target/linux/generic/files/drivers/leds/ledtrig-morse.c

   1 /*
   2  *  LED Morse Trigger
   3  *
   4  *  Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
   5  *
   6  *  This file was based on: drivers/led/ledtrig-timer.c
   7  *      Copyright 2005-2006 Openedhand Ltd.
   8  *      Author: Richard Purdie <rpurdie@openedhand.com>
   9  *
  10  *  also based on the patch '[PATCH] 2.5.59 morse code panics' posted
  11  *  in the LKML by Tomas Szepe at Thu, 30 Jan 2003
  12  *      Copyright (C) 2002 Andrew Rodland <arodland@noln.com>
  13  *      Copyright (C) 2003 Tomas Szepe <szepe@pinerecords.com>
  14  *
  15  *  This program is free software; you can redistribute it and/or modify it
  16  *  under the terms of the GNU General Public License version 2 as published
  17  *  by the Free Software Foundation.
  18  *
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/version.h>
  23 #include <linux/module.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/init.h>
  26 #include <linux/list.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/device.h>
  29 #include <linux/sysdev.h>
  30 #include <linux/timer.h>
  31 #include <linux/ctype.h>
  32 #include <linux/leds.h>
  33 #include <linux/slab.h>
  34
  35 #include "leds.h"
  36
  37 #define MORSE_DELAY_BASE        (HZ/2)
  38
  39 #define MORSE_STATE_BLINK_START 0
  40 #define MORSE_STATE_BLINK_STOP  1
  41
  42 #define MORSE_DIT_LEN   1
  43 #define MORSE_DAH_LEN   3
  44 #define MORSE_SPACE_LEN 7
  45
  46 struct morse_trig_data {
  47         unsigned long delay;
  48         char *msg;
  49
  50         unsigned char morse;
  51         unsigned char state;
  52         char *msgpos;
  53         struct timer_list timer;
  54 };
  55
  56 const unsigned char morsetable[] = {
  57         0122, 0, 0310, 0, 0, 0163,                              /* "#$%&' */
  58         055, 0155, 0, 0, 0163, 0141, 0152, 0051,                /* ()*+,-./ */
  59         077, 076, 074, 070, 060, 040, 041, 043, 047, 057,       /* 0-9 */
  60         0107, 0125, 0, 0061, 0, 0114, 0,                        /* :;<=>?@ */
  61         006, 021, 025, 011, 002, 024, 013, 020, 004,            /* A-I */
  62         036, 015, 022, 007, 005, 017, 026, 033, 012,            /* J-R */
  63         010, 003, 014, 030, 016, 031, 035, 023,                 /* S-Z */
  64         0, 0, 0, 0, 0154                                        /* [\]^_ */
  65 };
  66
  67 static inline unsigned char tomorse(char c) {
  68         if (c >= 'a' && c <= 'z')
  69                 c = c - 'a' + 'A';
  70         if (c >= '"' && c <= '_') {
  71                 return morsetable[c - '"'];
  72         } else
  73                 return 0;
  74 }
  75
  76 static inline unsigned long dit_len(struct morse_trig_data *morse_data)
  77 {
  78         return MORSE_DIT_LEN*morse_data->delay;
  79 }
  80
  81 static inline unsigned long dah_len(struct morse_trig_data *morse_data)
  82 {
  83         return MORSE_DAH_LEN*morse_data->delay;
  84 }
  85
  86 static inline unsigned long space_len(struct morse_trig_data *morse_data)
  87 {
  88         return MORSE_SPACE_LEN*morse_data->delay;
  89 }
  90
  91 static void morse_timer_function(unsigned long data)
  92 {
  93         struct led_classdev *led_cdev = (struct led_classdev *)data;
  94         struct morse_trig_data *morse_data = led_cdev->trigger_data;
  95         unsigned long brightness = LED_OFF;
  96         unsigned long delay = 0;
  97
  98         if (!morse_data->msg)
  99                 goto set_led;
 100
 101         switch (morse_data->state) {
 102         case MORSE_STATE_BLINK_START:
 103                 /* Starting a new blink.  We have a valid code in morse. */
 104                 delay = (morse_data->morse & 001) ? dah_len(morse_data):
 105                         dit_len(morse_data);
 106                 brightness = LED_FULL;
 107                 morse_data->state = MORSE_STATE_BLINK_STOP;
 108                 morse_data->morse >>= 1;
 109                 break;
 110         case MORSE_STATE_BLINK_STOP:
 111                 /* Coming off of a blink. */
 112                 morse_data->state = MORSE_STATE_BLINK_START;
 113
 114                 if (morse_data->morse > 1) {
 115                         /* Not done yet, just a one-dit pause. */
 116                         delay = dit_len(morse_data);
 117                         break;
 118                 }
 119
 120                 /* Get a new char, figure out how much space. */
 121                 /* First time through */
 122                 if (!morse_data->msgpos)
 123                         morse_data->msgpos = (char *)morse_data->msg;
 124
 125                 if (!*morse_data->msgpos) {
 126                         /* Repeating */
 127                         morse_data->msgpos = (char *)morse_data->msg;
 128                         delay = space_len(morse_data);
 129                 } else {
 130                         /* Inter-letter space */
 131                         delay = dah_len(morse_data);
 132                 }
 133
 134                 if (!(morse_data->morse = tomorse(*morse_data->msgpos))) {
 135                         delay = space_len(morse_data);
 136                         /* And get us back here */
 137                         morse_data->state = MORSE_STATE_BLINK_STOP;
 138                 }
 139                 morse_data->msgpos++;
 140                 break;
 141         }
 142
 143         mod_timer(&morse_data->timer, jiffies + msecs_to_jiffies(delay));
 144
 145 set_led:
 146         led_set_brightness(led_cdev, brightness);
 147 }
 148
 149 static ssize_t _morse_delay_show(struct led_classdev *led_cdev, char *buf)
 150 {
 151         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 152
 153         sprintf(buf, "%lu\n", morse_data->delay);
 154
 155         return strlen(buf) + 1;
 156 }
 157
 158 static ssize_t _morse_delay_store(struct led_classdev *led_cdev,
 159                 const char *buf, size_t size)
 160 {
 161         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 162         char *after;
 163         unsigned long state = simple_strtoul(buf, &after, 10);
 164         size_t count = after - buf;
 165         int ret = -EINVAL;
 166
 167         if (*after && isspace(*after))
 168                 count++;
 169
 170         if (count == size) {
 171                 morse_data->delay = state;
 172                 mod_timer(&morse_data->timer, jiffies + 1);
 173                 ret = count;
 174         }
 175
 176         return ret;
 177 }
 178
 179 static ssize_t _morse_msg_show(struct led_classdev *led_cdev, char *buf)
 180 {
 181         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 182
 183         if (!morse_data->msg)
 184                 sprintf(buf, "<none>\n");
 185         else
 186                 sprintf(buf, "%s\n", morse_data->msg);
 187
 188         return strlen(buf) + 1;
 189 }
 190
 191 static ssize_t _morse_msg_store(struct led_classdev *led_cdev,
 192                 const char *buf, size_t size)
 193 {
 194         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 195         char *m;
 196
 197         m = kmalloc(size, GFP_KERNEL);
 198         if (!m)
 199                 return -ENOMEM;
 200
 201         memcpy(m,buf,size);
 202         m[size]='\0';
 203
 204         if (morse_data->msg)
 205                 kfree(morse_data->msg);
 206
 207         morse_data->msg = m;
 208         morse_data->msgpos = NULL;
 209         morse_data->state = MORSE_STATE_BLINK_STOP;
 210
 211         mod_timer(&morse_data->timer, jiffies + 1);
 212
 213         return size;
 214 }
 215
 216 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
 217 static ssize_t morse_delay_show(struct device *dev,
 218                 struct device_attribute *attr, char *buf)
 219 {
 220         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 221
 222         return _morse_delay_show(led_cdev, buf);
 223 }
 224
 225 static ssize_t morse_delay_store(struct device *dev,
 226                 struct device_attribute *attr, const char *buf, size_t size)
 227 {
 228         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 229
 230         return _morse_delay_store(led_cdev, buf, size);
 231 }
 232
 233 static ssize_t morse_msg_show(struct device *dev,
 234                 struct device_attribute *attr, char *buf)
 235 {
 236         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 237
 238         return _morse_msg_show(led_cdev, buf);
 239 }
 240
 241 static ssize_t morse_msg_store(struct device *dev,
 242                 struct device_attribute *attr, const char *buf, size_t size)
 243 {
 244         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 245
 246         return _morse_msg_store(led_cdev, buf, size);
 247 }
 248
 249 static DEVICE_ATTR(delay, 0644, morse_delay_show, morse_delay_store);
 250 static DEVICE_ATTR(message, 0644, morse_msg_show, morse_msg_store);
 251
 252 #define led_device_create_file(leddev, attr) \
 253         device_create_file(leddev->dev, &dev_attr_ ## attr)
 254 #define led_device_remove_file(leddev, attr) \
 255         device_remove_file(leddev->dev, &dev_attr_ ## attr)
 256
 257 #else
 258 static ssize_t morse_delay_show(struct class_device *dev, char *buf)
 259 {
 260         struct led_classdev *led_cdev = class_get_devdata(dev);
 261
 262         return _morse_delay_show(led_cdev, buf);
 263 }
 264
 265 static ssize_t morse_delay_store(struct class_device *dev, const char *buf,
 266                 size_t size)
 267 {
 268         struct led_classdev *led_cdev = class_get_devdata(dev);
 269
 270         return _morse_delay_store(led_cdev, buf, size);
 271 }
 272
 273 static ssize_t morse_msg_show(struct class_device *dev, char *buf)
 274 {
 275         struct led_classdev *led_cdev = class_get_devdata(dev);
 276
 277         return _morse_msg_show(led_cdev, buf);
 278 }
 279
 280 static ssize_t morse_msg_store(struct class_device *dev, const char *buf,
 281                                 size_t size)
 282 {
 283         struct led_classdev *led_cdev = class_get_devdata(dev);
 284
 285         return _morse_msg_store(led_cdev, buf, size);
 286 }
 287
 288 static CLASS_DEVICE_ATTR(delay, 0644, morse_delay_show, morse_delay_store);
 289 static CLASS_DEVICE_ATTR(message, 0644, morse_msg_show, morse_msg_store);
 290
 291 #define led_device_create_file(leddev, attr) \
 292         class_device_create_file(leddev->class_dev, &class_device_attr_ ## attr)
 293 #define led_device_remove_file(leddev, attr) \
 294         class_device_remove_file(leddev->class_dev, &class_device_attr_ ## attr)
 295
 296 #endif
 297
 298 static void morse_trig_activate(struct led_classdev *led_cdev)
 299 {
 300         struct morse_trig_data *morse_data;
 301         int rc;
 302
 303         morse_data = kzalloc(sizeof(*morse_data), GFP_KERNEL);
 304         if (!morse_data)
 305                 return;
 306
 307         morse_data->delay = MORSE_DELAY_BASE;
 308         init_timer(&morse_data->timer);
 309         morse_data->timer.function = morse_timer_function;
 310         morse_data->timer.data = (unsigned long)led_cdev;
 311
 312         rc = led_device_create_file(led_cdev, delay);
 313         if (rc) goto err;
 314
 315         rc = led_device_create_file(led_cdev, message);
 316         if (rc) goto err_delay;
 317
 318         led_cdev->trigger_data = morse_data;
 319
 320         return;
 321
 322 err_delay:
 323         led_device_remove_file(led_cdev, delay);
 324 err:
 325         kfree(morse_data);
 326 }
 327
 328 static void morse_trig_deactivate(struct led_classdev *led_cdev)
 329 {
 330         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 331
 332         if (!morse_data)
 333                 return;
 334
 335         led_device_remove_file(led_cdev, message);
 336         led_device_remove_file(led_cdev, delay);
 337
 338         del_timer_sync(&morse_data->timer);
 339         if (morse_data->msg)
 340                 kfree(morse_data->msg);
 341
 342         kfree(morse_data);
 343 }
 344
 345 static struct led_trigger morse_led_trigger = {
 346         .name           = "morse",
 347         .activate       = morse_trig_activate,
 348         .deactivate     = morse_trig_deactivate,
 349 };
 350
 351 static int __init morse_trig_init(void)
 352 {
 353         return led_trigger_register(&morse_led_trigger);
 354 }
 355
 356 static void __exit morse_trig_exit(void)
 357 {
 358         led_trigger_unregister(&morse_led_trigger);
 359 }
 360
 361 module_init(morse_trig_init);
 362 module_exit(morse_trig_exit);
 363
 364 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 365 MODULE_DESCRIPTION("Morse LED trigger");
 366 MODULE_LICENSE("GPL");