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fdcac81021
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#ifndef I2C_GATEWAY_H |
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#define I2C_GATEWAY_H |
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#include <stdint.h> |
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#include <stddef.h> |
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void i2c_command(uint8_t *packet, size_t len); |
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#endif //I2C_GATEWAY_H
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@ -0,0 +1,181 @@ |
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#include <stdint.h> |
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#include <stdio.h> |
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#include "main.h" |
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#include "usbd_cdc_if.h" |
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#define I2C_DEBUG 0 |
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#define I2C_MTU 512 |
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#define HAL_CHECK(x) do { \ |
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int rv = (x); \
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if (rv != HAL_OK) { \
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printf("HAL ERR %d at %s:%d\r\n", rv, __FILE__, __LINE__); \
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}\
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} while (0) |
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/**
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* Packet format: |
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* |
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* Transmit packets |
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* LEN_MSB LEN_LSB ADDR Bytes... |
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* |
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* LEN does not include the length field itself! |
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* |
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* Command packets are sent as ADDR=255 |
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* 0xFF CMD ARGs... |
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* - Set address: 0x01 ADDR |
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* - Set speed: 0x02 Speed TODO!! |
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* - Speed 1 ... 100kHz |
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* - Speed 4 ... 400kHz |
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*/ |
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#define COMMAND_ADDRESS 0xFF |
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#define CMD_SET_ADDR 1 // the next param is the address, without shifting (i.e. 1-127)
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#define CMD_SET_SPEED 2 // speed is 1 or 4 (100khz, 400khz)
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enum FrameState { |
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FRAME_LEN_MSB, |
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FRAME_LEN_LSB, |
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FRAME_PAYLOAD, |
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}; |
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static uint16_t framelen = 0; |
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static uint8_t i2c_recbuf[I2C_MTU + 3] = {}; |
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static size_t recbuf_wp = 0; |
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static size_t framestate = FRAME_LEN_MSB; |
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static uint32_t last_rx_tick; |
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#define CMD_TIMEOUT_TICKS 500 |
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static void handle_pkt(uint8_t *packet, size_t len); |
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static void handle_control_pkt(uint8_t *packet, size_t len); |
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void i2c_command(uint8_t *packet, size_t len) |
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{ |
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uint32_t now = HAL_GetTick(); |
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if (framestate != FRAME_LEN_MSB && (now - last_rx_tick) > CMD_TIMEOUT_TICKS) { |
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framestate = FRAME_LEN_MSB; |
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} |
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last_rx_tick = now; |
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for (int i=0; i<len;i++) { |
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uint8_t b = packet[i]; |
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switch (framestate) { |
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case FRAME_LEN_MSB: |
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framelen = ((uint16_t)b) << 8; |
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framestate = FRAME_LEN_LSB; |
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break; |
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case FRAME_LEN_LSB: |
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framelen |= (uint16_t)b; |
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if (framelen == 0) { |
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framestate = FRAME_LEN_MSB; |
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} else { |
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framestate = FRAME_PAYLOAD; |
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recbuf_wp = 0; |
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} |
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break; |
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case FRAME_PAYLOAD: |
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i2c_recbuf[recbuf_wp++] = b; |
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if (recbuf_wp >= framelen) { |
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handle_pkt(i2c_recbuf, framelen); |
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framestate = FRAME_LEN_MSB; |
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} |
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break; |
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} |
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} |
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} |
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static void handle_pkt(uint8_t *packet, size_t len) |
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{ |
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#if I2C_DEBUG |
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printf("Handle packet (%d bytes): ", len); |
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for(int i=0; i<len;i++) { |
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printf("%02x ", packet[i]); |
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} |
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printf("\r\n"); |
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#endif |
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if (packet[0] == COMMAND_ADDRESS) { |
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printf("ctl: "); |
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// This is an in-band control packet
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handle_control_pkt(packet, len); |
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} else { |
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uint8_t dest = packet[0]; |
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#if I2C_DEBUG |
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printf("Tx(%d)->%d\r\n", len - 1, dest); |
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#endif |
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// Blocking transfer
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HAL_CHECK(HAL_I2C_DisableListen_IT(&hi2c1)); |
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HAL_CHECK(HAL_I2C_Master_Transmit(&hi2c1, (dest & 0x7F) << 1, &packet[1], len - 1, 100)); |
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HAL_CHECK(HAL_I2C_EnableListen_IT(&hi2c1)); |
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} |
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} |
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static void handle_control_pkt(uint8_t *packet, size_t len) |
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{ |
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uint8_t cmd = packet[1]; |
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uint8_t arg; |
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switch (cmd) { |
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case CMD_SET_ADDR: |
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if (len < 3) return; |
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arg = packet[2]; |
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printf("Addr=0x%02x\r\n", arg); |
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MODIFY_REG(hi2c1.Instance->OAR1, |
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(I2C_OAR1_ADDMODE | I2C_OAR1_ADD8_9 | I2C_OAR1_ADD1_7 | I2C_OAR1_ADD0), |
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(I2C_ADDRESSINGMODE_7BIT | ((arg & 0x7F) << 1) )); |
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HAL_CHECK(HAL_I2C_EnableListen_IT(&hi2c1)); |
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break; |
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default: |
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printf("bad cmd!\r\n"); |
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} |
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} |
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/**
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* @brief Slave Address Match callback. |
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* @param hi2c Pointer to a I2C_HandleTypeDef structure that contains |
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* the configuration information for the specified I2C. |
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* @param TransferDirection Master request Transfer Direction (Write/Read), value of @ref I2C_XferDirection_definition |
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* @param AddrMatchCode Address Match Code |
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* @retval None |
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*/ |
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void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirection, uint16_t AddrMatchCode) |
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{ |
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HAL_CHECK(HAL_I2C_Slave_Seq_Receive_IT(hi2c, i2c_recbuf, I2C_MTU, I2C_FIRST_AND_LAST_FRAME)); |
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} |
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/**
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* @brief Slave Rx Transfer completed callback. |
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* @param hi2c Pointer to a I2C_HandleTypeDef structure that contains |
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* the configuration information for the specified I2C. |
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* @retval None |
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*/ |
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void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *hi2c) |
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{ |
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int numBytes = I2C_MTU - hi2c->XferCount; |
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#if I2C_DEBUG |
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printf("rxd %d\r\n", numBytes); |
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#endif |
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UserTxBufferFS[0] = (numBytes >> 8) & 0xFF; |
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UserTxBufferFS[1] = numBytes & 0xFF; |
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memcpy(&UserTxBufferFS[2], i2c_recbuf, numBytes); |
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CDC_Transmit_FS(UserTxBufferFS, numBytes + 2); |
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} |
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/**
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* @brief Listen Complete callback. |
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* @param hi2c Pointer to a I2C_HandleTypeDef structure that contains |
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* the configuration information for the specified I2C. |
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* @retval None |
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*/ |
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void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef *hi2c) |
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{ |
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// Start again
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HAL_CHECK(HAL_I2C_EnableListen_IT(hi2c)); |
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} |
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