xref: /freebsd/sys/dev/led/led.c (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
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 __FBSDID("$FreeBSD$");
15 
16 #include <sys/param.h>
17 #include <sys/conf.h>
18 #include <sys/ctype.h>
19 #include <sys/kernel.h>
20 #include <sys/limits.h>
21 #include <sys/lock.h>
22 #include <sys/malloc.h>
23 #include <sys/mutex.h>
24 #include <sys/queue.h>
25 #include <sys/sbuf.h>
26 #include <sys/sx.h>
27 #include <sys/systm.h>
28 #include <sys/uio.h>
29 
30 #include <dev/led/led.h>
31 
32 struct ledsc {
33 	LIST_ENTRY(ledsc)	list;
34 	char			*name;
35 	void			*private;
36 	int			unit;
37 	led_t			*func;
38 	struct cdev *dev;
39 	struct sbuf		*spec;
40 	char			*str;
41 	char			*ptr;
42 	int			count;
43 	time_t			last_second;
44 };
45 
46 static struct unrhdr *led_unit;
47 static struct mtx led_mtx;
48 static struct sx led_sx;
49 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
50 static struct callout led_ch;
51 static int blinkers = 0;
52 
53 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
54 
55 static void
56 led_timeout(void *p)
57 {
58 	struct ledsc	*sc;
59 
60 	LIST_FOREACH(sc, &led_list, list) {
61 		if (sc->ptr == NULL)
62 			continue;
63 		if (sc->count > 0) {
64 			sc->count--;
65 			continue;
66 		}
67 		if (*sc->ptr == '.') {
68 			sc->ptr = NULL;
69 			blinkers--;
70 			continue;
71 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
72 			if (sc->last_second == time_second)
73 				continue;
74 			sc->last_second = time_second;
75 			sc->func(sc->private, *sc->ptr == 'U');
76 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
77 			sc->func(sc->private, 0);
78 			sc->count = (*sc->ptr & 0xf) - 1;
79 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
80 			sc->func(sc->private, 1);
81 			sc->count = (*sc->ptr & 0xf) - 1;
82 		}
83 		sc->ptr++;
84 		if (*sc->ptr == '\0')
85 			sc->ptr = sc->str;
86 	}
87 	if (blinkers > 0)
88 		callout_reset(&led_ch, hz / 10, led_timeout, p);
89 }
90 
91 static int
92 led_state(struct ledsc *sc, struct sbuf **sb, int state)
93 {
94 	struct sbuf *sb2 = NULL;
95 
96 	sb2 = sc->spec;
97 	sc->spec = *sb;
98 	if (*sb != NULL) {
99 		sc->str = sbuf_data(*sb);
100 		if (sc->ptr == NULL) {
101 			blinkers++;
102 			callout_reset(&led_ch, hz / 10, led_timeout, NULL);
103 		}
104 		sc->ptr = sc->str;
105 	} else {
106 		sc->str = NULL;
107 		if (sc->ptr != NULL)
108 			blinkers--;
109 		sc->ptr = NULL;
110 		sc->func(sc->private, state);
111 	}
112 	sc->count = 0;
113 	*sb = sb2;
114 	return(0);
115 }
116 
117 static int
118 led_parse(const char *s, struct sbuf **sb, int *state)
119 {
120 	int i, error;
121 
122 	/*
123 	 * Handle "on" and "off" immediately so people can flash really
124 	 * fast from userland if they want to
125 	 */
126 	if (*s == '0' || *s == '1') {
127 		*state = *s & 1;
128 		return (0);
129 	}
130 
131 	*state = 0;
132 	*sb = sbuf_new_auto();
133 	if (*sb == NULL)
134 		return (ENOMEM);
135 	switch(s[0]) {
136 		/*
137 		 * Flash, default is 100msec/100msec.
138 		 * 'f2' sets 200msec/200msec etc.
139 		 */
140 		case 'f':
141 			if (s[1] >= '1' && s[1] <= '9')
142 				i = s[1] - '1';
143 			else
144 				i = 0;
145 			sbuf_printf(*sb, "%c%c", 'A' + i, 'a' + i);
146 			break;
147 		/*
148 		 * Digits, flashes out numbers.
149 		 * 'd12' becomes -__________-_-______________________________
150 		 */
151 		case 'd':
152 			for(s++; *s; s++) {
153 				if (!isdigit(*s))
154 					continue;
155 				i = *s - '0';
156 				if (i == 0)
157 					i = 10;
158 				for (; i > 1; i--)
159 					sbuf_cat(*sb, "Aa");
160 				sbuf_cat(*sb, "Aj");
161 			}
162 			sbuf_cat(*sb, "jj");
163 			break;
164 		/*
165 		 * String, roll your own.
166 		 * 'a-j' gives "off" for n/10 sec.
167 		 * 'A-J' gives "on" for n/10 sec.
168 		 * no delay before repeat
169 		 * 'sAaAbBa' becomes _-_--__-
170 		 */
171 		case 's':
172 			for(s++; *s; s++) {
173 				if ((*s >= 'a' && *s <= 'j') ||
174 				    (*s >= 'A' && *s <= 'J') ||
175 				    *s == 'U' || *s <= 'u' ||
176 					*s == '.')
177 					sbuf_bcat(*sb, s, 1);
178 			}
179 			break;
180 		/*
181 		 * Morse.
182 		 * '.' becomes _-
183 		 * '-' becomes _---
184 		 * ' ' becomes __
185 		 * '\n' becomes ____
186 		 * 1sec pause between repeats
187 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
188 		 */
189 		case 'm':
190 			for(s++; *s; s++) {
191 				if (*s == '.')
192 					sbuf_cat(*sb, "aA");
193 				else if (*s == '-')
194 					sbuf_cat(*sb, "aC");
195 				else if (*s == ' ')
196 					sbuf_cat(*sb, "b");
197 				else if (*s == '\n')
198 					sbuf_cat(*sb, "d");
199 			}
200 			sbuf_cat(*sb, "j");
201 			break;
202 		default:
203 			sbuf_delete(*sb);
204 			return (EINVAL);
205 	}
206 	error = sbuf_finish(*sb);
207 	if (error != 0 || sbuf_len(*sb) == 0) {
208 		*sb = NULL;
209 		return (error);
210 	}
211 	return (0);
212 }
213 
214 static int
215 led_write(struct cdev *dev, struct uio *uio, int ioflag)
216 {
217 	struct ledsc	*sc;
218 	char *s;
219 	struct sbuf *sb = NULL;
220 	int error, state = 0;
221 
222 	if (uio->uio_resid > 512)
223 		return (EINVAL);
224 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
225 	s[uio->uio_resid] = '\0';
226 	error = uiomove(s, uio->uio_resid, uio);
227 	if (error) {
228 		free(s, M_DEVBUF);
229 		return (error);
230 	}
231 	error = led_parse(s, &sb, &state);
232 	free(s, M_DEVBUF);
233 	if (error)
234 		return (error);
235 	mtx_lock(&led_mtx);
236 	sc = dev->si_drv1;
237 	if (sc != NULL)
238 		error = led_state(sc, &sb, state);
239 	mtx_unlock(&led_mtx);
240 	if (sb != NULL)
241 		sbuf_delete(sb);
242 	return (error);
243 }
244 
245 int
246 led_set(char const *name, char const *cmd)
247 {
248 	struct ledsc	*sc;
249 	struct sbuf *sb = NULL;
250 	int error, state = 0;
251 
252 	error = led_parse(cmd, &sb, &state);
253 	if (error)
254 		return (error);
255 	mtx_lock(&led_mtx);
256 	LIST_FOREACH(sc, &led_list, list) {
257 		if (strcmp(sc->name, name) == 0)
258 			break;
259 	}
260 	if (sc != NULL)
261 		error = led_state(sc, &sb, state);
262 	else
263 		error = ENOENT;
264 	mtx_unlock(&led_mtx);
265 	if (sb != NULL)
266 		sbuf_delete(sb);
267 	return (error);
268 }
269 
270 static struct cdevsw led_cdevsw = {
271 	.d_version =	D_VERSION,
272 	.d_write =	led_write,
273 	.d_name =	"LED",
274 };
275 
276 struct cdev *
277 led_create(led_t *func, void *priv, char const *name)
278 {
279 
280 	return (led_create_state(func, priv, name, 0));
281 }
282 struct cdev *
283 led_create_state(led_t *func, void *priv, char const *name, int state)
284 {
285 	struct ledsc	*sc;
286 
287 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
288 
289 	sx_xlock(&led_sx);
290 	sc->name = strdup(name, M_LED);
291 	sc->unit = alloc_unr(led_unit);
292 	sc->private = priv;
293 	sc->func = func;
294 	sc->dev = make_dev(&led_cdevsw, sc->unit,
295 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
296 	sx_xunlock(&led_sx);
297 
298 	mtx_lock(&led_mtx);
299 	sc->dev->si_drv1 = sc;
300 	LIST_INSERT_HEAD(&led_list, sc, list);
301 	if (state != -1)
302 		sc->func(sc->private, state != 0);
303 	mtx_unlock(&led_mtx);
304 
305 	return (sc->dev);
306 }
307 
308 void
309 led_destroy(struct cdev *dev)
310 {
311 	struct ledsc *sc;
312 
313 	mtx_lock(&led_mtx);
314 	sc = dev->si_drv1;
315 	dev->si_drv1 = NULL;
316 	if (sc->ptr != NULL)
317 		blinkers--;
318 	LIST_REMOVE(sc, list);
319 	if (LIST_EMPTY(&led_list))
320 		callout_stop(&led_ch);
321 	mtx_unlock(&led_mtx);
322 
323 	sx_xlock(&led_sx);
324 	free_unr(led_unit, sc->unit);
325 	destroy_dev(dev);
326 	if (sc->spec != NULL)
327 		sbuf_delete(sc->spec);
328 	free(sc->name, M_LED);
329 	free(sc, M_LED);
330 	sx_xunlock(&led_sx);
331 }
332 
333 static void
334 led_drvinit(void *unused)
335 {
336 
337 	led_unit = new_unrhdr(0, INT_MAX, NULL);
338 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
339 	sx_init(&led_sx, "LED sx");
340 	callout_init_mtx(&led_ch, &led_mtx, 0);
341 }
342 
343 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
344