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/slab.h>
  13 #include <linux/input.h>
  14 #include <linux/input/sparse-keymap.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/interrupt.h>
  17
  18 #include <linux/i2c/dm355evm_msp.h>
  19 #include <linux/module.h>
  20
  21
  22 /*
  23  * The MSP430 firmware on the DM355 EVM monitors on-board pushbuttons
  24  * and an IR receptor used for the remote control.  When any key is
  25  * pressed, or its autorepeat kicks in, an event is sent.  This driver
  26  * read those events from the small (32 event) queue and reports them.
  27  *
  28  * Note that physically there can only be one of these devices.
  29  *
  30  * This driver was tested with firmware revision A4.
  31  */
  32 struct dm355evm_keys {
  33         struct input_dev        *input;
  34         struct device           *dev;
  35         int                     irq;
  36 };
  37
  38 /* These initial keycodes can be remapped */
  39 static const struct key_entry dm355evm_keys[] = {
  40         /*
  41          * Pushbuttons on the EVM board ... note that the labels for these
  42          * are SW10/SW11/etc on the PC board.  The left/right orientation
  43          * comes only from the firmware's documentation, and presumes the
  44          * power connector is immediately in front of you and the IR sensor
  45          * is to the right.  (That is, rotate the board counter-clockwise
  46          * by 90 degrees from the SW10/etc and "DM355 EVM" labels.)
  47          */
  48         { KE_KEY, 0x00d8, { KEY_OK } },         /* SW12 */
  49         { KE_KEY, 0x00b8, { KEY_UP } },         /* SW13 */
  50         { KE_KEY, 0x00e8, { KEY_DOWN } },       /* SW11 */
  51         { KE_KEY, 0x0078, { KEY_LEFT } },       /* SW14 */
  52         { KE_KEY, 0x00f0, { KEY_RIGHT } },      /* SW10 */
  53
  54         /*
  55          * IR buttons ... codes assigned to match the universal remote
  56          * provided with the EVM (Philips PM4S) using DVD code 0020.
  57          *
  58          * These event codes match firmware documentation, but other
  59          * remote controls could easily send more RC5-encoded events.
  60          * The PM4S manual was used in several cases to help select
  61          * a keycode reflecting the intended usage.
  62          *
  63          * RC5 codes are 14 bits, with two start bits (0x3 prefix)
  64          * and a toggle bit (masked out below).
  65          */
  66         { KE_KEY, 0x300c, { KEY_POWER } },      /* NOTE: docs omit this */
  67         { KE_KEY, 0x3000, { KEY_NUMERIC_0 } },
  68         { KE_KEY, 0x3001, { KEY_NUMERIC_1 } },
  69         { KE_KEY, 0x3002, { KEY_NUMERIC_2 } },
  70         { KE_KEY, 0x3003, { KEY_NUMERIC_3 } },
  71         { KE_KEY, 0x3004, { KEY_NUMERIC_4 } },
  72         { KE_KEY, 0x3005, { KEY_NUMERIC_5 } },
  73         { KE_KEY, 0x3006, { KEY_NUMERIC_6 } },
  74         { KE_KEY, 0x3007, { KEY_NUMERIC_7 } },
  75         { KE_KEY, 0x3008, { KEY_NUMERIC_8 } },
  76         { KE_KEY, 0x3009, { KEY_NUMERIC_9 } },
  77         { KE_KEY, 0x3022, { KEY_ENTER } },
  78         { KE_KEY, 0x30ec, { KEY_MODE } },       /* "tv/vcr/..." */
  79         { KE_KEY, 0x300f, { KEY_SELECT } },     /* "info" */
  80         { KE_KEY, 0x3020, { KEY_CHANNELUP } },  /* "up" */
  81         { KE_KEY, 0x302e, { KEY_MENU } },       /* "in/out" */
  82         { KE_KEY, 0x3011, { KEY_VOLUMEDOWN } }, /* "left" */
  83         { KE_KEY, 0x300d, { KEY_MUTE } },       /* "ok" */
  84         { KE_KEY, 0x3010, { KEY_VOLUMEUP } },   /* "right" */
  85         { KE_KEY, 0x301e, { KEY_SUBTITLE } },   /* "cc" */
  86         { KE_KEY, 0x3021, { KEY_CHANNELDOWN } },/* "down" */
  87         { KE_KEY, 0x3022, { KEY_PREVIOUS } },
  88         { KE_KEY, 0x3026, { KEY_SLEEP } },
  89         { KE_KEY, 0x3172, { KEY_REWIND } },     /* NOTE: docs wrongly say 0x30ca */
  90         { KE_KEY, 0x3175, { KEY_PLAY } },
  91         { KE_KEY, 0x3174, { KEY_FASTFORWARD } },
  92         { KE_KEY, 0x3177, { KEY_RECORD } },
  93         { KE_KEY, 0x3176, { KEY_STOP } },
  94         { KE_KEY, 0x3169, { KEY_PAUSE } },
  95 };
  96
  97 /*
  98  * Because we communicate with the MSP430 using I2C, and all I2C calls
  99  * in Linux sleep, we use a threaded IRQ handler.  The IRQ itself is
 100  * active low, but we go through the GPIO controller so we can trigger
 101  * on falling edges and not worry about enabling/disabling the IRQ in
 102  * the keypress handling path.
 103  */
 104 static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)
 105 {
 106         static u16 last_event;
 107         struct dm355evm_keys *keys = _keys;
 108         const struct key_entry *ke;
 109         unsigned int keycode;
 110         int status;
 111         u16 event;
 112
 113         /* For simplicity we ignore INPUT_COUNT and just read
 114          * events until we get the "queue empty" indicator.
 115          * Reading INPUT_LOW decrements the count.
 116          */
 117         for (;;) {
 118                 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_HIGH);
 119                 if (status < 0) {
 120                         dev_dbg(keys->dev, "input high err %d\n",
 121                                         status);
 122                         break;
 123                 }
 124                 event = status << 8;
 125
 126                 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_LOW);
 127                 if (status < 0) {
 128                         dev_dbg(keys->dev, "input low err %d\n",
 129                                         status);
 130                         break;
 131                 }
 132                 event |= status;
 133                 if (event == 0xdead)
 134                         break;
 135
 136                 /* Press and release a button:  two events, same code.
 137                  * Press and hold (autorepeat), then release: N events
 138                  * (N > 2), same code.  For RC5 buttons the toggle bits
 139                  * distinguish (for example) "1-autorepeat" from "1 1";
 140                  * but PCB buttons don't support that bit.
 141                  *
 142                  * So we must synthesize release events.  We do that by
 143                  * mapping events to a press/release event pair; then
 144                  * to avoid adding extra events, skip the second event
 145                  * of each pair.
 146                  */
 147                 if (event == last_event) {
 148                         last_event = 0;
 149                         continue;
 150                 }
 151                 last_event = event;
 152
 153                 /* ignore the RC5 toggle bit */
 154                 event &= ~0x0800;
 155
 156                 /* find the key, or report it as unknown */
 157                 ke = sparse_keymap_entry_from_scancode(keys->input, event);
 158                 keycode = ke ? ke->keycode : KEY_UNKNOWN;
 159                 dev_dbg(keys->dev,
 160                         "input event 0x%04x--> keycode %d\n",
 161                         event, keycode);
 162
 163                 /* report press + release */
 164                 input_report_key(keys->input, keycode, 1);
 165                 input_sync(keys->input);
 166                 input_report_key(keys->input, keycode, 0);
 167                 input_sync(keys->input);
 168         }
 169
 170         return IRQ_HANDLED;
 171 }
 172
 173 /*----------------------------------------------------------------------*/
 174
 175 static int dm355evm_keys_probe(struct platform_device *pdev)
 176 {
 177         struct dm355evm_keys    *keys;
 178         struct input_dev        *input;
 179         int                     status;
 180
 181         /* allocate instance struct and input dev */
 182         keys = kzalloc(sizeof *keys, GFP_KERNEL);
 183         input = input_allocate_device();
 184         if (!keys || !input) {
 185                 status = -ENOMEM;
 186                 goto fail1;
 187         }
 188
 189         keys->dev = &pdev->dev;
 190         keys->input = input;
 191
 192         /* set up "threaded IRQ handler" */
 193         status = platform_get_irq(pdev, 0);
 194         if (status < 0)
 195                 goto fail1;
 196         keys->irq = status;
 197
 198         input_set_drvdata(input, keys);
 199
 200         input->name = "DM355 EVM Controls";
 201         input->phys = "dm355evm/input0";
 202         input->dev.parent = &pdev->dev;
 203
 204         input->id.bustype = BUS_I2C;
 205         input->id.product = 0x0355;
 206         input->id.version = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 207
 208         status = sparse_keymap_setup(input, dm355evm_keys, NULL);
 209         if (status)
 210                 goto fail1;
 211
 212         /* REVISIT:  flush the event queue? */
 213
 214         status = request_threaded_irq(keys->irq, NULL, dm355evm_keys_irq,
 215                                       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 216                                       dev_name(&pdev->dev), keys);
 217         if (status < 0)
 218                 goto fail2;
 219
 220         /* register */
 221         status = input_register_device(input);
 222         if (status < 0)
 223                 goto fail3;
 224
 225         platform_set_drvdata(pdev, keys);
 226
 227         return 0;
 228
 229 fail3:
 230         free_irq(keys->irq, keys);
 231 fail2:
 232         sparse_keymap_free(input);
 233 fail1:
 234         input_free_device(input);
 235         kfree(keys);
 236         dev_err(&pdev->dev, "can't register, err %d\n", status);
 237
 238         return status;
 239 }
 240
 241 static int dm355evm_keys_remove(struct platform_device *pdev)
 242 {
 243         struct dm355evm_keys    *keys = platform_get_drvdata(pdev);
 244
 245         free_irq(keys->irq, keys);
 246         sparse_keymap_free(keys->input);
 247         input_unregister_device(keys->input);
 248         kfree(keys);
 249
 250         return 0;
 251 }
 252
 253 /* REVISIT:  add suspend/resume when DaVinci supports it.  The IRQ should
 254  * be able to wake up the system.  When device_may_wakeup(&pdev->dev), call
 255  * enable_irq_wake() on suspend, and disable_irq_wake() on resume.
 256  */
 257
 258 /*
 259  * I2C is used to talk to the MSP430, but this platform device is
 260  * exposed by an MFD driver that manages I2C communications.
 261  */
 262 static struct platform_driver dm355evm_keys_driver = {
 263         .probe          = dm355evm_keys_probe,
 264         .remove         = dm355evm_keys_remove,
 265         .driver         = {
 266                 .name   = "dm355evm_keys",
 267         },
 268 };
 269 module_platform_driver(dm355evm_keys_driver);
 270
 271 MODULE_LICENSE("GPL");