// this function is based on STM code int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) { machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)self_in; I2C_HandleTypeDef *hi2c = self->pyb->i2c; uint32_t Timeout = *self->timeout; /* Init tickstart for timeout management*/ uint32_t tickstart = HAL_GetTick(); #if 0 // TODO: for multi-master, here we could wait for the bus to be free // we'd need a flag to tell if we were in the middle of a set of transactions // (ie didn't send a stop bit in the last call) /* Wait until BUSY flag is reset */ if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY_FLAG, tickstart)) { return -MP_EBUSY; } #endif /* Check if the I2C is already enabled */ if ((hi2c->Instance->CR1 & I2C_CR1_PE) != I2C_CR1_PE) { /* Enable I2C peripheral */ __HAL_I2C_ENABLE(hi2c); } /* Disable Pos */ hi2c->Instance->CR1 &= ~I2C_CR1_POS; /* Enable Acknowledge */ hi2c->Instance->CR1 |= I2C_CR1_ACK; /* Send Slave Address */ int ret = send_addr_byte(hi2c, I2C_7BIT_ADD_READ(addr << 1), Timeout, tickstart); if (ret != 0) { return ret; } if (len == 0U) { /* Clear ADDR flag */ __HAL_I2C_CLEAR_ADDRFLAG(hi2c); /* Generate Stop */ if (stop) { hi2c->Instance->CR1 |= I2C_CR1_STOP; } } else if (len == 1U) { /* Disable Acknowledge */ hi2c->Instance->CR1 &= ~I2C_CR1_ACK; /* Clear ADDR flag */ __HAL_I2C_CLEAR_ADDRFLAG(hi2c); /* Generate Stop */ if (stop) { hi2c->Instance->CR1 |= I2C_CR1_STOP; } } else if (len == 2U) { /* Disable Acknowledge */ hi2c->Instance->CR1 &= ~I2C_CR1_ACK; /* Enable Pos */ hi2c->Instance->CR1 |= I2C_CR1_POS; /* Clear ADDR flag */ __HAL_I2C_CLEAR_ADDRFLAG(hi2c); } else { /* Enable Acknowledge */ hi2c->Instance->CR1 |= I2C_CR1_ACK; /* Clear ADDR flag */ __HAL_I2C_CLEAR_ADDRFLAG(hi2c); } while (len > 0U) { if (len <= 3U) { if (len == 1U) { /* Wait until RXNE flag is set */ int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart); if (ret != 0) { return ret; } /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; } else if (len == 2U) { /* Wait until BTF flag is set */ if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) { return -MP_ETIMEDOUT; } /* Generate Stop */ if (stop) { hi2c->Instance->CR1 |= I2C_CR1_STOP; } /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; } else { /* Wait until BTF flag is set */ if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) { return -MP_ETIMEDOUT; } /* Disable Acknowledge */ hi2c->Instance->CR1 &= ~I2C_CR1_ACK; /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; /* Wait until BTF flag is set */ if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) { return -MP_ETIMEDOUT; } /* Generate Stop */ if (stop) { hi2c->Instance->CR1 |= I2C_CR1_STOP; } /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; } } else { /* Wait until RXNE flag is set */ int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart); if (ret != 0) { return ret; } /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_BTF) == SET) { /* Read data from DR */ *dest++ = hi2c->Instance->DR; len--; } } } return 0; }
/** * @brief Receives in master mode an amount of data in blocking mode. * @param hi2c Pointer to a I2C_HandleTypeDef structure that contains * the configuration information for the specified I2C. * @param DevAddress Target device address The device 7 bits address value * in datasheet must be shifted to the left before calling the interface * @param pData Pointer to data buffer * @param Size Amount of data to be sent * @param Timeout Timeout duration * @param LastOp If set sends STOP, otherwise no STOP * @retval HAL status */ HAL_StatusTypeDef HAL_I2C_Master_Receive_Custom(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout, uint8_t LastOp) { uint32_t tickstart = 0U; uint8_t prev_mode = 0; HAL_StatusTypeDef rc; if (hi2c->State == HAL_I2C_STATE_READY) { /* Process Locked */ __HAL_LOCK(hi2c); /* Init tickstart for timeout management */ tickstart = HAL_GetTick(); prev_mode = hi2c->Mode; if (prev_mode != HAL_I2C_MODE_MASTER_SEL) { if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY, tickstart) != HAL_OK) { return HAL_TIMEOUT; } } hi2c->State = HAL_I2C_STATE_BUSY_RX; hi2c->Mode = HAL_I2C_MODE_MASTER; hi2c->ErrorCode = HAL_I2C_ERROR_NONE; /* Prepare transfer parameters */ hi2c->pBuffPtr = pData; hi2c->XferCount = Size; hi2c->XferISR = NULL; /* Send Slave Address */ /* Set NBYTES to write and reload if hi2c->XferCount > MAX_NBYTE_SIZE and generate RESTART */ if (hi2c->XferCount > MAX_NBYTE_SIZE) { hi2c->XferSize = MAX_NBYTE_SIZE; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_RELOAD_MODE, I2C_GENERATE_START_READ); } else if (!LastOp) { hi2c->XferSize = hi2c->XferCount; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_SOFTEND_MODE, I2C_GENERATE_START_READ); } else { hi2c->XferSize = hi2c->XferCount; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_AUTOEND_MODE, I2C_GENERATE_START_READ); } while (hi2c->XferCount > 0U) { /* Wait until RXNE flag is set */ rc = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart, prev_mode); if (rc != HAL_OK && rc != HAL_NACK) { if (hi2c->ErrorCode == HAL_I2C_ERROR_AF) { return HAL_ERROR; } else { return HAL_TIMEOUT; } } /* Read data from RXDR */ (*hi2c->pBuffPtr++) = hi2c->Instance->RXDR; hi2c->XferSize--; hi2c->XferCount--; if (rc == HAL_NACK) { break; } if ((hi2c->XferSize == 0U) && (hi2c->XferCount != 0U)) { /* Wait until TCR flag is set */ if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TCR, RESET, Timeout, tickstart) != HAL_OK) { return HAL_TIMEOUT; } if (hi2c->XferCount > MAX_NBYTE_SIZE) { hi2c->XferSize = MAX_NBYTE_SIZE; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_RELOAD_MODE, I2C_NO_STARTSTOP); } else if (!LastOp) { hi2c->XferSize = hi2c->XferCount; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_SOFTEND_MODE, I2C_NO_STARTSTOP); } else { hi2c->XferSize = hi2c->XferCount; I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_AUTOEND_MODE, I2C_NO_STARTSTOP); } } } if (LastOp) { /* No need to Check TC flag, with AUTOEND mode the stop is automatically generated */ /* Wait until STOPF flag is set */ if (I2C_WaitOnSTOPFlagUntilTimeout(hi2c, Timeout, tickstart) != HAL_OK) { if (hi2c->ErrorCode == HAL_I2C_ERROR_AF) { return HAL_ERROR; } else { return HAL_TIMEOUT; } } /* Clear STOP Flag */ __HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_STOPF); } else { /* No autoend/reload was requested, make sure transmission of last byte * has finished... */ if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TC, SET, Timeout, tickstart) != HAL_OK) { return HAL_TIMEOUT; } } /* Clear Configuration Register 2 */ I2C_RESET_CR2(hi2c); hi2c->State = HAL_I2C_STATE_READY; if (LastOp) { hi2c->Mode = HAL_I2C_MODE_NONE; } else { hi2c->Mode = HAL_I2C_MODE_MASTER_SEL; } /* Process Unlocked */ __HAL_UNLOCK(hi2c); return HAL_OK; } else { return HAL_BUSY; } }