drivers/net/can/m_can/tcan4x5x-core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // SPI to CAN driver for the Texas Instruments TCAN4x5x
 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/

 #include "tcan4x5x.h"

 #define TCAN4X5X_EXT_CLK_DEF 40000000

 #define TCAN4X5X_DEV_ID0 0x00
 #define TCAN4X5X_DEV_ID1 0x04
 #define TCAN4X5X_REV 0x08
 #define TCAN4X5X_STATUS 0x0C
 #define TCAN4X5X_ERROR_STATUS 0x10
 #define TCAN4X5X_CONTROL 0x14

 #define TCAN4X5X_CONFIG 0x800
 #define TCAN4X5X_TS_PRESCALE 0x804
 #define TCAN4X5X_TEST_REG 0x808
 #define TCAN4X5X_INT_FLAGS 0x820
 #define TCAN4X5X_MCAN_INT_REG 0x824
 #define TCAN4X5X_INT_EN 0x830

 /* Interrupt bits */
 #define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
 #define TCAN4X5X_CANHCANL_INT_EN BIT(29)
 #define TCAN4X5X_CANHBAT_INT_EN BIT(28)
 #define TCAN4X5X_CANLGND_INT_EN BIT(27)
 #define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
 #define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
 #define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
 #define TCAN4X5X_UVSUP_INT_EN BIT(22)
 #define TCAN4X5X_UVIO_INT_EN BIT(21)
 #define TCAN4X5X_TSD_INT_EN BIT(19)
 #define TCAN4X5X_ECCERR_INT_EN BIT(16)
 #define TCAN4X5X_CANINT_INT_EN BIT(15)
 #define TCAN4X5X_LWU_INT_EN BIT(14)
 #define TCAN4X5X_CANSLNT_INT_EN BIT(10)
 #define TCAN4X5X_CANDOM_INT_EN BIT(8)
 #define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
 #define TCAN4X5X_BUS_FAULT BIT(4)
 #define TCAN4X5X_MCAN_INT BIT(1)
 #define TCAN4X5X_ENABLE_TCAN_INT \
 	(TCAN4X5X_MCAN_INT | TCAN4X5X_BUS_FAULT | \
 	 TCAN4X5X_CANBUS_ERR_INT_EN | TCAN4X5X_CANINT_INT_EN)

 /* MCAN Interrupt bits */
 #define TCAN4X5X_MCAN_IR_ARA BIT(29)
 #define TCAN4X5X_MCAN_IR_PED BIT(28)
 #define TCAN4X5X_MCAN_IR_PEA BIT(27)
 #define TCAN4X5X_MCAN_IR_WD BIT(26)
 #define TCAN4X5X_MCAN_IR_BO BIT(25)
 #define TCAN4X5X_MCAN_IR_EW BIT(24)
 #define TCAN4X5X_MCAN_IR_EP BIT(23)
 #define TCAN4X5X_MCAN_IR_ELO BIT(22)
 #define TCAN4X5X_MCAN_IR_BEU BIT(21)
 #define TCAN4X5X_MCAN_IR_BEC BIT(20)
 #define TCAN4X5X_MCAN_IR_DRX BIT(19)
 #define TCAN4X5X_MCAN_IR_TOO BIT(18)
 #define TCAN4X5X_MCAN_IR_MRAF BIT(17)
 #define TCAN4X5X_MCAN_IR_TSW BIT(16)
 #define TCAN4X5X_MCAN_IR_TEFL BIT(15)
 #define TCAN4X5X_MCAN_IR_TEFF BIT(14)
 #define TCAN4X5X_MCAN_IR_TEFW BIT(13)
 #define TCAN4X5X_MCAN_IR_TEFN BIT(12)
 #define TCAN4X5X_MCAN_IR_TFE BIT(11)
 #define TCAN4X5X_MCAN_IR_TCF BIT(10)
 #define TCAN4X5X_MCAN_IR_TC BIT(9)
 #define TCAN4X5X_MCAN_IR_HPM BIT(8)
 #define TCAN4X5X_MCAN_IR_RF1L BIT(7)
 #define TCAN4X5X_MCAN_IR_RF1F BIT(6)
 #define TCAN4X5X_MCAN_IR_RF1W BIT(5)
 #define TCAN4X5X_MCAN_IR_RF1N BIT(4)
 #define TCAN4X5X_MCAN_IR_RF0L BIT(3)
 #define TCAN4X5X_MCAN_IR_RF0F BIT(2)
 #define TCAN4X5X_MCAN_IR_RF0W BIT(1)
 #define TCAN4X5X_MCAN_IR_RF0N BIT(0)
 #define TCAN4X5X_ENABLE_MCAN_INT \
 	(TCAN4X5X_MCAN_IR_TC | TCAN4X5X_MCAN_IR_RF0N | \
 	 TCAN4X5X_MCAN_IR_RF1N | TCAN4X5X_MCAN_IR_RF0F | \
 	 TCAN4X5X_MCAN_IR_RF1F)

 #define TCAN4X5X_MRAM_START 0x8000
 #define TCAN4X5X_MCAN_OFFSET 0x1000

 #define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
 #define TCAN4X5X_SET_ALL_INT 0xffffffff

 #define TCAN4X5X_MODE_SEL_MASK (BIT(7) | BIT(6))
 #define TCAN4X5X_MODE_SLEEP 0x00
 #define TCAN4X5X_MODE_STANDBY BIT(6)
 #define TCAN4X5X_MODE_NORMAL BIT(7)

 #define TCAN4X5X_DISABLE_WAKE_MSK	(BIT(31) | BIT(30))
 #define TCAN4X5X_DISABLE_INH_MSK	BIT(9)

 #define TCAN4X5X_SW_RESET BIT(2)

 #define TCAN4X5X_MCAN_CONFIGURED BIT(5)
 #define TCAN4X5X_WATCHDOG_EN BIT(3)
 #define TCAN4X5X_WD_60_MS_TIMER 0
 #define TCAN4X5X_WD_600_MS_TIMER BIT(28)
 #define TCAN4X5X_WD_3_S_TIMER BIT(29)
 #define TCAN4X5X_WD_6_S_TIMER (BIT(28) | BIT(29))

 static inline struct tcan4x5x_priv *cdev_to_priv(struct m_can_classdev *cdev)
 {
 	return container_of(cdev, struct tcan4x5x_priv, cdev);
 }

 static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
 {
 	int wake_state = 0;

 	if (priv->device_state_gpio)
 		wake_state = gpiod_get_value(priv->device_state_gpio);

 	if (priv->device_wake_gpio && wake_state) {
 		gpiod_set_value(priv->device_wake_gpio, 0);
 		usleep_range(5, 50);
 		gpiod_set_value(priv->device_wake_gpio, 1);
 	}
 }

 static int tcan4x5x_reset(struct tcan4x5x_priv *priv)
 {
 	int ret = 0;

 	if (priv->reset_gpio) {
 		gpiod_set_value(priv->reset_gpio, 1);

 		/* tpulse_width minimum 30us */
 		usleep_range(30, 100);
 		gpiod_set_value(priv->reset_gpio, 0);
 	} else {
 		ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG,
 				   TCAN4X5X_SW_RESET);
 		if (ret)
 			return ret;
 	}

 	usleep_range(700, 1000);

 	return ret;
 }

 static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
 {
 	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 	u32 val;

 	regmap_read(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, &val);

 	return val;
 }

 static int tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset,
 			      void *val, size_t val_count)
 {
 	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

 	return regmap_bulk_read(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
 }

 static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
 {
 	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

 	return regmap_write(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, val);
 }

 static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
 			       int addr_offset, const void *val, size_t val_count)
 {
 	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

 	return regmap_bulk_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
 }

 static int tcan4x5x_power_enable(struct regulator *reg, int enable)
 {
 	if (IS_ERR_OR_NULL(reg))
 		return 0;

 	if (enable)
 		return regulator_enable(reg);
 	else
 		return regulator_disable(reg);
 }

 static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
 				   int reg, int val)
 {
 	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

 	return regmap_write(priv->regmap, reg, val);
 }

 static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
 {
 	int ret;

 	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
 				      TCAN4X5X_CLEAR_ALL_INT);
 	if (ret)
 		return ret;

 	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
 				      TCAN4X5X_ENABLE_MCAN_INT);
 	if (ret)
 		return ret;

 	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
 				      TCAN4X5X_CLEAR_ALL_INT);
 	if (ret)
 		return ret;

 	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
 				       TCAN4X5X_CLEAR_ALL_INT);
 }

 static int tcan4x5x_init(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 	int ret;

 	tcan4x5x_check_wake(tcan4x5x);

 	ret = tcan4x5x_clear_interrupts(cdev);
 	if (ret)
 		return ret;

 	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
 				      TCAN4X5X_ENABLE_TCAN_INT);
 	if (ret)
 		return ret;

 	/* Zero out the MCAN buffers */
 	ret = m_can_init_ram(cdev);
 	if (ret)
 		return ret;

 	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
 	if (ret)
 		return ret;

 	return ret;
 }

 static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);

 	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				  TCAN4X5X_DISABLE_WAKE_MSK, 0x00);
 }

 static int tcan4x5x_disable_state(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);

 	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				  TCAN4X5X_DISABLE_INH_MSK, 0x01);
 }

 static int tcan4x5x_get_gpios(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 	int ret;

 	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
 						    GPIOD_OUT_HIGH);
 	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
 		if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;

 		tcan4x5x_disable_wake(cdev);
 	}

 	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
 						       GPIOD_OUT_LOW);
 	if (IS_ERR(tcan4x5x->reset_gpio))
 		tcan4x5x->reset_gpio = NULL;

 	ret = tcan4x5x_reset(tcan4x5x);
 	if (ret)
 		return ret;

 	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
 							      "device-state",
 							      GPIOD_IN);
 	if (IS_ERR(tcan4x5x->device_state_gpio)) {
 		tcan4x5x->device_state_gpio = NULL;
 		tcan4x5x_disable_state(cdev);
 	}

 	return 0;
 }

 static struct m_can_ops tcan4x5x_ops = {
 	.init = tcan4x5x_init,
 	.read_reg = tcan4x5x_read_reg,
 	.write_reg = tcan4x5x_write_reg,
 	.write_fifo = tcan4x5x_write_fifo,
 	.read_fifo = tcan4x5x_read_fifo,
 	.clear_interrupts = tcan4x5x_clear_interrupts,
 };

 static int tcan4x5x_can_probe(struct spi_device *spi)
 {
 	struct tcan4x5x_priv *priv;
 	struct m_can_classdev *mcan_class;
 	int freq, ret;

 	mcan_class = m_can_class_allocate_dev(&spi->dev,
 					      sizeof(struct tcan4x5x_priv));
 	if (!mcan_class)
 		return -ENOMEM;

 	priv = cdev_to_priv(mcan_class);

 	priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
 	if (PTR_ERR(priv->power) == -EPROBE_DEFER) {
 		ret = -EPROBE_DEFER;
 		goto out_m_can_class_free_dev;
 	} else {
 		priv->power = NULL;
 	}

 	m_can_class_get_clocks(mcan_class);
 	if (IS_ERR(mcan_class->cclk)) {
 		dev_err(&spi->dev, "no CAN clock source defined\n");
 		freq = TCAN4X5X_EXT_CLK_DEF;
 	} else {
 		freq = clk_get_rate(mcan_class->cclk);
 	}

 	/* Sanity check */
 	if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF) {
 		ret = -ERANGE;
 		goto out_m_can_class_free_dev;
 	}

 	priv->spi = spi;

 	mcan_class->pm_clock_support = 0;
 	mcan_class->can.clock.freq = freq;
 	mcan_class->dev = &spi->dev;
 	mcan_class->ops = &tcan4x5x_ops;
 	mcan_class->is_peripheral = true;
 	mcan_class->net->irq = spi->irq;

 	spi_set_drvdata(spi, priv);

 	/* Configure the SPI bus */
 	spi->bits_per_word = 8;
 	ret = spi_setup(spi);
 	if (ret)
 		goto out_m_can_class_free_dev;

 	ret = tcan4x5x_regmap_init(priv);
 	if (ret)
 		goto out_m_can_class_free_dev;

 	ret = tcan4x5x_power_enable(priv->power, 1);
 	if (ret)
 		goto out_m_can_class_free_dev;

 	ret = tcan4x5x_get_gpios(mcan_class);
 	if (ret)
 		goto out_power;

 	ret = tcan4x5x_init(mcan_class);
 	if (ret)
 		goto out_power;

 	ret = m_can_class_register(mcan_class);
 	if (ret)
 		goto out_power;

 	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
 	return 0;

 out_power:
 	tcan4x5x_power_enable(priv->power, 0);
  out_m_can_class_free_dev:
 	m_can_class_free_dev(mcan_class->net);
 	return ret;
 }

 static int tcan4x5x_can_remove(struct spi_device *spi)
 {
 	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);

 	m_can_class_unregister(&priv->cdev);

 	tcan4x5x_power_enable(priv->power, 0);

 	m_can_class_free_dev(priv->cdev.net);

 	return 0;
 }

 static const struct of_device_id tcan4x5x_of_match[] = {
 	{
 		.compatible = "ti,tcan4x5x",
 	}, {
 		/* sentinel */
 	},
 };
 MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);

 static const struct spi_device_id tcan4x5x_id_table[] = {
 	{
 		.name = "tcan4x5x",
 	}, {
 		/* sentinel */
 	},
 };
 MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);

 static struct spi_driver tcan4x5x_can_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.of_match_table = tcan4x5x_of_match,
 		.pm = NULL,
 	},
 	.id_table = tcan4x5x_id_table,
 	.probe = tcan4x5x_can_probe,
 	.remove = tcan4x5x_can_remove,
 };
 module_spi_driver(tcan4x5x_can_driver);

 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	// SPI to CAN driver for the Texas Instruments TCAN4x5x
	// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/

	#include "tcan4x5x.h"

	#define TCAN4X5X_EXT_CLK_DEF 40000000

	#define TCAN4X5X_DEV_ID0 0x00
	#define TCAN4X5X_DEV_ID1 0x04
	#define TCAN4X5X_REV 0x08
	#define TCAN4X5X_STATUS 0x0C
	#define TCAN4X5X_ERROR_STATUS 0x10
	#define TCAN4X5X_CONTROL 0x14

	#define TCAN4X5X_CONFIG 0x800
	#define TCAN4X5X_TS_PRESCALE 0x804
	#define TCAN4X5X_TEST_REG 0x808
	#define TCAN4X5X_INT_FLAGS 0x820
	#define TCAN4X5X_MCAN_INT_REG 0x824
	#define TCAN4X5X_INT_EN 0x830

	/* Interrupt bits */
	#define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
	#define TCAN4X5X_CANHCANL_INT_EN BIT(29)
	#define TCAN4X5X_CANHBAT_INT_EN BIT(28)
	#define TCAN4X5X_CANLGND_INT_EN BIT(27)
	#define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
	#define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
	#define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
	#define TCAN4X5X_UVSUP_INT_EN BIT(22)
	#define TCAN4X5X_UVIO_INT_EN BIT(21)
	#define TCAN4X5X_TSD_INT_EN BIT(19)
	#define TCAN4X5X_ECCERR_INT_EN BIT(16)
	#define TCAN4X5X_CANINT_INT_EN BIT(15)
	#define TCAN4X5X_LWU_INT_EN BIT(14)
	#define TCAN4X5X_CANSLNT_INT_EN BIT(10)
	#define TCAN4X5X_CANDOM_INT_EN BIT(8)
	#define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
	#define TCAN4X5X_BUS_FAULT BIT(4)
	#define TCAN4X5X_MCAN_INT BIT(1)
	#define TCAN4X5X_ENABLE_TCAN_INT \
	(TCAN4X5X_MCAN_INT \| TCAN4X5X_BUS_FAULT \| \
	TCAN4X5X_CANBUS_ERR_INT_EN \| TCAN4X5X_CANINT_INT_EN)

	/* MCAN Interrupt bits */
	#define TCAN4X5X_MCAN_IR_ARA BIT(29)
	#define TCAN4X5X_MCAN_IR_PED BIT(28)
	#define TCAN4X5X_MCAN_IR_PEA BIT(27)
	#define TCAN4X5X_MCAN_IR_WD BIT(26)
	#define TCAN4X5X_MCAN_IR_BO BIT(25)
	#define TCAN4X5X_MCAN_IR_EW BIT(24)
	#define TCAN4X5X_MCAN_IR_EP BIT(23)
	#define TCAN4X5X_MCAN_IR_ELO BIT(22)
	#define TCAN4X5X_MCAN_IR_BEU BIT(21)
	#define TCAN4X5X_MCAN_IR_BEC BIT(20)
	#define TCAN4X5X_MCAN_IR_DRX BIT(19)
	#define TCAN4X5X_MCAN_IR_TOO BIT(18)
	#define TCAN4X5X_MCAN_IR_MRAF BIT(17)
	#define TCAN4X5X_MCAN_IR_TSW BIT(16)
	#define TCAN4X5X_MCAN_IR_TEFL BIT(15)
	#define TCAN4X5X_MCAN_IR_TEFF BIT(14)
	#define TCAN4X5X_MCAN_IR_TEFW BIT(13)
	#define TCAN4X5X_MCAN_IR_TEFN BIT(12)
	#define TCAN4X5X_MCAN_IR_TFE BIT(11)
	#define TCAN4X5X_MCAN_IR_TCF BIT(10)
	#define TCAN4X5X_MCAN_IR_TC BIT(9)
	#define TCAN4X5X_MCAN_IR_HPM BIT(8)
	#define TCAN4X5X_MCAN_IR_RF1L BIT(7)
	#define TCAN4X5X_MCAN_IR_RF1F BIT(6)
	#define TCAN4X5X_MCAN_IR_RF1W BIT(5)
	#define TCAN4X5X_MCAN_IR_RF1N BIT(4)
	#define TCAN4X5X_MCAN_IR_RF0L BIT(3)
	#define TCAN4X5X_MCAN_IR_RF0F BIT(2)
	#define TCAN4X5X_MCAN_IR_RF0W BIT(1)
	#define TCAN4X5X_MCAN_IR_RF0N BIT(0)
	#define TCAN4X5X_ENABLE_MCAN_INT \
	(TCAN4X5X_MCAN_IR_TC \| TCAN4X5X_MCAN_IR_RF0N \| \
	TCAN4X5X_MCAN_IR_RF1N \| TCAN4X5X_MCAN_IR_RF0F \| \
	TCAN4X5X_MCAN_IR_RF1F)

	#define TCAN4X5X_MRAM_START 0x8000
	#define TCAN4X5X_MCAN_OFFSET 0x1000

	#define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
	#define TCAN4X5X_SET_ALL_INT 0xffffffff

	#define TCAN4X5X_MODE_SEL_MASK (BIT(7) \| BIT(6))
	#define TCAN4X5X_MODE_SLEEP 0x00
	#define TCAN4X5X_MODE_STANDBY BIT(6)
	#define TCAN4X5X_MODE_NORMAL BIT(7)

	#define TCAN4X5X_DISABLE_WAKE_MSK (BIT(31) \| BIT(30))
	#define TCAN4X5X_DISABLE_INH_MSK BIT(9)

	#define TCAN4X5X_SW_RESET BIT(2)

	#define TCAN4X5X_MCAN_CONFIGURED BIT(5)
	#define TCAN4X5X_WATCHDOG_EN BIT(3)
	#define TCAN4X5X_WD_60_MS_TIMER 0
	#define TCAN4X5X_WD_600_MS_TIMER BIT(28)
	#define TCAN4X5X_WD_3_S_TIMER BIT(29)
	#define TCAN4X5X_WD_6_S_TIMER (BIT(28) \| BIT(29))

	static inline struct tcan4x5x_priv cdev_to_priv(struct m_can_classdev cdev)
	{
	return container_of(cdev, struct tcan4x5x_priv, cdev);
	}

	static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
	{
	int wake_state = 0;

	if (priv->device_state_gpio)
	wake_state = gpiod_get_value(priv->device_state_gpio);

	if (priv->device_wake_gpio && wake_state) {
	gpiod_set_value(priv->device_wake_gpio, 0);
	usleep_range(5, 50);
	gpiod_set_value(priv->device_wake_gpio, 1);
	}
	}

	static int tcan4x5x_reset(struct tcan4x5x_priv *priv)
	{
	int ret = 0;

	if (priv->reset_gpio) {
	gpiod_set_value(priv->reset_gpio, 1);

	/* tpulse_width minimum 30us */
	usleep_range(30, 100);
	gpiod_set_value(priv->reset_gpio, 0);
	} else {
	ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG,
	TCAN4X5X_SW_RESET);
	if (ret)
	return ret;
	}

	usleep_range(700, 1000);

	return ret;
	}

	static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
	{
	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
	u32 val;

	regmap_read(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, &val);

	return val;
	}

	static int tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset,
	void *val, size_t val_count)
	{
	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

	return regmap_bulk_read(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
	}

	static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
	{
	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

	return regmap_write(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, val);
	}

	static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
	int addr_offset, const void *val, size_t val_count)
	{
	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

	return regmap_bulk_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
	}

	static int tcan4x5x_power_enable(struct regulator *reg, int enable)
	{
	if (IS_ERR_OR_NULL(reg))
	return 0;

	if (enable)
	return regulator_enable(reg);
	else
	return regulator_disable(reg);
	}

	static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
	int reg, int val)
	{
	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);

	return regmap_write(priv->regmap, reg, val);
	}

	static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
	{
	int ret;

	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
	TCAN4X5X_CLEAR_ALL_INT);
	if (ret)
	return ret;

	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
	TCAN4X5X_ENABLE_MCAN_INT);
	if (ret)
	return ret;

	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
	TCAN4X5X_CLEAR_ALL_INT);
	if (ret)
	return ret;

	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
	TCAN4X5X_CLEAR_ALL_INT);
	}

	static int tcan4x5x_init(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
	int ret;

	tcan4x5x_check_wake(tcan4x5x);

	ret = tcan4x5x_clear_interrupts(cdev);
	if (ret)
	return ret;

	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
	TCAN4X5X_ENABLE_TCAN_INT);
	if (ret)
	return ret;

	/* Zero out the MCAN buffers */
	ret = m_can_init_ram(cdev);
	if (ret)
	return ret;

	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
	TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
	if (ret)
	return ret;

	return ret;
	}

	static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);

	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
	TCAN4X5X_DISABLE_WAKE_MSK, 0x00);
	}

	static int tcan4x5x_disable_state(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);

	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
	TCAN4X5X_DISABLE_INH_MSK, 0x01);
	}

	static int tcan4x5x_get_gpios(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
	int ret;

	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
	GPIOD_OUT_HIGH);
	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
	if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
	return -EPROBE_DEFER;

	tcan4x5x_disable_wake(cdev);
	}

	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
	GPIOD_OUT_LOW);
	if (IS_ERR(tcan4x5x->reset_gpio))
	tcan4x5x->reset_gpio = NULL;

	ret = tcan4x5x_reset(tcan4x5x);
	if (ret)
	return ret;

	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
	"device-state",
	GPIOD_IN);
	if (IS_ERR(tcan4x5x->device_state_gpio)) {
	tcan4x5x->device_state_gpio = NULL;
	tcan4x5x_disable_state(cdev);
	}

	return 0;
	}

	static struct m_can_ops tcan4x5x_ops = {
	.init = tcan4x5x_init,
	.read_reg = tcan4x5x_read_reg,
	.write_reg = tcan4x5x_write_reg,
	.write_fifo = tcan4x5x_write_fifo,
	.read_fifo = tcan4x5x_read_fifo,
	.clear_interrupts = tcan4x5x_clear_interrupts,
	};

	static int tcan4x5x_can_probe(struct spi_device *spi)
	{
	struct tcan4x5x_priv *priv;
	struct m_can_classdev *mcan_class;
	int freq, ret;

	mcan_class = m_can_class_allocate_dev(&spi->dev,
	sizeof(struct tcan4x5x_priv));
	if (!mcan_class)
	return -ENOMEM;

	priv = cdev_to_priv(mcan_class);

	priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
	if (PTR_ERR(priv->power) == -EPROBE_DEFER) {
	ret = -EPROBE_DEFER;
	goto out_m_can_class_free_dev;
	} else {
	priv->power = NULL;
	}

	m_can_class_get_clocks(mcan_class);
	if (IS_ERR(mcan_class->cclk)) {
	dev_err(&spi->dev, "no CAN clock source defined\n");
	freq = TCAN4X5X_EXT_CLK_DEF;
	} else {
	freq = clk_get_rate(mcan_class->cclk);
	}

	/* Sanity check */
	if (freq < 20000000 \|\| freq > TCAN4X5X_EXT_CLK_DEF) {
	ret = -ERANGE;
	goto out_m_can_class_free_dev;
	}

	priv->spi = spi;

	mcan_class->pm_clock_support = 0;
	mcan_class->can.clock.freq = freq;
	mcan_class->dev = &spi->dev;
	mcan_class->ops = &tcan4x5x_ops;
	mcan_class->is_peripheral = true;
	mcan_class->net->irq = spi->irq;

	spi_set_drvdata(spi, priv);

	/* Configure the SPI bus */
	spi->bits_per_word = 8;
	ret = spi_setup(spi);
	if (ret)
	goto out_m_can_class_free_dev;

	ret = tcan4x5x_regmap_init(priv);
	if (ret)
	goto out_m_can_class_free_dev;

	ret = tcan4x5x_power_enable(priv->power, 1);
	if (ret)
	goto out_m_can_class_free_dev;

	ret = tcan4x5x_get_gpios(mcan_class);
	if (ret)
	goto out_power;

	ret = tcan4x5x_init(mcan_class);
	if (ret)
	goto out_power;

	ret = m_can_class_register(mcan_class);
	if (ret)
	goto out_power;

	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
	return 0;

	out_power:
	tcan4x5x_power_enable(priv->power, 0);
	out_m_can_class_free_dev:
	m_can_class_free_dev(mcan_class->net);
	return ret;
	}

	static int tcan4x5x_can_remove(struct spi_device *spi)
	{
	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);

	m_can_class_unregister(&priv->cdev);

	tcan4x5x_power_enable(priv->power, 0);

	m_can_class_free_dev(priv->cdev.net);

	return 0;
	}

	static const struct of_device_id tcan4x5x_of_match[] = {
	{
	.compatible = "ti,tcan4x5x",
	}, {
	/* sentinel */
	},
	};
	MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);

	static const struct spi_device_id tcan4x5x_id_table[] = {
	{
	.name = "tcan4x5x",
	}, {
	/* sentinel */
	},
	};
	MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);

	static struct spi_driver tcan4x5x_can_driver = {
	.driver = {
	.name = KBUILD_MODNAME,
	.of_match_table = tcan4x5x_of_match,
	.pm = NULL,
	},
	.id_table = tcan4x5x_id_table,
	.probe = tcan4x5x_can_probe,
	.remove = tcan4x5x_can_remove,
	};
	module_spi_driver(tcan4x5x_can_driver);

	MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
	MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
	MODULE_LICENSE("GPL v2");