drivers/gpio/wm8350-gpiolib.c

   1 /*
   2  * wm835x-gpiolib.c  --  gpiolib support for Wolfson WM835x PMICs
   3  *
   4  * Copyright 2009 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/mfd/core.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/seq_file.h>
  22
  23 #include <linux/mfd/wm8350/core.h>
  24 #include <linux/mfd/wm8350/gpio.h>
  25
  26 struct wm8350_gpio_data {
  27         struct wm8350 *wm8350;
  28         struct gpio_chip gpio_chip;
  29 };
  30
  31 static inline struct wm8350_gpio_data *to_wm8350_gpio(struct gpio_chip *chip)
  32 {
  33         return container_of(chip, struct wm8350_gpio_data, gpio_chip);
  34 }
  35
  36 static int wm8350_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  37 {
  38         struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  39         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  40
  41         return wm8350_set_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  42                                1 << offset);
  43 }
  44
  45 static int wm8350_gpio_get(struct gpio_chip *chip, unsigned offset)
  46 {
  47         struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  48         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  49         int ret;
  50
  51         ret = wm8350_reg_read(wm8350, WM8350_GPIO_LEVEL);
  52         if (ret < 0)
  53                 return ret;
  54
  55         if (ret & (1 << offset))
  56                 return 1;
  57         else
  58                 return 0;
  59 }
  60
  61 static void wm8350_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  62 {
  63         struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  64         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  65
  66         if (value)
  67                 wm8350_set_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  68         else
  69                 wm8350_clear_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  70 }
  71
  72 static int wm8350_gpio_direction_out(struct gpio_chip *chip,
  73                                      unsigned offset, int value)
  74 {
  75         struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  76         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  77         int ret;
  78
  79         ret = wm8350_clear_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  80                                 1 << offset);
  81         if (ret < 0)
  82                 return ret;
  83
  84         /* Don't have an atomic direction/value setup */
  85         wm8350_gpio_set(chip, offset, value);
  86
  87         return 0;
  88 }
  89
  90 static int wm8350_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  91 {
  92         struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
  93         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  94
  95         if (!wm8350->irq_base)
  96                 return -EINVAL;
  97
  98         return wm8350->irq_base + WM8350_IRQ_GPIO(offset);
  99 }
 100
 101 static struct gpio_chip template_chip = {
 102         .label                  = "wm8350",
 103         .owner                  = THIS_MODULE,
 104         .direction_input        = wm8350_gpio_direction_in,
 105         .get                    = wm8350_gpio_get,
 106         .direction_output       = wm8350_gpio_direction_out,
 107         .set                    = wm8350_gpio_set,
 108         .to_irq                 = wm8350_gpio_to_irq,
 109         .can_sleep              = 1,
 110 };
 111
 112 static int __devinit wm8350_gpio_probe(struct platform_device *pdev)
 113 {
 114         struct wm8350 *wm8350 = dev_get_drvdata(pdev->dev.parent);
 115         struct wm8350_platform_data *pdata = wm8350->dev->platform_data;
 116         struct wm8350_gpio_data *wm8350_gpio;
 117         int ret;
 118
 119         wm8350_gpio = kzalloc(sizeof(*wm8350_gpio), GFP_KERNEL);
 120         if (wm8350_gpio == NULL)
 121                 return -ENOMEM;
 122
 123         wm8350_gpio->wm8350 = wm8350;
 124         wm8350_gpio->gpio_chip = template_chip;
 125         wm8350_gpio->gpio_chip.ngpio = 13;
 126         wm8350_gpio->gpio_chip.dev = &pdev->dev;
 127         if (pdata && pdata->gpio_base)
 128                 wm8350_gpio->gpio_chip.base = pdata->gpio_base;
 129         else
 130                 wm8350_gpio->gpio_chip.base = -1;
 131
 132         ret = gpiochip_add(&wm8350_gpio->gpio_chip);
 133         if (ret < 0) {
 134                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 135                         ret);
 136                 goto err;
 137         }
 138
 139         platform_set_drvdata(pdev, wm8350_gpio);
 140
 141         return ret;
 142
 143 err:
 144         kfree(wm8350_gpio);
 145         return ret;
 146 }
 147
 148 static int __devexit wm8350_gpio_remove(struct platform_device *pdev)
 149 {
 150         struct wm8350_gpio_data *wm8350_gpio = platform_get_drvdata(pdev);
 151         int ret;
 152
 153         ret = gpiochip_remove(&wm8350_gpio->gpio_chip);
 154         if (ret == 0)
 155                 kfree(wm8350_gpio);
 156
 157         return ret;
 158 }
 159
 160 static struct platform_driver wm8350_gpio_driver = {
 161         .driver.name    = "wm8350-gpio",
 162         .driver.owner   = THIS_MODULE,
 163         .probe          = wm8350_gpio_probe,
 164         .remove         = __devexit_p(wm8350_gpio_remove),
 165 };
 166
 167 static int __init wm8350_gpio_init(void)
 168 {
 169         return platform_driver_register(&wm8350_gpio_driver);
 170 }
 171 subsys_initcall(wm8350_gpio_init);
 172
 173 static void __exit wm8350_gpio_exit(void)
 174 {
 175         platform_driver_unregister(&wm8350_gpio_driver);
 176 }
 177 module_exit(wm8350_gpio_exit);
 178
 179 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 180 MODULE_DESCRIPTION("GPIO interface for WM8350 PMICs");
 181 MODULE_LICENSE("GPL");
 182 MODULE_ALIAS("platform:wm8350-gpio");