SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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         int val = WM831X_GPN_DIR;
  42
  43         if (wm831x->has_gpio_ena)
  44                 val |= WM831X_GPN_TRI;
  45
  46         return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  47                                WM831X_GPN_DIR | WM831X_GPN_TRI, val);
  48 }
  49
  50 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  51 {
  52         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  53         struct wm831x *wm831x = wm831x_gpio->wm831x;
  54         int ret;
  55
  56         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  57         if (ret < 0)
  58                 return ret;
  59
  60         if (ret & 1 << offset)
  61                 return 1;
  62         else
  63                 return 0;
  64 }
  65
  66 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  67 {
  68         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  69         struct wm831x *wm831x = wm831x_gpio->wm831x;
  70
  71         wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  72                         value << offset);
  73 }
  74
  75 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  76                                      unsigned offset, int value)
  77 {
  78         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  79         struct wm831x *wm831x = wm831x_gpio->wm831x;
  80         int val = 0;
  81         int ret;
  82
  83         if (wm831x->has_gpio_ena)
  84                 val |= WM831X_GPN_TRI;
  85
  86         ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  87                               WM831X_GPN_DIR | WM831X_GPN_TRI, val);
  88         if (ret < 0)
  89                 return ret;
  90
  91         /* Can only set GPIO state once it's in output mode */
  92         wm831x_gpio_set(chip, offset, value);
  93
  94         return 0;
  95 }
  96
  97 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  98 {
  99         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 100         struct wm831x *wm831x = wm831x_gpio->wm831x;
 101
 102         if (!wm831x->irq_base)
 103                 return -EINVAL;
 104
 105         return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
 106 }
 107
 108 #ifdef CONFIG_DEBUG_FS
 109 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 110 {
 111         struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 112         struct wm831x *wm831x = wm831x_gpio->wm831x;
 113         int i, tristated;
 114
 115         for (i = 0; i < chip->ngpio; i++) {
 116                 int gpio = i + chip->base;
 117                 int reg;
 118                 const char *label, *pull, *powerdomain;
 119
 120                 /* We report the GPIO even if it's not requested since
 121                  * we're also reporting things like alternate
 122                  * functions which apply even when the GPIO is not in
 123                  * use as a GPIO.
 124                  */
 125                 label = gpiochip_is_requested(chip, i);
 126                 if (!label)
 127                         label = "Unrequested";
 128
 129                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 130
 131                 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 132                 if (reg < 0) {
 133                         dev_err(wm831x->dev,
 134                                 "GPIO control %d read failed: %d\n",
 135                                 gpio, reg);
 136                         seq_printf(s, "\n");
 137                         continue;
 138                 }
 139
 140                 switch (reg & WM831X_GPN_PULL_MASK) {
 141                 case WM831X_GPIO_PULL_NONE:
 142                         pull = "nopull";
 143                         break;
 144                 case WM831X_GPIO_PULL_DOWN:
 145                         pull = "pulldown";
 146                         break;
 147                 case WM831X_GPIO_PULL_UP:
 148                         pull = "pullup";
 149                 default:
 150                         pull = "INVALID PULL";
 151                         break;
 152                 }
 153
 154                 switch (i + 1) {
 155                 case 1 ... 3:
 156                 case 7 ... 9:
 157                         if (reg & WM831X_GPN_PWR_DOM)
 158                                 powerdomain = "VPMIC";
 159                         else
 160                                 powerdomain = "DBVDD";
 161                         break;
 162
 163                 case 4 ... 6:
 164                 case 10 ... 12:
 165                         if (reg & WM831X_GPN_PWR_DOM)
 166                                 powerdomain = "SYSVDD";
 167                         else
 168                                 powerdomain = "DBVDD";
 169                         break;
 170
 171                 case 13 ... 16:
 172                         powerdomain = "TPVDD";
 173                         break;
 174
 175                 default:
 176                         BUG();
 177                         break;
 178                 }
 179
 180                 tristated = reg & WM831X_GPN_TRI;
 181                 if (wm831x->has_gpio_ena)
 182                         tristated = !tristated;
 183
 184                 seq_printf(s, " %s %s %s %s%s\n"
 185                            "                                  %s%s (0x%4x)\n",
 186                            reg & WM831X_GPN_DIR ? "in" : "out",
 187                            wm831x_gpio_get(chip, i) ? "high" : "low",
 188                            pull,
 189                            powerdomain,
 190                            reg & WM831X_GPN_POL ? "" : " inverted",
 191                            reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 192                            tristated ? " tristated" : "",
 193                            reg);
 194         }
 195 }
 196 #else
 197 #define wm831x_gpio_dbg_show NULL
 198 #endif
 199
 200 static struct gpio_chip template_chip = {
 201         .label                  = "wm831x",
 202         .owner                  = THIS_MODULE,
 203         .direction_input        = wm831x_gpio_direction_in,
 204         .get                    = wm831x_gpio_get,
 205         .direction_output       = wm831x_gpio_direction_out,
 206         .set                    = wm831x_gpio_set,
 207         .to_irq                 = wm831x_gpio_to_irq,
 208         .dbg_show               = wm831x_gpio_dbg_show,
 209         .can_sleep              = 1,
 210 };
 211
 212 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 213 {
 214         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 215         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 216         struct wm831x_gpio *wm831x_gpio;
 217         int ret;
 218
 219         wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 220         if (wm831x_gpio == NULL)
 221                 return -ENOMEM;
 222
 223         wm831x_gpio->wm831x = wm831x;
 224         wm831x_gpio->gpio_chip = template_chip;
 225         wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 226         wm831x_gpio->gpio_chip.dev = &pdev->dev;
 227         if (pdata && pdata->gpio_base)
 228                 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 229         else
 230                 wm831x_gpio->gpio_chip.base = -1;
 231
 232         ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 233         if (ret < 0) {
 234                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 235                         ret);
 236                 goto err;
 237         }
 238
 239         platform_set_drvdata(pdev, wm831x_gpio);
 240
 241         return ret;
 242
 243 err:
 244         kfree(wm831x_gpio);
 245         return ret;
 246 }
 247
 248 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 249 {
 250         struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 251         int ret;
 252
 253         ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 254         if (ret == 0)
 255                 kfree(wm831x_gpio);
 256
 257         return ret;
 258 }
 259
 260 static struct platform_driver wm831x_gpio_driver = {
 261         .driver.name    = "wm831x-gpio",
 262         .driver.owner   = THIS_MODULE,
 263         .probe          = wm831x_gpio_probe,
 264         .remove         = __devexit_p(wm831x_gpio_remove),
 265 };
 266
 267 static int __init wm831x_gpio_init(void)
 268 {
 269         return platform_driver_register(&wm831x_gpio_driver);
 270 }
 271 subsys_initcall(wm831x_gpio_init);
 272
 273 static void __exit wm831x_gpio_exit(void)
 274 {
 275         platform_driver_unregister(&wm831x_gpio_driver);
 276 }
 277 module_exit(wm831x_gpio_exit);
 278
 279 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 280 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 281 MODULE_LICENSE("GPL");
 282 MODULE_ALIAS("platform:wm831x-gpio");