xref: /freebsd/sys/dev/led/led.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: Beerware
3  *
4  * ----------------------------------------------------------------------------
5  * "THE BEER-WARE LICENSE" (Revision 42):
6  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
7  * can do whatever you want with this stuff. If we meet some day, and you think
8  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
9  * ----------------------------------------------------------------------------
10  *
11  */
12 
13 #include <sys/cdefs.h>
14 #include <sys/param.h>
15 #include <sys/conf.h>
16 #include <sys/ctype.h>
17 #include <sys/kernel.h>
18 #include <sys/limits.h>
19 #include <sys/lock.h>
20 #include <sys/malloc.h>
21 #include <sys/mutex.h>
22 #include <sys/queue.h>
23 #include <sys/sbuf.h>
24 #include <sys/sx.h>
25 #include <sys/systm.h>
26 #include <sys/uio.h>
27 
28 #include <dev/led/led.h>
29 
30 struct ledsc {
31 	LIST_ENTRY(ledsc)	list;
32 	char			*name;
33 	void			*private;
34 	int			unit;
35 	led_t			*func;
36 	struct cdev *dev;
37 	struct sbuf		*spec;
38 	char			*str;
39 	char			*ptr;
40 	int			count;
41 	time_t			last_second;
42 };
43 
44 static struct unrhdr *led_unit;
45 static struct mtx led_mtx;
46 static struct sx led_sx;
47 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
48 static struct callout led_ch;
49 static int blinkers = 0;
50 
51 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
52 
53 static void
54 led_timeout(void *p)
55 {
56 	struct ledsc	*sc;
57 
58 	LIST_FOREACH(sc, &led_list, list) {
59 		if (sc->ptr == NULL)
60 			continue;
61 		if (sc->count > 0) {
62 			sc->count--;
63 			continue;
64 		}
65 		if (*sc->ptr == '.') {
66 			sc->ptr = NULL;
67 			blinkers--;
68 			continue;
69 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
70 			if (sc->last_second == time_second)
71 				continue;
72 			sc->last_second = time_second;
73 			sc->func(sc->private, *sc->ptr == 'U');
74 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
75 			sc->func(sc->private, 0);
76 			sc->count = (*sc->ptr & 0xf) - 1;
77 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
78 			sc->func(sc->private, 1);
79 			sc->count = (*sc->ptr & 0xf) - 1;
80 		}
81 		sc->ptr++;
82 		if (*sc->ptr == '\0')
83 			sc->ptr = sc->str;
84 	}
85 	if (blinkers > 0)
86 		callout_reset(&led_ch, hz / 10, led_timeout, p);
87 }
88 
89 static int
90 led_state(struct ledsc *sc, struct sbuf **sb, int state)
91 {
92 	struct sbuf *sb2 = NULL;
93 
94 	sb2 = sc->spec;
95 	sc->spec = *sb;
96 	if (*sb != NULL) {
97 		sc->str = sbuf_data(*sb);
98 		if (sc->ptr == NULL) {
99 			blinkers++;
100 			callout_reset(&led_ch, hz / 10, led_timeout, NULL);
101 		}
102 		sc->ptr = sc->str;
103 	} else {
104 		sc->str = NULL;
105 		if (sc->ptr != NULL)
106 			blinkers--;
107 		sc->ptr = NULL;
108 		sc->func(sc->private, state);
109 	}
110 	sc->count = 0;
111 	*sb = sb2;
112 	return(0);
113 }
114 
115 static int
116 led_parse(const char *s, struct sbuf **sb, int *state)
117 {
118 	int i, error;
119 
120 	/*
121 	 * Handle "on" and "off" immediately so people can flash really
122 	 * fast from userland if they want to
123 	 */
124 	if (*s == '0' || *s == '1') {
125 		*state = *s & 1;
126 		return (0);
127 	}
128 
129 	*state = 0;
130 	*sb = sbuf_new_auto();
131 	if (*sb == NULL)
132 		return (ENOMEM);
133 	switch(s[0]) {
134 		/*
135 		 * Flash, default is 100msec/100msec.
136 		 * 'f2' sets 200msec/200msec etc.
137 		 */
138 		case 'f':
139 			if (s[1] >= '1' && s[1] <= '9')
140 				i = s[1] - '1';
141 			else
142 				i = 0;
143 			sbuf_printf(*sb, "%c%c", 'A' + i, 'a' + i);
144 			break;
145 		/*
146 		 * Digits, flashes out numbers.
147 		 * 'd12' becomes -__________-_-______________________________
148 		 */
149 		case 'd':
150 			for(s++; *s; s++) {
151 				if (!isdigit(*s))
152 					continue;
153 				i = *s - '0';
154 				if (i == 0)
155 					i = 10;
156 				for (; i > 1; i--)
157 					sbuf_cat(*sb, "Aa");
158 				sbuf_cat(*sb, "Aj");
159 			}
160 			sbuf_cat(*sb, "jj");
161 			break;
162 		/*
163 		 * String, roll your own.
164 		 * 'a-j' gives "off" for n/10 sec.
165 		 * 'A-J' gives "on" for n/10 sec.
166 		 * no delay before repeat
167 		 * 'sAaAbBa' becomes _-_--__-
168 		 */
169 		case 's':
170 			for(s++; *s; s++) {
171 				if ((*s >= 'a' && *s <= 'j') ||
172 				    (*s >= 'A' && *s <= 'J') ||
173 				    *s == 'U' || *s <= 'u' ||
174 					*s == '.')
175 					sbuf_bcat(*sb, s, 1);
176 			}
177 			break;
178 		/*
179 		 * Morse.
180 		 * '.' becomes _-
181 		 * '-' becomes _---
182 		 * ' ' becomes __
183 		 * '\n' becomes ____
184 		 * 1sec pause between repeats
185 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
186 		 */
187 		case 'm':
188 			for(s++; *s; s++) {
189 				if (*s == '.')
190 					sbuf_cat(*sb, "aA");
191 				else if (*s == '-')
192 					sbuf_cat(*sb, "aC");
193 				else if (*s == ' ')
194 					sbuf_cat(*sb, "b");
195 				else if (*s == '\n')
196 					sbuf_cat(*sb, "d");
197 			}
198 			sbuf_cat(*sb, "j");
199 			break;
200 		default:
201 			sbuf_delete(*sb);
202 			return (EINVAL);
203 	}
204 	error = sbuf_finish(*sb);
205 	if (error != 0 || sbuf_len(*sb) == 0) {
206 		*sb = NULL;
207 		return (error);
208 	}
209 	return (0);
210 }
211 
212 static int
213 led_write(struct cdev *dev, struct uio *uio, int ioflag)
214 {
215 	struct ledsc	*sc;
216 	char *s;
217 	struct sbuf *sb = NULL;
218 	int error, state = 0;
219 
220 	if (uio->uio_resid > 512)
221 		return (EINVAL);
222 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
223 	s[uio->uio_resid] = '\0';
224 	error = uiomove(s, uio->uio_resid, uio);
225 	if (error) {
226 		free(s, M_DEVBUF);
227 		return (error);
228 	}
229 	error = led_parse(s, &sb, &state);
230 	free(s, M_DEVBUF);
231 	if (error)
232 		return (error);
233 	mtx_lock(&led_mtx);
234 	sc = dev->si_drv1;
235 	if (sc != NULL)
236 		error = led_state(sc, &sb, state);
237 	mtx_unlock(&led_mtx);
238 	if (sb != NULL)
239 		sbuf_delete(sb);
240 	return (error);
241 }
242 
243 int
244 led_set(char const *name, char const *cmd)
245 {
246 	struct ledsc	*sc;
247 	struct sbuf *sb = NULL;
248 	int error, state = 0;
249 
250 	error = led_parse(cmd, &sb, &state);
251 	if (error)
252 		return (error);
253 	mtx_lock(&led_mtx);
254 	LIST_FOREACH(sc, &led_list, list) {
255 		if (strcmp(sc->name, name) == 0)
256 			break;
257 	}
258 	if (sc != NULL)
259 		error = led_state(sc, &sb, state);
260 	else
261 		error = ENOENT;
262 	mtx_unlock(&led_mtx);
263 	if (sb != NULL)
264 		sbuf_delete(sb);
265 	return (error);
266 }
267 
268 static struct cdevsw led_cdevsw = {
269 	.d_version =	D_VERSION,
270 	.d_write =	led_write,
271 	.d_name =	"LED",
272 };
273 
274 struct cdev *
275 led_create(led_t *func, void *priv, char const *name)
276 {
277 
278 	return (led_create_state(func, priv, name, 0));
279 }
280 struct cdev *
281 led_create_state(led_t *func, void *priv, char const *name, int state)
282 {
283 	struct ledsc	*sc;
284 
285 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
286 
287 	sx_xlock(&led_sx);
288 	sc->name = strdup(name, M_LED);
289 	sc->unit = alloc_unr(led_unit);
290 	sc->private = priv;
291 	sc->func = func;
292 	sc->dev = make_dev(&led_cdevsw, sc->unit,
293 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
294 	sx_xunlock(&led_sx);
295 
296 	mtx_lock(&led_mtx);
297 	sc->dev->si_drv1 = sc;
298 	LIST_INSERT_HEAD(&led_list, sc, list);
299 	if (state != -1)
300 		sc->func(sc->private, state != 0);
301 	mtx_unlock(&led_mtx);
302 
303 	return (sc->dev);
304 }
305 
306 void
307 led_destroy(struct cdev *dev)
308 {
309 	struct ledsc *sc;
310 
311 	mtx_lock(&led_mtx);
312 	sc = dev->si_drv1;
313 	dev->si_drv1 = NULL;
314 	if (sc->ptr != NULL)
315 		blinkers--;
316 	LIST_REMOVE(sc, list);
317 	if (LIST_EMPTY(&led_list))
318 		callout_stop(&led_ch);
319 	mtx_unlock(&led_mtx);
320 
321 	sx_xlock(&led_sx);
322 	free_unr(led_unit, sc->unit);
323 	destroy_dev(dev);
324 	if (sc->spec != NULL)
325 		sbuf_delete(sc->spec);
326 	free(sc->name, M_LED);
327 	free(sc, M_LED);
328 	sx_xunlock(&led_sx);
329 }
330 
331 static void
332 led_drvinit(void *unused)
333 {
334 
335 	led_unit = new_unrhdr(0, INT_MAX, NULL);
336 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
337 	sx_init(&led_sx, "LED sx");
338 	callout_init_mtx(&led_ch, &led_mtx, 0);
339 }
340 
341 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
342