gpio-arizona.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* gpiolib support for Wolfson Arizona class devices
*
* Copyright 2012 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/mfd/arizona/core.h>
#include <linux/mfd/arizona/pdata.h>
#include <linux/mfd/arizona/registers.h>
struct arizona_gpio {
struct arizona *arizona;
struct gpio_chip gpio_chip;
};
static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
struct arizona *arizona = arizona_gpio->arizona;
bool persistent = gpiochip_line_is_persistent(chip, offset);
bool change;
int ret;
ret = regmap_update_bits_check(arizona->regmap,
ARIZONA_GPIO1_CTRL + offset,
ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
&change);
if (ret < 0)
return ret;
if (change && persistent) {
pm_runtime_mark_last_busy(chip->parent);
pm_runtime_put_autosuspend(chip->parent);
}
return 0;
}
static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
struct arizona *arizona = arizona_gpio->arizona;
unsigned int reg, val;
int ret;
reg = ARIZONA_GPIO1_CTRL + offset;
ret = regmap_read(arizona->regmap, reg, &val);
if (ret < 0)
return ret;
/* Resume to read actual registers for input pins */
if (val & ARIZONA_GPN_DIR) {
ret = pm_runtime_get_sync(chip->parent);
if (ret < 0) {
dev_err(chip->parent, "Failed to resume: %d\n", ret);
pm_runtime_put_autosuspend(chip->parent);
return ret;
}
/* Register is cached, drop it to ensure a physical read */
ret = regcache_drop_region(arizona->regmap, reg, reg);
if (ret < 0) {
dev_err(chip->parent, "Failed to drop cache: %d\n",
ret);
pm_runtime_put_autosuspend(chip->parent);
return ret;
}
ret = regmap_read(arizona->regmap, reg, &val);
if (ret < 0) {
pm_runtime_put_autosuspend(chip->parent);
return ret;
}
pm_runtime_mark_last_busy(chip->parent);
pm_runtime_put_autosuspend(chip->parent);
}
if (val & ARIZONA_GPN_LVL)
return 1;
else
return 0;
}
static int arizona_gpio_direction_out(struct gpio_chip *chip,
unsigned offset, int value)
{
struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
struct arizona *arizona = arizona_gpio->arizona;
bool persistent = gpiochip_line_is_persistent(chip, offset);
unsigned int val;
int ret;
ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
if (ret < 0)
return ret;
if ((val & ARIZONA_GPN_DIR) && persistent) {
ret = pm_runtime_get_sync(chip->parent);
if (ret < 0) {
dev_err(chip->parent, "Failed to resume: %d\n", ret);
pm_runtime_put(chip->parent);
return ret;
}
}
if (value)
value = ARIZONA_GPN_LVL;
return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
}
static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
struct arizona *arizona = arizona_gpio->arizona;
if (value)
value = ARIZONA_GPN_LVL;
regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
ARIZONA_GPN_LVL, value);
}
static const struct gpio_chip template_chip = {
.label = "arizona",
.owner = THIS_MODULE,
.direction_input = arizona_gpio_direction_in,
.get = arizona_gpio_get,
.direction_output = arizona_gpio_direction_out,
.set = arizona_gpio_set,
.can_sleep = true,
};
static int arizona_gpio_probe(struct platform_device *pdev)
{
struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
struct arizona_pdata *pdata = &arizona->pdata;
struct arizona_gpio *arizona_gpio;
int ret;
arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
GFP_KERNEL);
if (!arizona_gpio)
return -ENOMEM;
arizona_gpio->arizona = arizona;
arizona_gpio->gpio_chip = template_chip;
arizona_gpio->gpio_chip.parent = &pdev->dev;
#ifdef CONFIG_OF_GPIO
arizona_gpio->gpio_chip.of_node = arizona->dev->of_node;
#endif
switch (arizona->type) {
case WM5102:
case WM5110:
case WM8280:
case WM8997:
case WM8998:
case WM1814:
arizona_gpio->gpio_chip.ngpio = 5;
break;
case WM1831:
case CS47L24:
arizona_gpio->gpio_chip.ngpio = 2;
break;
default:
dev_err(&pdev->dev, "Unknown chip variant %d\n",
arizona->type);
return -EINVAL;
}
if (pdata->gpio_base)
arizona_gpio->gpio_chip.base = pdata->gpio_base;
else
arizona_gpio->gpio_chip.base = -1;
pm_runtime_enable(&pdev->dev);
ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
arizona_gpio);
if (ret < 0) {
pm_runtime_disable(&pdev->dev);
dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
ret);
return ret;
}
return 0;
}
static struct platform_driver arizona_gpio_driver = {
.driver.name = "arizona-gpio",
.probe = arizona_gpio_probe,
};
module_platform_driver(arizona_gpio_driver);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("GPIO interface for Arizona devices");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:arizona-gpio");