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
15 struct wcd_gpio_data {
16 struct regmap *map;
17 struct gpio_chip chip;
18 };
19
wcd_gpio_get_direction(struct gpio_chip * chip,unsigned int pin)20 static 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
wcd_gpio_direction_input(struct gpio_chip * chip,unsigned int pin)36 static 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
wcd_gpio_direction_output(struct gpio_chip * chip,unsigned int pin,int val)44 static 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
wcd_gpio_get(struct gpio_chip * chip,unsigned int pin)57 static 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
wcd_gpio_set(struct gpio_chip * chip,unsigned int pin,int val)67 static 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
wcd_gpio_probe(struct platform_device * pdev)75 static 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->can_sleep = false;
102
103 return devm_gpiochip_add_data(dev, chip, data);
104 }
105
106 static const struct of_device_id wcd_gpio_of_match[] = {
107 { .compatible = "qcom,wcd9340-gpio" },
108 { .compatible = "qcom,wcd9341-gpio" },
109 { }
110 };
111 MODULE_DEVICE_TABLE(of, wcd_gpio_of_match);
112
113 static struct platform_driver wcd_gpio_driver = {
114 .driver = {
115 .name = "wcd934x-gpio",
116 .of_match_table = wcd_gpio_of_match,
117 },
118 .probe = wcd_gpio_probe,
119 };
120
121 module_platform_driver(wcd_gpio_driver);
122 MODULE_DESCRIPTION("Qualcomm Technologies, Inc WCD GPIO control driver");
123 MODULE_LICENSE("GPL v2");
124