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 #include <linux/mfd/wm831x/irq.h>
  26
  27 struct wm831x_gpio {
  28         struct wm831x *wm831x;
  29         struct gpio_chip gpio_chip;
  30 };
  31
  32 static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
  33 {
  34         return container_of(chip, struct wm831x_gpio, gpio_chip);
  35 }
  36
  37 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  38 {
  39         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  40         struct wm831x *wm831x = wm831x_gpio->wm831x;
  41         int val = WM831X_GPN_DIR;
  42
  43         if (wm831x->has_gpio_ena)
  44                 val |= WM831X_GPN_TRI;
  45
  46         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  47                                WM831X_GPN_DIR | WM831X_GPN_TRI |
  48                                WM831X_GPN_FN_MASK, val);
  49 }
  50
  51 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  52 {
  53         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  54         struct wm831x *wm831x = wm831x_gpio->wm831x;
  55         int ret;
  56
  57         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  58         if (ret < 0)
  59                 return ret;
  60
  61         if (ret & 1 << offset)
  62                 return 1;
  63         else
  64                 return 0;
  65 }
  66
  67 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  68 {
  69         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  70         struct wm831x *wm831x = wm831x_gpio->wm831x;
  71
  72         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  73                         value << offset);
  74 }
  75
  76 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  77                                      unsigned offset, int value)
  78 {
  79         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  80         struct wm831x *wm831x = wm831x_gpio->wm831x;
  81         int val = 0;
  82         int ret;
  83
  84         if (wm831x->has_gpio_ena)
  85                 val |= WM831X_GPN_TRI;
  86
  87         ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  88                               WM831X_GPN_DIR | WM831X_GPN_TRI |
  89                               WM831X_GPN_FN_MASK, val);
  90         if (ret < 0)
  91                 return ret;
  92
  93         /* Can only set GPIO state once it's in output mode */
  94         wm831x_gpio_set(chip, offset, value);
  95
  96         return 0;
  97 }
  98
  99 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 100 {
 101         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 102         struct wm831x *wm831x = wm831x_gpio->wm831x;
 103
 104         if (!wm831x->irq_base)
 105                 return -EINVAL;
 106
 107         return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
 108 }
 109
 110 #ifdef CONFIG_DEBUG_FS
 111 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 112 {
 113         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 114         struct wm831x *wm831x = wm831x_gpio->wm831x;
 115         int i, tristated;
 116
 117         for (i = 0; i < chip->ngpio; i++) {
 118                 int gpio = i + chip->base;
 119                 int reg;
 120                 const char *label, *pull, *powerdomain;
 121
 122                 /* We report the GPIO even if it's not requested since
 123                  * we're also reporting things like alternate
 124                  * functions which apply even when the GPIO is not in
 125                  * use as a GPIO.
 126                  */
 127                 label = gpiochip_is_requested(chip, i);
 128                 if (!label)
 129                         label = "Unrequested";
 130
 131                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 132
 133                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 134                 if (reg < 0) {
 135                         dev_err(wm831x->dev,
 136                                 "GPIO control %d read failed: %d\n",
 137                                 gpio, reg);
 138                         seq_printf(s, "\n");
 139                         continue;
 140                 }
 141
 142                 switch (reg & WM831X_GPN_PULL_MASK) {
 143                 case WM831X_GPIO_PULL_NONE:
 144                         pull = "nopull";
 145                         break;
 146                 case WM831X_GPIO_PULL_DOWN:
 147                         pull = "pulldown";
 148                         break;
 149                 case WM831X_GPIO_PULL_UP:
 150                         pull = "pullup";
 151                 default:
 152                         pull = "INVALID PULL";
 153                         break;
 154                 }
 155
 156                 switch (i + 1) {
 157                 case 1 ... 3:
 158                 case 7 ... 9:
 159                         if (reg & WM831X_GPN_PWR_DOM)
 160                                 powerdomain = "VPMIC";
 161                         else
 162                                 powerdomain = "DBVDD";
 163                         break;
 164
 165                 case 4 ... 6:
 166                 case 10 ... 12:
 167                         if (reg & WM831X_GPN_PWR_DOM)
 168                                 powerdomain = "SYSVDD";
 169                         else
 170                                 powerdomain = "DBVDD";
 171                         break;
 172
 173                 case 13 ... 16:
 174                         powerdomain = "TPVDD";
 175                         break;
 176
 177                 default:
 178                         BUG();
 179                         break;
 180                 }
 181
 182                 tristated = reg & WM831X_GPN_TRI;
 183                 if (wm831x->has_gpio_ena)
 184                         tristated = !tristated;
 185
 186                 seq_printf(s, " %s %s %s %s%s\n"
 187                            "                                  %s%s (0x%4x)\n",
 188                            reg & WM831X_GPN_DIR ? "in" : "out",
 189                            wm831x_gpio_get(chip, i) ? "high" : "low",
 190                            pull,
 191                            powerdomain,
 192                            reg & WM831X_GPN_POL ? "" : " inverted",
 193                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 194                            tristated ? " tristated" : "",
 195                            reg);
 196         }
 197 }
 198 #else
 199 #define wm831x_gpio_dbg_show NULL
 200 #endif
 201
 202 static struct gpio_chip template_chip = {
 203         .label                  = "wm831x",
 204         .owner                  = THIS_MODULE,
 205         .direction_input        = wm831x_gpio_direction_in,
 206         .get                    = wm831x_gpio_get,
 207         .direction_output       = wm831x_gpio_direction_out,
 208         .set                    = wm831x_gpio_set,
 209         .to_irq                 = wm831x_gpio_to_irq,
 210         .dbg_show               = wm831x_gpio_dbg_show,
 211         .can_sleep              = 1,
 212 };
 213
 214 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 215 {
 216         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 217         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 218         struct wm831x_gpio *wm831x_gpio;
 219         int ret;
 220
 221         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 222         if (wm831x_gpio == NULL)
 223                 return -ENOMEM;
 224
 225         wm831x_gpio->wm831x = wm831x;
 226         wm831x_gpio->gpio_chip = template_chip;
 227         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 228         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 229         if (pdata && pdata->gpio_base)
 230                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 231         else
 232                 wm831x_gpio->gpio_chip.base = -1;
 233
 234         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 235         if (ret < 0) {
 236                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 237                         ret);
 238                 goto err;
 239         }
 240
 241         platform_set_drvdata(pdev, wm831x_gpio);
 242
 243         return ret;
 244
 245 err:
 246         kfree(wm831x_gpio);
 247         return ret;
 248 }
 249
 250 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 251 {
 252         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 253         int ret;
 254
 255         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 256         if (ret == 0)
 257                 kfree(wm831x_gpio);
 258
 259         return ret;
 260 }
 261
 262 static struct platform_driver wm831x_gpio_driver = {
 263         .driver.name    = "wm831x-gpio",
 264         .driver.owner   = THIS_MODULE,
 265         .probe          = wm831x_gpio_probe,
 266         .remove         = __devexit_p(wm831x_gpio_remove),
 267 };
 268
 269 static int __init wm831x_gpio_init(void)
 270 {
 271         return platform_driver_register(&wm831x_gpio_driver);
 272 }
 273 subsys_initcall(wm831x_gpio_init);
 274
 275 static void __exit wm831x_gpio_exit(void)
 276 {
 277         platform_driver_unregister(&wm831x_gpio_driver);
 278 }
 279 module_exit(wm831x_gpio_exit);
 280
 281 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 282 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 283 MODULE_LICENSE("GPL");
 284 MODULE_ALIAS("platform:wm831x-gpio");