linux/drivers/gpio/gpio-wm831x.c
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   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
  28struct wm831x_gpio {
  29        struct wm831x *wm831x;
  30        struct gpio_chip gpio_chip;
  31};
  32
  33static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
  34{
  35        return container_of(chip, struct wm831x_gpio, gpio_chip);
  36}
  37
  38static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  39{
  40        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  41        struct wm831x *wm831x = wm831x_gpio->wm831x;
  42        int val = WM831X_GPN_DIR;
  43
  44        if (wm831x->has_gpio_ena)
  45                val |= WM831X_GPN_TRI;
  46
  47        return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  48                               WM831X_GPN_DIR | WM831X_GPN_TRI |
  49                               WM831X_GPN_FN_MASK, val);
  50}
  51
  52static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
  53{
  54        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  55        struct wm831x *wm831x = wm831x_gpio->wm831x;
  56        int ret;
  57
  58        ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
  59        if (ret < 0)
  60                return ret;
  61
  62        if (ret & 1 << offset)
  63                return 1;
  64        else
  65                return 0;
  66}
  67
  68static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  69{
  70        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  71        struct wm831x *wm831x = wm831x_gpio->wm831x;
  72
  73        wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
  74                        value << offset);
  75}
  76
  77static int wm831x_gpio_direction_out(struct gpio_chip *chip,
  78                                     unsigned offset, int value)
  79{
  80        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
  81        struct wm831x *wm831x = wm831x_gpio->wm831x;
  82        int val = 0;
  83        int ret;
  84
  85        if (wm831x->has_gpio_ena)
  86                val |= WM831X_GPN_TRI;
  87
  88        ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
  89                              WM831X_GPN_DIR | WM831X_GPN_TRI |
  90                              WM831X_GPN_FN_MASK, val);
  91        if (ret < 0)
  92                return ret;
  93
  94        /* Can only set GPIO state once it's in output mode */
  95        wm831x_gpio_set(chip, offset, value);
  96
  97        return 0;
  98}
  99
 100static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 101{
 102        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 103        struct wm831x *wm831x = wm831x_gpio->wm831x;
 104
 105        return irq_create_mapping(wm831x->irq_domain,
 106                                  WM831X_IRQ_GPIO_1 + offset);
 107}
 108
 109static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
 110                                    unsigned debounce)
 111{
 112        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 113        struct wm831x *wm831x = wm831x_gpio->wm831x;
 114        int reg = WM831X_GPIO1_CONTROL + offset;
 115        int ret, fn;
 116
 117        ret = wm831x_reg_read(wm831x, reg);
 118        if (ret < 0)
 119                return ret;
 120
 121        switch (ret & WM831X_GPN_FN_MASK) {
 122        case 0:
 123        case 1:
 124                break;
 125        default:
 126                /* Not in GPIO mode */
 127                return -EBUSY;
 128        }
 129
 130        if (debounce >= 32 && debounce <= 64)
 131                fn = 0;
 132        else if (debounce >= 4000 && debounce <= 8000)
 133                fn = 1;
 134        else
 135                return -EINVAL;
 136
 137        return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
 138}
 139
 140#ifdef CONFIG_DEBUG_FS
 141static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 142{
 143        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 144        struct wm831x *wm831x = wm831x_gpio->wm831x;
 145        int i, tristated;
 146
 147        for (i = 0; i < chip->ngpio; i++) {
 148                int gpio = i + chip->base;
 149                int reg;
 150                const char *label, *pull, *powerdomain;
 151
 152                /* We report the GPIO even if it's not requested since
 153                 * we're also reporting things like alternate
 154                 * functions which apply even when the GPIO is not in
 155                 * use as a GPIO.
 156                 */
 157                label = gpiochip_is_requested(chip, i);
 158                if (!label)
 159                        label = "Unrequested";
 160
 161                seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 162
 163                reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 164                if (reg < 0) {
 165                        dev_err(wm831x->dev,
 166                                "GPIO control %d read failed: %d\n",
 167                                gpio, reg);
 168                        seq_printf(s, "\n");
 169                        continue;
 170                }
 171
 172                switch (reg & WM831X_GPN_PULL_MASK) {
 173                case WM831X_GPIO_PULL_NONE:
 174                        pull = "nopull";
 175                        break;
 176                case WM831X_GPIO_PULL_DOWN:
 177                        pull = "pulldown";
 178                        break;
 179                case WM831X_GPIO_PULL_UP:
 180                        pull = "pullup";
 181                        break;
 182                default:
 183                        pull = "INVALID PULL";
 184                        break;
 185                }
 186
 187                switch (i + 1) {
 188                case 1 ... 3:
 189                case 7 ... 9:
 190                        if (reg & WM831X_GPN_PWR_DOM)
 191                                powerdomain = "VPMIC";
 192                        else
 193                                powerdomain = "DBVDD";
 194                        break;
 195
 196                case 4 ... 6:
 197                case 10 ... 12:
 198                        if (reg & WM831X_GPN_PWR_DOM)
 199                                powerdomain = "SYSVDD";
 200                        else
 201                                powerdomain = "DBVDD";
 202                        break;
 203
 204                case 13 ... 16:
 205                        powerdomain = "TPVDD";
 206                        break;
 207
 208                default:
 209                        BUG();
 210                        break;
 211                }
 212
 213                tristated = reg & WM831X_GPN_TRI;
 214                if (wm831x->has_gpio_ena)
 215                        tristated = !tristated;
 216
 217                seq_printf(s, " %s %s %s %s%s\n"
 218                           "                                  %s%s (0x%4x)\n",
 219                           reg & WM831X_GPN_DIR ? "in" : "out",
 220                           wm831x_gpio_get(chip, i) ? "high" : "low",
 221                           pull,
 222                           powerdomain,
 223                           reg & WM831X_GPN_POL ? "" : " inverted",
 224                           reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 225                           tristated ? " tristated" : "",
 226                           reg);
 227        }
 228}
 229#else
 230#define wm831x_gpio_dbg_show NULL
 231#endif
 232
 233static struct gpio_chip template_chip = {
 234        .label                  = "wm831x",
 235        .owner                  = THIS_MODULE,
 236        .direction_input        = wm831x_gpio_direction_in,
 237        .get                    = wm831x_gpio_get,
 238        .direction_output       = wm831x_gpio_direction_out,
 239        .set                    = wm831x_gpio_set,
 240        .to_irq                 = wm831x_gpio_to_irq,
 241        .set_debounce           = wm831x_gpio_set_debounce,
 242        .dbg_show               = wm831x_gpio_dbg_show,
 243        .can_sleep              = 1,
 244};
 245
 246static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 247{
 248        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 249        struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 250        struct wm831x_gpio *wm831x_gpio;
 251        int ret;
 252
 253        wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
 254                                   GFP_KERNEL);
 255        if (wm831x_gpio == NULL)
 256                return -ENOMEM;
 257
 258        wm831x_gpio->wm831x = wm831x;
 259        wm831x_gpio->gpio_chip = template_chip;
 260        wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 261        wm831x_gpio->gpio_chip.dev = &pdev->dev;
 262        if (pdata && pdata->gpio_base)
 263                wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 264        else
 265                wm831x_gpio->gpio_chip.base = -1;
 266
 267        ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 268        if (ret < 0) {
 269                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 270                return ret;
 271        }
 272
 273        platform_set_drvdata(pdev, wm831x_gpio);
 274
 275        return ret;
 276}
 277
 278static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 279{
 280        struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 281
 282        return  gpiochip_remove(&wm831x_gpio->gpio_chip);
 283}
 284
 285static struct platform_driver wm831x_gpio_driver = {
 286        .driver.name    = "wm831x-gpio",
 287        .driver.owner   = THIS_MODULE,
 288        .probe          = wm831x_gpio_probe,
 289        .remove         = __devexit_p(wm831x_gpio_remove),
 290};
 291
 292static int __init wm831x_gpio_init(void)
 293{
 294        return platform_driver_register(&wm831x_gpio_driver);
 295}
 296subsys_initcall(wm831x_gpio_init);
 297
 298static void __exit wm831x_gpio_exit(void)
 299{
 300        platform_driver_unregister(&wm831x_gpio_driver);
 301}
 302module_exit(wm831x_gpio_exit);
 303
 304MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 305MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 306MODULE_LICENSE("GPL");
 307MODULE_ALIAS("platform:wm831x-gpio");
 308
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