drivers/gpio/wm831x-gpio.c

   1 /*
   2  * wm831x-gpio.c  --  gpiolib support for Wolfson WM831x 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/wm831x/core.h>
  23 #include <linux/mfd/wm831x/pdata.h>
  24 #include <linux/mfd/wm831x/gpio.h>
  25
  26 #define WM831X_GPIO_MAX 16
  27
  28 struct wm831x_gpio {
  29         struct wm831x *wm831x;
  30         struct gpio_chip gpio_chip;
  31 };
  32
  33 static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
  34 {
  35         return container_of(chip, struct wm831x_gpio, gpio_chip);
  36 }
  37
  38 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  39 {
  40         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  41         struct wm831x *wm831x = wm831x_gpio->wm831x;
  42
  43         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  44                                WM831X_GPN_DIR | WM831X_GPN_TRI,
  45                                WM831X_GPN_DIR);
  46 }
  47
  48 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  49 {
  50         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  51         struct wm831x *wm831x = wm831x_gpio->wm831x;
  52         int ret;
  53
  54         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  55         if (ret < 0)
  56                 return ret;
  57
  58         if (ret & 1 << offset)
  59                 return 1;
  60         else
  61                 return 0;
  62 }
  63
  64 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  65                                      unsigned offset, int value)
  66 {
  67         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  68         struct wm831x *wm831x = wm831x_gpio->wm831x;
  69
  70         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  71                                WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
  72 }
  73
  74 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  75 {
  76         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  77         struct wm831x *wm831x = wm831x_gpio->wm831x;
  78
  79         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  80                         value << offset);
  81 }
  82
  83 #ifdef CONFIG_DEBUG_FS
  84 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
  85 {
  86         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  87         struct wm831x *wm831x = wm831x_gpio->wm831x;
  88         int i;
  89
  90         for (i = 0; i < chip->ngpio; i++) {
  91                 int gpio = i + chip->base;
  92                 int reg;
  93                 const char *label, *pull, *powerdomain;
  94
  95                 /* We report the GPIO even if it's not requested since
  96                  * we're also reporting things like alternate
  97                  * functions which apply even when the GPIO is not in
  98                  * use as a GPIO.
  99                  */
 100                 label = gpiochip_is_requested(chip, i);
 101                 if (!label)
 102                         label = "Unrequested";
 103
 104                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 105
 106                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 107                 if (reg < 0) {
 108                         dev_err(wm831x->dev,
 109                                 "GPIO control %d read failed: %d\n",
 110                                 gpio, reg);
 111                         seq_printf(s, "\n");
 112                         continue;
 113                 }
 114
 115                 switch (reg & WM831X_GPN_PULL_MASK) {
 116                 case WM831X_GPIO_PULL_NONE:
 117                         pull = "nopull";
 118                         break;
 119                 case WM831X_GPIO_PULL_DOWN:
 120                         pull = "pulldown";
 121                         break;
 122                 case WM831X_GPIO_PULL_UP:
 123                         pull = "pullup";
 124                 default:
 125                         pull = "INVALID PULL";
 126                         break;
 127                 }
 128
 129                 switch (i + 1) {
 130                 case 1 ... 3:
 131                 case 7 ... 9:
 132                         if (reg & WM831X_GPN_PWR_DOM)
 133                                 powerdomain = "VPMIC";
 134                         else
 135                                 powerdomain = "DBVDD";
 136                         break;
 137
 138                 case 4 ... 6:
 139                 case 10 ... 12:
 140                         if (reg & WM831X_GPN_PWR_DOM)
 141                                 powerdomain = "SYSVDD";
 142                         else
 143                                 powerdomain = "DBVDD";
 144                         break;
 145
 146                 case 13 ... 16:
 147                         powerdomain = "TPVDD";
 148                         break;
 149
 150                 default:
 151                         BUG();
 152                         break;
 153                 }
 154
 155                 seq_printf(s, " %s %s %s %s%s\n"
 156                            "                                  %s%s (0x%4x)\n",
 157                            reg & WM831X_GPN_DIR ? "in" : "out",
 158                            wm831x_gpio_get(chip, i) ? "high" : "low",
 159                            pull,
 160                            powerdomain,
 161                            reg & WM831X_GPN_POL ? " inverted" : "",
 162                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 163                            reg & WM831X_GPN_TRI ? " tristated" : "",
 164                            reg);
 165         }
 166 }
 167 #else
 168 #define wm831x_gpio_dbg_show NULL
 169 #endif
 170
 171 static struct gpio_chip template_chip = {
 172         .label                  = "wm831x",
 173         .owner                  = THIS_MODULE,
 174         .direction_input        = wm831x_gpio_direction_in,
 175         .get                    = wm831x_gpio_get,
 176         .direction_output       = wm831x_gpio_direction_out,
 177         .set                    = wm831x_gpio_set,
 178         .dbg_show               = wm831x_gpio_dbg_show,
 179         .can_sleep              = 1,
 180 };
 181
 182 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 183 {
 184         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 185         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 186         struct wm831x_gpio *wm831x_gpio;
 187         int ret;
 188
 189         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 190         if (wm831x_gpio == NULL)
 191                 return -ENOMEM;
 192
 193         wm831x_gpio->wm831x = wm831x;
 194         wm831x_gpio->gpio_chip = template_chip;
 195         wm831x_gpio->gpio_chip.ngpio = WM831X_GPIO_MAX;
 196         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 197         if (pdata && pdata->gpio_base)
 198                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 199         else
 200                 wm831x_gpio->gpio_chip.base = -1;
 201
 202         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 203         if (ret < 0) {
 204                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 205                         ret);
 206                 goto err;
 207         }
 208
 209         platform_set_drvdata(pdev, wm831x_gpio);
 210
 211         return ret;
 212
 213 err:
 214         kfree(wm831x_gpio);
 215         return ret;
 216 }
 217
 218 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 219 {
 220         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 221         int ret;
 222
 223         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 224         if (ret == 0)
 225                 kfree(wm831x_gpio);
 226
 227         return ret;
 228 }
 229
 230 static struct platform_driver wm831x_gpio_driver = {
 231         .driver.name    = "wm831x-gpio",
 232         .driver.owner   = THIS_MODULE,
 233         .probe          = wm831x_gpio_probe,
 234         .remove         = __devexit_p(wm831x_gpio_remove),
 235 };
 236
 237 static int __init wm831x_gpio_init(void)
 238 {
 239         return platform_driver_register(&wm831x_gpio_driver);
 240 }
 241 subsys_initcall(wm831x_gpio_init);
 242
 243 static void __exit wm831x_gpio_exit(void)
 244 {
 245         platform_driver_unregister(&wm831x_gpio_driver);
 246 }
 247 module_exit(wm831x_gpio_exit);
 248
 249 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 250 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 251 MODULE_LICENSE("GPL");
 252 MODULE_ALIAS("platform:wm831x-gpio");