drivers/gpio/gpio-arizona.c

   1 /*
   2  * gpiolib support for Wolfson Arizona class devices
   3  *
   4  * Copyright 2012 Wolfson Microelectronics PLC.
   5  *
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  *
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/gpio.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/seq_file.h>
  21
  22 #include <linux/mfd/arizona/core.h>
  23 #include <linux/mfd/arizona/pdata.h>
  24 #include <linux/mfd/arizona/registers.h>
  25
  26 struct arizona_gpio {
  27         struct arizona *arizona;
  28         struct gpio_chip gpio_chip;
  29 };
  30
  31 static inline struct arizona_gpio *to_arizona_gpio(struct gpio_chip *chip)
  32 {
  33         return container_of(chip, struct arizona_gpio, gpio_chip);
  34 }
  35
  36 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  37 {
  38         struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
  39         struct arizona *arizona = arizona_gpio->arizona;
  40
  41         return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
  42                                   ARIZONA_GPN_DIR, ARIZONA_GPN_DIR);
  43 }
  44
  45 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
  46 {
  47         struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
  48         struct arizona *arizona = arizona_gpio->arizona;
  49         unsigned int val;
  50         int ret;
  51
  52         ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
  53         if (ret < 0)
  54                 return ret;
  55
  56         if (val & ARIZONA_GPN_LVL)
  57                 return 1;
  58         else
  59                 return 0;
  60 }
  61
  62 static int arizona_gpio_direction_out(struct gpio_chip *chip,
  63                                      unsigned offset, int value)
  64 {
  65         struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
  66         struct arizona *arizona = arizona_gpio->arizona;
  67
  68         if (value)
  69                 value = ARIZONA_GPN_LVL;
  70
  71         return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
  72                                   ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
  73 }
  74
  75 static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  76 {
  77         struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
  78         struct arizona *arizona = arizona_gpio->arizona;
  79
  80         if (value)
  81                 value = ARIZONA_GPN_LVL;
  82
  83         regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
  84                            ARIZONA_GPN_LVL, value);
  85 }
  86
  87 static struct gpio_chip template_chip = {
  88         .label                  = "arizona",
  89         .owner                  = THIS_MODULE,
  90         .direction_input        = arizona_gpio_direction_in,
  91         .get                    = arizona_gpio_get,
  92         .direction_output       = arizona_gpio_direction_out,
  93         .set                    = arizona_gpio_set,
  94         .can_sleep              = 1,
  95 };
  96
  97 static int arizona_gpio_probe(struct platform_device *pdev)
  98 {
  99         struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
 100         struct arizona_pdata *pdata = dev_get_platdata(arizona->dev);
 101         struct arizona_gpio *arizona_gpio;
 102         int ret;
 103
 104         arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
 105                                     GFP_KERNEL);
 106         if (arizona_gpio == NULL)
 107                 return -ENOMEM;
 108
 109         arizona_gpio->arizona = arizona;
 110         arizona_gpio->gpio_chip = template_chip;
 111         arizona_gpio->gpio_chip.dev = &pdev->dev;
 112
 113         switch (arizona->type) {
 114         case WM5102:
 115         case WM5110:
 116                 arizona_gpio->gpio_chip.ngpio = 5;
 117                 break;
 118         default:
 119                 dev_err(&pdev->dev, "Unknown chip variant %d\n",
 120                         arizona->type);
 121                 return -EINVAL;
 122         }
 123
 124         if (pdata && pdata->gpio_base)
 125                 arizona_gpio->gpio_chip.base = pdata->gpio_base;
 126         else
 127                 arizona_gpio->gpio_chip.base = -1;
 128
 129         ret = gpiochip_add(&arizona_gpio->gpio_chip);
 130         if (ret < 0) {
 131                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 132                         ret);
 133                 goto err;
 134         }
 135
 136         platform_set_drvdata(pdev, arizona_gpio);
 137
 138         return ret;
 139
 140 err:
 141         return ret;
 142 }
 143
 144 static int arizona_gpio_remove(struct platform_device *pdev)
 145 {
 146         struct arizona_gpio *arizona_gpio = platform_get_drvdata(pdev);
 147
 148         return gpiochip_remove(&arizona_gpio->gpio_chip);
 149 }
 150
 151 static struct platform_driver arizona_gpio_driver = {
 152         .driver.name    = "arizona-gpio",
 153         .driver.owner   = THIS_MODULE,
 154         .probe          = arizona_gpio_probe,
 155         .remove         = arizona_gpio_remove,
 156 };
 157
 158 module_platform_driver(arizona_gpio_driver);
 159
 160 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 161 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
 162 MODULE_LICENSE("GPL");
 163 MODULE_ALIAS("platform:arizona-gpio");