sys/dev/misc/led/led.c

   1 /*-
   2  * ----------------------------------------------------------------------------
   3  * "THE BEER-WARE LICENSE" (Revision 42):
   4  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
   5  * can do whatever you want with this stuff. If we meet some day, and you think
   6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
   7  * ----------------------------------------------------------------------------
   8  *
   9  * $FreeBSD: head/sys/dev/led/led.c 247008 2013-02-19 19:25:50Z mav $
  10  */
  11
  12 #include <sys/param.h>
  13 #include <sys/conf.h>
  14 #include <sys/kernel.h>
  15 #include <sys/systm.h>
  16 #include <sys/limits.h>
  17 #include <sys/malloc.h>
  18 #include <sys/ctype.h>
  19 #include <sys/sbuf.h>
  20 #include <sys/queue.h>
  21 #include <dev/misc/led/led.h>
  22 #include <sys/uio.h>
  23 #include <sys/device.h>
  24
  25 struct ledsc {
  26         LIST_ENTRY(ledsc)       list;
  27         char                    *name;
  28         void                    *private;
  29         int                     unit;
  30         led_t                   *func;
  31         struct cdev *dev;
  32         struct sbuf             *spec;
  33         char                    *str;
  34         char                    *ptr;
  35         int                     count;
  36         time_t                  last_second;
  37 };
  38
  39 static struct unrhdr *led_unit;
  40 static struct lock led_lock;
  41 static struct lock led_lock2;
  42 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
  43 static struct callout led_ch;
  44 static int blinkers = 0;
  45
  46 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
  47
  48 static void
  49 led_timeout(void *p)
  50 {
  51         struct ledsc    *sc;
  52
  53         lockmgr(&led_lock, LK_EXCLUSIVE);
  54         LIST_FOREACH(sc, &led_list, list) {
  55                 if (sc->ptr == NULL)
  56                         continue;
  57                 if (sc->count > 0) {
  58                         sc->count--;
  59                         continue;
  60                 }
  61                 if (*sc->ptr == '.') {
  62                         sc->ptr = NULL;
  63                         blinkers--;
  64                         continue;
  65                 } else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
  66                         if (sc->last_second == time_second)
  67                                 continue;
  68                         sc->last_second = time_second;
  69                         sc->func(sc->private, *sc->ptr == 'U');
  70                 } else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
  71                         sc->func(sc->private, 0);
  72                         sc->count = (*sc->ptr & 0xf) - 1;
  73                 } else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
  74                         sc->func(sc->private, 1);
  75                         sc->count = (*sc->ptr & 0xf) - 1;
  76                 }
  77                 sc->ptr++;
  78                 if (*sc->ptr == '\0')
  79                         sc->ptr = sc->str;
  80         }
  81         if (blinkers > 0)
  82                 callout_reset(&led_ch, hz / 10, led_timeout, p);
  83         lockmgr(&led_lock, LK_RELEASE);
  84 }
  85
  86 static int
  87 led_state(struct ledsc *sc, struct sbuf **sb, int state)
  88 {
  89         struct sbuf *sb2 = NULL;
  90
  91         sb2 = sc->spec;
  92         sc->spec = *sb;
  93         if (*sb != NULL) {
  94                 sc->str = sbuf_data(*sb);
  95                 if (sc->ptr == NULL) {
  96                         blinkers++;
  97                         callout_reset(&led_ch, hz / 10, led_timeout, NULL);
  98                 }
  99                 sc->ptr = sc->str;
 100         } else {
 101                 sc->str = NULL;
 102                 if (sc->ptr != NULL)
 103                         blinkers--;
 104                 sc->ptr = NULL;
 105                 sc->func(sc->private, state);
 106         }
 107         sc->count = 0;
 108         *sb = sb2;
 109         return(0);
 110 }
 111
 112 static int
 113 led_parse(const char *s, struct sbuf **sb, int *state)
 114 {
 115         int i, error;
 116
 117         /*
 118          * Handle "on" and "off" immediately so people can flash really
 119          * fast from userland if they want to
 120          */
 121         if (*s == '0' || *s == '1') {
 122                 *state = *s & 1;
 123                 return (0);
 124         }
 125
 126         *state = 0;
 127         *sb = sbuf_new_auto();
 128         if (*sb == NULL)
 129                 return (ENOMEM);
 130         switch(s[0]) {
 131                 /*
 132                  * Flash, default is 100msec/100msec.
 133                  * 'f2' sets 200msec/200msec etc.
 134                  */
 135                 case 'f':
 136                         if (s[1] >= '1' && s[1] <= '9')
 137                                 i = s[1] - '1';
 138                         else
 139                                 i = 0;
 140                         sbuf_printf(*sb, "%c%c", 'A' + i, 'a' + i);
 141                         break;
 142                 /*
 143                  * Digits, flashes out numbers.
 144                  * 'd12' becomes -__________-_-______________________________
 145                  */
 146                 case 'd':
 147                         for(s++; *s; s++) {
 148                                 if (!isdigit(*s))
 149                                         continue;
 150                                 i = *s - '0';
 151                                 if (i == 0)
 152                                         i = 10;
 153                                 for (; i > 1; i--)
 154                                         sbuf_cat(*sb, "Aa");
 155                                 sbuf_cat(*sb, "Aj");
 156                         }
 157                         sbuf_cat(*sb, "jj");
 158                         break;
 159                 /*
 160                  * String, roll your own.
 161                  * 'a-j' gives "off" for n/10 sec.
 162                  * 'A-J' gives "on" for n/10 sec.
 163                  * no delay before repeat
 164                  * 'sAaAbBa' becomes _-_--__-
 165                  */
 166                 case 's':
 167                         for(s++; *s; s++) {
 168                                 if ((*s >= 'a' && *s <= 'j') ||
 169                                     (*s >= 'A' && *s <= 'J') ||
 170                                     *s == 'U' || *s <= 'u' ||
 171                                         *s == '.')
 172                                         sbuf_bcat(*sb, s, 1);
 173                         }
 174                         break;
 175                 /*
 176                  * Morse.
 177                  * '.' becomes _-
 178                  * '-' becomes _---
 179                  * ' ' becomes __
 180                  * '\n' becomes ____
 181                  * 1sec pause between repeats
 182                  * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
 183                  */
 184                 case 'm':
 185                         for(s++; *s; s++) {
 186                                 if (*s == '.')
 187                                         sbuf_cat(*sb, "aA");
 188                                 else if (*s == '-')
 189                                         sbuf_cat(*sb, "aC");
 190                                 else if (*s == ' ')
 191                                         sbuf_cat(*sb, "b");
 192                                 else if (*s == '\n')
 193                                         sbuf_cat(*sb, "d");
 194                         }
 195                         sbuf_cat(*sb, "j");
 196                         break;
 197                 default:
 198                         sbuf_delete(*sb);
 199                         return (EINVAL);
 200         }
 201         error = sbuf_finish(*sb);
 202         if (error != 0 || sbuf_len(*sb) == 0) {
 203                 *sb = NULL;
 204                 return (error);
 205         }
 206         return (0);
 207 }
 208
 209 static int
 210 led_open(struct dev_open_args *ap)
 211 {
 212         return (0);
 213 }
 214
 215 static int
 216 led_close(struct dev_close_args *ap)
 217 {
 218         return (0);
 219 }
 220
 221 static int
 222 led_write(struct dev_write_args *ap)
 223 {
 224         struct uio *uio = ap->a_uio;
 225         cdev_t dev = ap->a_head.a_dev;
 226         struct ledsc    *sc;
 227         char *s;
 228         struct sbuf *sb = NULL;
 229         int error, state = 0;
 230
 231         if (uio->uio_resid > 512)
 232                 return (EINVAL);
 233         s = kmalloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
 234         s[uio->uio_resid] = '\0';
 235         error = uiomove(s, uio->uio_resid, uio);
 236         if (error) {
 237                 kfree(s, M_DEVBUF);
 238                 return (error);
 239         }
 240         error = led_parse(s, &sb, &state);
 241         kfree(s, M_DEVBUF);
 242         if (error)
 243                 return (error);
 244         lockmgr(&led_lock, LK_EXCLUSIVE);
 245         sc = dev->si_drv1;
 246         if (sc != NULL)
 247                 error = led_state(sc, &sb, state);
 248         lockmgr(&led_lock, LK_RELEASE);
 249         if (sb != NULL)
 250                 sbuf_delete(sb);
 251         return (error);
 252 }
 253
 254 int
 255 led_set(char const *name, char const *cmd)
 256 {
 257         struct ledsc    *sc;
 258         struct sbuf *sb = NULL;
 259         int error, state = 0;
 260
 261         error = led_parse(cmd, &sb, &state);
 262         if (error)
 263                 return (error);
 264         lockmgr(&led_lock, LK_EXCLUSIVE);
 265         LIST_FOREACH(sc, &led_list, list) {
 266                 if (strcmp(sc->name, name) == 0)
 267                         break;
 268         }
 269         if (sc != NULL)
 270                 error = led_state(sc, &sb, state);
 271         else
 272                 error = ENOENT;
 273         lockmgr(&led_lock, LK_RELEASE);
 274         if (sb != NULL)
 275                 sbuf_delete(sb);
 276         return (0);
 277 }
 278
 279 static struct dev_ops led_ops = {
 280         { "LED", 0, D_MPSAFE },
 281         .d_open =       led_open,
 282         .d_close =      led_close,
 283         .d_write =      led_write,
 284 };
 285
 286 struct cdev *
 287 led_create(led_t *func, void *priv, char const *name)
 288 {
 289
 290         return (led_create_state(func, priv, name, 0));
 291 }
 292 struct cdev *
 293 led_create_state(led_t *func, void *priv, char const *name, int state)
 294 {
 295         struct ledsc    *sc;
 296
 297         sc = kmalloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
 298
 299         lockmgr(&led_lock2, LK_EXCLUSIVE);
 300         sc->name = kstrdup(name, M_LED);
 301         sc->unit = alloc_unr(led_unit);
 302         sc->private = priv;
 303         sc->func = func;
 304         sc->dev = make_dev(&led_ops, sc->unit,
 305             UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
 306         lockmgr(&led_lock2, LK_RELEASE);
 307
 308         lockmgr(&led_lock, LK_EXCLUSIVE);
 309         sc->dev->si_drv1 = sc;
 310         LIST_INSERT_HEAD(&led_list, sc, list);
 311         sc->func(sc->private, state != 0);
 312         lockmgr(&led_lock, LK_RELEASE);
 313
 314         return (sc->dev);
 315 }
 316
 317 void
 318 led_destroy(struct cdev *dev)
 319 {
 320         struct ledsc *sc;
 321
 322         lockmgr(&led_lock, LK_EXCLUSIVE);
 323         sc = dev->si_drv1;
 324         dev->si_drv1 = NULL;
 325         if (sc->ptr != NULL)
 326                 blinkers--;
 327         LIST_REMOVE(sc, list);
 328         if (LIST_EMPTY(&led_list))
 329                 callout_stop(&led_ch);
 330         lockmgr(&led_lock, LK_RELEASE);
 331
 332         lockmgr(&led_lock2, LK_EXCLUSIVE);
 333         free_unr(led_unit, sc->unit);
 334         destroy_dev(dev);
 335         if (sc->spec != NULL)
 336                 sbuf_delete(sc->spec);
 337         kfree(sc->name, M_LED);
 338         kfree(sc, M_LED);
 339         lockmgr(&led_lock2, LK_RELEASE);
 340 }
 341
 342 static void
 343 led_drvinit(void *unused)
 344 {
 345
 346         led_unit = new_unrhdr(0, INT_MAX, NULL);
 347         lockinit(&led_lock, "LED lock", 0, LK_CANRECURSE);
 348         lockinit(&led_lock2, "LED lock2", 0, LK_CANRECURSE);
 349         callout_init_mp(&led_ch);
 350 }
 351
 352 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);