linux/drivers/gpio/gpio-wm8994.c
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   1/*
   2 * gpiolib support for Wolfson WM8994
   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#include <linux/regmap.h>
  23
  24#include <linux/mfd/wm8994/core.h>
  25#include <linux/mfd/wm8994/pdata.h>
  26#include <linux/mfd/wm8994/gpio.h>
  27#include <linux/mfd/wm8994/registers.h>
  28
  29struct wm8994_gpio {
  30        struct wm8994 *wm8994;
  31        struct gpio_chip gpio_chip;
  32};
  33
  34static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
  35{
  36        return container_of(chip, struct wm8994_gpio, gpio_chip);
  37}
  38
  39static int wm8994_gpio_request(struct gpio_chip *chip, unsigned offset)
  40{
  41        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  42        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  43
  44        switch (wm8994->type) {
  45        case WM8958:
  46                switch (offset) {
  47                case 1:
  48                case 2:
  49                case 3:
  50                case 4:
  51                case 6:
  52                        return -EINVAL;
  53                }
  54                break;
  55        default:
  56                break;
  57        }
  58
  59        return 0;
  60}
  61
  62static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  63{
  64        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  65        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  66
  67        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  68                               WM8994_GPN_DIR, WM8994_GPN_DIR);
  69}
  70
  71static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
  72{
  73        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  74        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  75        int ret;
  76
  77        ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
  78        if (ret < 0)
  79                return ret;
  80
  81        if (ret & WM8994_GPN_LVL)
  82                return 1;
  83        else
  84                return 0;
  85}
  86
  87static int wm8994_gpio_direction_out(struct gpio_chip *chip,
  88                                     unsigned offset, int value)
  89{
  90        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
  91        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
  92
  93        if (value)
  94                value = WM8994_GPN_LVL;
  95
  96        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
  97                               WM8994_GPN_DIR | WM8994_GPN_LVL, value);
  98}
  99
 100static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 101{
 102        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
 103        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 104
 105        if (value)
 106                value = WM8994_GPN_LVL;
 107
 108        wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
 109}
 110
 111static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 112{
 113        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
 114        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 115
 116        return regmap_irq_get_virq(wm8994->irq_data, offset);
 117}
 118
 119
 120#ifdef CONFIG_DEBUG_FS
 121static const char *wm8994_gpio_fn(u16 fn)
 122{
 123        switch (fn) {
 124        case WM8994_GP_FN_PIN_SPECIFIC:
 125                return "pin-specific";
 126        case WM8994_GP_FN_GPIO:
 127                return "GPIO";
 128        case WM8994_GP_FN_SDOUT:
 129                return "SDOUT";
 130        case WM8994_GP_FN_IRQ:
 131                return "IRQ";
 132        case WM8994_GP_FN_TEMPERATURE:
 133                return "Temperature";
 134        case WM8994_GP_FN_MICBIAS1_DET:
 135                return "MICBIAS1 detect";
 136        case WM8994_GP_FN_MICBIAS1_SHORT:
 137                return "MICBIAS1 short";
 138        case WM8994_GP_FN_MICBIAS2_DET:
 139                return "MICBIAS2 detect";
 140        case WM8994_GP_FN_MICBIAS2_SHORT:
 141                return "MICBIAS2 short";
 142        case WM8994_GP_FN_FLL1_LOCK:
 143                return "FLL1 lock";
 144        case WM8994_GP_FN_FLL2_LOCK:
 145                return "FLL2 lock";
 146        case WM8994_GP_FN_SRC1_LOCK:
 147                return "SRC1 lock";
 148        case WM8994_GP_FN_SRC2_LOCK:
 149                return "SRC2 lock";
 150        case WM8994_GP_FN_DRC1_ACT:
 151                return "DRC1 activity";
 152        case WM8994_GP_FN_DRC2_ACT:
 153                return "DRC2 activity";
 154        case WM8994_GP_FN_DRC3_ACT:
 155                return "DRC3 activity";
 156        case WM8994_GP_FN_WSEQ_STATUS:
 157                return "Write sequencer";
 158        case WM8994_GP_FN_FIFO_ERROR:
 159                return "FIFO error";
 160        case WM8994_GP_FN_OPCLK:
 161                return "OPCLK";
 162        case WM8994_GP_FN_THW:
 163                return "Thermal warning";
 164        case WM8994_GP_FN_DCS_DONE:
 165                return "DC servo";
 166        case WM8994_GP_FN_FLL1_OUT:
 167                return "FLL1 output";
 168        case WM8994_GP_FN_FLL2_OUT:
 169                return "FLL1 output";
 170        default:
 171                return "Unknown";
 172        }
 173}
 174
 175static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 176{
 177        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
 178        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
 179        int i;
 180
 181        for (i = 0; i < chip->ngpio; i++) {
 182                int gpio = i + chip->base;
 183                int reg;
 184                const char *label;
 185
 186                /* We report the GPIO even if it's not requested since
 187                 * we're also reporting things like alternate
 188                 * functions which apply even when the GPIO is not in
 189                 * use as a GPIO.
 190                 */
 191                label = gpiochip_is_requested(chip, i);
 192                if (!label)
 193                        label = "Unrequested";
 194
 195                seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
 196
 197                reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
 198                if (reg < 0) {
 199                        dev_err(wm8994->dev,
 200                                "GPIO control %d read failed: %d\n",
 201                                gpio, reg);
 202                        seq_printf(s, "\n");
 203                        continue;
 204                }
 205
 206                if (reg & WM8994_GPN_DIR)
 207                        seq_printf(s, "in ");
 208                else
 209                        seq_printf(s, "out ");
 210
 211                if (reg & WM8994_GPN_PU)
 212                        seq_printf(s, "pull up ");
 213
 214                if (reg & WM8994_GPN_PD)
 215                        seq_printf(s, "pull down ");
 216
 217                if (reg & WM8994_GPN_POL)
 218                        seq_printf(s, "inverted ");
 219                else
 220                        seq_printf(s, "noninverted ");
 221
 222                if (reg & WM8994_GPN_OP_CFG)
 223                        seq_printf(s, "open drain ");
 224                else
 225                        seq_printf(s, "CMOS ");
 226
 227                seq_printf(s, "%s (%x)\n",
 228                           wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), reg);
 229        }
 230}
 231#else
 232#define wm8994_gpio_dbg_show NULL
 233#endif
 234
 235static struct gpio_chip template_chip = {
 236        .label                  = "wm8994",
 237        .owner                  = THIS_MODULE,
 238        .request                = wm8994_gpio_request,
 239        .direction_input        = wm8994_gpio_direction_in,
 240        .get                    = wm8994_gpio_get,
 241        .direction_output       = wm8994_gpio_direction_out,
 242        .set                    = wm8994_gpio_set,
 243        .to_irq                 = wm8994_gpio_to_irq,
 244        .dbg_show               = wm8994_gpio_dbg_show,
 245        .can_sleep              = 1,
 246};
 247
 248static int wm8994_gpio_probe(struct platform_device *pdev)
 249{
 250        struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 251        struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 252        struct wm8994_gpio *wm8994_gpio;
 253        int ret;
 254
 255        wm8994_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm8994_gpio),
 256                                   GFP_KERNEL);
 257        if (wm8994_gpio == NULL)
 258                return -ENOMEM;
 259
 260        wm8994_gpio->wm8994 = wm8994;
 261        wm8994_gpio->gpio_chip = template_chip;
 262        wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
 263        wm8994_gpio->gpio_chip.dev = &pdev->dev;
 264        if (pdata && pdata->gpio_base)
 265                wm8994_gpio->gpio_chip.base = pdata->gpio_base;
 266        else
 267                wm8994_gpio->gpio_chip.base = -1;
 268
 269        ret = gpiochip_add(&wm8994_gpio->gpio_chip);
 270        if (ret < 0) {
 271                dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
 272                        ret);
 273                goto err;
 274        }
 275
 276        platform_set_drvdata(pdev, wm8994_gpio);
 277
 278        return ret;
 279
 280err:
 281        return ret;
 282}
 283
 284static int wm8994_gpio_remove(struct platform_device *pdev)
 285{
 286        struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
 287
 288        return gpiochip_remove(&wm8994_gpio->gpio_chip);
 289}
 290
 291static struct platform_driver wm8994_gpio_driver = {
 292        .driver.name    = "wm8994-gpio",
 293        .driver.owner   = THIS_MODULE,
 294        .probe          = wm8994_gpio_probe,
 295        .remove         = wm8994_gpio_remove,
 296};
 297
 298static int __init wm8994_gpio_init(void)
 299{
 300        return platform_driver_register(&wm8994_gpio_driver);
 301}
 302subsys_initcall(wm8994_gpio_init);
 303
 304static void __exit wm8994_gpio_exit(void)
 305{
 306        platform_driver_unregister(&wm8994_gpio_driver);
 307}
 308module_exit(wm8994_gpio_exit);
 309
 310MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 311MODULE_DESCRIPTION("GPIO interface for WM8994");
 312MODULE_LICENSE("GPL");
 313MODULE_ALIAS("platform:wm8994-gpio");
 314
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