1// SPDX-License-Identifier: GPL-2.0-only
  2// Copyright (C) 2018 ROHM Semiconductors
  3
  4#include <linux/gpio/driver.h>
  5#include <linux/mfd/rohm-bd71828.h>
  6#include <linux/module.h>
  7#include <linux/platform_device.h>
  8#include <linux/regmap.h>
  9
 10#define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off))
 11#define HALL_GPIO_OFFSET 3
 12
 13struct bd71828_gpio {
 14	struct rohm_regmap_dev chip;
 15	struct gpio_chip gpio;
 16};
 17
 18static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset,
 19			     int value)
 20{
 21	int ret;
 22	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
 23	u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO;
 24
 25	/*
 26	 * The HALL input pin can only be used as input. If this is the pin
 27	 * we are dealing with - then we are done
 28	 */
 29	if (offset == HALL_GPIO_OFFSET)
 30		return;
 31
 32	ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
 33				 BD71828_GPIO_OUT_MASK, val);
 34	if (ret)
 35		dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
 36}
 37
 38static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset)
 39{
 40	int ret;
 41	unsigned int val;
 42	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
 43
 44	if (offset == HALL_GPIO_OFFSET)
 45		ret = regmap_read(bdgpio->chip.regmap, BD71828_REG_IO_STAT,
 46				  &val);
 47	else
 48		ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
 49				  &val);
 50	if (!ret)
 51		ret = (val & BD71828_GPIO_OUT_MASK);
 52
 53	return ret;
 54}
 55
 56static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 57				   unsigned long config)
 58{
 59	struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
 60
 61	if (offset == HALL_GPIO_OFFSET)
 62		return -ENOTSUPP;
 63
 64	switch (pinconf_to_config_param(config)) {
 65	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 66		return regmap_update_bits(bdgpio->chip.regmap,
 67					  GPIO_OUT_REG(offset),
 68					  BD71828_GPIO_DRIVE_MASK,
 69					  BD71828_GPIO_OPEN_DRAIN);
 70	case PIN_CONFIG_DRIVE_PUSH_PULL:
 71		return regmap_update_bits(bdgpio->chip.regmap,
 72					  GPIO_OUT_REG(offset),
 73					  BD71828_GPIO_DRIVE_MASK,
 74					  BD71828_GPIO_PUSH_PULL);
 75	default:
 76		break;
 77	}
 78	return -ENOTSUPP;
 79}
 80
 81static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset)
 82{
 83	/*
 84	 * Pin usage is selected by OTP data. We can't read it runtime. Hence
 85	 * we trust that if the pin is not excluded by "gpio-reserved-ranges"
 86	 * the OTP configuration is set to OUT. (Other pins but HALL input pin
 87	 * on BD71828 can't really be used for general purpose input - input
 88	 * states are used for specific cases like regulator control or
 89	 * PMIC_ON_REQ.
 90	 */
 91	if (offset == HALL_GPIO_OFFSET)
 92		return GPIO_LINE_DIRECTION_IN;
 93
 94	return GPIO_LINE_DIRECTION_OUT;
 95}
 96
 97static int bd71828_probe(struct platform_device *pdev)
 98{
 99	struct bd71828_gpio *bdgpio;
100	struct rohm_regmap_dev *bd71828;
101
102	bd71828 = dev_get_drvdata(pdev->dev.parent);
103	if (!bd71828) {
104		dev_err(&pdev->dev, "No MFD driver data\n");
105		return -EINVAL;
106	}
107
108	bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
109			      GFP_KERNEL);
110	if (!bdgpio)
111		return -ENOMEM;
112
113	bdgpio->chip.dev = &pdev->dev;
114	bdgpio->gpio.parent = pdev->dev.parent;
115	bdgpio->gpio.label = "bd71828-gpio";
116	bdgpio->gpio.owner = THIS_MODULE;
117	bdgpio->gpio.get_direction = bd71828_get_direction;
118	bdgpio->gpio.set_config = bd71828_gpio_set_config;
119	bdgpio->gpio.can_sleep = true;
120	bdgpio->gpio.get = bd71828_gpio_get;
121	bdgpio->gpio.set = bd71828_gpio_set;
122	bdgpio->gpio.base = -1;
123
124	/*
125	 * See if we need some implementation to mark some PINs as
126	 * not controllable based on DT info or if core can handle
127	 * "gpio-reserved-ranges" and exclude them from control
128	 */
129	bdgpio->gpio.ngpio = 4;
130	bdgpio->gpio.of_node = pdev->dev.parent->of_node;
131	bdgpio->chip.regmap = bd71828->regmap;
132
133	return devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
134				     bdgpio);
135}
136
137static struct platform_driver bd71828_gpio = {
138	.driver = {
139		.name = "bd71828-gpio"
140	},
141	.probe = bd71828_probe,
142};
143
144module_platform_driver(bd71828_gpio);
145
146MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
147MODULE_DESCRIPTION("BD71828 voltage regulator driver");
148MODULE_LICENSE("GPL");
149MODULE_ALIAS("platform:bd71828-gpio");