xref: /freebsd/sys/dev/led/led.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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/param.h>
14 #include <sys/conf.h>
15 #include <sys/ctype.h>
16 #include <sys/kernel.h>
17 #include <sys/limits.h>
18 #include <sys/lock.h>
19 #include <sys/malloc.h>
20 #include <sys/mutex.h>
21 #include <sys/queue.h>
22 #include <sys/sbuf.h>
23 #include <sys/sx.h>
24 #include <sys/systm.h>
25 #include <sys/uio.h>
26 
27 #include <dev/led/led.h>
28 
29 struct ledsc {
30 	LIST_ENTRY(ledsc)	list;
31 	char			*name;
32 	void			*private;
33 	int			unit;
34 	led_t			*func;
35 	struct cdev *dev;
36 	struct sbuf		*spec;
37 	char			*str;
38 	char			*ptr;
39 	int			count;
40 	time_t			last_second;
41 };
42 
43 static struct unrhdr *led_unit;
44 static struct mtx led_mtx;
45 static struct sx led_sx;
46 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
47 static struct callout led_ch;
48 static int blinkers = 0;
49 
50 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
51 
52 static void
53 led_timeout(void *p)
54 {
55 	struct ledsc	*sc;
56 
57 	LIST_FOREACH(sc, &led_list, list) {
58 		if (sc->ptr == NULL)
59 			continue;
60 		if (sc->count > 0) {
61 			sc->count--;
62 			continue;
63 		}
64 		if (*sc->ptr == '.') {
65 			sc->ptr = NULL;
66 			blinkers--;
67 			continue;
68 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
69 			if (sc->last_second == time_second)
70 				continue;
71 			sc->last_second = time_second;
72 			sc->func(sc->private, *sc->ptr == 'U');
73 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
74 			sc->func(sc->private, 0);
75 			sc->count = (*sc->ptr & 0xf) - 1;
76 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
77 			sc->func(sc->private, 1);
78 			sc->count = (*sc->ptr & 0xf) - 1;
79 		}
80 		sc->ptr++;
81 		if (*sc->ptr == '\0')
82 			sc->ptr = sc->str;
83 	}
84 	if (blinkers > 0)
85 		callout_reset(&led_ch, hz / 10, led_timeout, p);
86 }
87 
88 static int
89 led_state(struct ledsc *sc, struct sbuf **sb, int state)
90 {
91 	struct sbuf *sb2 = NULL;
92 
93 	sb2 = sc->spec;
94 	sc->spec = *sb;
95 	if (*sb != NULL) {
96 		sc->str = sbuf_data(*sb);
97 		if (sc->ptr == NULL) {
98 			blinkers++;
99 			callout_reset(&led_ch, hz / 10, led_timeout, NULL);
100 		}
101 		sc->ptr = sc->str;
102 	} else {
103 		sc->str = NULL;
104 		if (sc->ptr != NULL)
105 			blinkers--;
106 		sc->ptr = NULL;
107 		sc->func(sc->private, state);
108 	}
109 	sc->count = 0;
110 	*sb = sb2;
111 	return(0);
112 }
113 
114 static int
115 led_parse(const char *s, struct sbuf **sb, int *state)
116 {
117 	int i, error;
118 
119 	/*
120 	 * Handle "on" and "off" immediately so people can flash really
121 	 * fast from userland if they want to
122 	 */
123 	if (*s == '0' || *s == '1') {
124 		*state = *s & 1;
125 		return (0);
126 	}
127 
128 	*state = 0;
129 	*sb = sbuf_new_auto();
130 	if (*sb == NULL)
131 		return (ENOMEM);
132 	switch(s[0]) {
133 		/*
134 		 * Flash, default is 100msec/100msec.
135 		 * 'f2' sets 200msec/200msec etc.
136 		 */
137 		case 'f':
138 			if (s[1] >= '1' && s[1] <= '9')
139 				i = s[1] - '1';
140 			else
141 				i = 0;
142 			sbuf_printf(*sb, "%c%c", 'A' + i, 'a' + i);
143 			break;
144 		/*
145 		 * Digits, flashes out numbers.
146 		 * 'd12' becomes -__________-_-______________________________
147 		 */
148 		case 'd':
149 			for(s++; *s; s++) {
150 				if (!isdigit(*s))
151 					continue;
152 				i = *s - '0';
153 				if (i == 0)
154 					i = 10;
155 				for (; i > 1; i--)
156 					sbuf_cat(*sb, "Aa");
157 				sbuf_cat(*sb, "Aj");
158 			}
159 			sbuf_cat(*sb, "jj");
160 			break;
161 		/*
162 		 * String, roll your own.
163 		 * 'a-j' gives "off" for n/10 sec.
164 		 * 'A-J' gives "on" for n/10 sec.
165 		 * no delay before repeat
166 		 * 'sAaAbBa' becomes _-_--__-
167 		 */
168 		case 's':
169 			for(s++; *s; s++) {
170 				if ((*s >= 'a' && *s <= 'j') ||
171 				    (*s >= 'A' && *s <= 'J') ||
172 				    *s == 'U' || *s <= 'u' ||
173 					*s == '.')
174 					sbuf_bcat(*sb, s, 1);
175 			}
176 			break;
177 		/*
178 		 * Morse.
179 		 * '.' becomes _-
180 		 * '-' becomes _---
181 		 * ' ' becomes __
182 		 * '\n' becomes ____
183 		 * 1sec pause between repeats
184 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
185 		 */
186 		case 'm':
187 			for(s++; *s; s++) {
188 				if (*s == '.')
189 					sbuf_cat(*sb, "aA");
190 				else if (*s == '-')
191 					sbuf_cat(*sb, "aC");
192 				else if (*s == ' ')
193 					sbuf_cat(*sb, "b");
194 				else if (*s == '\n')
195 					sbuf_cat(*sb, "d");
196 			}
197 			sbuf_cat(*sb, "j");
198 			break;
199 		default:
200 			sbuf_delete(*sb);
201 			return (EINVAL);
202 	}
203 	error = sbuf_finish(*sb);
204 	if (error != 0 || sbuf_len(*sb) == 0) {
205 		*sb = NULL;
206 		return (error);
207 	}
208 	return (0);
209 }
210 
211 static int
212 led_write(struct cdev *dev, struct uio *uio, int ioflag)
213 {
214 	struct ledsc	*sc;
215 	char *s;
216 	struct sbuf *sb = NULL;
217 	int error, state = 0;
218 
219 	if (uio->uio_resid > 512)
220 		return (EINVAL);
221 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
222 	s[uio->uio_resid] = '\0';
223 	error = uiomove(s, uio->uio_resid, uio);
224 	if (error) {
225 		free(s, M_DEVBUF);
226 		return (error);
227 	}
228 	error = led_parse(s, &sb, &state);
229 	free(s, M_DEVBUF);
230 	if (error)
231 		return (error);
232 	mtx_lock(&led_mtx);
233 	sc = dev->si_drv1;
234 	if (sc != NULL)
235 		error = led_state(sc, &sb, state);
236 	mtx_unlock(&led_mtx);
237 	if (sb != NULL)
238 		sbuf_delete(sb);
239 	return (error);
240 }
241 
242 int
243 led_set(char const *name, char const *cmd)
244 {
245 	struct ledsc	*sc;
246 	struct sbuf *sb = NULL;
247 	int error, state = 0;
248 
249 	error = led_parse(cmd, &sb, &state);
250 	if (error)
251 		return (error);
252 	mtx_lock(&led_mtx);
253 	LIST_FOREACH(sc, &led_list, list) {
254 		if (strcmp(sc->name, name) == 0)
255 			break;
256 	}
257 	if (sc != NULL)
258 		error = led_state(sc, &sb, state);
259 	else
260 		error = ENOENT;
261 	mtx_unlock(&led_mtx);
262 	if (sb != NULL)
263 		sbuf_delete(sb);
264 	return (error);
265 }
266 
267 static struct cdevsw led_cdevsw = {
268 	.d_version =	D_VERSION,
269 	.d_write =	led_write,
270 	.d_name =	"LED",
271 };
272 
273 struct cdev *
274 led_create(led_t *func, void *priv, char const *name)
275 {
276 
277 	return (led_create_state(func, priv, name, 0));
278 }
279 struct cdev *
280 led_create_state(led_t *func, void *priv, char const *name, int state)
281 {
282 	struct ledsc	*sc;
283 
284 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
285 
286 	sx_xlock(&led_sx);
287 	sc->name = strdup(name, M_LED);
288 	sc->unit = alloc_unr(led_unit);
289 	sc->private = priv;
290 	sc->func = func;
291 	sc->dev = make_dev(&led_cdevsw, sc->unit,
292 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
293 	sx_xunlock(&led_sx);
294 
295 	mtx_lock(&led_mtx);
296 	sc->dev->si_drv1 = sc;
297 	LIST_INSERT_HEAD(&led_list, sc, list);
298 	if (state != -1)
299 		sc->func(sc->private, state != 0);
300 	mtx_unlock(&led_mtx);
301 
302 	return (sc->dev);
303 }
304 
305 void
306 led_destroy(struct cdev *dev)
307 {
308 	struct ledsc *sc;
309 
310 	mtx_lock(&led_mtx);
311 	sc = dev->si_drv1;
312 	dev->si_drv1 = NULL;
313 	if (sc->ptr != NULL)
314 		blinkers--;
315 	LIST_REMOVE(sc, list);
316 	if (LIST_EMPTY(&led_list))
317 		callout_stop(&led_ch);
318 	mtx_unlock(&led_mtx);
319 
320 	sx_xlock(&led_sx);
321 	free_unr(led_unit, sc->unit);
322 	destroy_dev(dev);
323 	if (sc->spec != NULL)
324 		sbuf_delete(sc->spec);
325 	free(sc->name, M_LED);
326 	free(sc, M_LED);
327 	sx_xunlock(&led_sx);
328 }
329 
330 static void
331 led_drvinit(void *unused)
332 {
333 
334 	led_unit = new_unrhdr(0, INT_MAX, NULL);
335 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
336 	sx_init(&led_sx, "LED sx");
337 	callout_init_mtx(&led_ch, &led_mtx, 0);
338 }
339 
340 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
341