linux/drivers/gpio/wm831x-gpio.c
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   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/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        if (!wm831x->irq_base)
 106                return -EINVAL;
 107
 108        return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
 109}
 110
 111#ifdef CONFIG_DEBUG_FS
 112static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 113{
 114        struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
 115        struct wm831x *wm831x = wm831x_gpio->wm831x;
 116        int i, tristated;
 117
 118        for (i = 0; i < chip->ngpio; i++) {
 119                int gpio = i + chip->base;
 120                int reg;
 121                const char *label, *pull, *powerdomain;
 122
 123                /* We report the GPIO even if it's not requested since
 124                 * we're also reporting things like alternate
 125                 * functions which apply even when the GPIO is not in
 126                 * use as a GPIO.
 127                 */
 128                label = gpiochip_is_requested(chip, i);
 129                if (!label)
 130                        label = "Unrequested";
 131
 132                seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 133
 134                reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
 135                if (reg < 0) {
 136                        dev_err(wm831x->dev,
 137                                "GPIO control %d read failed: %d\n",
 138                                gpio, reg);
 139                        seq_printf(s, "\n");
 140                        continue;
 141                }
 142
 143                switch (reg & WM831X_GPN_PULL_MASK) {
 144                case WM831X_GPIO_PULL_NONE:
 145                        pull = "nopull";
 146                        break;
 147                case WM831X_GPIO_PULL_DOWN:
 148                        pull = "pulldown";
 149                        break;
 150                case WM831X_GPIO_PULL_UP:
 151                        pull = "pullup";
 152                default:
 153                        pull = "INVALID PULL";
 154                        break;
 155                }
 156
 157                switch (i + 1) {
 158                case 1 ... 3:
 159                case 7 ... 9:
 160                        if (reg & WM831X_GPN_PWR_DOM)
 161                                powerdomain = "VPMIC";
 162                        else
 163                                powerdomain = "DBVDD";
 164                        break;
 165
 166                case 4 ... 6:
 167                case 10 ... 12:
 168                        if (reg & WM831X_GPN_PWR_DOM)
 169                                powerdomain = "SYSVDD";
 170                        else
 171                                powerdomain = "DBVDD";
 172                        break;
 173
 174                case 13 ... 16:
 175                        powerdomain = "TPVDD";
 176                        break;
 177
 178                default:
 179                        BUG();
 180                        break;
 181                }
 182
 183                tristated = reg & WM831X_GPN_TRI;
 184                if (wm831x->has_gpio_ena)
 185                        tristated = !tristated;
 186
 187                seq_printf(s, " %s %s %s %s%s\n"
 188                           "                                  %s%s (0x%4x)\n",
 189                           reg & WM831X_GPN_DIR ? "in" : "out",
 190                           wm831x_gpio_get(chip, i) ? "high" : "low",
 191                           pull,
 192                           powerdomain,
 193                           reg & WM831X_GPN_POL ? "" : " inverted",
 194                           reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
 195                           tristated ? " tristated" : "",
 196                           reg);
 197        }
 198}
 199#else
 200#define wm831x_gpio_dbg_show NULL
 201#endif
 202
 203static struct gpio_chip template_chip = {
 204        .label                  = "wm831x",
 205        .owner                  = THIS_MODULE,
 206        .direction_input        = wm831x_gpio_direction_in,
 207        .get                    = wm831x_gpio_get,
 208        .direction_output       = wm831x_gpio_direction_out,
 209        .set                    = wm831x_gpio_set,
 210        .to_irq                 = wm831x_gpio_to_irq,
 211        .dbg_show               = wm831x_gpio_dbg_show,
 212        .can_sleep              = 1,
 213};
 214
 215static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
 216{
 217        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 218        struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 219        struct wm831x_gpio *wm831x_gpio;
 220        int ret;
 221
 222        wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
 223        if (wm831x_gpio == NULL)
 224                return -ENOMEM;
 225
 226        wm831x_gpio->wm831x = wm831x;
 227        wm831x_gpio->gpio_chip = template_chip;
 228        wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
 229        wm831x_gpio->gpio_chip.dev = &pdev->dev;
 230        if (pdata && pdata->gpio_base)
 231                wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 232        else
 233                wm831x_gpio->gpio_chip.base = -1;
 234
 235        ret = gpiochip_add(&wm831x_gpio->gpio_chip);
 236        if (ret < 0) {
 237                dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 238                        ret);
 239                goto err;
 240        }
 241
 242        platform_set_drvdata(pdev, wm831x_gpio);
 243
 244        return ret;
 245
 246err:
 247        kfree(wm831x_gpio);
 248        return ret;
 249}
 250
 251static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
 252{
 253        struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
 254        int ret;
 255
 256        ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
 257        if (ret == 0)
 258                kfree(wm831x_gpio);
 259
 260        return ret;
 261}
 262
 263static struct platform_driver wm831x_gpio_driver = {
 264        .driver.name    = "wm831x-gpio",
 265        .driver.owner   = THIS_MODULE,
 266        .probe          = wm831x_gpio_probe,
 267        .remove         = __devexit_p(wm831x_gpio_remove),
 268};
 269
 270static int __init wm831x_gpio_init(void)
 271{
 272        return platform_driver_register(&wm831x_gpio_driver);
 273}
 274subsys_initcall(wm831x_gpio_init);
 275
 276static void __exit wm831x_gpio_exit(void)
 277{
 278        platform_driver_unregister(&wm831x_gpio_driver);
 279}
 280module_exit(wm831x_gpio_exit);
 281
 282MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 283MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
 284MODULE_LICENSE("GPL");
 285MODULE_ALIAS("platform:wm831x-gpio");
 286
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