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