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// 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 regmap *regmap;
struct device *dev;
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 ... 15000:
val = BD70528_DEBOUNCE_15MS;
break;
case 15001 ... 30000:
val = BD70528_DEBOUNCE_30MS;
break;
case 30001 ... 50000:
val = BD70528_DEBOUNCE_50MS;
break;
default:
dev_err(bdgpio->dev,
"Invalid debounce value %u\n", debounce);
return -EINVAL;
}
return regmap_update_bits(bdgpio->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->regmap, GPIO_OUT_REG(offset), &val);
if (ret) {
dev_err(bdgpio->dev, "Could not read gpio direction\n");
return ret;
}
if (val & BD70528_GPIO_OUT_EN_MASK)
return GPIO_LINE_DIRECTION_OUT;
return GPIO_LINE_DIRECTION_IN;
}
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->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->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->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->regmap, GPIO_OUT_REG(offset),
BD70528_GPIO_OUT_MASK, val);
if (ret)
dev_err(bdgpio->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->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->regmap, GPIO_OUT_REG(offset), &val);
if (!ret)
ret = !!(val & BD70528_GPIO_OUT_MASK);
else
dev_err(bdgpio->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->regmap, BD70528_REG_GPIO_STATE, &val);
if (!ret)
ret = !(val & GPIO_IN_STATE_MASK(offset));
else
dev_err(bdgpio->dev, "GPIO (in) state read failed\n");
return ret;
}
static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
int ret;
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 == GPIO_LINE_DIRECTION_OUT)
ret = bd70528_gpio_get_o(bdgpio, offset);
else if (ret == GPIO_LINE_DIRECTION_IN)
ret = bd70528_gpio_get_i(bdgpio, offset);
else
dev_err(bdgpio->dev, "failed to read GPIO direction\n");
return ret;
}
static int bd70528_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct bd70528_gpio *bdgpio;
int ret;
bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL);
if (!bdgpio)
return -ENOMEM;
bdgpio->dev = dev;
bdgpio->gpio.parent = 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 = dev->parent->of_node;
#endif
bdgpio->regmap = dev_get_regmap(dev->parent, NULL);
if (!bdgpio->regmap)
return -ENODEV;
ret = devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio);
if (ret)
dev_err(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");
MODULE_ALIAS("platform:bd70528-gpio");
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