drivers/gpio/gpio-wm8994.c

   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
  29 struct wm8994_gpio {
  30         struct wm8994 *wm8994;
  31         struct gpio_chip gpio_chip;
  32 };
  33
  34 static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
  35 {
  36         return container_of(chip, struct wm8994_gpio, gpio_chip);
  37 }
  38
  39 static 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
  62 static 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
  71 static 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
  87 static 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
 100 static 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
 111 static 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
 121 static 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
 175 static 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
 235 static 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
 248 static 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
 280 err:
 281         return ret;
 282 }
 283
 284 static 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
 291 static 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
 298 static int __init wm8994_gpio_init(void)
 299 {
 300         return platform_driver_register(&wm8994_gpio_driver);
 301 }
 302 subsys_initcall(wm8994_gpio_init);
 303
 304 static void __exit wm8994_gpio_exit(void)
 305 {
 306         platform_driver_unregister(&wm8994_gpio_driver);
 307 }
 308 module_exit(wm8994_gpio_exit);
 309
 310 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 311 MODULE_DESCRIPTION("GPIO interface for WM8994");
 312 MODULE_LICENSE("GPL");
 313 MODULE_ALIAS("platform:wm8994-gpio");