drivers/net/can/m_can/tcan4x5x.c - third_party/kernel - 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 <linux/regmap.h>
 #include <linux/spi/spi.h>

 #include <linux/regulator/consumer.h>
 #include <linux/gpio/consumer.h>

 #include "m_can.h"

 #define DEVICE_NAME "tcan4x5x"
 #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_MAX_REGISTER 0x8ffc

 #define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
 #define TCAN4X5X_SET_ALL_INT 0xffffffff

 #define TCAN4X5X_WRITE_CMD (0x61 << 24)
 #define TCAN4X5X_READ_CMD (0x41 << 24)

 #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_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))

 struct tcan4x5x_priv {
 	struct regmap *regmap;
 	struct spi_device *spi;

 	struct m_can_classdev *mcan_dev;

 	struct gpio_desc *reset_gpio;
 	struct gpio_desc *device_wake_gpio;
 	struct gpio_desc *device_state_gpio;
 	struct regulator *power;

 	/* Register based ip */
 	int mram_start;
 	int reg_offset;
 };

 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 int regmap_spi_gather_write(void *context, const void *reg,
 				   size_t reg_len, const void *val,
 				   size_t val_len)
 {
 	struct device *dev = context;
 	struct spi_device *spi = to_spi_device(dev);
 	struct spi_message m;
 	u32 addr;
 	struct spi_transfer t[2] = {
 		{ .tx_buf = &addr, .len = reg_len, .cs_change = 0,},
 		{ .tx_buf = val, .len = val_len, },
 	};

 	addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 2;

 	spi_message_init(&m);
 	spi_message_add_tail(&t[0], &m);
 	spi_message_add_tail(&t[1], &m);

 	return spi_sync(spi, &m);
 }

 static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
 {
 	u16 *reg = (u16 *)(data);
 	const u32 *val = data + 4;

 	return regmap_spi_gather_write(context, reg, 4, val, count - 4);
 }

 static int regmap_spi_async_write(void *context,
 				  const void *reg, size_t reg_len,
 				  const void *val, size_t val_len,
 				  struct regmap_async *a)
 {
 	return -ENOTSUPP;
 }

 static struct regmap_async *regmap_spi_async_alloc(void)
 {
 	return NULL;
 }

 static int tcan4x5x_regmap_read(void *context,
 				const void *reg, size_t reg_size,
 				void *val, size_t val_size)
 {
 	struct device *dev = context;
 	struct spi_device *spi = to_spi_device(dev);

 	u32 addr = TCAN4X5X_READ_CMD | (*((u16 *)reg) << 8) | val_size >> 2;

 	return spi_write_then_read(spi, &addr, reg_size, (u32 *)val, val_size);
 }

 static struct regmap_bus tcan4x5x_bus = {
 	.write = tcan4x5x_regmap_write,
 	.gather_write = regmap_spi_gather_write,
 	.async_write = regmap_spi_async_write,
 	.async_alloc = regmap_spi_async_alloc,
 	.read = tcan4x5x_regmap_read,
 	.read_flag_mask = 0x00,
 	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
 	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
 };

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

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

 	return val;
 }

 static u32 tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset)
 {
 	struct tcan4x5x_priv *priv = cdev->device_data;
 	u32 val;

 	regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);

 	return val;
 }

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

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

 static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
 			       int addr_offset, int val)
 {
 	struct tcan4x5x_priv *priv = cdev->device_data;

 	return regmap_write(priv->regmap, priv->mram_start + addr_offset, val);
 }

 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->device_data;

 	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;

 	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
 				      TCAN4X5X_CLEAR_ALL_INT);
 	if (ret)
 		return ret;

 	return ret;
 }

 static int tcan4x5x_init(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
 	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 */
 	m_can_init_ram(cdev);

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

 	return ret;
 }

 static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
 	int ret;

 	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
 						    GPIOD_OUT_HIGH);
 	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
 		dev_err(cdev->dev, "device-wake gpio not defined\n");
 		return -EINVAL;
 	}

 	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->power = devm_regulator_get_optional(cdev->dev,
 						      "vsup");
 	if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;

 	return 0;
 }

 static const struct regmap_config tcan4x5x_regmap = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.cache_type = REGCACHE_NONE,
 	.max_register = TCAN4X5X_MAX_REGISTER,
 };

 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);
 	if (!mcan_class)
 		return -ENOMEM;

 	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	mcan_class->device_data = priv;

 	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)
 		return -ERANGE;

 	priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
 	priv->mram_start = TCAN4X5X_MRAM_START;
 	priv->spi = spi;
 	priv->mcan_dev = mcan_class;

 	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);

 	ret = tcan4x5x_parse_config(mcan_class);
 	if (ret)
 		goto out_clk;

 	/* Configure the SPI bus */
 	spi->bits_per_word = 32;
 	ret = spi_setup(spi);
 	if (ret)
 		goto out_clk;

 	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
 					&spi->dev, &tcan4x5x_regmap);
 	if (IS_ERR(priv->regmap)) {
 		ret = PTR_ERR(priv->regmap);
 		goto out_clk;
 	}

 	tcan4x5x_power_enable(priv->power, 1);

 	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_clk:
 	if (!IS_ERR(mcan_class->cclk)) {
 		clk_disable_unprepare(mcan_class->cclk);
 		clk_disable_unprepare(mcan_class->hclk);
 	}

 	dev_err(&spi->dev, "Probe failed, err=%d\n", ret);
 	return ret;
 }

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

 	m_can_class_unregister(priv->mcan_dev);

 	tcan4x5x_power_enable(priv->power, 0);

 	return 0;
 }

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

 static const struct spi_device_id tcan4x5x_id_table[] = {
 	{
 		.name		= "tcan4x5x",
 		.driver_data	= 0,
 	},
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);

 static struct spi_driver tcan4x5x_can_driver = {
 	.driver = {
 		.name = DEVICE_NAME,
 		.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 <linux/regmap.h>
	#include <linux/spi/spi.h>

	#include <linux/regulator/consumer.h>
	#include <linux/gpio/consumer.h>

	#include "m_can.h"

	#define DEVICE_NAME "tcan4x5x"
	#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_MAX_REGISTER 0x8ffc

	#define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
	#define TCAN4X5X_SET_ALL_INT 0xffffffff

	#define TCAN4X5X_WRITE_CMD (0x61 << 24)
	#define TCAN4X5X_READ_CMD (0x41 << 24)

	#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_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))

	struct tcan4x5x_priv {
	struct regmap *regmap;
	struct spi_device *spi;

	struct m_can_classdev *mcan_dev;

	struct gpio_desc *reset_gpio;
	struct gpio_desc *device_wake_gpio;
	struct gpio_desc *device_state_gpio;
	struct regulator *power;

	/* Register based ip */
	int mram_start;
	int reg_offset;
	};

	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 int regmap_spi_gather_write(void context, const void reg,
	size_t reg_len, const void *val,
	size_t val_len)
	{
	struct device *dev = context;
	struct spi_device *spi = to_spi_device(dev);
	struct spi_message m;
	u32 addr;
	struct spi_transfer t[2] = {
	{ .tx_buf = &addr, .len = reg_len, .cs_change = 0,},
	{ .tx_buf = val, .len = val_len, },
	};

	addr = TCAN4X5X_WRITE_CMD \| (((u16 )reg) << 8) \| val_len >> 2;

	spi_message_init(&m);
	spi_message_add_tail(&t[0], &m);
	spi_message_add_tail(&t[1], &m);

	return spi_sync(spi, &m);
	}

	static int tcan4x5x_regmap_write(void context, const void data, size_t count)
	{
	u16 reg = (u16 )(data);
	const u32 *val = data + 4;

	return regmap_spi_gather_write(context, reg, 4, val, count - 4);
	}

	static int regmap_spi_async_write(void *context,
	const void *reg, size_t reg_len,
	const void *val, size_t val_len,
	struct regmap_async *a)
	{
	return -ENOTSUPP;
	}

	static struct regmap_async *regmap_spi_async_alloc(void)
	{
	return NULL;
	}

	static int tcan4x5x_regmap_read(void *context,
	const void *reg, size_t reg_size,
	void *val, size_t val_size)
	{
	struct device *dev = context;
	struct spi_device *spi = to_spi_device(dev);

	u32 addr = TCAN4X5X_READ_CMD \| (((u16 )reg) << 8) \| val_size >> 2;

	return spi_write_then_read(spi, &addr, reg_size, (u32 *)val, val_size);
	}

	static struct regmap_bus tcan4x5x_bus = {
	.write = tcan4x5x_regmap_write,
	.gather_write = regmap_spi_gather_write,
	.async_write = regmap_spi_async_write,
	.async_alloc = regmap_spi_async_alloc,
	.read = tcan4x5x_regmap_read,
	.read_flag_mask = 0x00,
	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
	};

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

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

	return val;
	}

	static u32 tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset)
	{
	struct tcan4x5x_priv *priv = cdev->device_data;
	u32 val;

	regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);

	return val;
	}

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

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

	static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
	int addr_offset, int val)
	{
	struct tcan4x5x_priv *priv = cdev->device_data;

	return regmap_write(priv->regmap, priv->mram_start + addr_offset, val);
	}

	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->device_data;

	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;

	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
	TCAN4X5X_CLEAR_ALL_INT);
	if (ret)
	return ret;

	return ret;
	}

	static int tcan4x5x_init(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
	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 */
	m_can_init_ram(cdev);

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

	return ret;
	}

	static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
	{
	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
	int ret;

	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
	GPIOD_OUT_HIGH);
	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
	dev_err(cdev->dev, "device-wake gpio not defined\n");
	return -EINVAL;
	}

	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->power = devm_regulator_get_optional(cdev->dev,
	"vsup");
	if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
	return -EPROBE_DEFER;

	return 0;
	}

	static const struct regmap_config tcan4x5x_regmap = {
	.reg_bits = 32,
	.val_bits = 32,
	.cache_type = REGCACHE_NONE,
	.max_register = TCAN4X5X_MAX_REGISTER,
	};

	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);
	if (!mcan_class)
	return -ENOMEM;

	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	mcan_class->device_data = priv;

	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)
	return -ERANGE;

	priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
	priv->mram_start = TCAN4X5X_MRAM_START;
	priv->spi = spi;
	priv->mcan_dev = mcan_class;

	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);

	ret = tcan4x5x_parse_config(mcan_class);
	if (ret)
	goto out_clk;

	/* Configure the SPI bus */
	spi->bits_per_word = 32;
	ret = spi_setup(spi);
	if (ret)
	goto out_clk;

	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
	&spi->dev, &tcan4x5x_regmap);
	if (IS_ERR(priv->regmap)) {
	ret = PTR_ERR(priv->regmap);
	goto out_clk;
	}

	tcan4x5x_power_enable(priv->power, 1);

	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_clk:
	if (!IS_ERR(mcan_class->cclk)) {
	clk_disable_unprepare(mcan_class->cclk);
	clk_disable_unprepare(mcan_class->hclk);
	}

	dev_err(&spi->dev, "Probe failed, err=%d\n", ret);
	return ret;
	}

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

	m_can_class_unregister(priv->mcan_dev);

	tcan4x5x_power_enable(priv->power, 0);

	return 0;
	}

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

	static const struct spi_device_id tcan4x5x_id_table[] = {
	{
	.name = "tcan4x5x",
	.driver_data = 0,
	},
	{ }
	};
	MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);

	static struct spi_driver tcan4x5x_can_driver = {
	.driver = {
	.name = DEVICE_NAME,
	.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");