xref: /freebsd/sys/dev/led/led.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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/malloc.h>
19 #include <sys/ctype.h>
20 #include <sys/sbuf.h>
21 #include <sys/queue.h>
22 #include <dev/led/led.h>
23 #include <sys/uio.h>
24 #include <sys/sx.h>
25 
26 struct ledsc {
27 	LIST_ENTRY(ledsc)	list;
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 mtx led_mtx;
41 static struct sx led_sx;
42 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(&led_list);
43 static struct callout led_ch;
44 
45 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
46 
47 static void
48 led_timeout(void *p)
49 {
50 	struct ledsc	*sc;
51 
52 	mtx_lock(&led_mtx);
53 	LIST_FOREACH(sc, &led_list, list) {
54 		if (sc->ptr == NULL)
55 			continue;
56 		if (sc->count > 0) {
57 			sc->count--;
58 			continue;
59 		}
60 		if (*sc->ptr == '.') {
61 			sc->ptr = NULL;
62 			continue;
63 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
64 			if (sc->last_second == time_second)
65 				continue;
66 			sc->last_second = time_second;
67 			sc->func(sc->private, *sc->ptr == 'U');
68 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
69 			sc->func(sc->private, 0);
70 			sc->count = (*sc->ptr & 0xf) - 1;
71 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
72 			sc->func(sc->private, 1);
73 			sc->count = (*sc->ptr & 0xf) - 1;
74 		}
75 		sc->ptr++;
76 		if (*sc->ptr == '\0')
77 			sc->ptr = sc->str;
78 	}
79 	mtx_unlock(&led_mtx);
80 	callout_reset(&led_ch, hz / 10, led_timeout, p);
81 	return;
82 }
83 
84 static int
85 led_state(struct cdev *dev, struct sbuf *sb, int state)
86 {
87 	struct sbuf *sb2 = NULL;
88 	struct ledsc *sc;
89 
90 	mtx_lock(&led_mtx);
91 	sc = dev->si_drv1;
92 	if (sc != NULL) {
93 		sb2 = sc->spec;
94 		sc->spec = sb;
95 		if (sb != NULL) {
96 			sc->str = sbuf_data(sb);
97 			sc->ptr = sc->str;
98 		} else {
99 			sc->str = NULL;
100 			sc->ptr = NULL;
101 			sc->func(sc->private, state);
102 		}
103 		sc->count = 0;
104 	}
105 	mtx_unlock(&led_mtx);
106 	if (sb2 != NULL)
107 		sbuf_delete(sb2);
108 	if (sc == NULL)
109 		return (ENXIO);
110 	return(0);
111 }
112 
113 static int
114 led_write(struct cdev *dev, struct uio *uio, int ioflag)
115 {
116 	int error;
117 	char *s, *s2;
118 	struct sbuf *sb = NULL;
119 	int i;
120 
121 	if (dev->si_drv1 == NULL)
122 		return (ENXIO);
123 
124 	if (uio->uio_resid > 512)
125 		return (EINVAL);
126 	s2 = s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
127 	s[uio->uio_resid] = '\0';
128 	error = uiomove(s, uio->uio_resid, uio);
129 	if (error) {
130 		free(s2, M_DEVBUF);
131 		return (error);
132 	}
133 
134 	/*
135 	 * Handle "on" and "off" immediately so people can flash really
136 	 * fast from userland if they want to
137 	 */
138 	if (*s == '0' || *s == '1') {
139 		error = led_state(dev, NULL, *s & 1);
140 		free(s2, M_DEVBUF);
141 		return(error);
142 	}
143 
144 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
145 	if (sb == NULL) {
146 		free(s2, M_DEVBUF);
147 		return (ENOMEM);
148 	}
149 
150 	switch(s[0]) {
151 		/*
152 		 * Flash, default is 100msec/100msec.
153 		 * 'f2' sets 200msec/200msec etc.
154 		 */
155 		case 'f':
156 			if (s[1] >= '1' && s[1] <= '9')
157 				i = s[1] - '1';
158 			else
159 				i = 0;
160 			sbuf_printf(sb, "%c%c", 'A' + i, 'a' + i);
161 			break;
162 		/*
163 		 * Digits, flashes out numbers.
164 		 * 'd12' becomes -__________-_-______________________________
165 		 */
166 		case 'd':
167 			for(s++; *s; s++) {
168 				if (!isdigit(*s))
169 					continue;
170 				i = *s - '0';
171 				if (i == 0)
172 					i = 10;
173 				for (; i > 1; i--)
174 					sbuf_cat(sb, "Aa");
175 				sbuf_cat(sb, "Aj");
176 			}
177 			sbuf_cat(sb, "jj");
178 			break;
179 		/*
180 		 * String, roll your own.
181 		 * 'a-j' gives "off" for n/10 sec.
182 		 * 'A-J' gives "on" for n/10 sec.
183 		 * no delay before repeat
184 		 * 'sAaAbBa' becomes _-_--__-
185 		 */
186 		case 's':
187 			for(s++; *s; s++) {
188 				if ((*s >= 'a' && *s <= 'j') ||
189 				    (*s >= 'A' && *s <= 'J') ||
190 				    *s == 'U' || *s <= 'u' ||
191 					*s == '.')
192 					sbuf_bcat(sb, s, 1);
193 			}
194 			break;
195 		/*
196 		 * Morse.
197 		 * '.' becomes _-
198 		 * '-' becomes _---
199 		 * ' ' becomes __
200 		 * '\n' becomes ____
201 		 * 1sec pause between repeats
202 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
203 		 */
204 		case 'm':
205 			for(s++; *s; s++) {
206 				if (*s == '.')
207 					sbuf_cat(sb, "aA");
208 				else if (*s == '-')
209 					sbuf_cat(sb, "aC");
210 				else if (*s == ' ')
211 					sbuf_cat(sb, "b");
212 				else if (*s == '\n')
213 					sbuf_cat(sb, "d");
214 			}
215 			sbuf_cat(sb, "j");
216 			break;
217 		default:
218 			sbuf_delete(sb);
219 			free(s2, M_DEVBUF);
220 			return (EINVAL);
221 	}
222 	sbuf_finish(sb);
223 	free(s2, M_DEVBUF);
224 	if (sbuf_overflowed(sb)) {
225 		sbuf_delete(sb);
226 		return (ENOMEM);
227 	}
228 	if (sbuf_len(sb) == 0) {
229 		sbuf_delete(sb);
230 		return (0);
231 	}
232 
233 	return (led_state(dev, sb, 0));
234 }
235 
236 static struct cdevsw led_cdevsw = {
237 	.d_version =	D_VERSION,
238 	.d_write =	led_write,
239 	.d_name =	"LED",
240 };
241 
242 struct cdev *
243 led_create(led_t *func, void *priv, char const *name)
244 {
245 
246 	return (led_create_state(func, priv, name, 0));
247 }
248 struct cdev *
249 led_create_state(led_t *func, void *priv, char const *name, int state)
250 {
251 	struct ledsc	*sc;
252 
253 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
254 
255 	sx_xlock(&led_sx);
256 	sc->unit = alloc_unr(led_unit);
257 	sc->private = priv;
258 	sc->func = func;
259 	sc->dev = make_dev(&led_cdevsw, unit2minor(sc->unit),
260 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
261 	sx_xunlock(&led_sx);
262 
263 	mtx_lock(&led_mtx);
264 	sc->dev->si_drv1 = sc;
265 	if (LIST_EMPTY(&led_list))
266 		callout_reset(&led_ch, hz / 10, led_timeout, NULL);
267 	LIST_INSERT_HEAD(&led_list, sc, list);
268 	sc->func(sc->private, state != 0);
269 	mtx_unlock(&led_mtx);
270 
271 	return (sc->dev);
272 }
273 
274 void
275 led_destroy(struct cdev *dev)
276 {
277 	struct ledsc *sc;
278 
279 	mtx_lock(&led_mtx);
280 	sc = dev->si_drv1;
281 	dev->si_drv1 = NULL;
282 
283 	LIST_REMOVE(sc, list);
284 	if (LIST_EMPTY(&led_list))
285 		callout_stop(&led_ch);
286 	mtx_unlock(&led_mtx);
287 
288 	sx_xlock(&led_sx);
289 	free_unr(led_unit, sc->unit);
290 	destroy_dev(dev);
291 	if (sc->spec != NULL)
292 		sbuf_delete(sc->spec);
293 	free(sc, M_LED);
294 	sx_xunlock(&led_sx);
295 }
296 
297 static void
298 led_drvinit(void *unused)
299 {
300 
301 	led_unit = new_unrhdr(0, minor2unit(MAXMINOR), NULL);
302 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
303 	sx_init(&led_sx, "LED sx");
304 	callout_init(&led_ch, CALLOUT_MPSAFE);
305 }
306 
307 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
308