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