implement thread-safe i2c

Author: me-no-dev

cores/esp32/esp32-hal-i2c.c

@@ -15,51 +15,85 @@
 #include"esp32-hal-i2c.h"
 #include"freertos/FreeRTOS.h"
 #include"freertos/task.h"
+#include"freertos/semphr.h"
 #include"rom/ets_sys.h"
 #include"soc/i2c_reg.h"
 #include"soc/dport_reg.h"
 
-#defineI2C_DEV(i) (volatile i2c_dev_t *)((i)?DR_REG_I2C1_EXT_BASE:DR_REG_I2C_EXT_BASE)
-//#define I2C_DEV(i) ((i2c_dev_t *)(REG_I2C_BASE(i)))
 #defineI2C_SCL_IDX(p) ((p==0)?I2CEXT0_SCL_OUT_IDX:((p==1)?I2CEXT1_SCL_OUT_IDX:0))
 #defineI2C_SDA_IDX(p) ((p==0)?I2CEXT0_SDA_OUT_IDX:((p==1)?I2CEXT1_SDA_OUT_IDX:0))
 
+
+structi2c_struct_t{
+i2c_dev_t*dev;
+xSemaphoreHandlelock;
+uint8_tnum;
+};
+
+enum{
+I2C_CMD_RSTART,
+I2C_CMD_WRITE,
+I2C_CMD_READ,
+I2C_CMD_STOP,
+I2C_CMD_END
+};
+
+#defineI2C_MUTEX_LOCK() do{} while (xSemaphoreTake(i2c->lock, portMAX_DELAY) != pdPASS)
+#defineI2C_MUTEX_UNLOCK() xSemaphoreGive(i2c->lock)
+
+statici2c_t_i2c_bus_array[2] ={
+{(volatilei2c_dev_t*)(DR_REG_I2C_EXT_BASE), NULL, 0},
+{(volatilei2c_dev_t*)(DR_REG_I2C1_EXT_BASE), NULL, 1}
+};
+
 voidi2cAttachSCL(i2c_t*i2c, int8_tscl)
 {
+if(i2c==NULL){
+return;
+ }
+I2C_MUTEX_LOCK();
 pinMode(scl, OUTPUT);
 pinMatrixOutAttach(scl, I2C_SCL_IDX(i2c->num), false, false);
 pinMatrixInAttach(scl, I2C_SCL_IDX(i2c->num), false);
+I2C_MUTEX_UNLOCK();
 }
 
 voidi2cDetachSCL(i2c_t*i2c, int8_tscl)
 {
+if(i2c==NULL){
+return;
+ }
+I2C_MUTEX_LOCK();
 pinMatrixOutDetach(scl, false, false);
 pinMatrixInDetach(I2C_SCL_IDX(i2c->num), false, false);
 pinMode(scl, INPUT);
+I2C_MUTEX_UNLOCK();
 }
 
 voidi2cAttachSDA(i2c_t*i2c, int8_tsda)
 {
+if(i2c==NULL){
+return;
+ }
+I2C_MUTEX_LOCK();
 pinMode(sda, OUTPUT_OPEN_DRAIN);
 pinMatrixOutAttach(sda, I2C_SDA_IDX(i2c->num), false, false);
 pinMatrixInAttach(sda, I2C_SDA_IDX(i2c->num), false);
+I2C_MUTEX_UNLOCK();
 }
 
 voidi2cDetachSDA(i2c_t*i2c, int8_tsda)
 {
+if(i2c==NULL){
+return;
+ }
+I2C_MUTEX_LOCK();
 pinMatrixOutDetach(sda, false, false);
 pinMatrixInDetach(I2C_SDA_IDX(i2c->num), false, false);
 pinMode(sda, INPUT);
+I2C_MUTEX_UNLOCK();
 }
 
-enum{
-I2C_CMD_RSTART,
-I2C_CMD_WRITE,
-I2C_CMD_READ,
-I2C_CMD_STOP,
-I2C_CMD_END
-};
-
 /*
  * index - command index (0 to 15)
  * op_code - is the command
@@ -78,13 +112,27 @@ void i2cSetCmd(i2c_t * i2c, uint8_t index, uint8_t op_code, uint8_t byte_num, bo
 i2c->dev->command[index].op_code=op_code;
 }
 
+voidi2cResetFiFo(i2c_t*i2c)
+{
+i2c->dev->fifo_conf.tx_fifo_rst=1;
+i2c->dev->fifo_conf.tx_fifo_rst=0;
+i2c->dev->fifo_conf.rx_fifo_rst=1;
+i2c->dev->fifo_conf.rx_fifo_rst=0;
+}
+
 inti2cWrite(i2c_t*i2c, uint16_taddress, booladdr_10bit, uint8_t*data, uint8_tlen, boolsendStop)
 {
 inti;
 uint8_tindex=0;
 uint8_tdataLen=len+ (addr_10bit?2:1);
 address= (address << 1);
 
+if(i2c==NULL){
+return4;
+ }
+
+I2C_MUTEX_LOCK();
+
 while(dataLen){
 uint8_twillSend= (dataLen>32)?32:dataLen;
 uint8_tdataSend=willSend;
@@ -129,18 +177,21 @@ int i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uin
 //Bus failed (maybe check for this while waiting?
 if(i2c->dev->int_raw.arbitration_lost){
 //log_e("Bus Fail! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return4;
  }
 
 //Bus timeout
 if(i2c->dev->int_raw.time_out){
 //log_e("Bus Timeout! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return3;
  }
 
 //Transmission did not finish and ACK_ERR is set
 if(i2c->dev->int_raw.ack_err){
 //log_e("Ack Error! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return1;
  }
 
@@ -152,6 +203,7 @@ int i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uin
  }
 
  }
+I2C_MUTEX_UNLOCK();
 return0;
 }
 
@@ -163,6 +215,12 @@ int i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint
 uint8_tcmdIdx;
 uint8_twillRead;
 
+if(i2c==NULL){
+return4;
+ }
+
+I2C_MUTEX_LOCK();
+
 i2cResetFiFo(i2c);
 
 //CMD START
@@ -204,18 +262,21 @@ int i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint
 //Bus failed (maybe check for this while waiting?
 if(i2c->dev->int_raw.arbitration_lost){
 //log_e("Bus Fail! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return-4;
  }
 
 //Bus timeout
 if(i2c->dev->int_raw.time_out){
 //log_e("Bus Timeout! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return-3;
  }
 
 //Transmission did not finish and ACK_ERR is set
 if(i2c->dev->int_raw.ack_err){
 //log_e("Ack Error! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
 return-1;
  }
 if(i2c->dev->ctr.trans_start||i2c->dev->status_reg.bus_busy|| !(i2c->dev->int_raw.trans_complete) || !(i2c->dev->command[cmdIdx-1].done)){
@@ -232,22 +293,19 @@ int i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint
  }
 len-=willRead;
  }
+I2C_MUTEX_UNLOCK();
 return0;
 }
 
-voidi2cResetFiFo(i2c_t*i2c)
-{
-//TX FIFO
-i2c->dev->fifo_conf.tx_fifo_rst=1;
-i2c->dev->fifo_conf.tx_fifo_rst=0;
-//RX FIFO
-i2c->dev->fifo_conf.rx_fifo_rst=1;
-i2c->dev->fifo_conf.rx_fifo_rst=0;
-}
-
 voidi2cSetFrequency(i2c_t*i2c, uint32_tclk_speed)
 {
 uint32_tperiod= (APB_CLK_FREQ/clk_speed) / 2;
+
+if(i2c==NULL){
+return;
+ }
+
+I2C_MUTEX_LOCK();
 i2c->dev->scl_low_period.scl_low_period=period;
 i2c->dev->scl_high_period.period=period;
 
@@ -259,10 +317,15 @@ void i2cSetFrequency(i2c_t * i2c, uint32_t clk_speed)
 
 i2c->dev->sda_hold.time=25;
 i2c->dev->sda_sample.time=25;
+I2C_MUTEX_UNLOCK();
 }
 
 uint32_ti2cGetFrequency(i2c_t*i2c)
 {
+if(i2c==NULL){
+return0;
+ }
+
 returnAPB_CLK_FREQ/(i2c->dev->scl_low_period.scl_low_period+i2c->dev->scl_high_period.period);
 }
 
@@ -274,18 +337,23 @@ uint32_t i2cGetFrequency(i2c_t * i2c)
 
 i2c_t*i2cInit(uint8_ti2c_num, uint16_tslave_addr, booladdr_10bit_en)
 {
-i2c_t*i2c= (i2c_t*) malloc(sizeof(i2c_t));
-if(i2c==0){
+if(i2c_num>1){
 returnNULL;
  }
 
-i2c->num=i2c_num;
-i2c->dev=I2C_DEV(i2c_num);
+i2c_t*i2c=&_i2c_bus_array[i2c_num];
+
+if(i2c->lock==NULL){
+i2c->lock=xSemaphoreCreateMutex();
+if(i2c->lock==NULL){
+returnNULL;
+ }
+ }
 
-if(i2c->num==0){
+if(i2c_num==0){
 SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG,DPORT_I2C_EXT0_CLK_EN);
 CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT0_RST);
- } elseif(i2c->num==1) {
+ } else{
 SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG,DPORT_I2C_EXT1_CLK_EN);
 CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT1_RST);
  }

cores/esp32/esp32-hal-i2c.h

@@ -22,18 +22,14 @@ extern "C"{
 #include"esp32-hal.h"
 #include"soc/i2c_struct.h"
 
-typedefstruct{
-i2c_dev_t*dev;
-uint8_tnum;
-} i2c_t;
+structi2c_struct_t;
+typedefstructi2c_struct_ti2c_t;
 
 i2c_t*i2cInit(uint8_ti2c_num, uint16_tslave_addr, booladdr_10bit_en);
 
 voidi2cSetFrequency(i2c_t*i2c, uint32_tclk_speed);
 uint32_ti2cGetFrequency(i2c_t*i2c);
 
-voidi2cResetFiFo(i2c_t*i2c);
-
 voidi2cAttachSCL(i2c_t*i2c, int8_tscl);
 voidi2cDetachSCL(i2c_t*i2c, int8_tscl);
 voidi2cAttachSDA(i2c_t*i2c, int8_tsda);