summaryrefslogtreecommitdiff
path: root/drivers/input/misc/dm355evm_keys.c
blob: b6b7bd4e54625d80e1112640c0226d6c4df68e6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
/*
 * dm355evm_keys.c - support buttons and IR remote on DM355 EVM board
 *
 * Copyright (c) 2008 by David Brownell
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>

#include <linux/i2c/dm355evm_msp.h>
#include <linux/module.h>


/*
 * The MSP430 firmware on the DM355 EVM monitors on-board pushbuttons
 * and an IR receptor used for the remote control.  When any key is
 * pressed, or its autorepeat kicks in, an event is sent.  This driver
 * read those events from the small (32 event) queue and reports them.
 *
 * Note that physically there can only be one of these devices.
 *
 * This driver was tested with firmware revision A4.
 */
struct dm355evm_keys {
	struct input_dev	*input;
	struct device		*dev;
	int			irq;
};

/* These initial keycodes can be remapped */
static const struct key_entry dm355evm_keys[] = {
	/*
	 * Pushbuttons on the EVM board ... note that the labels for these
	 * are SW10/SW11/etc on the PC board.  The left/right orientation
	 * comes only from the firmware's documentation, and presumes the
	 * power connector is immediately in front of you and the IR sensor
	 * is to the right.  (That is, rotate the board counter-clockwise
	 * by 90 degrees from the SW10/etc and "DM355 EVM" labels.)
	 */
	{ KE_KEY, 0x00d8, { KEY_OK } },		/* SW12 */
	{ KE_KEY, 0x00b8, { KEY_UP } },		/* SW13 */
	{ KE_KEY, 0x00e8, { KEY_DOWN } },	/* SW11 */
	{ KE_KEY, 0x0078, { KEY_LEFT } },	/* SW14 */
	{ KE_KEY, 0x00f0, { KEY_RIGHT } },	/* SW10 */

	/*
	 * IR buttons ... codes assigned to match the universal remote
	 * provided with the EVM (Philips PM4S) using DVD code 0020.
	 *
	 * These event codes match firmware documentation, but other
	 * remote controls could easily send more RC5-encoded events.
	 * The PM4S manual was used in several cases to help select
	 * a keycode reflecting the intended usage.
	 *
	 * RC5 codes are 14 bits, with two start bits (0x3 prefix)
	 * and a toggle bit (masked out below).
	 */
	{ KE_KEY, 0x300c, { KEY_POWER } },	/* NOTE: docs omit this */
	{ KE_KEY, 0x3000, { KEY_NUMERIC_0 } },
	{ KE_KEY, 0x3001, { KEY_NUMERIC_1 } },
	{ KE_KEY, 0x3002, { KEY_NUMERIC_2 } },
	{ KE_KEY, 0x3003, { KEY_NUMERIC_3 } },
	{ KE_KEY, 0x3004, { KEY_NUMERIC_4 } },
	{ KE_KEY, 0x3005, { KEY_NUMERIC_5 } },
	{ KE_KEY, 0x3006, { KEY_NUMERIC_6 } },
	{ KE_KEY, 0x3007, { KEY_NUMERIC_7 } },
	{ KE_KEY, 0x3008, { KEY_NUMERIC_8 } },
	{ KE_KEY, 0x3009, { KEY_NUMERIC_9 } },
	{ KE_KEY, 0x3022, { KEY_ENTER } },
	{ KE_KEY, 0x30ec, { KEY_MODE } },	/* "tv/vcr/..." */
	{ KE_KEY, 0x300f, { KEY_SELECT } },	/* "info" */
	{ KE_KEY, 0x3020, { KEY_CHANNELUP } },	/* "up" */
	{ KE_KEY, 0x302e, { KEY_MENU } },	/* "in/out" */
	{ KE_KEY, 0x3011, { KEY_VOLUMEDOWN } },	/* "left" */
	{ KE_KEY, 0x300d, { KEY_MUTE } },	/* "ok" */
	{ KE_KEY, 0x3010, { KEY_VOLUMEUP } },	/* "right" */
	{ KE_KEY, 0x301e, { KEY_SUBTITLE } },	/* "cc" */
	{ KE_KEY, 0x3021, { KEY_CHANNELDOWN } },/* "down" */
	{ KE_KEY, 0x3022, { KEY_PREVIOUS } },
	{ KE_KEY, 0x3026, { KEY_SLEEP } },
	{ KE_KEY, 0x3172, { KEY_REWIND } },	/* NOTE: docs wrongly say 0x30ca */
	{ KE_KEY, 0x3175, { KEY_PLAY } },
	{ KE_KEY, 0x3174, { KEY_FASTFORWARD } },
	{ KE_KEY, 0x3177, { KEY_RECORD } },
	{ KE_KEY, 0x3176, { KEY_STOP } },
	{ KE_KEY, 0x3169, { KEY_PAUSE } },
};

/*
 * Because we communicate with the MSP430 using I2C, and all I2C calls
 * in Linux sleep, we use a threaded IRQ handler.  The IRQ itself is
 * active low, but we go through the GPIO controller so we can trigger
 * on falling edges and not worry about enabling/disabling the IRQ in
 * the keypress handling path.
 */
static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)
{
	static u16 last_event;
	struct dm355evm_keys *keys = _keys;
	const struct key_entry *ke;
	unsigned int keycode;
	int status;
	u16 event;

	/* For simplicity we ignore INPUT_COUNT and just read
	 * events until we get the "queue empty" indicator.
	 * Reading INPUT_LOW decrements the count.
	 */
	for (;;) {
		status = dm355evm_msp_read(DM355EVM_MSP_INPUT_HIGH);
		if (status < 0) {
			dev_dbg(keys->dev, "input high err %d\n",
					status);
			break;
		}
		event = status << 8;

		status = dm355evm_msp_read(DM355EVM_MSP_INPUT_LOW);
		if (status < 0) {
			dev_dbg(keys->dev, "input low err %d\n",
					status);
			break;
		}
		event |= status;
		if (event == 0xdead)
			break;

		/* Press and release a button:  two events, same code.
		 * Press and hold (autorepeat), then release: N events
		 * (N > 2), same code.  For RC5 buttons the toggle bits
		 * distinguish (for example) "1-autorepeat" from "1 1";
		 * but PCB buttons don't support that bit.
		 *
		 * So we must synthesize release events.  We do that by
		 * mapping events to a press/release event pair; then
		 * to avoid adding extra events, skip the second event
		 * of each pair.
		 */
		if (event == last_event) {
			last_event = 0;
			continue;
		}
		last_event = event;

		/* ignore the RC5 toggle bit */
		event &= ~0x0800;

		/* find the key, or report it as unknown */
		ke = sparse_keymap_entry_from_scancode(keys->input, event);
		keycode = ke ? ke->keycode : KEY_UNKNOWN;
		dev_dbg(keys->dev,
			"input event 0x%04x--> keycode %d\n",
			event, keycode);

		/* report press + release */
		input_report_key(keys->input, keycode, 1);
		input_sync(keys->input);
		input_report_key(keys->input, keycode, 0);
		input_sync(keys->input);
	}

	return IRQ_HANDLED;
}

/*----------------------------------------------------------------------*/

static int dm355evm_keys_probe(struct platform_device *pdev)
{
	struct dm355evm_keys	*keys;
	struct input_dev	*input;
	int			status;

	/* allocate instance struct and input dev */
	keys = kzalloc(sizeof *keys, GFP_KERNEL);
	input = input_allocate_device();
	if (!keys || !input) {
		status = -ENOMEM;
		goto fail1;
	}

	keys->dev = &pdev->dev;
	keys->input = input;

	/* set up "threaded IRQ handler" */
	status = platform_get_irq(pdev, 0);
	if (status < 0)
		goto fail1;
	keys->irq = status;

	input_set_drvdata(input, keys);

	input->name = "DM355 EVM Controls";
	input->phys = "dm355evm/input0";
	input->dev.parent = &pdev->dev;

	input->id.bustype = BUS_I2C;
	input->id.product = 0x0355;
	input->id.version = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);

	status = sparse_keymap_setup(input, dm355evm_keys, NULL);
	if (status)
		goto fail1;

	/* REVISIT:  flush the event queue? */

	status = request_threaded_irq(keys->irq, NULL, dm355evm_keys_irq,
				      IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
				      dev_name(&pdev->dev), keys);
	if (status < 0)
		goto fail2;

	/* register */
	status = input_register_device(input);
	if (status < 0)
		goto fail3;

	platform_set_drvdata(pdev, keys);

	return 0;

fail3:
	free_irq(keys->irq, keys);
fail2:
	sparse_keymap_free(input);
fail1:
	input_free_device(input);
	kfree(keys);
	dev_err(&pdev->dev, "can't register, err %d\n", status);

	return status;
}

static int dm355evm_keys_remove(struct platform_device *pdev)
{
	struct dm355evm_keys	*keys = platform_get_drvdata(pdev);

	free_irq(keys->irq, keys);
	sparse_keymap_free(keys->input);
	input_unregister_device(keys->input);
	kfree(keys);

	return 0;
}

/* REVISIT:  add suspend/resume when DaVinci supports it.  The IRQ should
 * be able to wake up the system.  When device_may_wakeup(&pdev->dev), call
 * enable_irq_wake() on suspend, and disable_irq_wake() on resume.
 */

/*
 * I2C is used to talk to the MSP430, but this platform device is
 * exposed by an MFD driver that manages I2C communications.
 */
static struct platform_driver dm355evm_keys_driver = {
	.probe		= dm355evm_keys_probe,
	.remove		= dm355evm_keys_remove,
	.driver		= {
		.name	= "dm355evm_keys",
	},
};
module_platform_driver(dm355evm_keys_driver);

MODULE_LICENSE("GPL");