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