TAG , " RTC I2C SCL GPIO invalid " ) ;
/* Verify that the SDA and SCL line belong to the RTC IO I2C function group */
if ( ( sda_io_num ! = GPIO_NUM_1 ) & & ( sda_io_num ! = GPIO_NUM_3 ) ) {
ESP_LOGE ( RTCI2C_TAG , " SDA pin can only be configured as GPIO#1 or GPIO#3 " ) ;
return ESP_ERR_INVALID_ARG ;
}
if ( ( scl_io_num ! = GPIO_NUM_0 ) & & ( scl_io_num ! = GPIO_NUM_2 ) ) {
ESP_LOGE ( RTCI2C_TAG , " SCL pin can only be configured as GPIO#0 or GPIO#2 " ) ;
return ESP_ERR_INVALID_ARG ;
}
return ESP_OK ;
}
static esp_err_t i2c_configure_io ( gpio_num_t io_num , bool pullup_en )
{
/* Initialize IO Pin */
ESP_RETURN_ON_ERROR ( rtc_gpio_init ( io_num ) , RTCI2C_TAG , " RTC GPIO Init failed for GPIO %d " , io_num ) ;
/* Set direction to input+output */
ESP_RETURN_ON_ERROR ( rtc_gpio_set_direction ( io_num , RTC_GPIO_MODE_INPUT_OUTPUT ) , RTCI2C_TAG , " RTC GPIO Set direction failed for %d " , io_num ) ;
/* Disable pulldown on the io pin */
ESP_RETURN_ON_ERROR ( rtc_gpio_pulldown_dis ( io_num ) , RTCI2C_TAG , " RTC GPIO pulldown disable failed for %d " , io_num ) ;
/* Enable pullup based on pullup_en flag */
if ( pullup_en ) {
ESP_RETURN_ON_ERROR ( rtc_gpio_pullup_en ( io_num ) , RTCI2C_TAG , " RTC GPIO pullup enable failed for %d " , io_num ) ;
} else {
ESP_RETURN_ON_ERROR ( rtc_gpio_pullup_dis ( io_num ) , RTCI2C_TAG , " RTC GPIO pullup disable failed for %d " , io_num ) ;
}
return ESP_OK ;
}
static esp_err_t i2c_set_pin ( const ulp_riscv_i2c_cfg_t * cfg )
{
gpio_num_t sda_io_num = cfg - > i2c_pin_cfg . sda_io_num ;
gpio_num_t scl_io_num = cfg - > i2c_pin_cfg . scl_io_num ;
bool sda_pullup_en = cfg - > i2c_pin_cfg . sda_pullup_en ;
bool scl_pullup_en = cfg - > i2c_pin_cfg . scl_pullup_en ;
/* Verify that the I2C GPIOs are valid */
ESP_RETURN_ON_ERROR ( i2c_gpio_is_cfg_valid ( sda_io_num , scl_io_num ) , RTCI2C_TAG , " RTC I2C GPIO config invalid " ) ;
/* Initialize SDA Pin */
ESP_RETURN_ON_ERROR ( i2c_configure_io ( sda_io_num , sda_pullup_en ) , RTCI2C_TAG , " RTC I2C SDA pin config failed " ) ;
/* Initialize SCL Pin */
ESP_RETURN_ON_ERROR ( i2c_configure_io ( scl_io_num , scl_pullup_en ) , RTCI2C_TAG , " RTC I2C SCL pin config failed " ) ;
/* Route SDA IO signal to the RTC subsystem */
rtc_io_dev - > touch_pad [ sda_io_num ] . mux_sel = 1 ;
/* Route SCL IO signal to the RTC subsystem */
rtc_io_dev - > touch_pad [ scl_io_num ] . mux_sel = 1 ;
/* Select RTC I2C function for SDA pin */
rtc_io_dev - > touch_pad [ sda_io_num ] . fun_sel = 3 ;
/* Select RTC I2C function for SCL pin */
rtc_io_dev - > touch_pad [ scl_io_num ] . fun_sel = 3 ;
/* Map the SDA and SCL signals to the RTC I2C controller */
if ( sda_io_num = = GPIO_NUM_1 ) {
rtc_io_dev - > sar_i2c_io . sda_sel = 0 ;
} else {
rtc_io_dev - > sar_i2c_io . sda_sel = 1 ;
}
if ( scl_io_num = = GPIO_NUM_0 ) {
rtc_io_dev - > sar_i2c_io . scl_sel = 0 ;
} else {
rtc_io_dev - > sar_i2c_io . scl_sel = 1 ;
}
return ESP_OK ;
}
static esp_err_t i2c_set_timing ( const ulp_riscv_i2c_cfg_t * cfg )
{
/* Convert all timing parameters from micro-seconds to period in RTC_FAST_CLK cycles.
* RTC_FAST_CLK = 8.5 MHz for esp32s2 and 17.5 MHz for esp32s3 .
* The following calculations approximate the period for each parameter .
*/
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float scl_low_period = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . scl_low_period ) ;
float scl_high_period = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . scl_high_period ) ;
float sda_duty_period = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . sda_duty_period ) ;
float scl_start_period = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . scl_start_period ) ;
float scl_stop_period = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . scl_stop_period ) ;
float i2c_trans_timeout = MICROSEC_TO_RTC_FAST_CLK ( cfg - > i2c_timing_cfg . i2c_trans_timeout ) ;
float setup_time_start = ( cfg - > i2c_timing_cfg . scl_high_period + cfg - > i2c_timing_cfg . sda_duty_period ) ;
float hold_time_start = ( cfg - > i2c_timing_cfg . scl_start_period - cfg - > i2c_timing_cfg . sda_duty_period ) ;
float setup_time_data = ( cfg - > i2c_timing_cfg . scl_low_period - cfg - > i2c_timing_cfg . sda_duty_period ) ;
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/* Verify timing constraints */
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ESP_RETURN_ON_FALSE ( cfg - > i2c_timing_cfg . scl_low_period > = 1.3f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SCL low period cannot be less than 1.3 micro seconds " ) ;
// TODO: As per specs, SCL high period must be greater than 0.6 micro seconds but after tests it is found that we can have a the period as 0.3 micro seconds to
// achieve performance close to I2C fast mode. Therefore, this criteria is relaxed.
ESP_RETURN_ON_FALSE ( cfg - > i2c_timing_cfg . scl_high_period > = 0.3f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SCL high period cannot be less than 0.3 micro seconds " ) ;
ESP_RETURN_ON_FALSE ( setup_time_start > = 0.6f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " Setup time cannot be less than 0.6 micro seconds " ) ;
ESP_RETURN_ON_FALSE ( hold_time_start > = 0.6f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " Data hold time cannot be less than 0.6 micro seconds " ) ;
ESP_RETURN_ON_FALSE ( cfg - > i2c_timing_cfg . scl_stop_period > = 0.6f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " Setup time cannot be less than 0.6 micro seconds " ) ;
ESP_RETURN_ON_FALSE ( cfg - > i2c_timing_cfg . sda_duty_period < = 3.45f , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " Data hold time cannot be greater than 3.45 micro seconds " ) ;
ESP_RETURN_ON_FALSE ( ( setup_time_data * 1000 ) > = 250 , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " Data setup time cannot be less than 250 nano seconds " ) ;
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/* Verify filtering constrains
*
* I2C may have glitches on the transition edge , so the edge will be filtered in the design ,
* which will also affect the value of the timing parameter register .
* Therefore , the following filtering constraints must be followed :
*/
ESP_RETURN_ON_FALSE ( scl_stop_period > scl_high_period , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SCL Stop period cannot be greater than SCL high period " ) ;
ESP_RETURN_ON_FALSE ( sda_duty_period < scl_low_period , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SDA duty period cannot be less than the SCL low period " ) ;
ESP_RETURN_ON_FALSE ( scl_start_period > 8 , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SCL start period must be greater than 8 RTC_FAST_CLK cycles " ) ;
ESP_RETURN_ON_FALSE ( ( scl_low_period + scl_high_period - sda_duty_period ) > 8 , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SCL low + SCL high - SDA duty must be greater than 8 RTC_FAST_CLK cycles " ) ;
/* Verify SDA duty num constraints */
ESP_RETURN_ON_FALSE ( sda_duty_period > 14 , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " SDA duty period must be greater than 14 RTC_FAST_CLK cycles " ) ;
/* Set the RTC I2C timing parameters */
# if CONFIG_IDF_TARGET_ESP32S2
i2c_dev - > scl_low . val = scl_low_period ; // SCL low period
i2c_dev - > scl_high . val = scl_high_period ; // SCL high period
i2c_dev - > sda_duty . val = sda_duty_period ; // SDA duty cycle
i2c_dev - > scl_start_period . val = scl_start_period ; // Wait time after START condition
i2c_dev - > scl_stop_period . val = scl_stop_period ; // Wait time before END condition
i2c_dev - > timeout . val = i2c_trans_timeout ; // I2C transaction timeout
# elif CONFIG_IDF_TARGET_ESP32S3
i2c_dev - > i2c_scl_low . val = scl_low_period ; // SCL low period
i2c_dev - > i2c_scl_high . val = scl_high_period ; // SCL high period
i2c_dev - > i2c_sda_duty . val = sda_duty_period ; // SDA duty cycle
i2c_dev - > i2c_scl_start_period . val = scl_start_period ; // Wait time after START condition
i2c_dev - > i2c_scl_stop_period . val = scl_stop_period ; // Wait time before END condition
i2c_dev - > i2c_to . val = i2c_trans_timeout ; // I2C transaction timeout
# endif // CONFIG_IDF_TARGET_ESP32S2
return ESP_OK ;
}
/*
* The RTC I2C controller follows the I2C command registers to perform read / write operations .
* The cmd registers have the following format :
*
* 31 30 : 14 13 : 11 10 9 8 7 : 0
* | - - - - - - - - - - | - - - - - - - - - - | - - - - - - - - - | - - - - - - - - - | - - - - - - - - - - | - - - - - - - - - - - - | - - - - - - - - - |
* | CMD_DONE | Reserved | OPCODE | ACK Value | ACK Expect | ACK Check En | Byte Num |
* | - - - - - - - - - - | - - - - - - - - - - | - - - - - - - - - | - - - - - - - - - | - - - - - - - - - - | - - - - - - - - - - - - | - - - - - - - - - |
*/
static void ulp_riscv_i2c_format_cmd ( uint32_t cmd_idx , uint8_t op_code , uint8_t ack_val ,
uint8_t ack_expected , uint8_t ack_check_en , uint8_t byte_num )
{
# if CONFIG_IDF_TARGET_ESP32S2
/* Reset cmd register */
i2c_dev - > command [ cmd_idx ] . val = 0 ;
/* Write new command to cmd register */
i2c_dev - > command [ cmd_idx ] . done = 0 ; // CMD Done
i2c_dev - > command [ cmd_idx ] . op_code = op_code ; // Opcode
i2c_dev - > command [ cmd_idx ] . ack_val = ack_val ; // ACK bit sent by I2C controller during READ.
// Ignored during RSTART, STOP, END and WRITE cmds.
i2c_dev - > command [ cmd_idx ] . ack_exp = ack_expected ; // ACK bit expected by I2C controller during WRITE.
// Ignored during RSTART, STOP, END and READ cmds.
i2c_dev - > command [ cmd_idx ] . ack_en = ack_check_en ; // I2C controller verifies that the ACK bit sent by the
// slave device matches the ACK expected bit during WRITE.
// Ignored during RSTART, STOP, END and READ cmds.
i2c_dev - > command [ cmd_idx ] . byte_num = byte_num ; // Byte Num
# elif CONFIG_IDF_TARGET_ESP32S3
/* Reset cmd register */
i2c_dev - > i2c_cmd [ cmd_idx ] . val = 0 ;
/* Write new command to cmd register */
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_command_done = 0 ; // CMD Done
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_op_code = op_code ; // Opcode
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_ack_val = ack_val ; // ACK bit sent by I2C controller during READ.
// Ignored during RSTART, STOP, END and WRITE cmds.
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_ack_exp = ack_expected ; // ACK bit expected by I2C controller during WRITE.
// Ignored during RSTART, STOP, END and READ cmds.
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_ack_en = ack_check_en ; // I2C controller verifies that the ACK bit sent by the
// slave device matches the ACK expected bit during WRITE.
// Ignored during RSTART, STOP, END and READ cmds.
i2c_dev - > i2c_cmd [ cmd_idx ] . i2c_byte_num = byte_num ; // Byte Num
# endif // CONFIG_IDF_TARGET_ESP32S2
}
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static inline esp_err_t ulp_riscv_i2c_wait_for_interrupt ( int32_t ticks_to_wait )
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{
uint32_t status = 0 ;
uint32_t to = 0 ;
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esp_err_t ret = ESP_OK ;
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while ( 1 ) {
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status = READ_PERI_REG ( RTC_I2C_INT_ST_REG ) ;
/* Return ESP_OK if Tx or Rx data interrupt bits are set. */
if ( ( status & RTC_I2C_TX_DATA_INT_ST ) | |
( status & RTC_I2C_RX_DATA_INT_ST ) ) {
ret = ESP_OK ;
break ;
/* In case of error status, break and return ESP_FAIL */
# if CONFIG_IDF_TARGET_ESP32S2
} else if ( ( status & RTC_I2C_TIMEOUT_INT_ST ) | |
# elif CONFIG_IDF_TARGET_ESP32S3
} else if ( ( status & RTC_I2C_TIME_OUT_INT_ST ) | |
# endif // CONFIG_IDF_TARGET_ESP32S2
( status & RTC_I2C_ACK_ERR_INT_ST ) | |
( status & RTC_I2C_ARBITRATION_LOST_INT_ST ) ) {
ret = ESP_FAIL ;
break ;
}
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if ( ticks_to_wait > - 1 ) {
/* If the ticks_to_wait value is not -1, keep track of ticks and
* break from the loop once the timeout is reached .
*/
vTaskDelay ( 1 ) ;
to + + ;
if ( to > = ticks_to_wait ) {
ret = ESP_ERR_TIMEOUT ;
break ;
}
}
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}
return ret ;
}
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void ulp_riscv_i2c_master_set_slave_addr ( uint8_t slave_addr )
{
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , I2C_CTRL_SLAVE_ADDR_MASK ) ;
SET_PERI_REG_BITS ( SENS_SAR_I2C_CTRL_REG , 0xFF , slave_addr , 0 ) ;
}
void ulp_riscv_i2c_master_set_slave_reg_addr ( uint8_t slave_reg_addr )
{
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , I2C_CTRL_SLAVE_REG_ADDR_MASK ) ;
SET_PERI_REG_BITS ( SENS_SAR_I2C_CTRL_REG , 0xFF , slave_reg_addr , 11 ) ;
}
/*
* I2C transactions when master reads one byte of data from the slave device :
*
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Master | START | SAD + W | | SUB | | SR | SAD + R | | | NACK | STOP |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Slave | | | ACK | | ACK | | | ACK | DATA | | |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
*
* I2C transactions when master reads multiple bytes of data from the slave device :
*
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Master | START | SAD + W | | SUB | | SR | SAD + R | | | ACK | | NACK | STOP |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Slave | | | ACK | | ACK | | | ACK | DATA | | DATA | | |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
*/
void ulp_riscv_i2c_master_read_from_device ( uint8_t * data_rd , size_t size )
{
uint32_t i = 0 ;
uint32_t cmd_idx = 0 ;
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esp_err_t ret = ESP_OK ;
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if ( size = = 0 ) {
// Quietly return
return ;
}
/* By default, RTC I2C controller is hard wired to use CMD2 register onwards for read operations */
cmd_idx = 2 ;
/* Write slave addr */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_WRITE , 0 , 0 , 1 , 2 ) ;
/* Repeated START */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_RESTART , 0 , 0 , 0 , 0 ) ;
/* Write slave register addr */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_WRITE , 0 , 0 , 1 , 1 ) ;
if ( size > 1 ) {
/* Read n - 1 bytes */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_READ , 0 , 0 , 1 , size - 1 ) ;
}
/* Read last byte + NACK */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_READ , 1 , 1 , 1 , 1 ) ;
/* STOP */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_STOP , 0 , 0 , 0 , 0 ) ;
/* Configure the RTC I2C controller in read mode */
SET_PERI_REG_BITS ( SENS_SAR_I2C_CTRL_REG , 0x1 , 0 , 27 ) ;
/* Start RTC I2C transmission */
SET_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START_FORCE ) ;
SET_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START ) ;
for ( i = 0 ; i < size ; i + + ) {
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/* Poll for RTC I2C Rx Data interrupt bit to be set */
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ret = ulp_riscv_i2c_wait_for_interrupt ( ULP_RISCV_I2C_RW_TIMEOUT ) ;
if ( ret = = ESP_OK ) {
/* Read the data
*
* Unfortunately , the RTC I2C has no fifo buffer to help us with reading and storing
* multiple bytes of data . Therefore , we need to read one byte at a time and clear the
* Rx interrupt to get ready for the next byte .
*/
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# if CONFIG_IDF_TARGET_ESP32S2
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data_rd [ i ] = REG_GET_FIELD ( RTC_I2C_DATA_REG , RTC_I2C_RDATA ) ;
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# elif CONFIG_IDF_TARGET_ESP32S3
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data_rd [ i ] = REG_GET_FIELD ( RTC_I2C_DATA_REG , RTC_I2C_I2C_RDATA ) ;
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# endif // CONFIG_IDF_TARGET_ESP32S2
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/* Clear the Rx data interrupt bit */
SET_PERI_REG_MASK ( RTC_I2C_INT_CLR_REG , RTC_I2C_RX_DATA_INT_CLR ) ;
} else {
ESP_LOGE ( RTCI2C_TAG , " Read Failed! " ) ;
uint32_t status = READ_PERI_REG ( RTC_I2C_INT_RAW_REG ) ;
ESP_LOGE ( RTCI2C_TAG , " RTC I2C Interrupt Raw Reg 0x% " PRIx32 " " , status ) ;
ESP_LOGE ( RTCI2C_TAG , " RTC I2C Status Reg 0x% " PRIx32 " " , READ_PERI_REG ( RTC_I2C_STATUS_REG ) ) ;
SET_PERI_REG_MASK ( RTC_I2C_INT_CLR_REG , status ) ;
break ;
}
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}
/* Clear the RTC I2C transmission bits */
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START_FORCE ) ;
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START ) ;
}
/*
* I2C transactions when master writes one byte of data to the slave device :
*
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Master | START | SAD + W | | SUB | | DATA | | STOP |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Slave | | | ACK | | ACK | | ACK | |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
*
* I2C transactions when master writes multiple bytes of data to the slave device :
*
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Master | START | SAD + W | | SUB | | DATA | | DATA | | STOP |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
* | Slave | | | ACK | | ACK | | ACK | | ACK | |
* | - - - - - - - - | - - - - - - - - | - - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - | - - - - - - - - |
*/
void ulp_riscv_i2c_master_write_to_device ( uint8_t * data_wr , size_t size )
{
uint32_t i = 0 ;
uint32_t cmd_idx = 0 ;
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esp_err_t ret = ESP_OK ;
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if ( size = = 0 ) {
// Quietly return
return ;
}
/* By default, RTC I2C controller is hard wired to use CMD0 and CMD1 registers for write operations */
cmd_idx = 0 ;
/* Write slave addr + reg addr + data */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_WRITE , 0 , 0 , 1 , 2 + size ) ;
/* Stop */
ulp_riscv_i2c_format_cmd ( cmd_idx + + , ULP_I2C_CMD_STOP , 0 , 0 , 0 , 0 ) ;
/* Configure the RTC I2C controller in write mode */
SET_PERI_REG_BITS ( SENS_SAR_I2C_CTRL_REG , 0x1 , 1 , 27 ) ;
for ( i = 0 ; i < size ; i + + ) {
/* Write the data to be transmitted */
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , I2C_CTRL_MASTER_TX_DATA_MASK ) ;
SET_PERI_REG_BITS ( SENS_SAR_I2C_CTRL_REG , 0xFF , data_wr [ i ] , 19 ) ;
if ( i = = 0 ) {
/* Start RTC I2C transmission. (Needn't do it for every byte) */
SET_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START_FORCE ) ;
SET_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START ) ;
}
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/* Poll for RTC I2C Tx Data interrupt bit to be set */
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ret = ulp_riscv_i2c_wait_for_interrupt ( ULP_RISCV_I2C_RW_TIMEOUT ) ;
if ( ret = = ESP_OK ) {
/* Clear the Tx data interrupt bit */
SET_PERI_REG_MASK ( RTC_I2C_INT_CLR_REG , RTC_I2C_TX_DATA_INT_CLR ) ;
} else {
ESP_LOGE ( RTCI2C_TAG , " Write Failed! " ) ;
uint32_t status = READ_PERI_REG ( RTC_I2C_INT_RAW_REG ) ;
ESP_LOGE ( RTCI2C_TAG , " RTC I2C Interrupt Raw Reg 0x% " PRIx32 " " , status ) ;
ESP_LOGE ( RTCI2C_TAG , " RTC I2C Status Reg 0x% " PRIx32 " " , READ_PERI_REG ( RTC_I2C_STATUS_REG ) ) ;
SET_PERI_REG_MASK ( RTC_I2C_INT_CLR_REG , status ) ;
break ;
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}
}
/* Clear the RTC I2C transmission bits */
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START_FORCE ) ;
CLEAR_PERI_REG_MASK ( SENS_SAR_I2C_CTRL_REG , SENS_SAR_I2C_START ) ;
}
esp_err_t ulp_riscv_i2c_master_init ( const ulp_riscv_i2c_cfg_t * cfg )
{
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/* Clear any stale config registers */
WRITE_PERI_REG ( RTC_I2C_CTRL_REG , 0 ) ;
WRITE_PERI_REG ( SENS_SAR_I2C_CTRL_REG , 0 ) ;
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/* Reset RTC I2C */
# if CONFIG_IDF_TARGET_ESP32S2
i2c_dev - > ctrl . i2c_reset = 1 ;
esp_rom_delay_us ( 20 ) ;
i2c_dev - > ctrl . i2c_reset = 0 ;
# elif CONFIG_IDF_TARGET_ESP32S3
SET_PERI_REG_MASK ( SENS_SAR_PERI_RESET_CONF_REG , SENS_RTC_I2C_RESET ) ;
i2c_dev - > i2c_ctrl . i2c_i2c_reset = 1 ;
esp_rom_delay_us ( 20 ) ;
i2c_dev - > i2c_ctrl . i2c_i2c_reset = 0 ;
CLEAR_PERI_REG_MASK ( SENS_SAR_PERI_RESET_CONF_REG , SENS_RTC_I2C_RESET ) ;
# endif // CONFIG_IDF_TARGET_ESP32S2
/* Verify that the input cfg param is valid */
ESP_RETURN_ON_FALSE ( cfg , ESP_ERR_INVALID_ARG , RTCI2C_TAG , " RTC I2C configuration is NULL " ) ;
/* Configure RTC I2C GPIOs */
ESP_RETURN_ON_ERROR ( i2c_set_pin ( cfg ) , RTCI2C_TAG , " Failed to configure RTC I2C GPIOs " ) ;
# if CONFIG_IDF_TARGET_ESP32S2
/* Configure the RTC I2C controller in master mode */
i2c_dev - > ctrl . ms_mode = 1 ;
/* Enable RTC I2C Clock gate */
i2c_dev - > ctrl . i2c_ctrl_clk_gate_en = 1 ;
# elif CONFIG_IDF_TARGET_ESP32S3
/* For esp32s3, we need to enable the rtc_i2c clock gate before accessing rtc i2c registers */
SET_PERI_REG_MASK ( SENS_SAR_PERI_CLK_GATE_CONF_REG , SENS_RTC_I2C_CLK_EN ) ;
/* Configure the RTC I2C controller in master mode */
i2c_dev - > i2c_ctrl . i2c_ms_mode = 1 ;
/* Enable RTC I2C Clock gate */
i2c_dev - > i2c_ctrl . i2c_i2c_ctrl_clk_gate_en = 1 ;
# endif // CONFIG_IDF_TARGET_ESP32S2
/* Configure RTC I2C timing paramters */
ESP_RETURN_ON_ERROR ( i2c_set_timing ( cfg ) , RTCI2C_TAG , " Failed to configure RTC I2C timing " ) ;
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/* Enable RTC I2C interrupts */
SET_PERI_REG_MASK ( RTC_I2C_INT_ENA_REG , RTC_I2C_RX_DATA_INT_ENA |
RTC_I2C_TX_DATA_INT_ENA |
RTC_I2C_ARBITRATION_LOST_INT_ENA |
RTC_I2C_ACK_ERR_INT_ENA |
# if CONFIG_IDF_TARGET_ESP32S2
RTC_I2C_TIMEOUT_INT_ENA ) ;
# elif CONFIG_IDF_TARGET_ESP32S3
RTC_I2C_TIME_OUT_INT_ENA ) ;
# endif // CONFIG_IDF_TARGET_ESP32S2
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return ESP_OK ;
}