Message-ID: <6b5ce732-bce1-7e35-2bf4-a1000bfc9208@grandegger.com>
Date:   Thu, 28 Feb 2019 18:50:11 +0100
From:   Wolfgang Grandegger <wg@...ndegger.com>
To:     Dan Murphy <dmurphy@...com>, mkl@...gutronix.de,
        davem@...emloft.net
Cc:     linux-can@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 5/5] can: tcan4x5x: Add tcan4x5x driver to the kernel



Am 14.02.19 um 19:27 schrieb Dan Murphy:
> Add the TCAN4x5x SPI CAN driver.  This device
> uses the Bosch MCAN IP core along with a SPI
> interface map.  Leverage the MCAN common core
> code to manage the MCAN IP.
> 
> This device has a special method to indicate a
> write/read operation on the data payload.

Please expand the text to approx. 72 lines.

> Signed-off-by: Dan Murphy <dmurphy@...com>
> ---
> 
> v5 - Changes to accomodate previous patches for functionality - https://lore.kernel.org/patchwork/patch/1033096/
> 
>  drivers/net/can/m_can/Kconfig    |   6 +
>  drivers/net/can/m_can/Makefile   |   1 +
>  drivers/net/can/m_can/tcan4x5x.c | 531 +++++++++++++++++++++++++++++++
>  3 files changed, 538 insertions(+)
>  create mode 100644 drivers/net/can/m_can/tcan4x5x.c
> 
> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
> index 66e31022a5fa..6c0ab4703fb7 100644
> --- a/drivers/net/can/m_can/Kconfig
> +++ b/drivers/net/can/m_can/Kconfig
> @@ -9,3 +9,9 @@ config CAN_M_CAN_PLATFORM
>  	depends on CAN_M_CAN
>  	---help---
>  	  Say Y here if you want to support for Bosch M_CAN controller.
> +
> +config CAN_M_CAN_TCAN4X5X
> +	depends on CAN_M_CAN
> +	tristate "TCAN4X5X M_CAN device"
> +	---help---
> +	  Say Y here if you want to support for TI M_CAN controller.

Could yo please be a bit more verbose here.

> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
> index 057bbcdb3c74..e77f0eccff97 100644
> --- a/drivers/net/can/m_can/Makefile
> +++ b/drivers/net/can/m_can/Makefile
> @@ -4,3 +4,4 @@
>  
>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>  obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
> +obj-$(CONFIG_CAN_M_CAN_TCAN4X5X) += tcan4x5x.o
> diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
> new file mode 100644
> index 000000000000..606cd1925009
> --- /dev/null
> +++ b/drivers/net/can/m_can/tcan4x5x.c
> @@ -0,0 +1,531 @@
> +// 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	0x8fff
> +
> +#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 mutex tcan4x5x_lock; /* SPI device lock */
> +
> +	struct m_can_classdev *mcan_dev;
> +
> +	struct gpio_desc *reset_gpio;
> +	struct gpio_desc *interrupt_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 struct can_bittiming_const tcan4x5x_bittiming_const = {
> +	.name = DEVICE_NAME,
> +	.tseg1_min = 2,
> +	.tseg1_max = 31,
> +	.tseg2_min = 2,
> +	.tseg2_max = 16,
> +	.sjw_max = 16,
> +	.brp_min = 1,
> +	.brp_max = 32,
> +	.brp_inc = 1,
> +};
> +
> +static struct can_bittiming_const tcan4x5x_data_bittiming_const = {
> +	.name = DEVICE_NAME,
> +	.tseg1_min = 1,
> +	.tseg1_max = 32,
> +	.tseg2_min = 1,
> +	.tseg2_max = 16,
> +	.sjw_max = 16,
> +	.brp_min = 1,
> +	.brp_max = 32,
> +	.brp_inc = 1,
> +};
> +
> +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, 1);
> +		udelay(100);

Do you need the setting above?

> +		gpiod_set_value(priv->device_wake_gpio, 0);
> +		udelay(100);
> +		gpiod_set_value(priv->device_wake_gpio, 1);
> +	}
> +}
> +
> +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, },};

	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 >> 3;



> +
> +	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);
> +}
> +
> +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 *m_can_class, int reg)
> +{
> +	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
> +	u32 val;
> +
> +	tcan4x5x_check_wake(priv);
> +
> +	regmap_read(priv->regmap, priv->reg_offset + reg, &val);
> +
> +	return val;
> +}
> +
> +static u32 tcan4x5x_read_fifo(struct m_can_classdev *m_can_class,
> +			      int addr_offset)
> +{
> +	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
> +	u32 val;
> +
> +	tcan4x5x_check_wake(priv);
> +
> +	regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);
> +
> +	return val;
> +}
> +
> +static int tcan4x5x_write_reg(struct m_can_classdev *m_can_class,
> +			      int reg, int val)
> +{
> +	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
> +
> +	tcan4x5x_check_wake(priv);
> +
> +	return regmap_write(priv->regmap, priv->reg_offset + reg, val);
> +}
> +
> +static int tcan4x5x_write_fifo(struct m_can_classdev *m_can_class,
> +			       int addr_offset, int val)
> +{
> +	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
> +
> +	tcan4x5x_check_wake(priv);
> +
> +	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 *m_can_class,
> +				   int reg, int val)
> +{
> +	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
> +
> +	tcan4x5x_check_wake(priv);
> +
> +	return regmap_write(priv->regmap, reg, val);
> +}
> +
> +static int tcan4x5x_clear_interrupts(struct m_can_classdev *class_dev)
> +{
> +	struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
> +	int ret;
> +
> +	tcan4x5x_check_wake(tcan4x5x);
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_STATUS,
> +				      TCAN4X5X_CLEAR_ALL_INT);
> +	if (ret)
> +		return -EIO;

Does "ret" not return a proper error code?

> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
> +				      TCAN4X5X_ENABLE_MCAN_INT);
> +	if (ret)
> +		return -EIO;
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
> +				      TCAN4X5X_CLEAR_ALL_INT);
> +	if (ret)
> +		return -EIO;
> +
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
> +				      TCAN4X5X_CLEAR_ALL_INT);
> +	if (ret)
> +		return -EIO;
> +
> +	return ret;
> +}
> +
> +static int tcan4x5x_init(struct m_can_classdev *class_dev)
> +{
> +	struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
> +	int ret;
> +
> +	tcan4x5x_check_wake(tcan4x5x);
> +
> +	ret = tcan4x5x_clear_interrupts(class_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_EN,
> +				      TCAN4X5X_ENABLE_TCAN_INT);
> +	if (ret)
> +		return -EIO;
> +
> +	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
> +				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
> +	if (ret)
> +		return -EIO;
> +
> +	/* Zero out the MCAN buffers */
> +	m_can_init_ram(class_dev);
> +
> +	return ret;
> +}
> +
> +static int tcan4x5x_parse_config(struct m_can_classdev *class_dev)
> +{
> +	struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
> +
> +	tcan4x5x->reset_gpio = devm_gpiod_get_optional(class_dev->dev,
> +						       "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(tcan4x5x->reset_gpio))
> +		tcan4x5x->reset_gpio = NULL;
> +
> +	tcan4x5x->device_wake_gpio = devm_gpiod_get_optional(class_dev->dev,
> +							     "device-wake",
> +							     GPIOD_OUT_HIGH);
> +	if (IS_ERR(tcan4x5x->device_wake_gpio))
> +		tcan4x5x->device_wake_gpio = NULL;
> +
> +	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(class_dev->dev,
> +							      "device-state",
> +							      GPIOD_IN);
> +	if (IS_ERR(tcan4x5x->device_state_gpio))
> +		tcan4x5x->device_state_gpio = NULL;
> +
> +	tcan4x5x->interrupt_gpio = devm_gpiod_get(class_dev->dev,
> +						  "data-ready", GPIOD_IN);
> +	if (IS_ERR(tcan4x5x->interrupt_gpio)) {
> +		dev_err(class_dev->dev, "data-ready gpio not defined\n");
> +		return -EINVAL;
> +	}
> +
> +	class_dev->net->irq = gpiod_to_irq(tcan4x5x->interrupt_gpio);
> +
> +	tcan4x5x->power = devm_regulator_get_optional(class_dev->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 = {
> +	.device_init = tcan4x5x_init,
> +	.read_reg = tcan4x5x_read_reg,
> +	.write_reg = tcan4x5x_write_reg,
> +	.write_fifo = tcan4x5x_write_fifo,
> +	.read_fifo = tcan4x5x_read_fifo,
> +	.clr_dev_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);
> +	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_peripherial = true;
> +	mcan_class->bit_timing = &tcan4x5x_bittiming_const;
> +	mcan_class->data_timing = &tcan4x5x_data_bittiming_const;
> +
> +	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);
> +
> +	mutex_init(&priv->tcan4x5x_lock);
> +
> +	tcan4x5x_power_enable(priv->power, 1);
> +
> +	ret = m_can_class_register(mcan_class);
> +	if (ret)
> +		goto reg_err;

out_power?

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

Just "ret" is fine!

> +	return ret;
> +}
> +
> +static int tcan4x5x_can_remove(struct spi_device *spi)
> +{
> +	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
> +
> +	tcan4x5x_power_enable(priv->power, 0);
> +
> +	m_can_class_unregister(priv->mcan_dev);
> +
> +	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@...com>");
> +MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
> +MODULE_LICENSE("GPL v2");
> 

The changes to the io-mapped driver look good and non-critical... time
to ask for beta-testers for the next version of the patch series.

Wolfgang.

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