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