diff mbox series

[v6,4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel

Message ID 20190301185043.9037-4-dmurphy@ti.com
State Awaiting Upstream
Delegated to: David Miller
Headers show
Series [v6,1/4] can: m_can: Create a m_can platform framework | expand

Commit Message

Dan Murphy March 1, 2019, 6:50 p.m. UTC
Add the TCAN4x5x SPI CAN driver.  This device uses the
Bosch MCAN IP core along with a SPI interface map.
Register to 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.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v6 - Updated Kconfig help and added REGMAP_SPI dependency, fixed coding style issues,
removed setting GPIO high in wake routine, change -EIO to return ret in init and
setup functions - https://lore.kernel.org/patchwork/patch/1042443/

 drivers/net/can/m_can/Kconfig    |   9 +
 drivers/net/can/m_can/Makefile   |   1 +
 drivers/net/can/m_can/tcan4x5x.c | 529 +++++++++++++++++++++++++++++++
 3 files changed, 539 insertions(+)
 create mode 100644 drivers/net/can/m_can/tcan4x5x.c

Comments

Wolfgang Grandegger March 4, 2019, 6:29 p.m. UTC | #1
Hello Dan,

Am 01.03.19 um 19:50 schrieb Dan Murphy:
> Add the TCAN4x5x SPI CAN driver.  This device uses the
> Bosch MCAN IP core along with a SPI interface map.
> Register to 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.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> 
> v6 - Updated Kconfig help and added REGMAP_SPI dependency, fixed coding style issues,
> removed setting GPIO high in wake routine, change -EIO to return ret in init and
> setup functions - https://lore.kernel.org/patchwork/patch/1042443/
> 
>  drivers/net/can/m_can/Kconfig    |   9 +
>  drivers/net/can/m_can/Makefile   |   1 +
>  drivers/net/can/m_can/tcan4x5x.c | 529 +++++++++++++++++++++++++++++++
>  3 files changed, 539 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 f7119fd72df4..cf4f32765efa 100644
> --- a/drivers/net/can/m_can/Kconfig
> +++ b/drivers/net/can/m_can/Kconfig
> @@ -12,3 +12,12 @@ config CAN_M_CAN_PLATFORM
>  	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>  	  This support is for devices that have the Bosch M_CAN controller
>  	  IP embedded into the device and the IP is IO Mapped to the processor.
> +
> +config CAN_M_CAN_TCAN4X5X
> +	depends on CAN_M_CAN
> +	depends on REGMAP_SPI
> +	tristate "TCAN4X5X M_CAN device"
> +	---help---
> +	  Say Y here if you want support for Texas Instruments TCAN4x5x
> +	  M_CAN controller.  This device is a peripherial device that uses the
> +	  SPI bus for communication.
> 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..a91b976bb522
> --- /dev/null
> +++ b/drivers/net/can/m_can/tcan4x5x.c
> @@ -0,0 +1,529 @@
> +// 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, 0);
> +		usleep_range(5, 50);
> +		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, },
> +	};
> +
> +	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 ret;
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
> +				      TCAN4X5X_ENABLE_MCAN_INT);
> +	if (ret)
> +		return ret;
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
> +				      TCAN4X5X_CLEAR_ALL_INT);
> +	if (ret)
> +		return ret;
> +
> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
> +				      TCAN4X5X_CLEAR_ALL_INT);
> +	if (ret)
> +		return ret;
> +
> +	return ret;
> +}

Hm, handling the interrupt seems to be a quite heavy operation. How does
the device and system digest small messages (dlc=0) coming in at a very
high rate?

Any chance to optimize accesses be reading more than on word?

Wolfgang.
Dan Murphy March 4, 2019, 7:07 p.m. UTC | #2
Wolfgang

On 3/4/19 12:29 PM, Wolfgang Grandegger wrote:
> Hello Dan,
> 
> Am 01.03.19 um 19:50 schrieb Dan Murphy:
>> Add the TCAN4x5x SPI CAN driver.  This device uses the
>> Bosch MCAN IP core along with a SPI interface map.
>> Register to 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.
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>
>> v6 - Updated Kconfig help and added REGMAP_SPI dependency, fixed coding style issues,
>> removed setting GPIO high in wake routine, change -EIO to return ret in init and
>> setup functions - https://lore.kernel.org/patchwork/patch/1042443/
>>
>>  drivers/net/can/m_can/Kconfig    |   9 +
>>  drivers/net/can/m_can/Makefile   |   1 +
>>  drivers/net/can/m_can/tcan4x5x.c | 529 +++++++++++++++++++++++++++++++
>>  3 files changed, 539 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 f7119fd72df4..cf4f32765efa 100644
>> --- a/drivers/net/can/m_can/Kconfig
>> +++ b/drivers/net/can/m_can/Kconfig
>> @@ -12,3 +12,12 @@ config CAN_M_CAN_PLATFORM
>>  	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>  	  This support is for devices that have the Bosch M_CAN controller
>>  	  IP embedded into the device and the IP is IO Mapped to the processor.
>> +
>> +config CAN_M_CAN_TCAN4X5X
>> +	depends on CAN_M_CAN
>> +	depends on REGMAP_SPI
>> +	tristate "TCAN4X5X M_CAN device"
>> +	---help---
>> +	  Say Y here if you want support for Texas Instruments TCAN4x5x
>> +	  M_CAN controller.  This device is a peripherial device that uses the
>> +	  SPI bus for communication.
>> 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..a91b976bb522
>> --- /dev/null
>> +++ b/drivers/net/can/m_can/tcan4x5x.c
>> @@ -0,0 +1,529 @@
>> +// 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, 0);
>> +		usleep_range(5, 50);
>> +		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, },
>> +	};
>> +
>> +	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 ret;
>> +
>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
>> +				      TCAN4X5X_ENABLE_MCAN_INT);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
>> +				      TCAN4X5X_CLEAR_ALL_INT);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
>> +				      TCAN4X5X_CLEAR_ALL_INT);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return ret;
>> +}
> 
> Hm, handling the interrupt seems to be a quite heavy operation. How does
> the device and system digest small messages (dlc=0) coming in at a very
> high rate?
> 
> Any chance to optimize accesses be reading more than on word?
> 

The device does support writing consecutive registers.  The MCAN_INT and INT_FLAGS are consecutive
and the STATUS and ERROR_STATUS are consecutive.  So we would still need 2 writes so not sure that this will
optimize enough for your concern.

Also the m_can code is missing bulk writes which I did not want to introduce at this time.
My concern was more functionality and maintaining current io mapped functionality.

Bulk writes for peripheral devices is preferred.

Dan

> Wolfgang.
>
Wolfgang Grandegger March 4, 2019, 7:33 p.m. UTC | #3
Hello Dan,

Am 04.03.19 um 20:07 schrieb Dan Murphy:
> Wolfgang
> 
> On 3/4/19 12:29 PM, Wolfgang Grandegger wrote:
>> Hello Dan,
>>
>> Am 01.03.19 um 19:50 schrieb Dan Murphy:
>>> Add the TCAN4x5x SPI CAN driver.  This device uses the
>>> Bosch MCAN IP core along with a SPI interface map.
>>> Register to 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.
>>>
>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>> ---
>>>
>>> v6 - Updated Kconfig help and added REGMAP_SPI dependency, fixed coding style issues,
>>> removed setting GPIO high in wake routine, change -EIO to return ret in init and
>>> setup functions - https://lore.kernel.org/patchwork/patch/1042443/
>>>
>>>  drivers/net/can/m_can/Kconfig    |   9 +
>>>  drivers/net/can/m_can/Makefile   |   1 +
>>>  drivers/net/can/m_can/tcan4x5x.c | 529 +++++++++++++++++++++++++++++++
>>>  3 files changed, 539 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 f7119fd72df4..cf4f32765efa 100644
>>> --- a/drivers/net/can/m_can/Kconfig
>>> +++ b/drivers/net/can/m_can/Kconfig
>>> @@ -12,3 +12,12 @@ config CAN_M_CAN_PLATFORM
>>>  	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>  	  This support is for devices that have the Bosch M_CAN controller
>>>  	  IP embedded into the device and the IP is IO Mapped to the processor.
>>> +
>>> +config CAN_M_CAN_TCAN4X5X
>>> +	depends on CAN_M_CAN
>>> +	depends on REGMAP_SPI
>>> +	tristate "TCAN4X5X M_CAN device"
>>> +	---help---
>>> +	  Say Y here if you want support for Texas Instruments TCAN4x5x
>>> +	  M_CAN controller.  This device is a peripherial device that uses the
>>> +	  SPI bus for communication.
>>> 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..a91b976bb522
>>> --- /dev/null
>>> +++ b/drivers/net/can/m_can/tcan4x5x.c
>>> @@ -0,0 +1,529 @@
>>> +// 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, 0);
>>> +		usleep_range(5, 50);
>>> +		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, },
>>> +	};
>>> +
>>> +	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 ret;
>>> +
>>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
>>> +				      TCAN4X5X_ENABLE_MCAN_INT);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
>>> +				      TCAN4X5X_CLEAR_ALL_INT);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
>>> +				      TCAN4X5X_CLEAR_ALL_INT);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	return ret;
>>> +}
>>
>> Hm, handling the interrupt seems to be a quite heavy operation. How does
>> the device and system digest small messages (dlc=0) coming in at a very
>> high rate?
>>
>> Any chance to optimize accesses be reading more than on word?
>>
> 
> The device does support writing consecutive registers.  The MCAN_INT and INT_FLAGS are consecutive
> and the STATUS and ERROR_STATUS are consecutive.  So we would still need 2 writes so not sure that this will
> optimize enough for your concern.

Yes, that's what I realized as well. Two SPI transfers instead of four
is already an improvement.

> Also the m_can code is missing bulk writes which I did not want to introduce at this time.
> My concern was more functionality and maintaining current io mapped functionality.

That's fine. I'm just curious.

> Bulk writes for peripheral devices is preferred.

Of course.

Wolfgang.
diff mbox series

Patch

diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index f7119fd72df4..cf4f32765efa 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -12,3 +12,12 @@  config CAN_M_CAN_PLATFORM
 	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
 	  This support is for devices that have the Bosch M_CAN controller
 	  IP embedded into the device and the IP is IO Mapped to the processor.
+
+config CAN_M_CAN_TCAN4X5X
+	depends on CAN_M_CAN
+	depends on REGMAP_SPI
+	tristate "TCAN4X5X M_CAN device"
+	---help---
+	  Say Y here if you want support for Texas Instruments TCAN4x5x
+	  M_CAN controller.  This device is a peripherial device that uses the
+	  SPI bus for communication.
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..a91b976bb522
--- /dev/null
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -0,0 +1,529 @@ 
+// 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, 0);
+		usleep_range(5, 50);
+		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, },
+	};
+
+	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 ret;
+
+	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
+				      TCAN4X5X_ENABLE_MCAN_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	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 ret;
+
+	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
+	if (ret)
+		return ret;
+
+	/* 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 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);
+
+	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");