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(gc: chip);
24 unsigned int value;
25 int ret;
26
27 ret = regmap_read(map: data->map, WCD_REG_DIR_CTL_OFFSET, val: &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(gc: chip);
40
41 return regmap_update_bits(map: data->map, WCD_REG_DIR_CTL_OFFSET,
42 WCD_PIN_MASK(pin), val: 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(gc: chip);
49
50 regmap_update_bits(map: data->map, WCD_REG_DIR_CTL_OFFSET,
51 WCD_PIN_MASK(pin), WCD_PIN_MASK(pin));
52
53 return regmap_update_bits(map: data->map, WCD_REG_VAL_CTL_OFFSET,
54 WCD_PIN_MASK(pin),
55 val: val ? WCD_PIN_MASK(pin) : 0);
56}
57
58static int wcd_gpio_get(struct gpio_chip *chip, unsigned int pin)
59{
60 struct wcd_gpio_data *data = gpiochip_get_data(gc: chip);
61 unsigned int value;
62
63 regmap_read(map: data->map, WCD_REG_VAL_CTL_OFFSET, val: &value);
64
65 return !!(value & WCD_PIN_MASK(pin));
66}
67
68static void wcd_gpio_set(struct gpio_chip *chip, unsigned int pin, int val)
69{
70 struct wcd_gpio_data *data = gpiochip_get_data(gc: chip);
71
72 regmap_update_bits(map: data->map, WCD_REG_VAL_CTL_OFFSET,
73 WCD_PIN_MASK(pin), val: val ? WCD_PIN_MASK(pin) : 0);
74}
75
76static int wcd_gpio_probe(struct platform_device *pdev)
77{
78 struct device *dev = &pdev->dev;
79 struct wcd_gpio_data *data;
80 struct gpio_chip *chip;
81
82 data = devm_kzalloc(dev, size: sizeof(*data), GFP_KERNEL);
83 if (!data)
84 return -ENOMEM;
85
86 data->map = dev_get_regmap(dev: dev->parent, NULL);
87 if (!data->map) {
88 dev_err(dev, "%s: failed to get regmap\n", __func__);
89 return -EINVAL;
90 }
91
92 chip = &data->chip;
93 chip->direction_input = wcd_gpio_direction_input;
94 chip->direction_output = wcd_gpio_direction_output;
95 chip->get_direction = wcd_gpio_get_direction;
96 chip->get = wcd_gpio_get;
97 chip->set = wcd_gpio_set;
98 chip->parent = dev;
99 chip->base = -1;
100 chip->ngpio = WCD934X_NPINS;
101 chip->label = dev_name(dev);
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");
125

source code of linux/drivers/gpio/gpio-wcd934x.c