Merge pull request espressif#751 from espressif/longReads

Add initial handling for long I2C reads.

Author: lonerzzz

cores/esp32/esp32-hal-i2c.c

@@ -31,6 +31,8 @@
 #define DR_REG_I2C_EXT_BASE_FIXED 0x60013000
 #define DR_REG_I2C1_EXT_BASE_FIXED 0x60027000
 
+#define COMMAND_BUFFER_LENGTH 16
+
 struct i2c_struct_t {
  i2c_dev_t * dev;
 #if !CONFIG_DISABLE_HAL_LOCKS
@@ -127,26 +129,25 @@ 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;
 }
 
-void i2cResetCmd(i2c_t * i2c){
- int i;
+void i2cResetCmd(i2c_t * i2c) {
+ uint8_t i;
  for(i=0;i<16;i++){
  i2c->dev->command[i].val = 0;
  }
 }
 
-void i2cResetFiFo(i2c_t * i2c)
-{
+void i2cResetFiFo(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;
 }
 
-i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint8_t len, bool sendStop)
+i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint16_t len, bool sendStop)
 {
  int i;
- uint8_t index = 0;
- uint8_t dataLen = len + (addr_10bit?2:1);
+ uint16_t index = 0;
+ uint16_t dataLen = len + (addr_10bit?2:1);
  address = (address << 1);
 
  if(i2c == NULL){
@@ -244,12 +245,25 @@ i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * dat
  return I2C_ERROR_OK;
 }
 
-i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint8_t len, bool sendStop)
+uint8_t inc( uint8_t* index )
+{
+ uint8_t i = index[ 0 ];
+ if (++index[ 0 ] == COMMAND_BUFFER_LENGTH)
+ {
+ index[ 0 ] = 0;
+ }
+
+ return i;
+}
+
+i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint16_t len, bool sendStop)
 {
  address = (address << 1) | 1;
  uint8_t addrLen = (addr_10bit?2:1);
- uint8_t index = 0;
- uint8_t cmdIdx;
+ uint8_t amountRead[16];
+ uint16_t index = 0;
+ uint8_t cmdIdx = 0, currentCmdIdx = 0, nextCmdCount;
+ bool stopped = false, isEndNear = false;
  uint8_t willRead;
 
  if(i2c == NULL){
@@ -269,86 +283,90 @@ i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data
  i2cResetCmd(i2c);
 
  //CMD START
- i2cSetCmd(i2c, 0, I2C_CMD_RSTART, 0, false, false, false);
+ i2cSetCmd(i2c, cmdIdx++, I2C_CMD_RSTART, 0, false, false, false);
 
  //CMD WRITE ADDRESS
  i2c->dev->fifo_data.val = address & 0xFF;
  if(addr_10bit) {
  i2c->dev->fifo_data.val = (address >> 8) & 0xFF;
  }
- i2cSetCmd(i2c, 1, I2C_CMD_WRITE, addrLen, false, false, true);
+ i2cSetCmd(i2c, cmdIdx++, I2C_CMD_WRITE, addrLen, false, false, true);
+ nextCmdCount = cmdIdx;
 
- while(len) {
- cmdIdx = (index)?0:2;
- willRead = (len > 32)?32:(len-1);
- if(cmdIdx){
- i2cResetFiFo(i2c);
- }
-
- if(willRead){
- i2cSetCmd(i2c, cmdIdx++, I2C_CMD_READ, willRead, false, false, false);
- }
-
- if((len - willRead) > 1) {
- i2cSetCmd(i2c, cmdIdx++, I2C_CMD_END, 0, false, false, false);
- } else {
- willRead++;
- i2cSetCmd(i2c, cmdIdx++, I2C_CMD_READ, 1, true, false, false);
- if(sendStop) {
- i2cSetCmd(i2c, cmdIdx++, I2C_CMD_STOP, 0, false, false, false);
- }
- }
-
- //Clear Interrupts
- i2c->dev->int_clr.val = 0xFFFFFFFF;
-
- //START Transmission
- i2c->dev->ctr.trans_start = 1;
+ //Clear Interrupts
+ i2c->dev->int_clr.val = 0x00001FFF;
 
+ //START Transmission
+ i2c->dev->ctr.trans_start = 1;
+ while (!stopped) {
  //WAIT Transmission
  uint32_t startAt = millis();
  while(1) {
  //have been looping for too long
- if((millis() - startAt)>50){
- log_e("Timeout! Addr: %x", address >> 1);
+ if((millis() - startAt)>50) {
+ log_e("Timeout! Addr: %x, index %d", (address >> 1), index);
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_BUS;
  }
 
  //Bus failed (maybe check for this while waiting?
  if(i2c->dev->int_raw.arbitration_lost) {
- log_e("Bus Fail! Addr: %x", address >> 1);
+ log_e("Bus Fail! Addr: %x", (address >> 1));
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_BUS;
  }
 
  //Bus timeout
  if(i2c->dev->int_raw.time_out) {
- log_e("Bus Timeout! Addr: %x", address >> 1);
+ log_e("Bus Timeout! Addr: %x, index %d", (address >> 1), index );
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_TIMEOUT;
  }
 
  //Transmission did not finish and ACK_ERR is set
  if(i2c->dev->int_raw.ack_err) {
  log_w("Ack Error! Addr: %x", address >> 1);
+ while((i2c->dev->status_reg.bus_busy) && ((millis() - startAt)<50));
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_ACK;
  }
 
- if(i2c->dev->command[cmdIdx-1].done) {
- break;
+ // Save bytes from the buffer as they arrive instead of doing them at the end of the loop since there is no
+ // pause from an END operation in this approach.
+ if((!isEndNear) && (nextCmdCount < 2)) {
+ if (willRead = ((len>32)?32:len)) {
+ if (willRead > 1) {
+ i2cSetCmd(i2c, cmdIdx, I2C_CMD_READ, (amountRead[ inc( &cmdIdx ) ] = willRead -1), false, false, false);
+ nextCmdCount++;
+ }
+ i2cSetCmd(i2c, cmdIdx, I2C_CMD_READ, (amountRead[ inc( &cmdIdx ) ] = 1), (len<=32), false, false);
+ nextCmdCount++;
+ len -= willRead;
+ } else {
+ i2cSetCmd(i2c, inc( &cmdIdx ), I2C_CMD_STOP, 0, false, false, false);
+ isEndNear = true;
+ nextCmdCount++;
+ }
  }
- }
 
- int i = 0;
- while(i<willRead) {
- i++;
- data[index++] = i2c->dev->fifo_data.val & 0xFF;
+ if(i2c->dev->command[currentCmdIdx].done) {
+ nextCmdCount--;
+ if (i2c->dev->command[currentCmdIdx].op_code == I2C_CMD_READ) {
+ while(amountRead[currentCmdIdx]>0) {
+ data[index++] = i2c->dev->fifo_data.val & 0xFF;
+ amountRead[currentCmdIdx]--;
+ }
+ i2cResetFiFo(i2c);
+ } else if (i2c->dev->command[currentCmdIdx].op_code == I2C_CMD_STOP) {
+ stopped = true;
+ }
+ inc( &currentCmdIdx );
+ break;
+ }
  }
- len -= willRead;
  }
  I2C_MUTEX_UNLOCK();
+
  return I2C_ERROR_OK;
 }
 
@@ -425,7 +443,7 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
  DPORT_SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG,DPORT_I2C_EXT1_CLK_EN);
  DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT1_RST);
  }
- 
+
  I2C_MUTEX_LOCK();
  i2c->dev->ctr.val = 0;
  i2c->dev->ctr.ms_mode = (slave_addr == 0);
@@ -434,7 +452,7 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
  i2c->dev->ctr.clk_en = 1;
 
  //the max clock number of receiving a data
- i2c->dev->timeout.tout = 400000;//clocks max=1048575
+ i2c->dev->timeout.tout = 1048575;//clocks max=1048575
  //disable apb nonfifo access
  i2c->dev->fifo_conf.nonfifo_en = 0;
 

cores/esp32/esp32-hal-i2c.h

@@ -48,8 +48,8 @@ i2c_err_t i2cDetachSCL(i2c_t * i2c, int8_t scl);
 i2c_err_t i2cAttachSDA(i2c_t * i2c, int8_t sda);
 i2c_err_t i2cDetachSDA(i2c_t * i2c, int8_t sda);
 
-i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint8_t len, bool sendStop);
-i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint8_t len, bool sendStop);
+i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint16_t len, bool sendStop);
+i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data, uint16_t len, bool sendStop);
 
 void i2cReset(i2c_t* i2c);