drivers/gpio/wm8994-gpio.c

   1 /*
   2  * wm8994-gpio.c  --  gpiolib support for Wolfson WM8994
   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/wm8994/core.h>
  24 #include <linux/mfd/wm8994/pdata.h>
  25 #include <linux/mfd/wm8994/gpio.h>
  26 #include <linux/mfd/wm8994/registers.h>
  27
  28 struct wm8994_gpio {
  29         struct wm8994 *wm8994;
  30         struct gpio_chip gpio_chip;
  31 };
  32
  33 static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
  34 {
  35         return container_of(chip, struct wm8994_gpio, gpio_chip);
  36 }
  37
  38 static int wm8994_gpio_request(struct gpio_chip *chip, unsigned offset)
  39 {
  40         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  41         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  42
  43         switch (wm8994->type) {
  44         case WM8958:
  45                 switch (offset) {
  46                 case 1:
  47                 case 2:
  48                 case 3:
  49                 case 4:
  50                 case 6:
  51                         return -EINVAL;
  52                 }
  53                 break;
  54         default:
  55                 break;
  56         }
  57
  58         return 0;
  59 }
  60
  61 static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  62 {
  63         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  64         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  65
  66         return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  67                                WM8994_GPN_DIR, WM8994_GPN_DIR);
  68 }
  69
  70 static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
  71 {
  72         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  73         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  74         int ret;
  75
  76         ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
  77         if (ret < 0)
  78                 return ret;
  79
  80         if (ret & WM8994_GPN_LVL)
  81                 return 1;
  82         else
  83                 return 0;
  84 }
  85
  86 static int wm8994_gpio_direction_out(struct gpio_chip *chip,
  87                                      unsigned offset, int value)
  88 {
  89         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  90         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  91
  92         return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  93                                WM8994_GPN_DIR, 0);
  94 }
  95
  96 static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  97 {
  98         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  99         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 100
 101         if (value)
 102                 value = WM8994_GPN_LVL;
 103
 104         wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
 105 }
 106
 107 static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 108 {
 109         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
 110         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 111
 112         if (!wm8994->irq_base)
 113                 return -EINVAL;
 114
 115         return wm8994->irq_base + offset;
 116 }
 117
 118
 119 #ifdef CONFIG_DEBUG_FS
 120 static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 121 {
 122         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
 123         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 124         int i;
 125
 126         for (i = 0; i < chip->ngpio; i++) {
 127                 int gpio = i + chip->base;
 128                 int reg;
 129                 const char *label;
 130
 131                 /* We report the GPIO even if it's not requested since
 132                  * we're also reporting things like alternate
 133                  * functions which apply even when the GPIO is not in
 134                  * use as a GPIO.
 135                  */
 136                 label = gpiochip_is_requested(chip, i);
 137                 if (!label)
 138                         label = "Unrequested";
 139
 140                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 141
 142                 reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
 143                 if (reg < 0) {
 144                         dev_err(wm8994->dev,
 145                                 "GPIO control %d read failed: %d\n",
 146                                 gpio, reg);
 147                         seq_printf(s, "\n");
 148                         continue;
 149                 }
 150
 151                 /* No decode yet; note that GPIO2 is special */
 152                 seq_printf(s, "(%x)\n", reg);
 153         }
 154 }
 155 #else
 156 #define wm8994_gpio_dbg_show NULL
 157 #endif
 158
 159 static struct gpio_chip template_chip = {
 160         .label                  = "wm8994",
 161         .owner                  = THIS_MODULE,
 162         .request                = wm8994_gpio_request,
 163         .direction_input        = wm8994_gpio_direction_in,
 164         .get                    = wm8994_gpio_get,
 165         .direction_output       = wm8994_gpio_direction_out,
 166         .set                    = wm8994_gpio_set,
 167         .to_irq                 = wm8994_gpio_to_irq,
 168         .dbg_show               = wm8994_gpio_dbg_show,
 169         .can_sleep              = 1,
 170 };
 171
 172 static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
 173 {
 174         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 175         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 176         struct wm8994_gpio *wm8994_gpio;
 177         int ret;
 178
 179         wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
 180         if (wm8994_gpio == NULL)
 181                 return -ENOMEM;
 182
 183         wm8994_gpio->wm8994 = wm8994;
 184         wm8994_gpio->gpio_chip = template_chip;
 185         wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
 186         wm8994_gpio->gpio_chip.dev = &pdev->dev;
 187         if (pdata && pdata->gpio_base)
 188                 wm8994_gpio->gpio_chip.base = pdata->gpio_base;
 189         else
 190                 wm8994_gpio->gpio_chip.base = -1;
 191
 192         ret = gpiochip_add(&wm8994_gpio->gpio_chip);
 193         if (ret < 0) {
 194                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 195                         ret);
 196                 goto err;
 197         }
 198
 199         platform_set_drvdata(pdev, wm8994_gpio);
 200
 201         return ret;
 202
 203 err:
 204         kfree(wm8994_gpio);
 205         return ret;
 206 }
 207
 208 static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
 209 {
 210         struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
 211         int ret;
 212
 213         ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
 214         if (ret == 0)
 215                 kfree(wm8994_gpio);
 216
 217         return ret;
 218 }
 219
 220 static struct platform_driver wm8994_gpio_driver = {
 221         .driver.name    = "wm8994-gpio",
 222         .driver.owner   = THIS_MODULE,
 223         .probe          = wm8994_gpio_probe,
 224         .remove         = __devexit_p(wm8994_gpio_remove),
 225 };
 226
 227 static int __init wm8994_gpio_init(void)
 228 {
 229         return platform_driver_register(&wm8994_gpio_driver);
 230 }
 231 subsys_initcall(wm8994_gpio_init);
 232
 233 static void __exit wm8994_gpio_exit(void)
 234 {
 235         platform_driver_unregister(&wm8994_gpio_driver);
 236 }
 237 module_exit(wm8994_gpio_exit);
 238
 239 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 240 MODULE_DESCRIPTION("GPIO interface for WM8994");
 241 MODULE_LICENSE("GPL");
 242 MODULE_ALIAS("platform:wm8994-gpio");