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                 default:
 184                         pull = "INVALID PULL";
 185                         break;
 186                 }
 187
 188                 switch (i + 1) {
 189                 case 1 ... 3:
 190                 case 7 ... 9:
 191                         if (reg & WM831X_GPN_PWR_DOM)
 192                                 powerdomain = "VPMIC";
 193                         else
 194                                 powerdomain = "DBVDD";
 195                         break;
 196
 197                 case 4 ... 6:
 198                 case 10 ... 12:
 199                         if (reg & WM831X_GPN_PWR_DOM)
 200                                 powerdomain = "SYSVDD";
 201                         else
 202                                 powerdomain = "DBVDD";
 203                         break;
 204
 205                 case 13 ... 16:
 206                         powerdomain = "TPVDD";
 207                         break;
 208
 209                 default:
 210                         BUG();
 211                         break;
 212                 }
 213
 214                 tristated = reg & WM831X_GPN_TRI;
 215                 if (wm831x->has_gpio_ena)
 216                         tristated = !tristated;
 217
 218                 seq_printf(s, " %s %s %s %s%s\n"
 219                            "                                  %s%s (0x%4x)\n",
 220                            reg & WM831X_GPN_DIR ? "in" : "out",
 221                            wm831x_gpio_get(chip, i) ? "high" : "low",
 222                            pull,
 223                            powerdomain,
 224                            reg & WM831X_GPN_POL ? "" : " inverted",
 225                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 226                            tristated ? " tristated" : "",
 227                            reg);
 228         }
 229 }
 230 #else
 231 #define wm831x_gpio_dbg_show NULL
 232 #endif
 233
 234 static struct gpio_chip template_chip = {
 235         .label                  = "wm831x",
 236         .owner                  = THIS_MODULE,
 237         .direction_input        = wm831x_gpio_direction_in,
 238         .get                    = wm831x_gpio_get,
 239         .direction_output       = wm831x_gpio_direction_out,
 240         .set                    = wm831x_gpio_set,
 241         .to_irq                 = wm831x_gpio_to_irq,
 242         .set_debounce           = wm831x_gpio_set_debounce,
 243         .dbg_show               = wm831x_gpio_dbg_show,
 244         .can_sleep              = 1,
 245 };
 246
 247 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 248 {
 249         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 250         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 251         struct wm831x_gpio *wm831x_gpio;
 252         int ret;
 253
 254         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 255         if (wm831x_gpio == NULL)
 256                 return -ENOMEM;
 257
 258         wm831x_gpio->wm831x = wm831x;
 259         wm831x_gpio->gpio_chip = template_chip;
 260         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 261         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 262         if (pdata && pdata->gpio_base)
 263                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 264         else
 265                 wm831x_gpio->gpio_chip.base = -1;
 266
 267         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 268         if (ret < 0) {
 269                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 270                         ret);
 271                 goto err;
 272         }
 273
 274         platform_set_drvdata(pdev, wm831x_gpio);
 275
 276         return ret;
 277
 278 err:
 279         kfree(wm831x_gpio);
 280         return ret;
 281 }
 282
 283 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 284 {
 285         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 286         int ret;
 287
 288         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 289         if (ret == 0)
 290                 kfree(wm831x_gpio);
 291
 292         return ret;
 293 }
 294
 295 static struct platform_driver wm831x_gpio_driver = {
 296         .driver.name    = "wm831x-gpio",
 297         .driver.owner   = THIS_MODULE,
 298         .probe          = wm831x_gpio_probe,
 299         .remove         = __devexit_p(wm831x_gpio_remove),
 300 };
 301
 302 static int __init wm831x_gpio_init(void)
 303 {
 304         return platform_driver_register(&wm831x_gpio_driver);
 305 }
 306 subsys_initcall(wm831x_gpio_init);
 307
 308 static void __exit wm831x_gpio_exit(void)
 309 {
 310         platform_driver_unregister(&wm831x_gpio_driver);
 311 }
 312 module_exit(wm831x_gpio_exit);
 313
 314 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 315 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 316 MODULE_LICENSE("GPL");
 317 MODULE_ALIAS("platform:wm831x-gpio");