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