Re: [PATCH v5 5/5] can: tcan4x5x: Add tcan4x5x driver to the kernel

[Wolfgang Grandegger <wg@grandegger.com>]

Am 28.02.19 um 19:03 schrieb Dan Murphy:
> 
> Wolfgang
> 
> On 2/28/19 11:50 AM, Wolfgang Grandegger wrote:
>>
>>
>> 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.>>
> 
> 72 lines or characters?

Characters, of course!

>>> Signed-off-by: Dan Murphy <dmurphy@ti.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.
> 
> ACK
> 
>>
>>> 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?
>>
> 
> Do you mean do I need to set the reset line then delay?

I mean, do you need to set the gpio value to 1 at the beginning? Is 0->1
not enough?

> 
>>> +		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,},
>> 	};
>>
>>
> 
> I am assuming LTL issue here.

LTL means? I just reformatted the declaration.

> 
>>> +
>>> +	addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 3;
>>
>>
> 
> There is nothing here 

It's OK.

> 
>>
>>> +
>>> +	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?
> 
> I can change it to ret.

Browsing some kernel code, returning "ret" seems the usual approach
(apart from ignoring the return 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;
> 
> Same comment as above
> 
>>> +
>>> +	/* 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?
>>
> 
> Not sure what you are asking?

"reg_err" stands for what? Above you use "out_clk" to disable clock
settings. Therefore "out_power" does make sense to me (or something
similar). Next time I will be a bit more verbose, sorry!

> 
>>> +
>>> +	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!
>>
> 
> Ack
> 
>>> +	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@ti.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.
>>
> 
> OK.  I also tested this here on one of our boards that use the iomapped code.

I know, you are testing on a dra76x from?

  https://www.spinics.net/lists/linux-can/msg00886.html

More testing would be nice.

Wolfgang.