Added i2c_master.*

- I2C_Write - I2C_Read - I2C_ReadReg
4 weeks ago · 8e27f8818e
parent 61a5785908
commit 8e27f8818e
2 changed files with 147 additions and 0 deletions
--- a/Core/Inc/i2c_master.h
+++ b/Core/Inc/i2c_master.h
@ -0,0 +1,13 @@
+#ifndef __I2C_MASTER_H__
+#define __I2C_MASTER_H__
+
+#include <stdint.h>
+#include <stm32h5xx_ll_i2c.h>
+
+
+extern int I2C_Write(I2C_TypeDef* I2Cx, uint8_t addr, const uint8_t* data, uint16_t len);
+extern int I2C_Read(I2C_TypeDef* I2Cx, uint8_t addr, uint8_t* data, uint16_t len);
+extern int I2C_ReadReg(I2C_TypeDef* I2Cx, uint8_t addr, const uint8_t* reg, uint16_t reglen, uint8_t* data, uint16_t datalen);
+
+
+#endif
--- a/Core/Src/i2c_master.c
+++ b/Core/Src/i2c_master.c
@ -0,0 +1,134 @@
+/***************************************************************************//**
+* @file  i2c_master.c
+* @brief I2C master functions for STM32H5 using LL library
+*//****************************************************************************/
+
+//------------------------------C library---------------------------------------
+#include <stdint.h>
+//----------------------------user includes-------------------------------------
+#include "i2c_master.h"
+#include "main.h"
+//------------------------------------------------------------------------------
+
+
+/* Private macros ------------------------------------------------------------*/
+#define I2C_TIMEOUT_US     5000
+
+
+// SOFTEND in the write section prevents STOP --> Restart possible
+// AUTOEND in the read section generates correct STOP
+// TXIS/RXNE polling is mandatory for H5
+// STOP-flag-clear is necessary, otherwise the next transaction will hang.
+
+
+/* Functions -----------------------------------------------------------------*/
+
+static int I2C_Tout(I2C_TypeDef* I2Cx, int val) {
+   LL_I2C_GenerateStopCondition(I2Cx);
+   LL_I2C_Disable(I2Cx);
+   LL_I2C_Enable(I2Cx);
+   LL_I2C_ClearFlag_NACK(I2Cx);
+   LL_I2C_ClearFlag_STOP(I2Cx);
+   LL_I2C_ClearFlag_ADDR(I2Cx);
+   return val;
+}
+
+/***************************************************************************//**
+* @brief  Write data to I2C slave device
+* @param  I2Cx: I2C peripheral (e.g. I2C1)
+* @param  addr: 7-bit I2C slave address, left-aligned
+* @param  data: pointer to data buffer to write
+* @param  len:  number of bytes to write
+* @return 0 on success, -1 on TXIS timeout, -2 on STOP timeout
+*//****************************************************************************/
+int I2C_Write(I2C_TypeDef* I2Cx, uint8_t addr, const uint8_t* data, uint16_t len) {
+   LL_I2C_HandleTransfer(I2Cx, addr, LL_I2C_ADDRSLAVE_7BIT, len, LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_WRITE);
+   for (uint16_t i = 0; i < len; i++) {
+      uint32_t tref = usTimerGetAbs();
+      while (!LL_I2C_IsActiveFlag_TXIS(I2Cx)) {
+         if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+             return I2C_Tout(I2Cx, -1);               // error: TXIS timeout
+         }
+      }
+      LL_I2C_TransmitData8(I2Cx, data[i]);         // send data
+   }
+   uint32_t tref = usTimerGetAbs();
+   while (!LL_I2C_IsActiveFlag_STOP(I2Cx)) {
+      if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+         return I2C_Tout(I2Cx, -2);                // error: STOP timeout
+      }
+   }
+   LL_I2C_ClearFlag_STOP(I2Cx);
+   return 0;
+}
+
+/***************************************************************************//**
+* @brief  Read data from I2C slave device
+* @param  I2Cx: I2C peripheral (e.g. I2C1)
+* @param  addr: 7-bit I2C slave address, left-aligned
+* @param  data: pointer to data buffer to store read data
+* @param  len:  number of bytes to read
+* @return 0 on success, -1 on RXNE timeout, -2 on STOP timeout
+*//****************************************************************************/
+int I2C_Read(I2C_TypeDef* I2Cx, uint8_t addr, uint8_t* data, uint16_t len) {
+   LL_I2C_HandleTransfer(I2Cx, addr, LL_I2C_ADDRSLAVE_7BIT, len, LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_READ);
+   for (uint16_t i = 0; i < len; i++) {
+      uint32_t tref = usTimerGetAbs();
+      while (!LL_I2C_IsActiveFlag_RXNE(I2Cx)) {
+         if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+             return I2C_Tout(I2Cx, -1);               // error: RXNE timeout
+         }
+      }
+      data[i] = LL_I2C_ReceiveData8(I2Cx);         // read data
+   }
+   uint32_t tref = usTimerGetAbs();
+   while (!LL_I2C_IsActiveFlag_STOP(I2Cx)) {
+      if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+         return I2C_Tout(I2Cx, -2);                // error: STOP timeout
+      }
+   }
+   LL_I2C_ClearFlag_STOP(I2Cx);
+   return 0;
+}
+
+/***************************************************************************//**
+* @brief  Read data from I2C slave device register
+* @param  I2Cx: I2C peripheral (e.g. I2C1)
+* @param  addr: 7-bit I2C slave address, left-aligned
+* @param  reg: pointer to register address buffer (1-2 bytes)
+* @param  reglen: number of bytes in register address (1 or 2)
+* @param  data: pointer to data buffer to store read data
+* @param  datalen: number of bytes to read
+* @return 0 on success, -1 on TXIS timeout, -2 on RXNE timeout, -3 on STOP timeout
+*//****************************************************************************/
+int I2C_ReadReg(I2C_TypeDef* I2Cx, uint8_t addr, const uint8_t* reg, uint16_t reglen, uint8_t* data, uint16_t datalen) {
+   LL_I2C_HandleTransfer(I2Cx, addr, LL_I2C_ADDRSLAVE_7BIT, reglen, LL_I2C_MODE_SOFTEND, LL_I2C_GENERATE_START_WRITE);
+   for (uint16_t i = 0; i < reglen; i++) {
+      uint32_t tref = usTimerGetAbs();
+      while (!LL_I2C_IsActiveFlag_TXIS(I2Cx)) {
+         if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+             return I2C_Tout(I2Cx, -1);               // error: TXIS timeout
+         }
+      }
+      LL_I2C_TransmitData8(I2Cx, reg[i]);             // send register address
+   }
+   LL_I2C_HandleTransfer(I2Cx, addr, LL_I2C_ADDRSLAVE_7BIT, datalen, LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_RESTART_7BIT_READ);
+   for (uint16_t i = 0; i < datalen; i++) {
+      uint32_t tref = usTimerGetAbs();
+      while (!LL_I2C_IsActiveFlag_RXNE(I2Cx)) {
+         if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+             return I2C_Tout(I2Cx, -2);               // error: RXNE timeout
+         }
+      }
+      data[i] = LL_I2C_ReceiveData8(I2Cx);         // read data
+   }
+   uint32_t tref = usTimerGetAbs();
+   while (!LL_I2C_IsActiveFlag_STOP(I2Cx)) {
+      if (usTimerGetRel(tref) > I2C_TIMEOUT_US) {  // timeout expired
+         return I2C_Tout(I2Cx, -3);                // error: STOP timeout
+      }
+   }
+   LL_I2C_ClearFlag_STOP(I2Cx);
+   return 0;
+}
+