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 int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  34 {
  35         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
  36         struct wm831x *wm831x = wm831x_gpio->wm831x;
  37         int val = WM831X_GPN_DIR;
  38
  39         if (wm831x->has_gpio_ena)
  40                 val |= WM831X_GPN_TRI;
  41
  42         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  43                                WM831X_GPN_DIR | WM831X_GPN_TRI |
  44                                WM831X_GPN_FN_MASK, val);
  45 }
  46
  47 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  48 {
  49         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
  50         struct wm831x *wm831x = wm831x_gpio->wm831x;
  51         int ret;
  52
  53         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  54         if (ret < 0)
  55                 return ret;
  56
  57         if (ret & 1 << offset)
  58                 return 1;
  59         else
  60                 return 0;
  61 }
  62
  63 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  64 {
  65         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
  66         struct wm831x *wm831x = wm831x_gpio->wm831x;
  67
  68         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  69                         value << offset);
  70 }
  71
  72 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  73                                      unsigned offset, int value)
  74 {
  75         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
  76         struct wm831x *wm831x = wm831x_gpio->wm831x;
  77         int val = 0;
  78         int ret;
  79
  80         if (wm831x->has_gpio_ena)
  81                 val |= WM831X_GPN_TRI;
  82
  83         ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  84                               WM831X_GPN_DIR | WM831X_GPN_TRI |
  85                               WM831X_GPN_FN_MASK, val);
  86         if (ret < 0)
  87                 return ret;
  88
  89         /* Can only set GPIO state once it's in output mode */
  90         wm831x_gpio_set(chip, offset, value);
  91
  92         return 0;
  93 }
  94
  95 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  96 {
  97         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
  98         struct wm831x *wm831x = wm831x_gpio->wm831x;
  99
 100         return irq_create_mapping(wm831x->irq_domain,
 101                                   WM831X_IRQ_GPIO_1 + offset);
 102 }
 103
 104 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
 105                                     unsigned debounce)
 106 {
 107         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 108         struct wm831x *wm831x = wm831x_gpio->wm831x;
 109         int reg = WM831X_GPIO1_CONTROL + offset;
 110         int ret, fn;
 111
 112         ret = wm831x_reg_read(wm831x, reg);
 113         if (ret < 0)
 114                 return ret;
 115
 116         switch (ret & WM831X_GPN_FN_MASK) {
 117         case 0:
 118         case 1:
 119                 break;
 120         default:
 121                 /* Not in GPIO mode */
 122                 return -EBUSY;
 123         }
 124
 125         if (debounce >= 32 && debounce <= 64)
 126                 fn = 0;
 127         else if (debounce >= 4000 && debounce <= 8000)
 128                 fn = 1;
 129         else
 130                 return -EINVAL;
 131
 132         return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
 133 }
 134
 135 static int wm831x_set_single_ended(struct gpio_chip *chip,
 136                                    unsigned int offset,
 137                                    enum single_ended_mode mode)
 138 {
 139         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 140         struct wm831x *wm831x = wm831x_gpio->wm831x;
 141         int reg = WM831X_GPIO1_CONTROL + offset;
 142
 143         switch (mode) {
 144         case LINE_MODE_OPEN_DRAIN:
 145                 return wm831x_set_bits(wm831x, reg,
 146                                        WM831X_GPN_OD_MASK, WM831X_GPN_OD);
 147         case LINE_MODE_PUSH_PULL:
 148                 return wm831x_set_bits(wm831x, reg,
 149                                        WM831X_GPN_OD_MASK, 0);
 150         default:
 151                 break;
 152         }
 153
 154         return -ENOTSUPP;
 155 }
 156
 157 #ifdef CONFIG_DEBUG_FS
 158 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 159 {
 160         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 161         struct wm831x *wm831x = wm831x_gpio->wm831x;
 162         int i, tristated;
 163
 164         for (i = 0; i < chip->ngpio; i++) {
 165                 int gpio = i + chip->base;
 166                 int reg;
 167                 const char *label, *pull, *powerdomain;
 168
 169                 /* We report the GPIO even if it's not requested since
 170                  * we're also reporting things like alternate
 171                  * functions which apply even when the GPIO is not in
 172                  * use as a GPIO.
 173                  */
 174                 label = gpiochip_is_requested(chip, i);
 175                 if (!label)
 176                         label = "Unrequested";
 177
 178                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 179
 180                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 181                 if (reg < 0) {
 182                         dev_err(wm831x->dev,
 183                                 "GPIO control %d read failed: %d\n",
 184                                 gpio, reg);
 185                         seq_printf(s, "\n");
 186                         continue;
 187                 }
 188
 189                 switch (reg & WM831X_GPN_PULL_MASK) {
 190                 case WM831X_GPIO_PULL_NONE:
 191                         pull = "nopull";
 192                         break;
 193                 case WM831X_GPIO_PULL_DOWN:
 194                         pull = "pulldown";
 195                         break;
 196                 case WM831X_GPIO_PULL_UP:
 197                         pull = "pullup";
 198                         break;
 199                 default:
 200                         pull = "INVALID PULL";
 201                         break;
 202                 }
 203
 204                 switch (i + 1) {
 205                 case 1 ... 3:
 206                 case 7 ... 9:
 207                         if (reg & WM831X_GPN_PWR_DOM)
 208                                 powerdomain = "VPMIC";
 209                         else
 210                                 powerdomain = "DBVDD";
 211                         break;
 212
 213                 case 4 ... 6:
 214                 case 10 ... 12:
 215                         if (reg & WM831X_GPN_PWR_DOM)
 216                                 powerdomain = "SYSVDD";
 217                         else
 218                                 powerdomain = "DBVDD";
 219                         break;
 220
 221                 case 13 ... 16:
 222                         powerdomain = "TPVDD";
 223                         break;
 224
 225                 default:
 226                         BUG();
 227                         break;
 228                 }
 229
 230                 tristated = reg & WM831X_GPN_TRI;
 231                 if (wm831x->has_gpio_ena)
 232                         tristated = !tristated;
 233
 234                 seq_printf(s, " %s %s %s %s%s\n"
 235                            "                                  %s%s (0x%4x)\n",
 236                            reg & WM831X_GPN_DIR ? "in" : "out",
 237                            wm831x_gpio_get(chip, i) ? "high" : "low",
 238                            pull,
 239                            powerdomain,
 240                            reg & WM831X_GPN_POL ? "" : " inverted",
 241                            reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
 242                            tristated ? " tristated" : "",
 243                            reg);
 244         }
 245 }
 246 #else
 247 #define wm831x_gpio_dbg_show NULL
 248 #endif
 249
 250 static const struct gpio_chip template_chip = {
 251         .label                  = "wm831x",
 252         .owner                  = THIS_MODULE,
 253         .direction_input        = wm831x_gpio_direction_in,
 254         .get                    = wm831x_gpio_get,
 255         .direction_output       = wm831x_gpio_direction_out,
 256         .set                    = wm831x_gpio_set,
 257         .to_irq                 = wm831x_gpio_to_irq,
 258         .set_debounce           = wm831x_gpio_set_debounce,
 259         .set_single_ended       = wm831x_set_single_ended,
 260         .dbg_show               = wm831x_gpio_dbg_show,
 261         .can_sleep              = true,
 262 };
 263
 264 static int wm831x_gpio_probe(struct platform_device *pdev)
 265 {
 266         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 267         struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 268         struct wm831x_gpio *wm831x_gpio;
 269         int ret;
 270
 271         wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
 272                                    GFP_KERNEL);
 273         if (wm831x_gpio == NULL)
 274                 return -ENOMEM;
 275
 276         wm831x_gpio->wm831x = wm831x;
 277         wm831x_gpio->gpio_chip = template_chip;
 278         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 279         wm831x_gpio->gpio_chip.parent = &pdev->dev;
 280         if (pdata && pdata->gpio_base)
 281                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 282         else
 283                 wm831x_gpio->gpio_chip.base = -1;
 284
 285         ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
 286                                      wm831x_gpio);
 287         if (ret < 0) {
 288                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 289                 return ret;
 290         }
 291
 292         platform_set_drvdata(pdev, wm831x_gpio);
 293
 294         return ret;
 295 }
 296
 297 static struct platform_driver wm831x_gpio_driver = {
 298         .driver.name    = "wm831x-gpio",
 299         .probe          = wm831x_gpio_probe,
 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");