Commit 2d52dabb authored by Timo Schlüßler's avatar Timo Schlüßler Committed by Marc Kleine-Budde
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can: mcp251x: add GPIO support 



The mcp251x variants feature 3 general purpose digital inputs and 2
outputs. With this patch they are accessible through the gpio framework.

Signed-off-by: default avatarTimo Schlüßler <schluessler@krause.de>
Tested-by: default avatarTimo Schlüßler <schluessler@krause.de>
Link: https://lore.kernel.org/r/20200915223527.1417033-28-mkl@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent cfc24a0a

drivers/net/can/spi/mcp251x.c

+243 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
 * Copyright 2007

 */



#include <linux/bitfield.h>

#include <linux/can/core.h>

#include <linux/can/dev.h>

#include <linux/can/led.h>
@@ -27,6 +28,8 @@ 
#include <linux/delay.h>

#include <linux/device.h>

#include <linux/freezer.h>

#include <linux/gpio.h>

#include <linux/gpio/driver.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/kernel.h>
@@ -52,6 +55,30 @@ 
#define INSTRUCTION_RTS(n)	(0x80 | ((n) & 0x07))



/* MPC251x registers */

#define BFPCTRL			0x0c

#  define BFPCTRL_B0BFM		BIT(0)

#  define BFPCTRL_B1BFM		BIT(1)

#  define BFPCTRL_BFM(n)	(BFPCTRL_B0BFM << (n))

#  define BFPCTRL_BFM_MASK	GENMASK(1, 0)

#  define BFPCTRL_B0BFE		BIT(2)

#  define BFPCTRL_B1BFE		BIT(3)

#  define BFPCTRL_BFE(n)	(BFPCTRL_B0BFE << (n))

#  define BFPCTRL_BFE_MASK	GENMASK(3, 2)

#  define BFPCTRL_B0BFS		BIT(4)

#  define BFPCTRL_B1BFS		BIT(5)

#  define BFPCTRL_BFS(n)	(BFPCTRL_B0BFS << (n))

#  define BFPCTRL_BFS_MASK	GENMASK(5, 4)

#define TXRTSCTRL		0x0d

#  define TXRTSCTRL_B0RTSM	BIT(0)

#  define TXRTSCTRL_B1RTSM	BIT(1)

#  define TXRTSCTRL_B2RTSM	BIT(2)

#  define TXRTSCTRL_RTSM(n)	(TXRTSCTRL_B0RTSM << (n))

#  define TXRTSCTRL_RTSM_MASK	GENMASK(2, 0)

#  define TXRTSCTRL_B0RTS	BIT(3)

#  define TXRTSCTRL_B1RTS	BIT(4)

#  define TXRTSCTRL_B2RTS	BIT(5)

#  define TXRTSCTRL_RTS(n)	(TXRTSCTRL_B0RTS << (n))

#  define TXRTSCTRL_RTS_MASK	GENMASK(5, 3)

#define CANSTAT	      0x0e

#define CANCTRL	      0x0f

#  define CANCTRL_REQOP_MASK	    0xe0
@@ -225,6 +252,10 @@ struct mcp251x_priv { 
	struct regulator *power;

	struct regulator *transceiver;

	struct clk *clk;

#ifdef CONFIG_GPIOLIB

	struct gpio_chip gpio;

	u8 reg_bfpctrl;

#endif

};



#define MCP251X_IS(_model) \
@@ -345,6 +376,213 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg, 
	mcp251x_spi_trans(spi, 4);

}



#ifdef CONFIG_GPIOLIB

enum {

	MCP251X_GPIO_TX0RTS = 0,		/* inputs */

	MCP251X_GPIO_TX1RTS,

	MCP251X_GPIO_TX2RTS,

	MCP251X_GPIO_RX0BF,			/* outputs */

	MCP251X_GPIO_RX1BF,

};



#define MCP251X_GPIO_INPUT_MASK \

	GENMASK(MCP251X_GPIO_TX2RTS, MCP251X_GPIO_TX0RTS)

#define MCP251X_GPIO_OUTPUT_MASK \

	GENMASK(MCP251X_GPIO_RX1BF, MCP251X_GPIO_RX0BF)



static const char * const mcp251x_gpio_names[] = {

	[MCP251X_GPIO_TX0RTS] = "TX0RTS",	/* inputs */

	[MCP251X_GPIO_TX1RTS] = "TX1RTS",

	[MCP251X_GPIO_TX2RTS] = "TX2RTS",

	[MCP251X_GPIO_RX0BF] = "RX0BF",		/* outputs */

	[MCP251X_GPIO_RX1BF] = "RX1BF",

};



static inline bool mcp251x_gpio_is_input(unsigned int offset)

{

	return offset <= MCP251X_GPIO_TX2RTS;

}



static int mcp251x_gpio_request(struct gpio_chip *chip,

				unsigned int offset)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	u8 val;



	/* nothing to be done for inputs */

	if (mcp251x_gpio_is_input(offset))

		return 0;



	val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);



	mutex_lock(&priv->mcp_lock);

	mcp251x_write_bits(priv->spi, BFPCTRL, val, val);

	mutex_unlock(&priv->mcp_lock);



	priv->reg_bfpctrl |= val;



	return 0;

}



static void mcp251x_gpio_free(struct gpio_chip *chip,

			      unsigned int offset)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	u8 val;



	/* nothing to be done for inputs */

	if (mcp251x_gpio_is_input(offset))

		return;



	val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);



	mutex_lock(&priv->mcp_lock);

	mcp251x_write_bits(priv->spi, BFPCTRL, val, 0);

	mutex_unlock(&priv->mcp_lock);



	priv->reg_bfpctrl &= ~val;

}



static int mcp251x_gpio_get_direction(struct gpio_chip *chip,

				      unsigned int offset)

{

	if (mcp251x_gpio_is_input(offset))

		return GPIOF_DIR_IN;



	return GPIOF_DIR_OUT;

}



static int mcp251x_gpio_get(struct gpio_chip *chip, unsigned int offset)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	u8 reg, mask, val;



	if (mcp251x_gpio_is_input(offset)) {

		reg = TXRTSCTRL;

		mask = TXRTSCTRL_RTS(offset);

	} else {

		reg = BFPCTRL;

		mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);

	}



	mutex_lock(&priv->mcp_lock);

	val = mcp251x_read_reg(priv->spi, reg);

	mutex_unlock(&priv->mcp_lock);



	return !!(val & mask);

}



static int mcp251x_gpio_get_multiple(struct gpio_chip *chip,

				     unsigned long *maskp, unsigned long *bitsp)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	unsigned long bits = 0;

	u8 val;



	mutex_lock(&priv->mcp_lock);

	if (maskp[0] & MCP251X_GPIO_INPUT_MASK) {

		val = mcp251x_read_reg(priv->spi, TXRTSCTRL);

		val = FIELD_GET(TXRTSCTRL_RTS_MASK, val);

		bits |= FIELD_PREP(MCP251X_GPIO_INPUT_MASK, val);

	}

	if (maskp[0] & MCP251X_GPIO_OUTPUT_MASK) {

		val = mcp251x_read_reg(priv->spi, BFPCTRL);

		val = FIELD_GET(BFPCTRL_BFS_MASK, val);

		bits |= FIELD_PREP(MCP251X_GPIO_OUTPUT_MASK, val);

	}

	mutex_unlock(&priv->mcp_lock);



	bitsp[0] = bits;

	return 0;

}



static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset,

			     int value)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	u8 mask, val;



	mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);

	val = value ? mask : 0;



	mutex_lock(&priv->mcp_lock);

	mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);

	mutex_unlock(&priv->mcp_lock);



	priv->reg_bfpctrl &= ~mask;

	priv->reg_bfpctrl |= val;

}



static void

mcp251x_gpio_set_multiple(struct gpio_chip *chip,

			  unsigned long *maskp, unsigned long *bitsp)

{

	struct mcp251x_priv *priv = gpiochip_get_data(chip);

	u8 mask, val;



	mask = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, maskp[0]);

	mask = FIELD_PREP(BFPCTRL_BFS_MASK, mask);



	val = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, bitsp[0]);

	val = FIELD_PREP(BFPCTRL_BFS_MASK, val);



	if (!mask)

		return;



	mutex_lock(&priv->mcp_lock);

	mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);

	mutex_unlock(&priv->mcp_lock);



	priv->reg_bfpctrl &= ~mask;

	priv->reg_bfpctrl |= val;

}



static void mcp251x_gpio_restore(struct spi_device *spi)

{

	struct mcp251x_priv *priv = spi_get_drvdata(spi);



	mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl);

}



static int mcp251x_gpio_setup(struct mcp251x_priv *priv)

{

	struct gpio_chip *gpio = &priv->gpio;



	if (!device_property_present(&priv->spi->dev, "gpio-controller"))

		return 0;



	/* gpiochip handles TX[0..2]RTS and RX[0..1]BF */

	gpio->label = priv->spi->modalias;

	gpio->parent = &priv->spi->dev;

	gpio->owner = THIS_MODULE;

	gpio->request = mcp251x_gpio_request;

	gpio->free = mcp251x_gpio_free;

	gpio->get_direction = mcp251x_gpio_get_direction;

	gpio->get = mcp251x_gpio_get;

	gpio->get_multiple = mcp251x_gpio_get_multiple;

	gpio->set = mcp251x_gpio_set;

	gpio->set_multiple = mcp251x_gpio_set_multiple;

	gpio->base = -1;

	gpio->ngpio = ARRAY_SIZE(mcp251x_gpio_names);

	gpio->names = mcp251x_gpio_names;

	gpio->can_sleep = true;

#ifdef CONFIG_OF_GPIO

	gpio->of_node = priv->spi->dev.of_node;

#endif



	return devm_gpiochip_add_data(&priv->spi->dev, gpio, priv);

}

#else

static inline void mcp251x_gpio_restore(struct spi_device *spi)

{

}



static inline int mcp251x_gpio_setup(struct mcp251x_priv *priv)

{

	return 0;

}

#endif



static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,

				int len, int tx_buf_idx)

{
@@ -761,6 +999,7 @@ static void mcp251x_restart_work_handler(struct work_struct *ws) 
		if (priv->after_suspend & AFTER_SUSPEND_POWER) {

			mcp251x_hw_reset(spi);

			mcp251x_setup(net, spi);

			mcp251x_gpio_restore(spi);

		} else {

			mcp251x_hw_wake(spi);

		}
@@ -1136,6 +1375,10 @@ static int mcp251x_can_probe(struct spi_device *spi) 


	devm_can_led_init(net);



	ret = mcp251x_gpio_setup(priv);

	if (ret)

		goto error_probe;



	netdev_info(net, "MCP%x successfully initialized.\n", priv->model);

	return 0;