2 /* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
42 #include <linux/spi/spi.h>
45 /* SPI interface instruction set */
196 /* Buffer size required for the largest SPI transfer (i.e., reading a
230 	struct spi_device *spi;  member
233 	struct mutex mcp_lock; /* SPI device lock */
263 static inline int mcp251x_is_##_model(struct spi_device *spi) \
265 	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
285  * registers via SPI is not really different conceptually than using
296 static int mcp251x_spi_trans(struct spi_device *spi, int len)  in mcp251x_spi_trans()  argument
298 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_spi_trans()
311 	ret = spi_sync(spi, &m);  in mcp251x_spi_trans()
313 		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);  in mcp251x_spi_trans()
317 static int mcp251x_spi_write(struct spi_device *spi, int len)  in mcp251x_spi_write()  argument
319 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_spi_write()
322 	ret = spi_write(spi, priv->spi_tx_buf, len);  in mcp251x_spi_write()
324 		dev_err(&spi->dev, "spi write failed: ret = %d\n", ret);  in mcp251x_spi_write()
329 static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg)  in mcp251x_read_reg()  argument
331 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_read_reg()
337 	if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {  in mcp251x_read_reg()
338 		spi_write_then_read(spi, priv->spi_tx_buf, 2, &val, 1);  in mcp251x_read_reg()
340 		mcp251x_spi_trans(spi, 3);  in mcp251x_read_reg()
347 static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2)  in mcp251x_read_2regs()  argument
349 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_read_2regs()
354 	if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {  in mcp251x_read_2regs()
357 		spi_write_then_read(spi, priv->spi_tx_buf, 2, val, 2);  in mcp251x_read_2regs()
361 		mcp251x_spi_trans(spi, 4);  in mcp251x_read_2regs()
368 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val)  in mcp251x_write_reg()  argument
370 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_write_reg()
376 	mcp251x_spi_write(spi, 3);  in mcp251x_write_reg()
379 static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2)  in mcp251x_write_2regs()  argument
381 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_write_2regs()
388 	mcp251x_spi_write(spi, 4);  in mcp251x_write_2regs()
391 static void mcp251x_write_bits(struct spi_device *spi, u8 reg,  in mcp251x_write_bits()  argument
394 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_write_bits()
401 	mcp251x_spi_write(spi, 4);  in mcp251x_write_bits()
404 static u8 mcp251x_read_stat(struct spi_device *spi)  in mcp251x_read_stat()  argument
406 	return mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK;  in mcp251x_read_stat()
453 	mcp251x_write_bits(priv->spi, BFPCTRL, val, val);  in mcp251x_gpio_request()
474 	mcp251x_write_bits(priv->spi, BFPCTRL, val, 0);  in mcp251x_gpio_free()
503 	val = mcp251x_read_reg(priv->spi, reg);  in mcp251x_gpio_get()
518 		val = mcp251x_read_reg(priv->spi, TXRTSCTRL);  in mcp251x_gpio_get_multiple()
523 		val = mcp251x_read_reg(priv->spi, BFPCTRL);  in mcp251x_gpio_get_multiple()
543 	mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);  in mcp251x_gpio_set()
567 	mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);  in mcp251x_gpio_set_multiple()
574 static void mcp251x_gpio_restore(struct spi_device *spi)  in mcp251x_gpio_restore()  argument
576 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_gpio_restore()
578 	mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl);  in mcp251x_gpio_restore()
585 	if (!device_property_present(&priv->spi->dev, "gpio-controller"))  in mcp251x_gpio_setup()
589 	gpio->label = priv->spi->modalias;  in mcp251x_gpio_setup()
590 	gpio->parent = &priv->spi->dev;  in mcp251x_gpio_setup()
604 	return devm_gpiochip_add_data(&priv->spi->dev, gpio, priv);  in mcp251x_gpio_setup()
607 static inline void mcp251x_gpio_restore(struct spi_device *spi)  in mcp251x_gpio_restore()  argument
617 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,  in mcp251x_hw_tx_frame()  argument
620 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_tx_frame()
622 	if (mcp251x_is_2510(spi)) {  in mcp251x_hw_tx_frame()
626 			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,  in mcp251x_hw_tx_frame()
630 		mcp251x_spi_write(spi, TXBDAT_OFF + len);  in mcp251x_hw_tx_frame()
634 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,  in mcp251x_hw_tx()  argument
637 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_tx()
658 	mcp251x_hw_tx_frame(spi, buf, frame->len, tx_buf_idx);  in mcp251x_hw_tx()
662 	mcp251x_spi_write(priv->spi, 1);  in mcp251x_hw_tx()
665 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,  in mcp251x_hw_rx_frame()  argument
668 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_rx_frame()
670 	if (mcp251x_is_2510(spi)) {  in mcp251x_hw_rx_frame()
674 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);  in mcp251x_hw_rx_frame()
678 			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);  in mcp251x_hw_rx_frame()
681 		if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {  in mcp251x_hw_rx_frame()
682 			spi_write_then_read(spi, priv->spi_tx_buf, 1,  in mcp251x_hw_rx_frame()
688 			mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);  in mcp251x_hw_rx_frame()
694 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)  in mcp251x_hw_rx()  argument
696 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_rx()
703 		dev_err(&spi->dev, "cannot allocate RX skb\n");  in mcp251x_hw_rx()
708 	mcp251x_hw_rx_frame(spi, buf, buf_idx);  in mcp251x_hw_rx()
743 static void mcp251x_hw_sleep(struct spi_device *spi)  in mcp251x_hw_sleep()  argument
745 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);  in mcp251x_hw_sleep()
749 static int mcp251x_hw_wake(struct spi_device *spi)  in mcp251x_hw_wake()  argument
755 	disable_irq_nosync(spi->irq);  in mcp251x_hw_wake()
756 	mcp251x_write_2regs(spi, CANINTE, CANINTE_WAKIE, CANINTF_WAKIF);  in mcp251x_hw_wake()
762 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_CONF);  in mcp251x_hw_wake()
765 	ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF,  in mcp251x_hw_wake()
769 		dev_err(&spi->dev, "MCP251x didn't enter in config mode\n");  in mcp251x_hw_wake()
774 	mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);  in mcp251x_hw_wake()
775 	enable_irq(spi->irq);  in mcp251x_hw_wake()
784 	struct spi_device *spi = priv->spi;  in mcp251x_hard_start_xmit()  local
787 		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");  in mcp251x_hard_start_xmit()
808 		/* We have to delay work since SPI I/O may sleep */  in mcp251x_do_set_mode()
822 static int mcp251x_set_normal_mode(struct spi_device *spi)  in mcp251x_set_normal_mode()  argument
824 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_set_normal_mode()
829 	mcp251x_write_reg(spi, CANINTE,  in mcp251x_set_normal_mode()
835 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);  in mcp251x_set_normal_mode()
838 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);  in mcp251x_set_normal_mode()
841 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);  in mcp251x_set_normal_mode()
844 		ret = mcp251x_read_stat_poll_timeout(spi, value, value == 0,  in mcp251x_set_normal_mode()
848 			dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n");  in mcp251x_set_normal_mode()
860 	struct spi_device *spi = priv->spi;  in mcp251x_do_set_bittiming()  local
862 	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |  in mcp251x_do_set_bittiming()
864 	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |  in mcp251x_do_set_bittiming()
869 	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,  in mcp251x_do_set_bittiming()
871 	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",  in mcp251x_do_set_bittiming()
872 		mcp251x_read_reg(spi, CNF1),  in mcp251x_do_set_bittiming()
873 		mcp251x_read_reg(spi, CNF2),  in mcp251x_do_set_bittiming()
874 		mcp251x_read_reg(spi, CNF3));  in mcp251x_do_set_bittiming()
879 static int mcp251x_setup(struct net_device *net, struct spi_device *spi)  in mcp251x_setup()  argument
883 	mcp251x_write_reg(spi, RXBCTRL(0),  in mcp251x_setup()
885 	mcp251x_write_reg(spi, RXBCTRL(1),  in mcp251x_setup()
890 static int mcp251x_hw_reset(struct spi_device *spi)  in mcp251x_hw_reset()  argument
892 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_hw_reset()
900 	ret = mcp251x_spi_write(spi, 1);  in mcp251x_hw_reset()
908 	ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF,  in mcp251x_hw_reset()
912 		dev_err(&spi->dev, "MCP251x didn't enter in conf mode after reset\n");  in mcp251x_hw_reset()
916 static int mcp251x_hw_probe(struct spi_device *spi)  in mcp251x_hw_probe()  argument
921 	ret = mcp251x_hw_reset(spi);  in mcp251x_hw_probe()
925 	ctrl = mcp251x_read_reg(spi, CANCTRL);  in mcp251x_hw_probe()
927 	dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);  in mcp251x_hw_probe()
950 	struct spi_device *spi = priv->spi;  in mcp251x_stop()  local
955 	free_irq(spi->irq, priv);  in mcp251x_stop()
960 	mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);  in mcp251x_stop()
962 	mcp251x_write_reg(spi, TXBCTRL(0), 0);  in mcp251x_stop()
965 	mcp251x_hw_sleep(spi);  in mcp251x_stop()
995 	struct spi_device *spi = priv->spi;  in mcp251x_tx_work_handler()  local
1008 			mcp251x_hw_tx(spi, frame, 0);  in mcp251x_tx_work_handler()
1021 	struct spi_device *spi = priv->spi;  in mcp251x_restart_work_handler()  local
1027 			mcp251x_hw_reset(spi);  in mcp251x_restart_work_handler()
1028 			mcp251x_setup(net, spi);  in mcp251x_restart_work_handler()
1029 			mcp251x_gpio_restore(spi);  in mcp251x_restart_work_handler()
1031 			mcp251x_hw_wake(spi);  in mcp251x_restart_work_handler()
1035 			mcp251x_set_normal_mode(spi);  in mcp251x_restart_work_handler()
1039 			mcp251x_set_normal_mode(spi);  in mcp251x_restart_work_handler()
1042 			mcp251x_hw_sleep(spi);  in mcp251x_restart_work_handler()
1049 		mcp251x_write_reg(spi, TXBCTRL(0), 0);  in mcp251x_restart_work_handler()
1060 	struct spi_device *spi = priv->spi;  in mcp251x_can_ist()  local
1070 		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);  in mcp251x_can_ist()
1074 			mcp251x_hw_rx(spi, 0);  in mcp251x_can_ist()
1078 			if (mcp251x_is_2510(spi))  in mcp251x_can_ist()
1079 				mcp251x_write_bits(spi, CANINTF,  in mcp251x_can_ist()
1087 				mcp251x_read_2regs(spi, CANINTF, &intf1, &eflag1);  in mcp251x_can_ist()
1097 			mcp251x_hw_rx(spi, 1);  in mcp251x_can_ist()
1099 			if (mcp251x_is_2510(spi))  in mcp251x_can_ist()
1110 			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);  in mcp251x_can_ist()
1113 			mcp251x_write_bits(spi, EFLG, eflag, 0x00);  in mcp251x_can_ist()
1178 				mcp251x_hw_sleep(spi);  in mcp251x_can_ist()
1203 	struct spi_device *spi = priv->spi;  in mcp251x_open()  local
1209 		dev_err(&spi->dev, "unable to set initial baudrate!\n");  in mcp251x_open()
1220 	if (!dev_fwnode(&spi->dev))  in mcp251x_open()
1223 	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,  in mcp251x_open()
1224 				   flags | IRQF_ONESHOT, dev_name(&spi->dev),  in mcp251x_open()
1227 		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);  in mcp251x_open()
1231 	ret = mcp251x_hw_wake(spi);  in mcp251x_open()
1234 	ret = mcp251x_setup(net, spi);  in mcp251x_open()
1237 	ret = mcp251x_set_normal_mode(spi);  in mcp251x_open()
1247 	free_irq(spi->irq, priv);  in mcp251x_open()
1248 	mcp251x_hw_sleep(spi);  in mcp251x_open()
1299 MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1301 static int mcp251x_can_probe(struct spi_device *spi)  in mcp251x_can_probe()  argument
1309 	clk = devm_clk_get_optional(&spi->dev, NULL);  in mcp251x_can_probe()
1315 		device_property_read_u32(&spi->dev, "clock-frequency", &freq);  in mcp251x_can_probe()
1340 	priv->model = (enum mcp251x_model)(uintptr_t)spi_get_device_match_data(spi);  in mcp251x_can_probe()
1344 	spi_set_drvdata(spi, priv);  in mcp251x_can_probe()
1346 	/* Configure the SPI bus */  in mcp251x_can_probe()
1347 	spi->bits_per_word = 8;  in mcp251x_can_probe()
1348 	if (mcp251x_is_2510(spi))  in mcp251x_can_probe()
1349 		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;  in mcp251x_can_probe()
1351 		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;  in mcp251x_can_probe()
1352 	ret = spi_setup(spi);  in mcp251x_can_probe()
1356 	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");  in mcp251x_can_probe()
1357 	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");  in mcp251x_can_probe()
1377 	priv->spi = spi;  in mcp251x_can_probe()
1380 	priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,  in mcp251x_can_probe()
1387 	priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,  in mcp251x_can_probe()
1394 	SET_NETDEV_DEV(net, &spi->dev);  in mcp251x_can_probe()
1397 	ret = mcp251x_hw_probe(spi);  in mcp251x_can_probe()
1400 			dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n",  in mcp251x_can_probe()
1405 	mcp251x_hw_sleep(spi);  in mcp251x_can_probe()
1432 	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);  in mcp251x_can_probe()
1436 static void mcp251x_can_remove(struct spi_device *spi)  in mcp251x_can_remove()  argument
1438 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_remove()
1455 	struct spi_device *spi = to_spi_device(dev);  in mcp251x_can_suspend()  local
1456 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_suspend()
1460 	disable_irq(spi->irq);  in mcp251x_can_suspend()
1467 		mcp251x_hw_sleep(spi);  in mcp251x_can_suspend()
1482 	struct spi_device *spi = to_spi_device(dev);  in mcp251x_can_resume()  local
1483 	struct mcp251x_priv *priv = spi_get_drvdata(spi);  in mcp251x_can_resume()
1496 	enable_irq(spi->irq);  in mcp251x_can_resume()