drivers: CAN: MCP2515: Add and use Read RX Buffer instruction (0c5ef3e1) · Commits · Wenxi XU / zephyr

drivers/can/can_mcp2515.c

+55 −8

Original line number	Diff line number	Diff line
		@@ -139,6 +139,43 @@ static int mcp2515_cmd_read_reg(struct device *dev, u8_t reg_addr,
		&tx, &rx);
		}

		/*
		* Read RX Buffer instruction
		*
		* When reading a receive buffer, reduces the overhead of a normal READ
		* command by placing the Address Pointer at one of four locations selected by
		* parameter nm:
		* 0: Receive Buffer 0, Start at RXB0SIDH (0x61)
		* 1: Receive Buffer 0, Start at RXB0D0 (0x66)
		* 2: Receive Buffer 1, Start at RXB1SIDH (0x71)
		* 3: Receive Buffer 1, Start at RXB1D0 (0x76)
		*/
		static int mcp2515_cmd_read_rx_buffer(struct device *dev, u8_t nm,
		u8_t *buf_data, u8_t buf_len)
		{
		__ASSERT(nm <= 0x03, "nm <= 0x03");

		u8_t cmd_buf[] = { MCP2515_OPCODE_READ_RX_BUFFER \| (nm << 1) };

		struct spi_buf tx_buf[] = {
		{ .buf = cmd_buf, .len = sizeof(cmd_buf) },
		{ .buf = NULL, .len = buf_len }
		};
		const struct spi_buf_set tx = {
		.buffers = tx_buf, .count = ARRAY_SIZE(tx_buf)
		};
		struct spi_buf rx_buf[] = {
		{ .buf = NULL, .len = sizeof(cmd_buf) },
		{ .buf = buf_data, .len = buf_len }
		};
		const struct spi_buf_set rx = {
		.buffers = rx_buf, .count = ARRAY_SIZE(rx_buf)
		};

		return spi_transceive(DEV_DATA(dev)->spi, &DEV_DATA(dev)->spi_cfg,
		&tx, &rx);
		}

		static u8_t mcp2515_convert_canmode_to_mcp2515mode(enum can_mode mode)
		{
		switch (mode) {
		@@ -499,15 +536,17 @@ static void mcp2515_rx_filter(struct device dev, struct zcan_frame msg)

		static void mcp2515_rx(struct device *dev, u8_t rx_idx)
		{
		__ASSERT(rx_idx < MCP2515_RX_CNT, "rx_idx < MCP2515_RX_CNT");

		struct zcan_frame msg;
		u8_t rx_frame[MCP2515_FRAME_LEN];
		u8_t addr_rx_ctrl = MCP2515_ADDR_RXB0CTRL +
		(rx_idx * MCP2515_ADDR_OFFSET_FRAME2FRAME);
		u8_t nm;

		/* Address Pointer selection */
		nm = 2 * rx_idx;

		/* Fetch rx buffer */
		mcp2515_cmd_read_reg(dev,
		addr_rx_ctrl + MCP2515_ADDR_OFFSET_CTRL2FRAME,
		rx_frame, sizeof(rx_frame));
		mcp2515_cmd_read_rx_buffer(dev, nm, rx_frame, sizeof(rx_frame));
		mcp2515_convert_mcp2515frame_to_zcanframe(rx_frame, &msg);
		mcp2515_rx_filter(dev, &msg);
		}
		@@ -611,10 +650,16 @@ static void mcp2515_handle_interrupts(struct device *dev)

		if (canintf & MCP2515_CANINTF_RX0IF) {
		mcp2515_rx(dev, 0);

		/* RX0IF flag cleared automatically during read */
		canintf &= ~MCP2515_CANINTF_RX0IF;
		}

		if (canintf & MCP2515_CANINTF_RX1IF) {
		mcp2515_rx(dev, 1);

		/* RX1IF flag cleared automatically during read */
		canintf &= ~MCP2515_CANINTF_RX1IF;
		}

		if (canintf & MCP2515_CANINTF_TX0IF) {
		@@ -633,9 +678,11 @@ static void mcp2515_handle_interrupts(struct device *dev)
		mcp2515_handle_errors(dev);
		}

		/* clear the flags we handled */
		mcp2515_cmd_bit_modify(dev, MCP2515_ADDR_CANINTF, canintf,
		~canintf);
		if (canintf != 0) {
		/* Clear remaining flags */
		mcp2515_cmd_bit_modify(dev, MCP2515_ADDR_CANINTF,
		canintf, ~canintf);
		}

		/* Break from loop if INT pin is no longer low */
		ret = gpio_pin_read(dev_data->int_gpio, dev_cfg->int_pin, &pin);

drivers/can/can_mcp2515.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -10,6 +10,7 @@

		#include <drivers/can.h>

		#define MCP2515_RX_CNT 2
		#define MCP2515_TX_CNT 3
		#define MCP2515_FRAME_LEN 13

		@@ -84,6 +85,7 @@ struct mcp2515_config {
		#define MCP2515_OPCODE_BIT_MODIFY 0x05
		#define MCP2515_OPCODE_LOAD_TX_BUFFER 0x40
		#define MCP2515_OPCODE_RTS 0x80
		#define MCP2515_OPCODE_READ_RX_BUFFER 0x90
		#define MCP2515_OPCODE_READ_STATUS 0xA0
		#define MCP2515_OPCODE_RESET 0xC0

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