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
16 struct wcd_gpio_data {
17 struct regmap *map;
18 struct gpio_chip chip;
19 };
20
wcd_gpio_get_direction(struct gpio_chip * chip,unsigned int pin)21 static 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
wcd_gpio_direction_input(struct gpio_chip * chip,unsigned int pin)37 static 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
wcd_gpio_direction_output(struct gpio_chip * chip,unsigned int pin,int val)45 static 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
50 regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
51 WCD_PIN_MASK(pin), WCD_PIN_MASK(pin));
52
53 return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
54 WCD_PIN_MASK(pin),
55 val ? WCD_PIN_MASK(pin) : 0);
56 }
57
wcd_gpio_get(struct gpio_chip * chip,unsigned int pin)58 static int wcd_gpio_get(struct gpio_chip *chip, unsigned int pin)
59 {
60 struct wcd_gpio_data *data = gpiochip_get_data(chip);
61 unsigned int value;
62
63 regmap_read(data->map, WCD_REG_VAL_CTL_OFFSET, &value);
64
65 return !!(value & WCD_PIN_MASK(pin));
66 }
67
wcd_gpio_set(struct gpio_chip * chip,unsigned int pin,int val)68 static void wcd_gpio_set(struct gpio_chip *chip, unsigned int pin, int val)
69 {
70 struct wcd_gpio_data *data = gpiochip_get_data(chip);
71
72 regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
73 WCD_PIN_MASK(pin), val ? WCD_PIN_MASK(pin) : 0);
74 }
75
wcd_gpio_probe(struct platform_device * pdev)76 static 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, sizeof(*data), GFP_KERNEL);
83 if (!data)
84 return -ENOMEM;
85
86 data->map = dev_get_regmap(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
107 static const struct of_device_id wcd_gpio_of_match[] = {
108 { .compatible = "qcom,wcd9340-gpio" },
109 { .compatible = "qcom,wcd9341-gpio" },
110 { }
111 };
112 MODULE_DEVICE_TABLE(of, wcd_gpio_of_match);
113
114 static 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
122 module_platform_driver(wcd_gpio_driver);
123 MODULE_DESCRIPTION("Qualcomm Technologies, Inc WCD GPIO control driver");
124 MODULE_LICENSE("GPL v2");
125