target/linux/generic-2.6/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/module.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/kernel.h>
  24 #include <linux/init.h>
  25 #include <linux/list.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/device.h>
  28 #include <linux/sysdev.h>
  29 #include <linux/timer.h>
  30 #include <linux/ctype.h>
  31 #include <linux/leds.h>
  32
  33 #include "leds.h"
  34
  35 #define MORSE_DELAY_BASE        (HZ/2)
  36
  37 #define MORSE_STATE_BLINK_START 0
  38 #define MORSE_STATE_BLINK_STOP  1
  39
  40 #define MORSE_DIT_LEN   1
  41 #define MORSE_DAH_LEN   3
  42 #define MORSE_SPACE_LEN 7
  43
  44 struct morse_trig_data {
  45         unsigned long delay;
  46         char *msg;
  47
  48         unsigned char morse;
  49         unsigned char state;
  50         char *msgpos;
  51         struct timer_list timer;
  52 };
  53
  54 const unsigned char morsetable[] = {
  55         0122, 0, 0310, 0, 0, 0163,                              /* "#$%&' */
  56         055, 0155, 0, 0, 0163, 0141, 0152, 0051,                /* ()*+,-./ */
  57         077, 076, 074, 070, 060, 040, 041, 043, 047, 057,       /* 0-9 */
  58         0107, 0125, 0, 0061, 0, 0114, 0,                        /* :;<=>?@ */
  59         006, 021, 025, 011, 002, 024, 013, 020, 004,            /* A-I */
  60         036, 015, 022, 007, 005, 017, 026, 033, 012,            /* J-R */
  61         010, 003, 014, 030, 016, 031, 035, 023,                 /* S-Z */
  62         0, 0, 0, 0, 0154                                        /* [\]^_ */
  63 };
  64
  65 static inline unsigned char tomorse(char c) {
  66         if (c >= 'a' && c <= 'z')
  67                 c = c - 'a' + 'A';
  68         if (c >= '"' && c <= '_') {
  69                 return morsetable[c - '"'];
  70         } else
  71                 return 0;
  72 }
  73
  74 static inline unsigned long dit_len(struct morse_trig_data *morse_data)
  75 {
  76         return MORSE_DIT_LEN*morse_data->delay;
  77 }
  78
  79 static inline unsigned long dah_len(struct morse_trig_data *morse_data)
  80 {
  81         return MORSE_DAH_LEN*morse_data->delay;
  82 }
  83
  84 static inline unsigned long space_len(struct morse_trig_data *morse_data)
  85 {
  86         return MORSE_SPACE_LEN*morse_data->delay;
  87 }
  88
  89 static void morse_timer_function(unsigned long data)
  90 {
  91         struct led_classdev *led_cdev = (struct led_classdev *) data;
  92         struct morse_trig_data *morse_data = led_cdev->trigger_data;
  93         unsigned long brightness = LED_OFF;
  94         unsigned long delay = 0;
  95
  96         if (!morse_data->msg)
  97                 goto set_led;
  98
  99         switch (morse_data->state) {
 100         case MORSE_STATE_BLINK_START:
 101                 /* Starting a new blink.  We have a valid code in morse. */
 102                 delay = (morse_data->morse & 001) ? dah_len(morse_data):
 103                         dit_len(morse_data);
 104                 brightness = LED_FULL;
 105                 morse_data->state = MORSE_STATE_BLINK_STOP;
 106                 morse_data->morse >>= 1;
 107                 break;
 108         case MORSE_STATE_BLINK_STOP:
 109                 /* Coming off of a blink. */
 110                 morse_data->state = MORSE_STATE_BLINK_START;
 111
 112                 if (morse_data->morse > 1) {
 113                         /* Not done yet, just a one-dit pause. */
 114                         delay = dit_len(morse_data);
 115                         break;
 116                 }
 117
 118                 /* Get a new char, figure out how much space. */
 119                 /* First time through */
 120                 if (!morse_data->msgpos)
 121                         morse_data->msgpos = (char *)morse_data->msg;
 122
 123                 if (!*morse_data->msgpos) {
 124                         /* Repeating */
 125                         morse_data->msgpos = (char *)morse_data->msg;
 126                         delay = space_len(morse_data);
 127                 } else {
 128                         /* Inter-letter space */
 129                         delay = dah_len(morse_data);
 130                 }
 131
 132                 if (!(morse_data->morse = tomorse(*morse_data->msgpos))) {
 133                         delay = space_len(morse_data);
 134                         /* And get us back here */
 135                         morse_data->state = MORSE_STATE_BLINK_STOP;
 136                 }
 137                 morse_data->msgpos++;
 138                 break;
 139         }
 140
 141         mod_timer(&morse_data->timer, jiffies + msecs_to_jiffies(delay));
 142
 143 set_led:
 144         led_set_brightness(led_cdev, brightness);
 145 }
 146
 147 static ssize_t morse_delay_show(struct class_device *dev, char *buf)
 148 {
 149         struct led_classdev *led_cdev = class_get_devdata(dev);
 150         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 151
 152         sprintf(buf, "%lu\n", morse_data->delay);
 153
 154         return strlen(buf) + 1;
 155 }
 156
 157 static ssize_t morse_delay_store(struct class_device *dev, const char *buf,
 158                 size_t size)
 159 {
 160         struct led_classdev *led_cdev = class_get_devdata(dev);
 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 class_device *dev, char *buf)
 180 {
 181         struct led_classdev *led_cdev = class_get_devdata(dev);
 182         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 183
 184         if (!morse_data->msg)
 185                 sprintf(buf, "<none>\n");
 186         else
 187                 sprintf(buf, "%s\n", morse_data->msg);
 188
 189         return strlen(buf) + 1;
 190 }
 191
 192 static ssize_t morse_msg_store(struct class_device *dev, const char *buf,
 193                                 size_t size)
 194 {
 195         struct led_classdev *led_cdev = class_get_devdata(dev);
 196         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 197         char *m;
 198
 199         m = kmalloc(size, GFP_KERNEL);
 200         if (!m)
 201                 return -ENOMEM;
 202
 203         memcpy(m,buf,size);
 204         m[size]='\0';
 205
 206         if (morse_data->msg)
 207                 kfree(morse_data->msg);
 208
 209         morse_data->msg = m;
 210         morse_data->msgpos = NULL;
 211         morse_data->state = MORSE_STATE_BLINK_STOP;
 212
 213         mod_timer(&morse_data->timer, jiffies + 1);
 214
 215         return size;
 216 }
 217
 218 static CLASS_DEVICE_ATTR(delay, 0644, morse_delay_show, morse_delay_store);
 219 static CLASS_DEVICE_ATTR(message, 0644, morse_msg_show, morse_msg_store);
 220
 221 static void morse_trig_activate(struct led_classdev *led_cdev)
 222 {
 223         struct morse_trig_data *morse_data;
 224         int rc;
 225
 226         morse_data = kzalloc(sizeof(*morse_data), GFP_KERNEL);
 227         if (!morse_data)
 228                 return;
 229
 230         morse_data->delay = MORSE_DELAY_BASE;
 231         init_timer(&morse_data->timer);
 232         morse_data->timer.function = morse_timer_function;
 233         morse_data->timer.data = (unsigned long)led_cdev;
 234
 235         rc = class_device_create_file(led_cdev->class_dev,
 236                                 &class_device_attr_delay);
 237         if (rc) goto err;
 238
 239         rc = class_device_create_file(led_cdev->class_dev,
 240                                 &class_device_attr_message);
 241         if (rc) goto err_delay;
 242
 243         led_cdev->trigger_data = morse_data;
 244
 245         return;
 246
 247 err_delay:
 248         class_device_remove_file(led_cdev->class_dev,
 249                                 &class_device_attr_delay);
 250 err:
 251         kfree(morse_data);
 252 }
 253
 254 static void morse_trig_deactivate(struct led_classdev *led_cdev)
 255 {
 256         struct morse_trig_data *morse_data = led_cdev->trigger_data;
 257
 258         if (!morse_data)
 259                 return;
 260
 261         class_device_remove_file(led_cdev->class_dev,
 262                 &class_device_attr_message);
 263         class_device_remove_file(led_cdev->class_dev,
 264                 &class_device_attr_delay);
 265
 266         del_timer_sync(&morse_data->timer);
 267         if (morse_data->msg)
 268                 kfree(morse_data->msg);
 269
 270         kfree(morse_data);
 271 }
 272
 273 static struct led_trigger morse_led_trigger = {
 274         .name           = "morse",
 275         .activate       = morse_trig_activate,
 276         .deactivate     = morse_trig_deactivate,
 277 };
 278
 279 static int __init morse_trig_init(void)
 280 {
 281         return led_trigger_register(&morse_led_trigger);
 282 }
 283
 284 static void __exit morse_trig_exit(void)
 285 {
 286         led_trigger_unregister(&morse_led_trigger);
 287 }
 288
 289 module_init(morse_trig_init);
 290 module_exit(morse_trig_exit);
 291
 292 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 293 MODULE_DESCRIPTION("Morse LED trigger");
 294 MODULE_LICENSE("GPL");