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 #ifdef CONFIG_DEBUG_FS
 136 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 137 {
 138         struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 139         struct wm831x *wm831x = wm831x_gpio->wm831x;
 140         int i, tristated;
 141
 142         for (i = 0; i < chip->ngpio; i++) {
 143                 int gpio = i + chip->base;
 144                 int reg;
 145                 const char *label, *pull, *powerdomain;
 146
 147                 /* We report the GPIO even if it's not requested since
 148                  * we're also reporting things like alternate
 149                  * functions which apply even when the GPIO is not in
 150                  * use as a GPIO.
 151                  */
 152                 label = gpiochip_is_requested(chip, i);
 153                 if (!label)
 154                         label = "Unrequested";
 155
 156                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 157
 158                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 159                 if (reg < 0) {
 160                         dev_err(wm831x->dev,
 161                                 "GPIO control %d read failed: %d\n",
 162                                 gpio, reg);
 163                         seq_printf(s, "\n");
 164                         continue;
 165                 }
 166
 167                 switch (reg & WM831X_GPN_PULL_MASK) {
 168                 case WM831X_GPIO_PULL_NONE:
 169                         pull = "nopull";
 170                         break;
 171                 case WM831X_GPIO_PULL_DOWN:
 172                         pull = "pulldown";
 173                         break;
 174                 case WM831X_GPIO_PULL_UP:
 175                         pull = "pullup";
 176                         break;
 177                 default:
 178                         pull = "INVALID PULL";
 179                         break;
 180                 }
 181
 182                 switch (i + 1) {
 183                 case 1 ... 3:
 184                 case 7 ... 9:
 185                         if (reg & WM831X_GPN_PWR_DOM)
 186                                 powerdomain = "VPMIC";
 187                         else
 188                                 powerdomain = "DBVDD";
 189                         break;
 190
 191                 case 4 ... 6:
 192                 case 10 ... 12:
 193                         if (reg & WM831X_GPN_PWR_DOM)
 194                                 powerdomain = "SYSVDD";
 195                         else
 196                                 powerdomain = "DBVDD";
 197                         break;
 198
 199                 case 13 ... 16:
 200                         powerdomain = "TPVDD";
 201                         break;
 202
 203                 default:
 204                         BUG();
 205                         break;
 206                 }
 207
 208                 tristated = reg & WM831X_GPN_TRI;
 209                 if (wm831x->has_gpio_ena)
 210                         tristated = !tristated;
 211
 212                 seq_printf(s, " %s %s %s %s%s\n"
 213                            "                                  %s%s (0x%4x)\n",
 214                            reg & WM831X_GPN_DIR ? "in" : "out",
 215                            wm831x_gpio_get(chip, i) ? "high" : "low",
 216                            pull,
 217                            powerdomain,
 218                            reg & WM831X_GPN_POL ? "" : " inverted",
 219                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 220                            tristated ? " tristated" : "",
 221                            reg);
 222         }
 223 }
 224 #else
 225 #define wm831x_gpio_dbg_show NULL
 226 #endif
 227
 228 static struct gpio_chip template_chip = {
 229         .label                  = "wm831x",
 230         .owner                  = THIS_MODULE,
 231         .direction_input        = wm831x_gpio_direction_in,
 232         .get                    = wm831x_gpio_get,
 233         .direction_output       = wm831x_gpio_direction_out,
 234         .set                    = wm831x_gpio_set,
 235         .to_irq                 = wm831x_gpio_to_irq,
 236         .set_debounce           = wm831x_gpio_set_debounce,
 237         .dbg_show               = wm831x_gpio_dbg_show,
 238         .can_sleep              = true,
 239 };
 240
 241 static int wm831x_gpio_probe(struct platform_device *pdev)
 242 {
 243         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 244         struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 245         struct wm831x_gpio *wm831x_gpio;
 246         int ret;
 247
 248         wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
 249                                    GFP_KERNEL);
 250         if (wm831x_gpio == NULL)
 251                 return -ENOMEM;
 252
 253         wm831x_gpio->wm831x = wm831x;
 254         wm831x_gpio->gpio_chip = template_chip;
 255         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 256         wm831x_gpio->gpio_chip.parent = &pdev->dev;
 257         if (pdata && pdata->gpio_base)
 258                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 259         else
 260                 wm831x_gpio->gpio_chip.base = -1;
 261
 262         ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
 263                                      wm831x_gpio);
 264         if (ret < 0) {
 265                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 266                 return ret;
 267         }
 268
 269         platform_set_drvdata(pdev, wm831x_gpio);
 270
 271         return ret;
 272 }
 273
 274 static struct platform_driver wm831x_gpio_driver = {
 275         .driver.name    = "wm831x-gpio",
 276         .driver.owner   = THIS_MODULE,
 277         .probe          = wm831x_gpio_probe,
 278 };
 279
 280 static int __init wm831x_gpio_init(void)
 281 {
 282         return platform_driver_register(&wm831x_gpio_driver);
 283 }
 284 subsys_initcall(wm831x_gpio_init);
 285
 286 static void __exit wm831x_gpio_exit(void)
 287 {
 288         platform_driver_unregister(&wm831x_gpio_driver);
 289 }
 290 module_exit(wm831x_gpio_exit);
 291
 292 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 293 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 294 MODULE_LICENSE("GPL");
 295 MODULE_ALIAS("platform:wm831x-gpio");