xref: /freebsd/sys/dev/led/led.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
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  */
10 
11 #include <sys/cdefs.h>
12 __FBSDID("$FreeBSD$");
13 
14 #include <sys/param.h>
15 #include <sys/conf.h>
16 #include <sys/kernel.h>
17 #include <sys/systm.h>
18 #include <sys/limits.h>
19 #include <sys/malloc.h>
20 #include <sys/ctype.h>
21 #include <sys/sbuf.h>
22 #include <sys/queue.h>
23 #include <dev/led/led.h>
24 #include <sys/uio.h>
25 #include <sys/sx.h>
26 
27 struct ledsc {
28 	LIST_ENTRY(ledsc)	list;
29 	char			*name;
30 	void			*private;
31 	int			unit;
32 	led_t			*func;
33 	struct cdev *dev;
34 	struct sbuf		*spec;
35 	char			*str;
36 	char			*ptr;
37 	int			count;
38 	time_t			last_second;
39 };
40 
41 static struct unrhdr *led_unit;
42 static struct mtx led_mtx;
43 static struct sx led_sx;
44 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
45 static struct callout led_ch;
46 static int blinkers = 0;
47 
48 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
49 
50 static void
51 led_timeout(void *p)
52 {
53 	struct ledsc	*sc;
54 
55 	LIST_FOREACH(sc, &led_list, list) {
56 		if (sc->ptr == NULL)
57 			continue;
58 		if (sc->count > 0) {
59 			sc->count--;
60 			continue;
61 		}
62 		if (*sc->ptr == '.') {
63 			sc->ptr = NULL;
64 			blinkers--;
65 			continue;
66 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
67 			if (sc->last_second == time_second)
68 				continue;
69 			sc->last_second = time_second;
70 			sc->func(sc->private, *sc->ptr == 'U');
71 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
72 			sc->func(sc->private, 0);
73 			sc->count = (*sc->ptr & 0xf) - 1;
74 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
75 			sc->func(sc->private, 1);
76 			sc->count = (*sc->ptr & 0xf) - 1;
77 		}
78 		sc->ptr++;
79 		if (*sc->ptr == '\0')
80 			sc->ptr = sc->str;
81 	}
82 	if (blinkers > 0)
83 		callout_reset(&led_ch, hz / 10, led_timeout, p);
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_write(struct cdev *dev, struct uio *uio, int ioflag)
211 {
212 	struct ledsc	*sc;
213 	char *s;
214 	struct sbuf *sb = NULL;
215 	int error, state = 0;
216 
217 	if (uio->uio_resid > 512)
218 		return (EINVAL);
219 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
220 	s[uio->uio_resid] = '\0';
221 	error = uiomove(s, uio->uio_resid, uio);
222 	if (error) {
223 		free(s, M_DEVBUF);
224 		return (error);
225 	}
226 	error = led_parse(s, &sb, &state);
227 	free(s, M_DEVBUF);
228 	if (error)
229 		return (error);
230 	mtx_lock(&led_mtx);
231 	sc = dev->si_drv1;
232 	if (sc != NULL)
233 		error = led_state(sc, &sb, state);
234 	mtx_unlock(&led_mtx);
235 	if (sb != NULL)
236 		sbuf_delete(sb);
237 	return (error);
238 }
239 
240 int
241 led_set(char const *name, char const *cmd)
242 {
243 	struct ledsc	*sc;
244 	struct sbuf *sb = NULL;
245 	int error, state = 0;
246 
247 	error = led_parse(cmd, &sb, &state);
248 	if (error)
249 		return (error);
250 	mtx_lock(&led_mtx);
251 	LIST_FOREACH(sc, &led_list, list) {
252 		if (strcmp(sc->name, name) == 0)
253 			break;
254 	}
255 	if (sc != NULL)
256 		error = led_state(sc, &sb, state);
257 	else
258 		error = ENOENT;
259 	mtx_unlock(&led_mtx);
260 	if (sb != NULL)
261 		sbuf_delete(sb);
262 	return (0);
263 }
264 
265 static struct cdevsw led_cdevsw = {
266 	.d_version =	D_VERSION,
267 	.d_write =	led_write,
268 	.d_name =	"LED",
269 };
270 
271 struct cdev *
272 led_create(led_t *func, void *priv, char const *name)
273 {
274 
275 	return (led_create_state(func, priv, name, 0));
276 }
277 struct cdev *
278 led_create_state(led_t *func, void *priv, char const *name, int state)
279 {
280 	struct ledsc	*sc;
281 
282 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
283 
284 	sx_xlock(&led_sx);
285 	sc->name = strdup(name, M_LED);
286 	sc->unit = alloc_unr(led_unit);
287 	sc->private = priv;
288 	sc->func = func;
289 	sc->dev = make_dev(&led_cdevsw, sc->unit,
290 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
291 	sx_xunlock(&led_sx);
292 
293 	mtx_lock(&led_mtx);
294 	sc->dev->si_drv1 = sc;
295 	LIST_INSERT_HEAD(&led_list, sc, list);
296 	if (state != -1)
297 		sc->func(sc->private, state != 0);
298 	mtx_unlock(&led_mtx);
299 
300 	return (sc->dev);
301 }
302 
303 void
304 led_destroy(struct cdev *dev)
305 {
306 	struct ledsc *sc;
307 
308 	mtx_lock(&led_mtx);
309 	sc = dev->si_drv1;
310 	dev->si_drv1 = NULL;
311 	if (sc->ptr != NULL)
312 		blinkers--;
313 	LIST_REMOVE(sc, list);
314 	if (LIST_EMPTY(&led_list))
315 		callout_stop(&led_ch);
316 	mtx_unlock(&led_mtx);
317 
318 	sx_xlock(&led_sx);
319 	free_unr(led_unit, sc->unit);
320 	destroy_dev(dev);
321 	if (sc->spec != NULL)
322 		sbuf_delete(sc->spec);
323 	free(sc->name, M_LED);
324 	free(sc, M_LED);
325 	sx_xunlock(&led_sx);
326 }
327 
328 static void
329 led_drvinit(void *unused)
330 {
331 
332 	led_unit = new_unrhdr(0, INT_MAX, NULL);
333 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
334 	sx_init(&led_sx, "LED sx");
335 	callout_init_mtx(&led_ch, &led_mtx, 0);
336 }
337 
338 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
339