tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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 */
32struct dm355evm_keys {
33 struct input_dev *input;
34 struct device *dev;
35};
36
37/* These initial keycodes can be remapped */
38static 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 */
103static 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
174static 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 */
234static struct platform_driver dm355evm_keys_driver = {
235 .probe = dm355evm_keys_probe,
236 .driver = {
237 .name = "dm355evm_keys",
238 },
239};
240module_platform_driver(dm355evm_keys_driver);
241
242MODULE_LICENSE("GPL");