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 int wm831x_gpio_direction_out(struct gpio_chip *chip,
  64                                      unsigned offset, int value)
  65 {
  66         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  67         struct wm831x *wm831x = wm831x_gpio->wm831x;
  68
  69         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  70                                WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
  71 }
  72
  73 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  74 {
  75         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  76         struct wm831x *wm831x = wm831x_gpio->wm831x;
  77
  78         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  79                         value << offset);
  80 }
  81
  82 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  83 {
  84         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  85         struct wm831x *wm831x = wm831x_gpio->wm831x;
  86
  87         if (!wm831x->irq_base)
  88                 return -EINVAL;
  89
  90         return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
  91 }
  92
  93 #ifdef CONFIG_DEBUG_FS
  94 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
  95 {
  96         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  97         struct wm831x *wm831x = wm831x_gpio->wm831x;
  98         int i;
  99
 100         for (i = 0; i < chip->ngpio; i++) {
 101                 int gpio = i + chip->base;
 102                 int reg;
 103                 const char *label, *pull, *powerdomain;
 104
 105                 /* We report the GPIO even if it's not requested since
 106                  * we're also reporting things like alternate
 107                  * functions which apply even when the GPIO is not in
 108                  * use as a GPIO.
 109                  */
 110                 label = gpiochip_is_requested(chip, i);
 111                 if (!label)
 112                         label = "Unrequested";
 113
 114                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 115
 116                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 117                 if (reg < 0) {
 118                         dev_err(wm831x->dev,
 119                                 "GPIO control %d read failed: %d\n",
 120                                 gpio, reg);
 121                         seq_printf(s, "\n");
 122                         continue;
 123                 }
 124
 125                 switch (reg & WM831X_GPN_PULL_MASK) {
 126                 case WM831X_GPIO_PULL_NONE:
 127                         pull = "nopull";
 128                         break;
 129                 case WM831X_GPIO_PULL_DOWN:
 130                         pull = "pulldown";
 131                         break;
 132                 case WM831X_GPIO_PULL_UP:
 133                         pull = "pullup";
 134                 default:
 135                         pull = "INVALID PULL";
 136                         break;
 137                 }
 138
 139                 switch (i + 1) {
 140                 case 1 ... 3:
 141                 case 7 ... 9:
 142                         if (reg & WM831X_GPN_PWR_DOM)
 143                                 powerdomain = "VPMIC";
 144                         else
 145                                 powerdomain = "DBVDD";
 146                         break;
 147
 148                 case 4 ... 6:
 149                 case 10 ... 12:
 150                         if (reg & WM831X_GPN_PWR_DOM)
 151                                 powerdomain = "SYSVDD";
 152                         else
 153                                 powerdomain = "DBVDD";
 154                         break;
 155
 156                 case 13 ... 16:
 157                         powerdomain = "TPVDD";
 158                         break;
 159
 160                 default:
 161                         BUG();
 162                         break;
 163                 }
 164
 165                 seq_printf(s, " %s %s %s %s%s\n"
 166                            "                                  %s%s (0x%4x)\n",
 167                            reg & WM831X_GPN_DIR ? "in" : "out",
 168                            wm831x_gpio_get(chip, i) ? "high" : "low",
 169                            pull,
 170                            powerdomain,
 171                            reg & WM831X_GPN_POL ? " inverted" : "",
 172                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 173                            reg & WM831X_GPN_TRI ? " tristated" : "",
 174                            reg);
 175         }
 176 }
 177 #else
 178 #define wm831x_gpio_dbg_show NULL
 179 #endif
 180
 181 static struct gpio_chip template_chip = {
 182         .label                  = "wm831x",
 183         .owner                  = THIS_MODULE,
 184         .direction_input        = wm831x_gpio_direction_in,
 185         .get                    = wm831x_gpio_get,
 186         .direction_output       = wm831x_gpio_direction_out,
 187         .set                    = wm831x_gpio_set,
 188         .to_irq                 = wm831x_gpio_to_irq,
 189         .dbg_show               = wm831x_gpio_dbg_show,
 190         .can_sleep              = 1,
 191 };
 192
 193 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 194 {
 195         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 196         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 197         struct wm831x_gpio *wm831x_gpio;
 198         int ret;
 199
 200         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 201         if (wm831x_gpio == NULL)
 202                 return -ENOMEM;
 203
 204         wm831x_gpio->wm831x = wm831x;
 205         wm831x_gpio->gpio_chip = template_chip;
 206         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 207         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 208         if (pdata && pdata->gpio_base)
 209                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 210         else
 211                 wm831x_gpio->gpio_chip.base = -1;
 212
 213         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 214         if (ret < 0) {
 215                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 216                         ret);
 217                 goto err;
 218         }
 219
 220         platform_set_drvdata(pdev, wm831x_gpio);
 221
 222         return ret;
 223
 224 err:
 225         kfree(wm831x_gpio);
 226         return ret;
 227 }
 228
 229 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 230 {
 231         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 232         int ret;
 233
 234         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 235         if (ret == 0)
 236                 kfree(wm831x_gpio);
 237
 238         return ret;
 239 }
 240
 241 static struct platform_driver wm831x_gpio_driver = {
 242         .driver.name    = "wm831x-gpio",
 243         .driver.owner   = THIS_MODULE,
 244         .probe          = wm831x_gpio_probe,
 245         .remove         = __devexit_p(wm831x_gpio_remove),
 246 };
 247
 248 static int __init wm831x_gpio_init(void)
 249 {
 250         return platform_driver_register(&wm831x_gpio_driver);
 251 }
 252 subsys_initcall(wm831x_gpio_init);
 253
 254 static void __exit wm831x_gpio_exit(void)
 255 {
 256         platform_driver_unregister(&wm831x_gpio_driver);
 257 }
 258 module_exit(wm831x_gpio_exit);
 259
 260 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 261 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 262 MODULE_LICENSE("GPL");
 263 MODULE_ALIAS("platform:wm831x-gpio");