drivers/gpio/gpio-tps6586x.c

// SPDX-License-Identifier: GPL-2.0
/*
 * TI TPS6586x GPIO driver
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 * Author: Laxman dewangan <ldewangan@nvidia.com>
 *
 * Based on tps6586x.c
 * Copyright (c) 2010 CompuLab Ltd.
 * Mike Rapoport <mike@compulab.co.il>
 */

#include <linux/errno.h>
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mfd/tps6586x.h>
#include <linux/of.h>
#include <linux/platform_device.h>

/* GPIO control registers */
#define TPS6586X_GPIOSET1	0x5d
#define TPS6586X_GPIOSET2	0x5e

struct tps6586x_gpio {
	struct gpio_chip gpio_chip;
	struct device *parent;
};

static int tps6586x_gpio_get(struct gpio_chip *gc, unsigned offset)
{
	struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
	uint8_t val;
	int ret;

	ret = tps6586x_read(tps6586x_gpio->parent, TPS6586X_GPIOSET2, &val);
	if (ret)
		return ret;

	return !!(val & (1 << offset));
}

static void tps6586x_gpio_set(struct gpio_chip *gc, unsigned offset,
			      int value)
{
	struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);

	tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET2,
			value << offset, 1 << offset);
}

static int tps6586x_gpio_output(struct gpio_chip *gc, unsigned offset,
				int value)
{
	struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
	uint8_t val, mask;

	tps6586x_gpio_set(gc, offset, value);

	val = 0x1 << (offset * 2);
	mask = 0x3 << (offset * 2);

	return tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET1,
				val, mask);
}

static int tps6586x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);

	return tps6586x_irq_get_virq(tps6586x_gpio->parent,
				TPS6586X_INT_PLDO_0 + offset);
}

static int tps6586x_gpio_probe(struct platform_device *pdev)
{
	struct tps6586x_platform_data *pdata;
	struct tps6586x_gpio *tps6586x_gpio;

	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));

	pdata = dev_get_platdata(pdev->dev.parent);
	tps6586x_gpio = devm_kzalloc(&pdev->dev,
				sizeof(*tps6586x_gpio), GFP_KERNEL);
	if (!tps6586x_gpio)
		return -ENOMEM;

	tps6586x_gpio->parent = pdev->dev.parent;

	tps6586x_gpio->gpio_chip.owner = THIS_MODULE;
	tps6586x_gpio->gpio_chip.label = pdev->name;
	tps6586x_gpio->gpio_chip.parent = &pdev->dev;
	tps6586x_gpio->gpio_chip.ngpio = 4;
	tps6586x_gpio->gpio_chip.can_sleep = true;

	/* FIXME: add handling of GPIOs as dedicated inputs */
	tps6586x_gpio->gpio_chip.direction_output = tps6586x_gpio_output;
	tps6586x_gpio->gpio_chip.set	= tps6586x_gpio_set;
	tps6586x_gpio->gpio_chip.get	= tps6586x_gpio_get;
	tps6586x_gpio->gpio_chip.to_irq	= tps6586x_gpio_to_irq;

	if (pdata && pdata->gpio_base)
		tps6586x_gpio->gpio_chip.base = pdata->gpio_base;
	else
		tps6586x_gpio->gpio_chip.base = -1;

	return devm_gpiochip_add_data(&pdev->dev, &tps6586x_gpio->gpio_chip,
				      tps6586x_gpio);
}

static struct platform_driver tps6586x_gpio_driver = {
	.driver.name	= "tps6586x-gpio",
	.probe		= tps6586x_gpio_probe,
};

static int __init tps6586x_gpio_init(void)
{
	return platform_driver_register(&tps6586x_gpio_driver);
}
subsys_initcall(tps6586x_gpio_init);