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/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/wm831x/core.h>
  24 #include <linux/mfd/wm831x/pdata.h>
  25 #include <linux/mfd/wm831x/gpio.h>
  26 #include <linux/mfd/wm831x/irq.h>
  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         int val = WM831X_GPN_DIR;
  43
  44         if (wm831x->has_gpio_ena)
  45                 val |= WM831X_GPN_TRI;
  46
  47         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  48                                WM831X_GPN_DIR | WM831X_GPN_TRI |
  49                                WM831X_GPN_FN_MASK, val);
  50 }
  51
  52 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  53 {
  54         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  55         struct wm831x *wm831x = wm831x_gpio->wm831x;
  56         int ret;
  57
  58         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  59         if (ret < 0)
  60                 return ret;
  61
  62         if (ret & 1 << offset)
  63                 return 1;
  64         else
  65                 return 0;
  66 }
  67
  68 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  69 {
  70         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  71         struct wm831x *wm831x = wm831x_gpio->wm831x;
  72
  73         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  74                         value << offset);
  75 }
  76
  77 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  78                                      unsigned offset, int value)
  79 {
  80         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  81         struct wm831x *wm831x = wm831x_gpio->wm831x;
  82         int val = 0;
  83         int ret;
  84
  85         if (wm831x->has_gpio_ena)
  86                 val |= WM831X_GPN_TRI;
  87
  88         ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  89                               WM831X_GPN_DIR | WM831X_GPN_TRI |
  90                               WM831X_GPN_FN_MASK, val);
  91         if (ret < 0)
  92                 return ret;
  93
  94         /* Can only set GPIO state once it's in output mode */
  95         wm831x_gpio_set(chip, offset, value);
  96
  97         return 0;
  98 }
  99
 100 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 101 {
 102         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 103         struct wm831x *wm831x = wm831x_gpio->wm831x;
 104
 105         if (!wm831x->irq_base)
 106                 return -EINVAL;
 107
 108         return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
 109 }
 110
 111 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
 112                                     unsigned debounce)
 113 {
 114         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 115         struct wm831x *wm831x = wm831x_gpio->wm831x;
 116         int reg = WM831X_GPIO1_CONTROL + offset;
 117         int ret, fn;
 118
 119         ret = wm831x_reg_read(wm831x, reg);
 120         if (ret < 0)
 121                 return ret;
 122
 123         switch (ret & WM831X_GPN_FN_MASK) {
 124         case 0:
 125         case 1:
 126                 break;
 127         default:
 128                 /* Not in GPIO mode */
 129                 return -EBUSY;
 130         }
 131
 132         if (debounce >= 32 && debounce <= 64)
 133                 fn = 0;
 134         else if (debounce >= 4000 && debounce <= 8000)
 135                 fn = 1;
 136         else
 137                 return -EINVAL;
 138
 139         return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
 140 }
 141
 142 #ifdef CONFIG_DEBUG_FS
 143 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 144 {
 145         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 146         struct wm831x *wm831x = wm831x_gpio->wm831x;
 147         int i, tristated;
 148
 149         for (i = 0; i < chip->ngpio; i++) {
 150                 int gpio = i + chip->base;
 151                 int reg;
 152                 const char *label, *pull, *powerdomain;
 153
 154                 /* We report the GPIO even if it's not requested since
 155                  * we're also reporting things like alternate
 156                  * functions which apply even when the GPIO is not in
 157                  * use as a GPIO.
 158                  */
 159                 label = gpiochip_is_requested(chip, i);
 160                 if (!label)
 161                         label = "Unrequested";
 162
 163                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 164
 165                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 166                 if (reg < 0) {
 167                         dev_err(wm831x->dev,
 168                                 "GPIO control %d read failed: %d\n",
 169                                 gpio, reg);
 170                         seq_printf(s, "\n");
 171                         continue;
 172                 }
 173
 174                 switch (reg & WM831X_GPN_PULL_MASK) {
 175                 case WM831X_GPIO_PULL_NONE:
 176                         pull = "nopull";
 177                         break;
 178                 case WM831X_GPIO_PULL_DOWN:
 179                         pull = "pulldown";
 180                         break;
 181                 case WM831X_GPIO_PULL_UP:
 182                         pull = "pullup";
 183                         break;
 184                 default:
 185                         pull = "INVALID PULL";
 186                         break;
 187                 }
 188
 189                 switch (i + 1) {
 190                 case 1 ... 3:
 191                 case 7 ... 9:
 192                         if (reg & WM831X_GPN_PWR_DOM)
 193                                 powerdomain = "VPMIC";
 194                         else
 195                                 powerdomain = "DBVDD";
 196                         break;
 197
 198                 case 4 ... 6:
 199                 case 10 ... 12:
 200                         if (reg & WM831X_GPN_PWR_DOM)
 201                                 powerdomain = "SYSVDD";
 202                         else
 203                                 powerdomain = "DBVDD";
 204                         break;
 205
 206                 case 13 ... 16:
 207                         powerdomain = "TPVDD";
 208                         break;
 209
 210                 default:
 211                         BUG();
 212                         break;
 213                 }
 214
 215                 tristated = reg & WM831X_GPN_TRI;
 216                 if (wm831x->has_gpio_ena)
 217                         tristated = !tristated;
 218
 219                 seq_printf(s, " %s %s %s %s%s\n"
 220                            "                                  %s%s (0x%4x)\n",
 221                            reg & WM831X_GPN_DIR ? "in" : "out",
 222                            wm831x_gpio_get(chip, i) ? "high" : "low",
 223                            pull,
 224                            powerdomain,
 225                            reg & WM831X_GPN_POL ? "" : " inverted",
 226                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 227                            tristated ? " tristated" : "",
 228                            reg);
 229         }
 230 }
 231 #else
 232 #define wm831x_gpio_dbg_show NULL
 233 #endif
 234
 235 static struct gpio_chip template_chip = {
 236         .label                  = "wm831x",
 237         .owner                  = THIS_MODULE,
 238         .direction_input        = wm831x_gpio_direction_in,
 239         .get                    = wm831x_gpio_get,
 240         .direction_output       = wm831x_gpio_direction_out,
 241         .set                    = wm831x_gpio_set,
 242         .to_irq                 = wm831x_gpio_to_irq,
 243         .set_debounce           = wm831x_gpio_set_debounce,
 244         .dbg_show               = wm831x_gpio_dbg_show,
 245         .can_sleep              = 1,
 246 };
 247
 248 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 249 {
 250         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 251         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 252         struct wm831x_gpio *wm831x_gpio;
 253         int ret;
 254
 255         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 256         if (wm831x_gpio == NULL)
 257                 return -ENOMEM;
 258
 259         wm831x_gpio->wm831x = wm831x;
 260         wm831x_gpio->gpio_chip = template_chip;
 261         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 262         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 263         if (pdata && pdata->gpio_base)
 264                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 265         else
 266                 wm831x_gpio->gpio_chip.base = -1;
 267
 268         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 269         if (ret < 0) {
 270                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 271                         ret);
 272                 goto err;
 273         }
 274
 275         platform_set_drvdata(pdev, wm831x_gpio);
 276
 277         return ret;
 278
 279 err:
 280         kfree(wm831x_gpio);
 281         return ret;
 282 }
 283
 284 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 285 {
 286         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 287         int ret;
 288
 289         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 290         if (ret == 0)
 291                 kfree(wm831x_gpio);
 292
 293         return ret;
 294 }
 295
 296 static struct platform_driver wm831x_gpio_driver = {
 297         .driver.name    = "wm831x-gpio",
 298         .driver.owner   = THIS_MODULE,
 299         .probe          = wm831x_gpio_probe,
 300         .remove         = __devexit_p(wm831x_gpio_remove),
 301 };
 302
 303 static int __init wm831x_gpio_init(void)
 304 {
 305         return platform_driver_register(&wm831x_gpio_driver);
 306 }
 307 subsys_initcall(wm831x_gpio_init);
 308
 309 static void __exit wm831x_gpio_exit(void)
 310 {
 311         platform_driver_unregister(&wm831x_gpio_driver);
 312 }
 313 module_exit(wm831x_gpio_exit);
 314
 315 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 316 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 317 MODULE_LICENSE("GPL");
 318 MODULE_ALIAS("platform:wm831x-gpio");