2 /* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
39 #include <linux/spi/spi.h>
43 /* SPI interface instruction set */
170 /* Buffer size required for the largest SPI transfer (i.e., reading a
204 	struct spi_device *spi;  member
207 	struct mutex mcp_lock; /* SPI device lock */
232 static inline int mcp251x_is_##_model(struct spi_device *spi) \
234 	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
254  * registers via SPI is not really different conceptually than using
265 static int mcp251x_spi_trans(struct spi_device *spi, int len)  in mcp251x_spi_trans()  argument
267 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_spi_trans()
280 	ret = spi_sync(spi, &m);  in mcp251x_spi_trans()
282 		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);  in mcp251x_spi_trans()
286 static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg)  in mcp251x_read_reg()  argument
288 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_read_reg()
294 	mcp251x_spi_trans(spi, 3);  in mcp251x_read_reg()
300 static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2)  in mcp251x_read_2regs()  argument
302 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_read_2regs()
307 	mcp251x_spi_trans(spi, 4);  in mcp251x_read_2regs()
313 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val)  in mcp251x_write_reg()  argument
315 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_write_reg()
321 	mcp251x_spi_trans(spi, 3);  in mcp251x_write_reg()
324 static void mcp251x_write_bits(struct spi_device *spi, u8 reg,  in mcp251x_write_bits()  argument
327 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_write_bits()
334 	mcp251x_spi_trans(spi, 4);  in mcp251x_write_bits()
337 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,  in mcp251x_hw_tx_frame()  argument
340 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_tx_frame()
342 	if (mcp251x_is_2510(spi)) {  in mcp251x_hw_tx_frame()
346 			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,  in mcp251x_hw_tx_frame()
350 		mcp251x_spi_trans(spi, TXBDAT_OFF + len);  in mcp251x_hw_tx_frame()
354 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,  in mcp251x_hw_tx()  argument
357 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_tx()
378 	mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);  in mcp251x_hw_tx()
382 	mcp251x_spi_trans(priv->spi, 1);  in mcp251x_hw_tx()
385 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,  in mcp251x_hw_rx_frame()  argument
388 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_rx_frame()
390 	if (mcp251x_is_2510(spi)) {  in mcp251x_hw_rx_frame()
394 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);  in mcp251x_hw_rx_frame()
398 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);  in mcp251x_hw_rx_frame()
401 		mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);  in mcp251x_hw_rx_frame()
406 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)  in mcp251x_hw_rx()  argument
408 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_rx()
415 		dev_err(&spi->dev, "cannot allocate RX skb\n");  in mcp251x_hw_rx()
420 	mcp251x_hw_rx_frame(spi, buf, buf_idx);  in mcp251x_hw_rx()
455 static void mcp251x_hw_sleep(struct spi_device *spi)  in mcp251x_hw_sleep()  argument
457 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);  in mcp251x_hw_sleep()
464 	struct spi_device *spi = priv->spi;  in mcp251x_hard_start_xmit()  local
467 		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");  in mcp251x_hard_start_xmit()
488 		/* We have to delay work since SPI I/O may sleep */  in mcp251x_do_set_mode()
502 static int mcp251x_set_normal_mode(struct spi_device *spi)  in mcp251x_set_normal_mode()  argument
504 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_set_normal_mode()
508 	mcp251x_write_reg(spi, CANINTE,  in mcp251x_set_normal_mode()
514 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);  in mcp251x_set_normal_mode()
517 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);  in mcp251x_set_normal_mode()
520 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);  in mcp251x_set_normal_mode()
524 		while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {  in mcp251x_set_normal_mode()
527 				dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n");  in mcp251x_set_normal_mode()
540 	struct spi_device *spi = priv->spi;  in mcp251x_do_set_bittiming()  local
542 	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |  in mcp251x_do_set_bittiming()
544 	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |  in mcp251x_do_set_bittiming()
549 	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,  in mcp251x_do_set_bittiming()
551 	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",  in mcp251x_do_set_bittiming()
552 		mcp251x_read_reg(spi, CNF1),  in mcp251x_do_set_bittiming()
553 		mcp251x_read_reg(spi, CNF2),  in mcp251x_do_set_bittiming()
554 		mcp251x_read_reg(spi, CNF3));  in mcp251x_do_set_bittiming()
559 static int mcp251x_setup(struct net_device *net, struct spi_device *spi)  in mcp251x_setup()  argument
563 	mcp251x_write_reg(spi, RXBCTRL(0),  in mcp251x_setup()
565 	mcp251x_write_reg(spi, RXBCTRL(1),  in mcp251x_setup()
570 static int mcp251x_hw_reset(struct spi_device *spi)  in mcp251x_hw_reset()  argument
572 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_reset()
580 	ret = mcp251x_spi_trans(spi, 1);  in mcp251x_hw_reset()
589 	while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=  in mcp251x_hw_reset()
595 			dev_err(&spi->dev,  in mcp251x_hw_reset()
603 static int mcp251x_hw_probe(struct spi_device *spi)  in mcp251x_hw_probe()  argument
608 	ret = mcp251x_hw_reset(spi);  in mcp251x_hw_probe()
612 	ctrl = mcp251x_read_reg(spi, CANCTRL);  in mcp251x_hw_probe()
614 	dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);  in mcp251x_hw_probe()
637 	struct spi_device *spi = priv->spi;  in mcp251x_stop()  local
642 	free_irq(spi->irq, priv);  in mcp251x_stop()
649 	mcp251x_write_reg(spi, CANINTE, 0x00);  in mcp251x_stop()
650 	mcp251x_write_reg(spi, CANINTF, 0x00);  in mcp251x_stop()
652 	mcp251x_write_reg(spi, TXBCTRL(0), 0);  in mcp251x_stop()
655 	mcp251x_hw_sleep(spi);  in mcp251x_stop()
687 	struct spi_device *spi = priv->spi;  in mcp251x_tx_work_handler()  local
700 			mcp251x_hw_tx(spi, frame, 0);  in mcp251x_tx_work_handler()
713 	struct spi_device *spi = priv->spi;  in mcp251x_restart_work_handler()  local
718 		mcp251x_hw_reset(spi);  in mcp251x_restart_work_handler()
719 		mcp251x_setup(net, spi);  in mcp251x_restart_work_handler()
722 			mcp251x_set_normal_mode(spi);  in mcp251x_restart_work_handler()
726 			mcp251x_set_normal_mode(spi);  in mcp251x_restart_work_handler()
729 			mcp251x_hw_sleep(spi);  in mcp251x_restart_work_handler()
736 		mcp251x_write_reg(spi, TXBCTRL(0), 0);  in mcp251x_restart_work_handler()
747 	struct spi_device *spi = priv->spi;  in mcp251x_can_ist()  local
757 		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);  in mcp251x_can_ist()
764 			mcp251x_hw_rx(spi, 0);  in mcp251x_can_ist()
768 			if (mcp251x_is_2510(spi))  in mcp251x_can_ist()
769 				mcp251x_write_bits(spi, CANINTF,  in mcp251x_can_ist()
775 			mcp251x_hw_rx(spi, 1);  in mcp251x_can_ist()
777 			if (mcp251x_is_2510(spi))  in mcp251x_can_ist()
785 			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);  in mcp251x_can_ist()
788 			mcp251x_write_bits(spi, EFLG, eflag, 0x00);  in mcp251x_can_ist()
853 				mcp251x_hw_sleep(spi);  in mcp251x_can_ist()
879 	struct spi_device *spi = priv->spi;  in mcp251x_open()  local
885 		dev_err(&spi->dev, "unable to set initial baudrate!\n");  in mcp251x_open()
896 	if (!dev_fwnode(&spi->dev))  in mcp251x_open()
899 	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,  in mcp251x_open()
900 				   flags | IRQF_ONESHOT, dev_name(&spi->dev),  in mcp251x_open()
903 		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);  in mcp251x_open()
916 	ret = mcp251x_hw_reset(spi);  in mcp251x_open()
919 	ret = mcp251x_setup(net, spi);  in mcp251x_open()
922 	ret = mcp251x_set_normal_mode(spi);  in mcp251x_open()
936 	free_irq(spi->irq, priv);  in mcp251x_open()
937 	mcp251x_hw_sleep(spi);  in mcp251x_open()
984 MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
986 static int mcp251x_can_probe(struct spi_device *spi)  in mcp251x_can_probe()  argument
988 	const void *match = device_get_match_data(&spi->dev);  in mcp251x_can_probe()
989 	struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);  in mcp251x_can_probe()
995 	clk = devm_clk_get_optional(&spi->dev, NULL);  in mcp251x_can_probe()
1028 		priv->model = spi_get_device_id(spi)->driver_data;  in mcp251x_can_probe()
1032 	spi_set_drvdata(spi, priv);  in mcp251x_can_probe()
1034 	/* Configure the SPI bus */  in mcp251x_can_probe()
1035 	spi->bits_per_word = 8;  in mcp251x_can_probe()
1036 	if (mcp251x_is_2510(spi))  in mcp251x_can_probe()
1037 		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;  in mcp251x_can_probe()
1039 		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;  in mcp251x_can_probe()
1040 	ret = spi_setup(spi);  in mcp251x_can_probe()
1044 	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");  in mcp251x_can_probe()
1045 	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");  in mcp251x_can_probe()
1056 	priv->spi = spi;  in mcp251x_can_probe()
1059 	priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,  in mcp251x_can_probe()
1066 	priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,  in mcp251x_can_probe()
1073 	SET_NETDEV_DEV(net, &spi->dev);  in mcp251x_can_probe()
1076 	ret = mcp251x_hw_probe(spi);  in mcp251x_can_probe()
1079 			dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n",  in mcp251x_can_probe()
1084 	mcp251x_hw_sleep(spi);  in mcp251x_can_probe()
1104 	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);  in mcp251x_can_probe()
1108 static int mcp251x_can_remove(struct spi_device *spi)  in mcp251x_can_remove()  argument
1110 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_remove()
1126 	struct spi_device *spi = to_spi_device(dev);  in mcp251x_can_suspend()  local
1127 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_suspend()
1131 	disable_irq(spi->irq);  in mcp251x_can_suspend()
1138 		mcp251x_hw_sleep(spi);  in mcp251x_can_suspend()
1153 	struct spi_device *spi = to_spi_device(dev);  in mcp251x_can_resume()  local
1154 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_resume()
1167 	enable_irq(spi->irq);  in mcp251x_can_resume()