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