drivers/gpio/gpio-wm831x.c

   1 /*
   2  * 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         return irq_create_mapping(wm831x->irq_domain,
 106                                   WM831X_IRQ_GPIO_1 + offset);
 107 }
 108
 109 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
 110                                     unsigned debounce)
 111 {
 112         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 113         struct wm831x *wm831x = wm831x_gpio->wm831x;
 114         int reg = WM831X_GPIO1_CONTROL + offset;
 115         int ret, fn;
 116
 117         ret = wm831x_reg_read(wm831x, reg);
 118         if (ret < 0)
 119                 return ret;
 120
 121         switch (ret & WM831X_GPN_FN_MASK) {
 122         case 0:
 123         case 1:
 124                 break;
 125         default:
 126                 /* Not in GPIO mode */
 127                 return -EBUSY;
 128         }
 129
 130         if (debounce >= 32 && debounce <= 64)
 131                 fn = 0;
 132         else if (debounce >= 4000 && debounce <= 8000)
 133                 fn = 1;
 134         else
 135                 return -EINVAL;
 136
 137         return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
 138 }
 139
 140 #ifdef CONFIG_DEBUG_FS
 141 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 142 {
 143         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 144         struct wm831x *wm831x = wm831x_gpio->wm831x;
 145         int i, tristated;
 146
 147         for (i = 0; i < chip->ngpio; i++) {
 148                 int gpio = i + chip->base;
 149                 int reg;
 150                 const char *label, *pull, *powerdomain;
 151
 152                 /* We report the GPIO even if it's not requested since
 153                  * we're also reporting things like alternate
 154                  * functions which apply even when the GPIO is not in
 155                  * use as a GPIO.
 156                  */
 157                 label = gpiochip_is_requested(chip, i);
 158                 if (!label)
 159                         label = "Unrequested";
 160
 161                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 162
 163                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 164                 if (reg < 0) {
 165                         dev_err(wm831x->dev,
 166                                 "GPIO control %d read failed: %d\n",
 167                                 gpio, reg);
 168                         seq_printf(s, "\n");
 169                         continue;
 170                 }
 171
 172                 switch (reg & WM831X_GPN_PULL_MASK) {
 173                 case WM831X_GPIO_PULL_NONE:
 174                         pull = "nopull";
 175                         break;
 176                 case WM831X_GPIO_PULL_DOWN:
 177                         pull = "pulldown";
 178                         break;
 179                 case WM831X_GPIO_PULL_UP:
 180                         pull = "pullup";
 181                         break;
 182                 default:
 183                         pull = "INVALID PULL";
 184                         break;
 185                 }
 186
 187                 switch (i + 1) {
 188                 case 1 ... 3:
 189                 case 7 ... 9:
 190                         if (reg & WM831X_GPN_PWR_DOM)
 191                                 powerdomain = "VPMIC";
 192                         else
 193                                 powerdomain = "DBVDD";
 194                         break;
 195
 196                 case 4 ... 6:
 197                 case 10 ... 12:
 198                         if (reg & WM831X_GPN_PWR_DOM)
 199                                 powerdomain = "SYSVDD";
 200                         else
 201                                 powerdomain = "DBVDD";
 202                         break;
 203
 204                 case 13 ... 16:
 205                         powerdomain = "TPVDD";
 206                         break;
 207
 208                 default:
 209                         BUG();
 210                         break;
 211                 }
 212
 213                 tristated = reg & WM831X_GPN_TRI;
 214                 if (wm831x->has_gpio_ena)
 215                         tristated = !tristated;
 216
 217                 seq_printf(s, " %s %s %s %s%s\n"
 218                            "                                  %s%s (0x%4x)\n",
 219                            reg & WM831X_GPN_DIR ? "in" : "out",
 220                            wm831x_gpio_get(chip, i) ? "high" : "low",
 221                            pull,
 222                            powerdomain,
 223                            reg & WM831X_GPN_POL ? "" : " inverted",
 224                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 225                            tristated ? " tristated" : "",
 226                            reg);
 227         }
 228 }
 229 #else
 230 #define wm831x_gpio_dbg_show NULL
 231 #endif
 232
 233 static struct gpio_chip template_chip = {
 234         .label                  = "wm831x",
 235         .owner                  = THIS_MODULE,
 236         .direction_input        = wm831x_gpio_direction_in,
 237         .get                    = wm831x_gpio_get,
 238         .direction_output       = wm831x_gpio_direction_out,
 239         .set                    = wm831x_gpio_set,
 240         .to_irq                 = wm831x_gpio_to_irq,
 241         .set_debounce           = wm831x_gpio_set_debounce,
 242         .dbg_show               = wm831x_gpio_dbg_show,
 243         .can_sleep              = true,
 244 };
 245
 246 static int wm831x_gpio_probe(struct platform_device *pdev)
 247 {
 248         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 249         struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 250         struct wm831x_gpio *wm831x_gpio;
 251         int ret;
 252
 253         wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
 254                                    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", ret);
 270                 return ret;
 271         }
 272
 273         platform_set_drvdata(pdev, wm831x_gpio);
 274
 275         return ret;
 276 }
 277
 278 static int wm831x_gpio_remove(struct platform_device *pdev)
 279 {
 280         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 281
 282         gpiochip_remove(&wm831x_gpio->gpio_chip);
 283         return 0;
 284 }
 285
 286 static struct platform_driver wm831x_gpio_driver = {
 287         .driver.name    = "wm831x-gpio",
 288         .driver.owner   = THIS_MODULE,
 289         .probe          = wm831x_gpio_probe,
 290         .remove         = wm831x_gpio_remove,
 291 };
 292
 293 static int __init wm831x_gpio_init(void)
 294 {
 295         return platform_driver_register(&wm831x_gpio_driver);
 296 }
 297 subsys_initcall(wm831x_gpio_init);
 298
 299 static void __exit wm831x_gpio_exit(void)
 300 {
 301         platform_driver_unregister(&wm831x_gpio_driver);
 302 }
 303 module_exit(wm831x_gpio_exit);
 304
 305 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 306 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 307 MODULE_LICENSE("GPL");
 308 MODULE_ALIAS("platform:wm831x-gpio");