drivers/gpio/gpio-wcd934x.c

   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 - 1)
  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
  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
  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
  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
  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
  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
  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->of_gpio_n_cells = 2;
 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");