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Linux/drivers/input/misc/dm355evm_keys.c

  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  */
 32 struct dm355evm_keys {
 33         struct input_dev        *input;
 34         struct device           *dev;
 35         int                     irq;
 36 };
 37 
 38 /* These initial keycodes can be remapped */
 39 static 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  */
104 static 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 
175 static 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 
229 fail3:
230         free_irq(keys->irq, keys);
231 fail2:
232         sparse_keymap_free(input);
233 fail1:
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 
241 static 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  */
262 static 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 };
270 module_platform_driver(dm355evm_keys_driver);
271 
272 MODULE_LICENSE("GPL");
273 

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