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 */ 32struct dm355evm_keys { 33 struct input_dev *input; 34 struct device *dev; 35 int irq; 36}; 37 38/* These initial keycodes can be remapped */ 39static 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 */ 104static 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 175static 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 229fail3: 230 free_irq(keys->irq, keys); 231fail2: 232 sparse_keymap_free(input); 233fail1: 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 241static 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 */ 262static struct platform_driver dm355evm_keys_driver = { 263 .probe = dm355evm_keys_probe, 264 .remove = dm355evm_keys_remove, 265 .driver = { 266 .owner = THIS_MODULE, 267 .name = "dm355evm_keys", 268 }, 269}; 270module_platform_driver(dm355evm_keys_driver); 271 272MODULE_LICENSE("GPL"); 273