dm355evm_keys.c (7232B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * dm355evm_keys.c - support buttons and IR remote on DM355 EVM board 4 * 5 * Copyright (c) 2008 by David Brownell 6 */ 7#include <linux/kernel.h> 8#include <linux/slab.h> 9#include <linux/input.h> 10#include <linux/input/sparse-keymap.h> 11#include <linux/platform_device.h> 12#include <linux/interrupt.h> 13 14#include <linux/mfd/dm355evm_msp.h> 15#include <linux/module.h> 16 17 18/* 19 * The MSP430 firmware on the DM355 EVM monitors on-board pushbuttons 20 * and an IR receptor used for the remote control. When any key is 21 * pressed, or its autorepeat kicks in, an event is sent. This driver 22 * read those events from the small (32 event) queue and reports them. 23 * 24 * Note that physically there can only be one of these devices. 25 * 26 * This driver was tested with firmware revision A4. 27 */ 28struct dm355evm_keys { 29 struct input_dev *input; 30 struct device *dev; 31}; 32 33/* These initial keycodes can be remapped */ 34static const struct key_entry dm355evm_keys[] = { 35 /* 36 * Pushbuttons on the EVM board ... note that the labels for these 37 * are SW10/SW11/etc on the PC board. The left/right orientation 38 * comes only from the firmware's documentation, and presumes the 39 * power connector is immediately in front of you and the IR sensor 40 * is to the right. (That is, rotate the board counter-clockwise 41 * by 90 degrees from the SW10/etc and "DM355 EVM" labels.) 42 */ 43 { KE_KEY, 0x00d8, { KEY_OK } }, /* SW12 */ 44 { KE_KEY, 0x00b8, { KEY_UP } }, /* SW13 */ 45 { KE_KEY, 0x00e8, { KEY_DOWN } }, /* SW11 */ 46 { KE_KEY, 0x0078, { KEY_LEFT } }, /* SW14 */ 47 { KE_KEY, 0x00f0, { KEY_RIGHT } }, /* SW10 */ 48 49 /* 50 * IR buttons ... codes assigned to match the universal remote 51 * provided with the EVM (Philips PM4S) using DVD code 0020. 52 * 53 * These event codes match firmware documentation, but other 54 * remote controls could easily send more RC5-encoded events. 55 * The PM4S manual was used in several cases to help select 56 * a keycode reflecting the intended usage. 57 * 58 * RC5 codes are 14 bits, with two start bits (0x3 prefix) 59 * and a toggle bit (masked out below). 60 */ 61 { KE_KEY, 0x300c, { KEY_POWER } }, /* NOTE: docs omit this */ 62 { KE_KEY, 0x3000, { KEY_NUMERIC_0 } }, 63 { KE_KEY, 0x3001, { KEY_NUMERIC_1 } }, 64 { KE_KEY, 0x3002, { KEY_NUMERIC_2 } }, 65 { KE_KEY, 0x3003, { KEY_NUMERIC_3 } }, 66 { KE_KEY, 0x3004, { KEY_NUMERIC_4 } }, 67 { KE_KEY, 0x3005, { KEY_NUMERIC_5 } }, 68 { KE_KEY, 0x3006, { KEY_NUMERIC_6 } }, 69 { KE_KEY, 0x3007, { KEY_NUMERIC_7 } }, 70 { KE_KEY, 0x3008, { KEY_NUMERIC_8 } }, 71 { KE_KEY, 0x3009, { KEY_NUMERIC_9 } }, 72 { KE_KEY, 0x3022, { KEY_ENTER } }, 73 { KE_KEY, 0x30ec, { KEY_MODE } }, /* "tv/vcr/..." */ 74 { KE_KEY, 0x300f, { KEY_SELECT } }, /* "info" */ 75 { KE_KEY, 0x3020, { KEY_CHANNELUP } }, /* "up" */ 76 { KE_KEY, 0x302e, { KEY_MENU } }, /* "in/out" */ 77 { KE_KEY, 0x3011, { KEY_VOLUMEDOWN } }, /* "left" */ 78 { KE_KEY, 0x300d, { KEY_MUTE } }, /* "ok" */ 79 { KE_KEY, 0x3010, { KEY_VOLUMEUP } }, /* "right" */ 80 { KE_KEY, 0x301e, { KEY_SUBTITLE } }, /* "cc" */ 81 { KE_KEY, 0x3021, { KEY_CHANNELDOWN } },/* "down" */ 82 { KE_KEY, 0x3022, { KEY_PREVIOUS } }, 83 { KE_KEY, 0x3026, { KEY_SLEEP } }, 84 { KE_KEY, 0x3172, { KEY_REWIND } }, /* NOTE: docs wrongly say 0x30ca */ 85 { KE_KEY, 0x3175, { KEY_PLAY } }, 86 { KE_KEY, 0x3174, { KEY_FASTFORWARD } }, 87 { KE_KEY, 0x3177, { KEY_RECORD } }, 88 { KE_KEY, 0x3176, { KEY_STOP } }, 89 { KE_KEY, 0x3169, { KEY_PAUSE } }, 90}; 91 92/* 93 * Because we communicate with the MSP430 using I2C, and all I2C calls 94 * in Linux sleep, we use a threaded IRQ handler. The IRQ itself is 95 * active low, but we go through the GPIO controller so we can trigger 96 * on falling edges and not worry about enabling/disabling the IRQ in 97 * the keypress handling path. 98 */ 99static irqreturn_t dm355evm_keys_irq(int irq, void *_keys) 100{ 101 static u16 last_event; 102 struct dm355evm_keys *keys = _keys; 103 const struct key_entry *ke; 104 unsigned int keycode; 105 int status; 106 u16 event; 107 108 /* For simplicity we ignore INPUT_COUNT and just read 109 * events until we get the "queue empty" indicator. 110 * Reading INPUT_LOW decrements the count. 111 */ 112 for (;;) { 113 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_HIGH); 114 if (status < 0) { 115 dev_dbg(keys->dev, "input high err %d\n", 116 status); 117 break; 118 } 119 event = status << 8; 120 121 status = dm355evm_msp_read(DM355EVM_MSP_INPUT_LOW); 122 if (status < 0) { 123 dev_dbg(keys->dev, "input low err %d\n", 124 status); 125 break; 126 } 127 event |= status; 128 if (event == 0xdead) 129 break; 130 131 /* Press and release a button: two events, same code. 132 * Press and hold (autorepeat), then release: N events 133 * (N > 2), same code. For RC5 buttons the toggle bits 134 * distinguish (for example) "1-autorepeat" from "1 1"; 135 * but PCB buttons don't support that bit. 136 * 137 * So we must synthesize release events. We do that by 138 * mapping events to a press/release event pair; then 139 * to avoid adding extra events, skip the second event 140 * of each pair. 141 */ 142 if (event == last_event) { 143 last_event = 0; 144 continue; 145 } 146 last_event = event; 147 148 /* ignore the RC5 toggle bit */ 149 event &= ~0x0800; 150 151 /* find the key, or report it as unknown */ 152 ke = sparse_keymap_entry_from_scancode(keys->input, event); 153 keycode = ke ? ke->keycode : KEY_UNKNOWN; 154 dev_dbg(keys->dev, 155 "input event 0x%04x--> keycode %d\n", 156 event, keycode); 157 158 /* report press + release */ 159 input_report_key(keys->input, keycode, 1); 160 input_sync(keys->input); 161 input_report_key(keys->input, keycode, 0); 162 input_sync(keys->input); 163 } 164 165 return IRQ_HANDLED; 166} 167 168/*----------------------------------------------------------------------*/ 169 170static int dm355evm_keys_probe(struct platform_device *pdev) 171{ 172 struct dm355evm_keys *keys; 173 struct input_dev *input; 174 int irq; 175 int error; 176 177 keys = devm_kzalloc(&pdev->dev, sizeof (*keys), GFP_KERNEL); 178 if (!keys) 179 return -ENOMEM; 180 181 input = devm_input_allocate_device(&pdev->dev); 182 if (!input) 183 return -ENOMEM; 184 185 keys->dev = &pdev->dev; 186 keys->input = input; 187 188 input->name = "DM355 EVM Controls"; 189 input->phys = "dm355evm/input0"; 190 191 input->id.bustype = BUS_I2C; 192 input->id.product = 0x0355; 193 input->id.version = dm355evm_msp_read(DM355EVM_MSP_FIRMREV); 194 195 error = sparse_keymap_setup(input, dm355evm_keys, NULL); 196 if (error) 197 return error; 198 199 /* REVISIT: flush the event queue? */ 200 201 /* set up "threaded IRQ handler" */ 202 irq = platform_get_irq(pdev, 0); 203 if (irq < 0) 204 return irq; 205 206 error = devm_request_threaded_irq(&pdev->dev, irq, 207 NULL, dm355evm_keys_irq, 208 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 209 dev_name(&pdev->dev), keys); 210 if (error) 211 return error; 212 213 /* register */ 214 error = input_register_device(input); 215 if (error) 216 return error; 217 218 return 0; 219} 220 221/* REVISIT: add suspend/resume when DaVinci supports it. The IRQ should 222 * be able to wake up the system. When device_may_wakeup(&pdev->dev), call 223 * enable_irq_wake() on suspend, and disable_irq_wake() on resume. 224 */ 225 226/* 227 * I2C is used to talk to the MSP430, but this platform device is 228 * exposed by an MFD driver that manages I2C communications. 229 */ 230static struct platform_driver dm355evm_keys_driver = { 231 .probe = dm355evm_keys_probe, 232 .driver = { 233 .name = "dm355evm_keys", 234 }, 235}; 236module_platform_driver(dm355evm_keys_driver); 237 238MODULE_LICENSE("GPL");