gpio-wcd934x.c

  1// SPDX-License-Identifier: GPL-2.0
  2// Copyright (c) 2019, Linaro Limited
  3
  4#include <linux/mod_devicetable.h>
  5#include <linux/module.h>
  6#include <linux/gpio/driver.h>
  7#include <linux/platform_device.h>
  8#include <linux/regmap.h>
  9#include <linux/slab.h>
 10
 11#define WCD_PIN_MASK(p) BIT(p)
 12#define WCD_REG_DIR_CTL_OFFSET 0x42
 13#define WCD_REG_VAL_CTL_OFFSET 0x43
 14#define WCD934X_NPINS		5
 15
 16struct wcd_gpio_data {
 17	struct regmap *map;
 18	struct gpio_chip chip;
 19};
 20
 21static int wcd_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
 22{
 23	struct wcd_gpio_data *data = gpiochip_get_data(chip);
 24	unsigned int value;
 25	int ret;
 26
 27	ret = regmap_read(data->map, WCD_REG_DIR_CTL_OFFSET, &value);
 28	if (ret < 0)
 29		return ret;
 30
 31	if (value & WCD_PIN_MASK(pin))
 32		return GPIO_LINE_DIRECTION_OUT;
 33
 34	return GPIO_LINE_DIRECTION_IN;
 35}
 36
 37static int wcd_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
 38{
 39	struct wcd_gpio_data *data = gpiochip_get_data(chip);
 40
 41	return regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
 42				  WCD_PIN_MASK(pin), 0);
 43}
 44
 45static int wcd_gpio_direction_output(struct gpio_chip *chip, unsigned int pin,
 46				     int val)
 47{
 48	struct wcd_gpio_data *data = gpiochip_get_data(chip);
 49	int ret;
 50
 51	ret = regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
 52				 WCD_PIN_MASK(pin), WCD_PIN_MASK(pin));
 53	if (ret)
 54		return ret;
 55
 56	return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
 57				  WCD_PIN_MASK(pin),
 58				  val ? WCD_PIN_MASK(pin) : 0);
 59}
 60
 61static int wcd_gpio_get(struct gpio_chip *chip, unsigned int pin)
 62{
 63	struct wcd_gpio_data *data = gpiochip_get_data(chip);
 64	unsigned int value;
 65
 66	regmap_read(data->map, WCD_REG_VAL_CTL_OFFSET, &value);
 67
 68	return !!(value & WCD_PIN_MASK(pin));
 69}
 70
 71static int wcd_gpio_set(struct gpio_chip *chip, unsigned int pin, int val)
 72{
 73	struct wcd_gpio_data *data = gpiochip_get_data(chip);
 74
 75	return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
 76				  WCD_PIN_MASK(pin),
 77				  val ? WCD_PIN_MASK(pin) : 0);
 78}
 79
 80static int wcd_gpio_probe(struct platform_device *pdev)
 81{
 82	struct device *dev = &pdev->dev;
 83	struct wcd_gpio_data *data;
 84	struct gpio_chip *chip;
 85
 86	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 87	if (!data)
 88		return -ENOMEM;
 89
 90	data->map = dev_get_regmap(dev->parent, NULL);
 91	if (!data->map) {
 92		dev_err(dev, "%s: failed to get regmap\n", __func__);
 93		return  -EINVAL;
 94	}
 95
 96	chip = &data->chip;
 97	chip->direction_input  = wcd_gpio_direction_input;
 98	chip->direction_output = wcd_gpio_direction_output;
 99	chip->get_direction = wcd_gpio_get_direction;
100	chip->get = wcd_gpio_get;
101	chip->set = wcd_gpio_set;
102	chip->parent = dev;
103	chip->base = -1;
104	chip->ngpio = WCD934X_NPINS;
105	chip->label = dev_name(dev);
106	chip->can_sleep = true;
107
108	return devm_gpiochip_add_data(dev, chip, data);
109}
110
111static const struct of_device_id wcd_gpio_of_match[] = {
112	{ .compatible = "qcom,wcd9340-gpio" },
113	{ .compatible = "qcom,wcd9341-gpio" },
114	{ }
115};
116MODULE_DEVICE_TABLE(of, wcd_gpio_of_match);
117
118static struct platform_driver wcd_gpio_driver = {
119	.driver = {
120		   .name = "wcd934x-gpio",
121		   .of_match_table = wcd_gpio_of_match,
122	},
123	.probe = wcd_gpio_probe,
124};
125
126module_platform_driver(wcd_gpio_driver);
127MODULE_DESCRIPTION("Qualcomm Technologies, Inc WCD GPIO control driver");
128MODULE_LICENSE("GPL v2");