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");