linux/drivers/gpio/gpio-arizona.c
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   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
  26struct arizona_gpio {
  27        struct arizona *arizona;
  28        struct gpio_chip gpio_chip;
  29};
  30
  31static inline struct arizona_gpio *to_arizona_gpio(struct gpio_chip *chip)
  32{
  33        return container_of(chip, struct arizona_gpio, gpio_chip);
  34}
  35
  36static 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
  45static 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
  62static 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
  75static 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
  87static 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
  97static int arizona_gpio_probe(struct platform_device *pdev)
  98{
  99        struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
 100        struct arizona_pdata *pdata = arizona->dev->platform_data;
 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
 140err:
 141        return ret;
 142}
 143
 144static 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
 151static 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
 158module_platform_driver(arizona_gpio_driver);
 159
 160MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 161MODULE_DESCRIPTION("GPIO interface for Arizona devices");
 162MODULE_LICENSE("GPL");
 163MODULE_ALIAS("platform:arizona-gpio");
 164
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