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Commit 18bc64b3 authored by Matti Vaittinen's avatar Matti Vaittinen Committed by Lee Jones
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gpio: Initial support for ROHM bd70528 GPIO block 



ROHM BD70528 PMIC has 4 GPIO pins. Allow them to be
controlled by GPIO framework.

IRQs are handled by regmap-irq and GPIO driver is not
aware of the irq usage.

Signed-off-by: default avatarMatti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 478bb8f3

drivers/gpio/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -977,6 +977,17 @@ config GPIO_ARIZONA 
	help

	  Support for GPIOs on Wolfson Arizona class devices.



config GPIO_BD70528

	tristate "ROHM BD70528 GPIO support"

	depends on MFD_ROHM_BD70528

	help

	  Support for GPIOs on ROHM BD70528 PMIC. There are four GPIOs

	  available on the ROHM PMIC in total. The GPIOs can also

	  generate interrupts.



	  This driver can also be built as a module. If so, the module

	  will be called gpio-bd70528.



config GPIO_BD9571MWV

	tristate "ROHM BD9571 GPIO support"

	depends on MFD_BD9571MWV

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o 
obj-$(CONFIG_GPIO_ASPEED)	+= gpio-aspeed.o

obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)	+= gpio-raspberrypi-exp.o

obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o

obj-$(CONFIG_GPIO_BD70528) 	+= gpio-bd70528.o

obj-$(CONFIG_GPIO_BD9571MWV)	+= gpio-bd9571mwv.o

obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o

obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o

drivers/gpio/gpio-bd70528.c

0 → 100644
+232 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2018 ROHM Semiconductors

// gpio-bd70528.c ROHM BD70528MWV gpio driver



#include <linux/gpio/driver.h>

#include <linux/mfd/rohm-bd70528.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>



#define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + (offset) * 2)

#define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + (offset) * 2)



struct bd70528_gpio {

	struct rohm_regmap_dev chip;

	struct gpio_chip gpio;

};



static int bd70528_set_debounce(struct bd70528_gpio *bdgpio,

				unsigned int offset, unsigned int debounce)

{

	u8 val;



	switch (debounce) {

	case 0:

		val = BD70528_DEBOUNCE_DISABLE;

		break;

	case 1 ... 15:

		val = BD70528_DEBOUNCE_15MS;

		break;

	case 16 ... 30:

		val = BD70528_DEBOUNCE_30MS;

		break;

	case 31 ... 50:

		val = BD70528_DEBOUNCE_50MS;

		break;

	default:

		dev_err(bdgpio->chip.dev,

			"Invalid debouce value %u\n", debounce);

		return -EINVAL;

	}

	return regmap_update_bits(bdgpio->chip.regmap, GPIO_IN_REG(offset),

				 BD70528_DEBOUNCE_MASK, val);

}



static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset)

{

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	int val, ret;



	/* Do we need to do something to IRQs here? */

	ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);

	if (ret) {

		dev_err(bdgpio->chip.dev, "Could not read gpio direction\n");

		return ret;

	}



	return !(val & BD70528_GPIO_OUT_EN_MASK);

}



static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,

				   unsigned long config)

{

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);



	switch (pinconf_to_config_param(config)) {

	case PIN_CONFIG_DRIVE_OPEN_DRAIN:

		return regmap_update_bits(bdgpio->chip.regmap,

					  GPIO_OUT_REG(offset),

					  BD70528_GPIO_DRIVE_MASK,

					  BD70528_GPIO_OPEN_DRAIN);

		break;

	case PIN_CONFIG_DRIVE_PUSH_PULL:

		return regmap_update_bits(bdgpio->chip.regmap,

					  GPIO_OUT_REG(offset),

					  BD70528_GPIO_DRIVE_MASK,

					  BD70528_GPIO_PUSH_PULL);

		break;

	case PIN_CONFIG_INPUT_DEBOUNCE:

		return bd70528_set_debounce(bdgpio, offset,

					    pinconf_to_config_argument(config));

		break;

	default:

		break;

	}

	return -ENOTSUPP;

}



static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)

{

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);



	/* Do we need to do something to IRQs here? */

	return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),

				 BD70528_GPIO_OUT_EN_MASK,

				 BD70528_GPIO_OUT_DISABLE);

}



static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,

			     int value)

{

	int ret;

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;



	ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),

				 BD70528_GPIO_OUT_MASK, val);

	if (ret)

		dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);

}



static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,

				    int value)

{

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);



	bd70528_gpio_set(chip, offset, value);

	return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),

				 BD70528_GPIO_OUT_EN_MASK,

				 BD70528_GPIO_OUT_ENABLE);

}



#define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset))



static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)

{

	int ret;

	unsigned int val;



	ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);

	if (!ret)

		ret = !!(val & BD70528_GPIO_OUT_MASK);

	else

		dev_err(bdgpio->chip.dev, "GPIO (out) state read failed\n");



	return ret;

}



static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)

{

	unsigned int val;

	int ret;



	ret = regmap_read(bdgpio->chip.regmap, BD70528_REG_GPIO_STATE, &val);



	if (!ret)

		ret = !(val & GPIO_IN_STATE_MASK(offset));

	else

		dev_err(bdgpio->chip.dev, "GPIO (in) state read failed\n");



	return ret;

}



static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)

{

	int ret = -EINVAL;

	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);



	/*

	 * There is a race condition where someone might be changing the

	 * GPIO direction after we get it but before we read the value. But

	 * application design where GPIO direction may be changed just when

	 * we read GPIO value would be pointless as reader could not know

	 * whether the returned high/low state is caused by input or output.

	 * Or then there must be other ways to mitigate the issue. Thus

	 * locking would make no sense.

	 */

	ret = bd70528_get_direction(chip, offset);

	if (ret == 0)

		ret = bd70528_gpio_get_o(bdgpio, offset);

	else if (ret == 1)

		ret = bd70528_gpio_get_i(bdgpio, offset);

	else

		dev_err(bdgpio->chip.dev, "failed to read GPIO direction\n");



	return ret;

}



static int bd70528_probe(struct platform_device *pdev)

{

	struct bd70528_gpio *bdgpio;

	struct rohm_regmap_dev *bd70528;

	int ret;



	bd70528 = dev_get_drvdata(pdev->dev.parent);

	if (!bd70528) {

		dev_err(&pdev->dev, "No MFD driver data\n");

		return -EINVAL;

	}



	bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),

			      GFP_KERNEL);

	if (!bdgpio)

		return -ENOMEM;

	bdgpio->chip.dev = &pdev->dev;

	bdgpio->gpio.parent = pdev->dev.parent;

	bdgpio->gpio.label = "bd70528-gpio";

	bdgpio->gpio.owner = THIS_MODULE;

	bdgpio->gpio.get_direction = bd70528_get_direction;

	bdgpio->gpio.direction_input = bd70528_direction_input;

	bdgpio->gpio.direction_output = bd70528_direction_output;

	bdgpio->gpio.set_config = bd70528_gpio_set_config;

	bdgpio->gpio.can_sleep = true;

	bdgpio->gpio.get = bd70528_gpio_get;

	bdgpio->gpio.set = bd70528_gpio_set;

	bdgpio->gpio.ngpio = 4;

	bdgpio->gpio.base = -1;

#ifdef CONFIG_OF_GPIO

	bdgpio->gpio.of_node = pdev->dev.parent->of_node;

#endif

	bdgpio->chip.regmap = bd70528->regmap;



	ret = devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,

				     bdgpio);

	if (ret)

		dev_err(&pdev->dev, "gpio_init: Failed to add bd70528-gpio\n");



	return ret;

}



static struct platform_driver bd70528_gpio = {

	.driver = {

		.name = "bd70528-gpio"

	},

	.probe = bd70528_probe,

};



module_platform_driver(bd70528_gpio);



MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");

MODULE_DESCRIPTION("BD70528 voltage regulator driver");

MODULE_LICENSE("GPL");