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/module.h>
  17 #include <linux/gpio.h>
  18 #include <linux/mfd/core.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/seq_file.h>
  21
  22 #include <linux/mfd/wm831x/core.h>
  23 #include <linux/mfd/wm831x/pdata.h>
  24 #include <linux/mfd/wm831x/gpio.h>
  25 #include <linux/mfd/wm831x/irq.h>
  26
  27 struct wm831x_gpio {
  28         struct wm831x *wm831x;
  29         struct gpio_chip gpio_chip;
  30 };
  31
  32 static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
  33 {
  34         return container_of(chip, struct wm831x_gpio, gpio_chip);
  35 }
  36
  37 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  38 {
  39         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  40         struct wm831x *wm831x = wm831x_gpio->wm831x;
  41
  42         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  43                                WM831X_GPN_DIR | WM831X_GPN_TRI,
  44                                WM831X_GPN_DIR);
  45 }
  46
  47 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  48 {
  49         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(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 = to_wm831x_gpio(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 = to_wm831x_gpio(chip);
  76         struct wm831x *wm831x = wm831x_gpio->wm831x;
  77         int ret;
  78
  79         ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  80                               WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
  81         if (ret < 0)
  82                 return ret;
  83
  84         /* Can only set GPIO state once it's in output mode */
  85         wm831x_gpio_set(chip, offset, value);
  86
  87         return 0;
  88 }
  89
  90 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  91 {
  92         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  93         struct wm831x *wm831x = wm831x_gpio->wm831x;
  94
  95         if (!wm831x->irq_base)
  96                 return -EINVAL;
  97
  98         return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
  99 }
 100
 101 #ifdef CONFIG_DEBUG_FS
 102 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 103 {
 104         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 105         struct wm831x *wm831x = wm831x_gpio->wm831x;
 106         int i;
 107
 108         for (i = 0; i < chip->ngpio; i++) {
 109                 int gpio = i + chip->base;
 110                 int reg;
 111                 const char *label, *pull, *powerdomain;
 112
 113                 /* We report the GPIO even if it's not requested since
 114                  * we're also reporting things like alternate
 115                  * functions which apply even when the GPIO is not in
 116                  * use as a GPIO.
 117                  */
 118                 label = gpiochip_is_requested(chip, i);
 119                 if (!label)
 120                         label = "Unrequested";
 121
 122                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 123
 124                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 125                 if (reg < 0) {
 126                         dev_err(wm831x->dev,
 127                                 "GPIO control %d read failed: %d\n",
 128                                 gpio, reg);
 129                         seq_printf(s, "\n");
 130                         continue;
 131                 }
 132
 133                 switch (reg & WM831X_GPN_PULL_MASK) {
 134                 case WM831X_GPIO_PULL_NONE:
 135                         pull = "nopull";
 136                         break;
 137                 case WM831X_GPIO_PULL_DOWN:
 138                         pull = "pulldown";
 139                         break;
 140                 case WM831X_GPIO_PULL_UP:
 141                         pull = "pullup";
 142                 default:
 143                         pull = "INVALID PULL";
 144                         break;
 145                 }
 146
 147                 switch (i + 1) {
 148                 case 1 ... 3:
 149                 case 7 ... 9:
 150                         if (reg & WM831X_GPN_PWR_DOM)
 151                                 powerdomain = "VPMIC";
 152                         else
 153                                 powerdomain = "DBVDD";
 154                         break;
 155
 156                 case 4 ... 6:
 157                 case 10 ... 12:
 158                         if (reg & WM831X_GPN_PWR_DOM)
 159                                 powerdomain = "SYSVDD";
 160                         else
 161                                 powerdomain = "DBVDD";
 162                         break;
 163
 164                 case 13 ... 16:
 165                         powerdomain = "TPVDD";
 166                         break;
 167
 168                 default:
 169                         BUG();
 170                         break;
 171                 }
 172
 173                 seq_printf(s, " %s %s %s %s%s\n"
 174                            "                                  %s%s (0x%4x)\n",
 175                            reg & WM831X_GPN_DIR ? "in" : "out",
 176                            wm831x_gpio_get(chip, i) ? "high" : "low",
 177                            pull,
 178                            powerdomain,
 179                            reg & WM831X_GPN_POL ? " inverted" : "",
 180                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 181                            reg & WM831X_GPN_TRI ? " tristated" : "",
 182                            reg);
 183         }
 184 }
 185 #else
 186 #define wm831x_gpio_dbg_show NULL
 187 #endif
 188
 189 static struct gpio_chip template_chip = {
 190         .label                  = "wm831x",
 191         .owner                  = THIS_MODULE,
 192         .direction_input        = wm831x_gpio_direction_in,
 193         .get                    = wm831x_gpio_get,
 194         .direction_output       = wm831x_gpio_direction_out,
 195         .set                    = wm831x_gpio_set,
 196         .to_irq                 = wm831x_gpio_to_irq,
 197         .dbg_show               = wm831x_gpio_dbg_show,
 198         .can_sleep              = 1,
 199 };
 200
 201 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 202 {
 203         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 204         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 205         struct wm831x_gpio *wm831x_gpio;
 206         int ret;
 207
 208         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 209         if (wm831x_gpio == NULL)
 210                 return -ENOMEM;
 211
 212         wm831x_gpio->wm831x = wm831x;
 213         wm831x_gpio->gpio_chip = template_chip;
 214         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 215         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 216         if (pdata && pdata->gpio_base)
 217                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 218         else
 219                 wm831x_gpio->gpio_chip.base = -1;
 220
 221         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 222         if (ret < 0) {
 223                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 224                         ret);
 225                 goto err;
 226         }
 227
 228         platform_set_drvdata(pdev, wm831x_gpio);
 229
 230         return ret;
 231
 232 err:
 233         kfree(wm831x_gpio);
 234         return ret;
 235 }
 236
 237 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 238 {
 239         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 240         int ret;
 241
 242         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 243         if (ret == 0)
 244                 kfree(wm831x_gpio);
 245
 246         return ret;
 247 }
 248
 249 static struct platform_driver wm831x_gpio_driver = {
 250         .driver.name    = "wm831x-gpio",
 251         .driver.owner   = THIS_MODULE,
 252         .probe          = wm831x_gpio_probe,
 253         .remove         = __devexit_p(wm831x_gpio_remove),
 254 };
 255
 256 static int __init wm831x_gpio_init(void)
 257 {
 258         return platform_driver_register(&wm831x_gpio_driver);
 259 }
 260 subsys_initcall(wm831x_gpio_init);
 261
 262 static void __exit wm831x_gpio_exit(void)
 263 {
 264         platform_driver_unregister(&wm831x_gpio_driver);
 265 }
 266 module_exit(wm831x_gpio_exit);
 267
 268 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 269 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 270 MODULE_LICENSE("GPL");
 271 MODULE_ALIAS("platform:wm831x-gpio");