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 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
wcd_gpio_get(struct gpio_chip * chip,unsigned int pin)61 static 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
wcd_gpio_set(struct gpio_chip * chip,unsigned int pin,int val)71 static void 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 regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
76 WCD_PIN_MASK(pin), val ? WCD_PIN_MASK(pin) : 0);
77 }
78
wcd_gpio_probe(struct platform_device * pdev)79 static int wcd_gpio_probe(struct platform_device *pdev)
80 {
81 struct device *dev = &pdev->dev;
82 struct wcd_gpio_data *data;
83 struct gpio_chip *chip;
84
85 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
86 if (!data)
87 return -ENOMEM;
88
89 data->map = dev_get_regmap(dev->parent, NULL);
90 if (!data->map) {
91 dev_err(dev, "%s: failed to get regmap\n", __func__);
92 return -EINVAL;
93 }
94
95 chip = &data->chip;
96 chip->direction_input = wcd_gpio_direction_input;
97 chip->direction_output = wcd_gpio_direction_output;
98 chip->get_direction = wcd_gpio_get_direction;
99 chip->get = wcd_gpio_get;
100 chip->set = wcd_gpio_set;
101 chip->parent = dev;
102 chip->base = -1;
103 chip->ngpio = WCD934X_NPINS;
104 chip->label = dev_name(dev);
105 chip->can_sleep = false;
106
107 return devm_gpiochip_add_data(dev, chip, data);
108 }
109
110 static const struct of_device_id wcd_gpio_of_match[] = {
111 { .compatible = "qcom,wcd9340-gpio" },
112 { .compatible = "qcom,wcd9341-gpio" },
113 { }
114 };
115 MODULE_DEVICE_TABLE(of, wcd_gpio_of_match);
116
117 static struct platform_driver wcd_gpio_driver = {
118 .driver = {
119 .name = "wcd934x-gpio",
120 .of_match_table = wcd_gpio_of_match,
121 },
122 .probe = wcd_gpio_probe,
123 };
124
125 module_platform_driver(wcd_gpio_driver);
126 MODULE_DESCRIPTION("Qualcomm Technologies, Inc WCD GPIO control driver");
127 MODULE_LICENSE("GPL v2");
128