drivers/input/misc/dm355evm_keys.c

   1 /*
   2  * dm355evm_keys.c - support buttons and IR remote on DM355 EVM board
   3  *
   4  * Copyright (c) 2008 by David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/input.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/interrupt.h>
  16
  17 #include <linux/i2c/dm355evm_msp.h>
  18
  19
  20 /*
  21  * The MSP430 firmware on the DM355 EVM monitors on-board pushbuttons
  22  * and an IR receptor used for the remote control.  When any key is
  23  * pressed, or its autorepeat kicks in, an event is sent.  This driver
  24  * read those events from the small (32 event) queue and reports them.
  25  *
  26  * Note that physically there can only be one of these devices.
  27  *
  28  * This driver was tested with firmware revision A4.
  29  */
  30 struct dm355evm_keys {
  31         struct input_dev        *input;
  32         struct device           *dev;
  33         int                     irq;
  34 };
  35
  36 /* These initial keycodes can be remapped by dm355evm_setkeycode(). */
  37 static struct {
  38         u16     event;
  39         u16     keycode;
  40 } dm355evm_keys[] = {
  41
  42         /*
  43          * Pushbuttons on the EVM board ... note that the labels for these
  44          * are SW10/SW11/etc on the PC board.  The left/right orientation
  45          * comes only from the firmware's documentation, and presumes the
  46          * power connector is immediately in front of you and the IR sensor
  47          * is to the right.  (That is, rotate the board counter-clockwise
  48          * by 90 degrees from the SW10/etc and "DM355 EVM" labels.)
  49          */
  50         { 0x00d8, KEY_OK, },            /* SW12 */
  51         { 0x00b8, KEY_UP, },            /* SW13 */
  52         { 0x00e8, KEY_DOWN, },          /* SW11 */
  53         { 0x0078, KEY_LEFT, },          /* SW14 */
  54         { 0x00f0, KEY_RIGHT, },         /* SW10 */
  55
  56         /*
  57          * IR buttons ... codes assigned to match the universal remote
  58          * provided with the EVM (Philips PM4S) using DVD code 0020.
  59          *
  60          * These event codes match firmware documentation, but other
  61          * remote controls could easily send more RC5-encoded events.
  62          * The PM4S manual was used in several cases to help select
  63          * a keycode reflecting the intended usage.
  64          *
  65          * RC5 codes are 14 bits, with two start bits (0x3 prefix)
  66          * and a toggle bit (masked out below).
  67          */
  68         { 0x300c, KEY_POWER, },         /* NOTE: docs omit this */
  69         { 0x3000, KEY_NUMERIC_0, },
  70         { 0x3001, KEY_NUMERIC_1, },
  71         { 0x3002, KEY_NUMERIC_2, },
  72         { 0x3003, KEY_NUMERIC_3, },
  73         { 0x3004, KEY_NUMERIC_4, },
  74         { 0x3005, KEY_NUMERIC_5, },
  75         { 0x3006, KEY_NUMERIC_6, },
  76         { 0x3007, KEY_NUMERIC_7, },
  77         { 0x3008, KEY_NUMERIC_8, },
  78         { 0x3009, KEY_NUMERIC_9, },
  79         { 0x3022, KEY_ENTER, },
  80         { 0x30ec, KEY_MODE, },          /* "tv/vcr/..." */
  81         { 0x300f, KEY_SELECT, },        /* "info" */
  82         { 0x3020, KEY_CHANNELUP, },     /* "up" */
  83         { 0x302e, KEY_MENU, },          /* "in/out" */
  84         { 0x3011, KEY_VOLUMEDOWN, },    /* "left" */
  85         { 0x300d, KEY_MUTE, },          /* "ok" */
  86         { 0x3010, KEY_VOLUMEUP, },      /* "right" */
  87         { 0x301e, KEY_SUBTITLE, },      /* "cc" */
  88         { 0x3021, KEY_CHANNELDOWN, },   /* "down" */
  89         { 0x3022, KEY_PREVIOUS, },
  90         { 0x3026, KEY_SLEEP, },
  91         { 0x3172, KEY_REWIND, },        /* NOTE: docs wrongly say 0x30ca */
  92         { 0x3175, KEY_PLAY, },
  93         { 0x3174, KEY_FASTFORWARD, },
  94         { 0x3177, KEY_RECORD, },
  95         { 0x3176, KEY_STOP, },
  96         { 0x3169, KEY_PAUSE, },
  97 };
  98
  99 /* runs in an IRQ thread -- can (and will!) sleep */
 100 static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)
 101 {
 102         struct dm355evm_keys    *keys = _keys;
 103         int                     status;
 104
 105         /* For simplicity we ignore INPUT_COUNT and just read
 106          * events until we get the "queue empty" indicator.
 107          * Reading INPUT_LOW decrements the count.
 108          */
 109         for (;;) {
 110                 static u16      last_event;
 111                 u16             event;
 112                 int             keycode;
 113                 int             i;
 114
 115                 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_HIGH);
 116                 if (status < 0) {
 117                         dev_dbg(keys->dev, "input high err %d\n",
 118                                         status);
 119                         break;
 120                 }
 121                 event = status << 8;
 122
 123                 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_LOW);
 124                 if (status < 0) {
 125                         dev_dbg(keys->dev, "input low err %d\n",
 126                                         status);
 127                         break;
 128                 }
 129                 event |= status;
 130                 if (event == 0xdead)
 131                         break;
 132
 133                 /* Press and release a button:  two events, same code.
 134                  * Press and hold (autorepeat), then release: N events
 135                  * (N > 2), same code.  For RC5 buttons the toggle bits
 136                  * distinguish (for example) "1-autorepeat" from "1 1";
 137                  * but PCB buttons don't support that bit.
 138                  *
 139                  * So we must synthesize release events.  We do that by
 140                  * mapping events to a press/release event pair; then
 141                  * to avoid adding extra events, skip the second event
 142                  * of each pair.
 143                  */
 144                 if (event == last_event) {
 145                         last_event = 0;
 146                         continue;
 147                 }
 148                 last_event = event;
 149
 150                 /* ignore the RC5 toggle bit */
 151                 event &= ~0x0800;
 152
 153                 /* find the key, or leave it as unknown */
 154                 keycode = KEY_UNKNOWN;
 155                 for (i = 0; i < ARRAY_SIZE(dm355evm_keys); i++) {
 156                         if (dm355evm_keys[i].event != event)
 157                                 continue;
 158                         keycode = dm355evm_keys[i].keycode;
 159                         break;
 160                 }
 161                 dev_dbg(keys->dev,
 162                         "input event 0x%04x--> keycode %d\n",
 163                         event, keycode);
 164
 165                 /* report press + release */
 166                 input_report_key(keys->input, keycode, 1);
 167                 input_sync(keys->input);
 168                 input_report_key(keys->input, keycode, 0);
 169                 input_sync(keys->input);
 170         }
 171         return IRQ_HANDLED;
 172 }
 173
 174 /*
 175  * Because we communicate with the MSP430 using I2C, and all I2C calls
 176  * in Linux sleep, we use a threaded IRQ handler.  The IRQ itself is
 177  * active low, but we go through the GPIO controller so we can trigger
 178  * on falling edges and not worry about enabling/disabling the IRQ in
 179  * the keypress handling path.
 180  */
 181 static irqreturn_t dm355evm_keys_hardirq(int irq, void *_keys)
 182 {
 183         return IRQ_WAKE_THREAD;
 184 }
 185
 186 static int dm355evm_setkeycode(struct input_dev *dev, int index, int keycode)
 187 {
 188         u16             old_keycode;
 189         unsigned        i;
 190
 191         if (((unsigned)index) >= ARRAY_SIZE(dm355evm_keys))
 192                 return -EINVAL;
 193
 194         old_keycode = dm355evm_keys[index].keycode;
 195         dm355evm_keys[index].keycode = keycode;
 196         set_bit(keycode, dev->keybit);
 197
 198         for (i = 0; i < ARRAY_SIZE(dm355evm_keys); i++) {
 199                 if (dm355evm_keys[index].keycode == old_keycode)
 200                         goto done;
 201         }
 202         clear_bit(old_keycode, dev->keybit);
 203 done:
 204         return 0;
 205 }
 206
 207 static int dm355evm_getkeycode(struct input_dev *dev, int index, int *keycode)
 208 {
 209         if (((unsigned)index) >= ARRAY_SIZE(dm355evm_keys))
 210                 return -EINVAL;
 211
 212         return dm355evm_keys[index].keycode;
 213 }
 214
 215 /*----------------------------------------------------------------------*/
 216
 217 static int __devinit dm355evm_keys_probe(struct platform_device *pdev)
 218 {
 219         struct dm355evm_keys    *keys;
 220         struct input_dev        *input;
 221         int                     status;
 222         int                     i;
 223
 224         /* allocate instance struct and input dev */
 225         keys = kzalloc(sizeof *keys, GFP_KERNEL);
 226         input = input_allocate_device();
 227         if (!keys || !input) {
 228                 status = -ENOMEM;
 229                 goto fail1;
 230         }
 231
 232         keys->dev = &pdev->dev;
 233         keys->input = input;
 234
 235         /* set up "threaded IRQ handler" */
 236         status = platform_get_irq(pdev, 0);
 237         if (status < 0)
 238                 goto fail1;
 239         keys->irq = status;
 240
 241         input_set_drvdata(input, keys);
 242
 243         input->name = "DM355 EVM Controls";
 244         input->phys = "dm355evm/input0";
 245         input->dev.parent = &pdev->dev;
 246
 247         input->id.bustype = BUS_I2C;
 248         input->id.product = 0x0355;
 249         input->id.version = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 250
 251         input->evbit[0] = BIT(EV_KEY);
 252         for (i = 0; i < ARRAY_SIZE(dm355evm_keys); i++)
 253                 __set_bit(dm355evm_keys[i].keycode, input->keybit);
 254
 255         input->setkeycode = dm355evm_setkeycode;
 256         input->getkeycode = dm355evm_getkeycode;
 257
 258         /* REVISIT:  flush the event queue? */
 259
 260         status = request_threaded_irq(keys->irq,
 261                         dm355evm_keys_hardirq, dm355evm_keys_irq,
 262                         IRQF_TRIGGER_FALLING,
 263                         dev_name(&pdev->dev), keys);
 264         if (status < 0)
 265                 goto fail1;
 266
 267         /* register */
 268         status = input_register_device(input);
 269         if (status < 0)
 270                 goto fail2;
 271
 272         platform_set_drvdata(pdev, keys);
 273
 274         return 0;
 275
 276 fail2:
 277         free_irq(keys->irq, keys);
 278 fail1:
 279         input_free_device(input);
 280         kfree(keys);
 281         dev_err(&pdev->dev, "can't register, err %d\n", status);
 282
 283         return status;
 284 }
 285
 286 static int __devexit dm355evm_keys_remove(struct platform_device *pdev)
 287 {
 288         struct dm355evm_keys    *keys = platform_get_drvdata(pdev);
 289
 290         free_irq(keys->irq, keys);
 291         input_unregister_device(keys->input);
 292         kfree(keys);
 293
 294         return 0;
 295 }
 296
 297 /* REVISIT:  add suspend/resume when DaVinci supports it.  The IRQ should
 298  * be able to wake up the system.  When device_may_wakeup(&pdev->dev), call
 299  * enable_irq_wake() on suspend, and disable_irq_wake() on resume.
 300  */
 301
 302 /*
 303  * I2C is used to talk to the MSP430, but this platform device is
 304  * exposed by an MFD driver that manages I2C communications.
 305  */
 306 static struct platform_driver dm355evm_keys_driver = {
 307         .probe          = dm355evm_keys_probe,
 308         .remove         = __devexit_p(dm355evm_keys_remove),
 309         .driver         = {
 310                 .owner  = THIS_MODULE,
 311                 .name   = "dm355evm_keys",
 312         },
 313 };
 314
 315 static int __init dm355evm_keys_init(void)
 316 {
 317         return platform_driver_register(&dm355evm_keys_driver);
 318 }
 319 module_init(dm355evm_keys_init);
 320
 321 static void __exit dm355evm_keys_exit(void)
 322 {
 323         platform_driver_unregister(&dm355evm_keys_driver);
 324 }
 325 module_exit(dm355evm_keys_exit);
 326
 327 MODULE_LICENSE("GPL");