drivers: CAN: MCP2515: Add and use Load TX Buffer instruction (4816d06c) · Commits · Wenxi XU / zephyr

drivers/can/can_mcp2515.c

+40 −4

Original line number	Diff line number	Diff line
		@@ -60,6 +60,38 @@ static int mcp2515_cmd_write_reg(struct device *dev, u8_t reg_addr,
		return spi_write(DEV_DATA(dev)->spi, &DEV_DATA(dev)->spi_cfg, &tx);
		}

		/*
		* Load TX buffer instruction
		*
		* When loading a transmit buffer, reduces the overhead of a normal WRITE
		* command by placing the Address Pointer at one of six locations, as
		* selected by parameter abc.
		*
		* 0: TX Buffer 0, Start at TXB0SIDH (0x31)
		* 1: TX Buffer 0, Start at TXB0D0 (0x36)
		* 2: TX Buffer 1, Start at TXB1SIDH (0x41)
		* 3: TX Buffer 1, Start at TXB1D0 (0x46)
		* 4: TX Buffer 2, Start at TXB2SIDH (0x51)
		* 5: TX Buffer 2, Start at TXB2D0 (0x56)
		*/
		static int mcp2515_cmd_load_tx_buffer(struct device *dev, u8_t abc,
		u8_t *buf_data, u8_t buf_len)
		{
		__ASSERT(abc <= 5, "abc <= 5");

		u8_t cmd_buf[] = { MCP2515_OPCODE_LOAD_TX_BUFFER \| abc };

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

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

		static int mcp2515_cmd_read_reg(struct device *dev, u8_t reg_addr,
		u8_t *buf_data, u8_t buf_len)
		{
		@@ -292,6 +324,7 @@ static int mcp2515_send(struct device dev, const struct zcan_frame msg,
		{
		struct mcp2515_data *dev_data = DEV_DATA(dev);
		u8_t tx_idx = 0U;
		u8_t abc;
		u8_t addr_tx_ctrl;
		u8_t tx_frame[MCP2515_FRAME_LEN];

		@@ -323,9 +356,12 @@ static int mcp2515_send(struct device dev, const struct zcan_frame msg,
		(tx_idx * MCP2515_ADDR_OFFSET_FRAME2FRAME);

		mcp2515_convert_zcanframe_to_mcp2515frame(msg, tx_frame);
		mcp2515_cmd_write_reg(dev,
		addr_tx_ctrl + MCP2515_ADDR_OFFSET_CTRL2FRAME,
		tx_frame, sizeof(tx_frame));

		/* Address Pointer selection */
		abc = 2 * tx_idx;

		mcp2515_cmd_load_tx_buffer(dev, abc, tx_frame, sizeof(tx_frame));

		/* request tx slot transmission */
		mcp2515_cmd_bit_modify(dev, addr_tx_ctrl, MCP2515_TXCTRL_TXREQ,
		MCP2515_TXCTRL_TXREQ);
		@@ -632,7 +668,7 @@ static int mcp2515_init(struct device *dev)

		k_sem_init(&dev_data->int_sem, 0, 1);
		k_mutex_init(&dev_data->mutex);
		k_sem_init(&dev_data->tx_sem, 3, 3);
		k_sem_init(&dev_data->tx_sem, MCP2515_TX_CNT, MCP2515_TX_CNT);
		k_sem_init(&dev_data->tx_cb[0].sem, 0, 1);
		k_sem_init(&dev_data->tx_cb[1].sem, 0, 1);
		k_sem_init(&dev_data->tx_cb[2].sem, 0, 1);

drivers/can/can_mcp2515.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -82,6 +82,7 @@ struct mcp2515_config {
		#define MCP2515_OPCODE_WRITE 0x02
		#define MCP2515_OPCODE_READ 0x03
		#define MCP2515_OPCODE_BIT_MODIFY 0x05
		#define MCP2515_OPCODE_LOAD_TX_BUFFER 0x40
		#define MCP2515_OPCODE_READ_STATUS 0xA0
		#define MCP2515_OPCODE_RESET 0xC0

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