xref: /freebsd/sys/dev/led/led.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 
47 static MALLOC_DEFINE(M_LED, "LED", "LED driver");
48 
49 static void
50 led_timeout(void *p)
51 {
52 	struct ledsc	*sc;
53 
54 	mtx_lock(&led_mtx);
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 			continue;
65 		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
66 			if (sc->last_second == time_second)
67 				continue;
68 			sc->last_second = time_second;
69 			sc->func(sc->private, *sc->ptr == 'U');
70 		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
71 			sc->func(sc->private, 0);
72 			sc->count = (*sc->ptr & 0xf) - 1;
73 		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
74 			sc->func(sc->private, 1);
75 			sc->count = (*sc->ptr & 0xf) - 1;
76 		}
77 		sc->ptr++;
78 		if (*sc->ptr == '\0')
79 			sc->ptr = sc->str;
80 	}
81 	mtx_unlock(&led_mtx);
82 	callout_reset(&led_ch, hz / 10, led_timeout, p);
83 	return;
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 		sc->ptr = sc->str;
96 	} else {
97 		sc->str = NULL;
98 		sc->ptr = NULL;
99 		sc->func(sc->private, state);
100 	}
101 	sc->count = 0;
102 	*sb = sb2;
103 	return(0);
104 }
105 
106 static int
107 led_parse(const char *s, struct sbuf **sb, int *state)
108 {
109 	int i, error;
110 
111 	/*
112 	 * Handle "on" and "off" immediately so people can flash really
113 	 * fast from userland if they want to
114 	 */
115 	if (*s == '0' || *s == '1') {
116 		*state = *s & 1;
117 		return (0);
118 	}
119 
120 	*state = 0;
121 	*sb = sbuf_new_auto();
122 	if (*sb == NULL)
123 		return (ENOMEM);
124 	switch(s[0]) {
125 		/*
126 		 * Flash, default is 100msec/100msec.
127 		 * 'f2' sets 200msec/200msec etc.
128 		 */
129 		case 'f':
130 			if (s[1] >= '1' && s[1] <= '9')
131 				i = s[1] - '1';
132 			else
133 				i = 0;
134 			sbuf_printf(*sb, "%c%c", 'A' + i, 'a' + i);
135 			break;
136 		/*
137 		 * Digits, flashes out numbers.
138 		 * 'd12' becomes -__________-_-______________________________
139 		 */
140 		case 'd':
141 			for(s++; *s; s++) {
142 				if (!isdigit(*s))
143 					continue;
144 				i = *s - '0';
145 				if (i == 0)
146 					i = 10;
147 				for (; i > 1; i--)
148 					sbuf_cat(*sb, "Aa");
149 				sbuf_cat(*sb, "Aj");
150 			}
151 			sbuf_cat(*sb, "jj");
152 			break;
153 		/*
154 		 * String, roll your own.
155 		 * 'a-j' gives "off" for n/10 sec.
156 		 * 'A-J' gives "on" for n/10 sec.
157 		 * no delay before repeat
158 		 * 'sAaAbBa' becomes _-_--__-
159 		 */
160 		case 's':
161 			for(s++; *s; s++) {
162 				if ((*s >= 'a' && *s <= 'j') ||
163 				    (*s >= 'A' && *s <= 'J') ||
164 				    *s == 'U' || *s <= 'u' ||
165 					*s == '.')
166 					sbuf_bcat(*sb, s, 1);
167 			}
168 			break;
169 		/*
170 		 * Morse.
171 		 * '.' becomes _-
172 		 * '-' becomes _---
173 		 * ' ' becomes __
174 		 * '\n' becomes ____
175 		 * 1sec pause between repeats
176 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
177 		 */
178 		case 'm':
179 			for(s++; *s; s++) {
180 				if (*s == '.')
181 					sbuf_cat(*sb, "aA");
182 				else if (*s == '-')
183 					sbuf_cat(*sb, "aC");
184 				else if (*s == ' ')
185 					sbuf_cat(*sb, "b");
186 				else if (*s == '\n')
187 					sbuf_cat(*sb, "d");
188 			}
189 			sbuf_cat(*sb, "j");
190 			break;
191 		default:
192 			sbuf_delete(*sb);
193 			return (EINVAL);
194 	}
195 	error = sbuf_finish(*sb);
196 	if (error != 0 || sbuf_len(*sb) == 0) {
197 		*sb = NULL;
198 		return (error);
199 	}
200 	return (0);
201 }
202 
203 static int
204 led_write(struct cdev *dev, struct uio *uio, int ioflag)
205 {
206 	struct ledsc	*sc;
207 	char *s;
208 	struct sbuf *sb = NULL;
209 	int error, state = 0;
210 
211 	if (uio->uio_resid > 512)
212 		return (EINVAL);
213 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
214 	s[uio->uio_resid] = '\0';
215 	error = uiomove(s, uio->uio_resid, uio);
216 	if (error) {
217 		free(s, M_DEVBUF);
218 		return (error);
219 	}
220 	error = led_parse(s, &sb, &state);
221 	free(s, M_DEVBUF);
222 	if (error)
223 		return (error);
224 	mtx_lock(&led_mtx);
225 	sc = dev->si_drv1;
226 	if (sc != NULL)
227 		error = led_state(sc, &sb, state);
228 	mtx_unlock(&led_mtx);
229 	if (sb != NULL)
230 		sbuf_delete(sb);
231 	return (error);
232 }
233 
234 int
235 led_set(char const *name, char const *cmd)
236 {
237 	struct ledsc	*sc;
238 	struct sbuf *sb = NULL;
239 	int error, state = 0;
240 
241 	error = led_parse(cmd, &sb, &state);
242 	if (error)
243 		return (error);
244 	mtx_lock(&led_mtx);
245 	LIST_FOREACH(sc, &led_list, list) {
246 		if (strcmp(sc->name, name) == 0)
247 			break;
248 	}
249 	if (sc != NULL)
250 		error = led_state(sc, &sb, state);
251 	else
252 		error = ENOENT;
253 	mtx_unlock(&led_mtx);
254 	if (sb != NULL)
255 		sbuf_delete(sb);
256 	return (0);
257 }
258 
259 static struct cdevsw led_cdevsw = {
260 	.d_version =	D_VERSION,
261 	.d_write =	led_write,
262 	.d_name =	"LED",
263 };
264 
265 struct cdev *
266 led_create(led_t *func, void *priv, char const *name)
267 {
268 
269 	return (led_create_state(func, priv, name, 0));
270 }
271 struct cdev *
272 led_create_state(led_t *func, void *priv, char const *name, int state)
273 {
274 	struct ledsc	*sc;
275 
276 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
277 
278 	sx_xlock(&led_sx);
279 	sc->name = strdup(name, M_LED);
280 	sc->unit = alloc_unr(led_unit);
281 	sc->private = priv;
282 	sc->func = func;
283 	sc->dev = make_dev(&led_cdevsw, sc->unit,
284 	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
285 	sx_xunlock(&led_sx);
286 
287 	mtx_lock(&led_mtx);
288 	sc->dev->si_drv1 = sc;
289 	if (LIST_EMPTY(&led_list))
290 		callout_reset(&led_ch, hz / 10, led_timeout, NULL);
291 	LIST_INSERT_HEAD(&led_list, sc, list);
292 	sc->func(sc->private, state != 0);
293 	mtx_unlock(&led_mtx);
294 
295 	return (sc->dev);
296 }
297 
298 void
299 led_destroy(struct cdev *dev)
300 {
301 	struct ledsc *sc;
302 
303 	mtx_lock(&led_mtx);
304 	sc = dev->si_drv1;
305 	dev->si_drv1 = NULL;
306 
307 	LIST_REMOVE(sc, list);
308 	if (LIST_EMPTY(&led_list))
309 		callout_stop(&led_ch);
310 	mtx_unlock(&led_mtx);
311 
312 	sx_xlock(&led_sx);
313 	free_unr(led_unit, sc->unit);
314 	destroy_dev(dev);
315 	if (sc->spec != NULL)
316 		sbuf_delete(sc->spec);
317 	free(sc->name, M_LED);
318 	free(sc, M_LED);
319 	sx_xunlock(&led_sx);
320 }
321 
322 static void
323 led_drvinit(void *unused)
324 {
325 
326 	led_unit = new_unrhdr(0, INT_MAX, NULL);
327 	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
328 	sx_init(&led_sx, "LED sx");
329 	callout_init(&led_ch, CALLOUT_MPSAFE);
330 }
331 
332 SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
333