drivers/gpio/gpio-wm8350.c

   1 /*
   2  * 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 int wm8350_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  32 {
  33         struct wm8350_gpio_data *wm8350_gpio = gpiochip_get_data(chip);
  34         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  35
  36         return wm8350_set_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  37                                1 << offset);
  38 }
  39
  40 static int wm8350_gpio_get(struct gpio_chip *chip, unsigned offset)
  41 {
  42         struct wm8350_gpio_data *wm8350_gpio = gpiochip_get_data(chip);
  43         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  44         int ret;
  45
  46         ret = wm8350_reg_read(wm8350, WM8350_GPIO_LEVEL);
  47         if (ret < 0)
  48                 return ret;
  49
  50         if (ret & (1 << offset))
  51                 return 1;
  52         else
  53                 return 0;
  54 }
  55
  56 static void wm8350_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  57 {
  58         struct wm8350_gpio_data *wm8350_gpio = gpiochip_get_data(chip);
  59         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  60
  61         if (value)
  62                 wm8350_set_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  63         else
  64                 wm8350_clear_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
  65 }
  66
  67 static int wm8350_gpio_direction_out(struct gpio_chip *chip,
  68                                      unsigned offset, int value)
  69 {
  70         struct wm8350_gpio_data *wm8350_gpio = gpiochip_get_data(chip);
  71         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  72         int ret;
  73
  74         ret = wm8350_clear_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
  75                                 1 << offset);
  76         if (ret < 0)
  77                 return ret;
  78
  79         /* Don't have an atomic direction/value setup */
  80         wm8350_gpio_set(chip, offset, value);
  81
  82         return 0;
  83 }
  84
  85 static int wm8350_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  86 {
  87         struct wm8350_gpio_data *wm8350_gpio = gpiochip_get_data(chip);
  88         struct wm8350 *wm8350 = wm8350_gpio->wm8350;
  89
  90         if (!wm8350->irq_base)
  91                 return -EINVAL;
  92
  93         return wm8350->irq_base + WM8350_IRQ_GPIO(offset);
  94 }
  95
  96 static const struct gpio_chip template_chip = {
  97         .label                  = "wm8350",
  98         .owner                  = THIS_MODULE,
  99         .direction_input        = wm8350_gpio_direction_in,
 100         .get                    = wm8350_gpio_get,
 101         .direction_output       = wm8350_gpio_direction_out,
 102         .set                    = wm8350_gpio_set,
 103         .to_irq                 = wm8350_gpio_to_irq,
 104         .can_sleep              = true,
 105 };
 106
 107 static int wm8350_gpio_probe(struct platform_device *pdev)
 108 {
 109         struct wm8350 *wm8350 = dev_get_drvdata(pdev->dev.parent);
 110         struct wm8350_platform_data *pdata = dev_get_platdata(wm8350->dev);
 111         struct wm8350_gpio_data *wm8350_gpio;
 112         int ret;
 113
 114         wm8350_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm8350_gpio),
 115                                    GFP_KERNEL);
 116         if (wm8350_gpio == NULL)
 117                 return -ENOMEM;
 118
 119         wm8350_gpio->wm8350 = wm8350;
 120         wm8350_gpio->gpio_chip = template_chip;
 121         wm8350_gpio->gpio_chip.ngpio = 13;
 122         wm8350_gpio->gpio_chip.parent = &pdev->dev;
 123         if (pdata && pdata->gpio_base)
 124                 wm8350_gpio->gpio_chip.base = pdata->gpio_base;
 125         else
 126                 wm8350_gpio->gpio_chip.base = -1;
 127
 128         ret = devm_gpiochip_add_data(&pdev->dev, &wm8350_gpio->gpio_chip,
 129                                      wm8350_gpio);
 130         if (ret < 0) {
 131                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 132                 return ret;
 133         }
 134
 135         platform_set_drvdata(pdev, wm8350_gpio);
 136
 137         return ret;
 138 }
 139
 140 static struct platform_driver wm8350_gpio_driver = {
 141         .driver.name    = "wm8350-gpio",
 142         .probe          = wm8350_gpio_probe,
 143 };
 144
 145 static int __init wm8350_gpio_init(void)
 146 {
 147         return platform_driver_register(&wm8350_gpio_driver);
 148 }
 149 subsys_initcall(wm8350_gpio_init);
 150
 151 static void __exit wm8350_gpio_exit(void)
 152 {
 153         platform_driver_unregister(&wm8350_gpio_driver);
 154 }
 155 module_exit(wm8350_gpio_exit);
 156
 157 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 158 MODULE_DESCRIPTION("GPIO interface for WM8350 PMICs");
 159 MODULE_LICENSE("GPL");
 160 MODULE_ALIAS("platform:wm8350-gpio");