led.c revision 201145 
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: head/sys/dev/led/led.c 201145 2009-12-28 22:56:30Z antoine $");
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
27struct ledsc {
28	LIST_ENTRY(ledsc)	list;
29	void			*private;
30	int			unit;
31	led_t			*func;
32	struct cdev *dev;
33	struct sbuf		*spec;
34	char			*str;
35	char			*ptr;
36	int			count;
37	time_t			last_second;
38};
39
40static struct unrhdr *led_unit;
41static struct mtx led_mtx;
42static struct sx led_sx;
43static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(led_list);
44static struct callout led_ch;
45
46static MALLOC_DEFINE(M_LED, "LED", "LED driver");
47
48static void
49led_timeout(void *p)
50{
51	struct ledsc	*sc;
52
53	mtx_lock(&led_mtx);
54	LIST_FOREACH(sc, &led_list, list) {
55		if (sc->ptr == NULL)
56			continue;
57		if (sc->count > 0) {
58			sc->count--;
59			continue;
60		}
61		if (*sc->ptr == '.') {
62			sc->ptr = NULL;
63			continue;
64		} else if (*sc->ptr == 'U' || *sc->ptr == 'u') {
65			if (sc->last_second == time_second)
66				continue;
67			sc->last_second = time_second;
68			sc->func(sc->private, *sc->ptr == 'U');
69		} else if (*sc->ptr >= 'a' && *sc->ptr <= 'j') {
70			sc->func(sc->private, 0);
71			sc->count = (*sc->ptr & 0xf) - 1;
72		} else if (*sc->ptr >= 'A' && *sc->ptr <= 'J') {
73			sc->func(sc->private, 1);
74			sc->count = (*sc->ptr & 0xf) - 1;
75		}
76		sc->ptr++;
77		if (*sc->ptr == '\0')
78			sc->ptr = sc->str;
79	}
80	mtx_unlock(&led_mtx);
81	callout_reset(&led_ch, hz / 10, led_timeout, p);
82	return;
83}
84
85static int
86led_state(struct cdev *dev, struct sbuf *sb, int state)
87{
88	struct sbuf *sb2 = NULL;
89	struct ledsc *sc;
90
91	mtx_lock(&led_mtx);
92	sc = dev->si_drv1;
93	if (sc != NULL) {
94		sb2 = sc->spec;
95		sc->spec = sb;
96		if (sb != NULL) {
97			sc->str = sbuf_data(sb);
98			sc->ptr = sc->str;
99		} else {
100			sc->str = NULL;
101			sc->ptr = NULL;
102			sc->func(sc->private, state);
103		}
104		sc->count = 0;
105	}
106	mtx_unlock(&led_mtx);
107	if (sb2 != NULL)
108		sbuf_delete(sb2);
109	if (sc == NULL)
110		return (ENXIO);
111	return(0);
112}
113
114static int
115led_write(struct cdev *dev, struct uio *uio, int ioflag)
116{
117	int error;
118	char *s, *s2;
119	struct sbuf *sb = NULL;
120	int i;
121
122	if (dev->si_drv1 == NULL)
123		return (ENXIO);
124
125	if (uio->uio_resid > 512)
126		return (EINVAL);
127	s2 = s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
128	s[uio->uio_resid] = '\0';
129	error = uiomove(s, uio->uio_resid, uio);
130	if (error) {
131		free(s2, M_DEVBUF);
132		return (error);
133	}
134
135	/*
136	 * Handle "on" and "off" immediately so people can flash really
137	 * fast from userland if they want to
138	 */
139	if (*s == '0' || *s == '1') {
140		error = led_state(dev, NULL, *s & 1);
141		free(s2, M_DEVBUF);
142		return(error);
143	}
144
145	sb = sbuf_new_auto();
146	if (sb == NULL) {
147		free(s2, M_DEVBUF);
148		return (ENOMEM);
149	}
150
151	switch(s[0]) {
152		/*
153		 * Flash, default is 100msec/100msec.
154		 * 'f2' sets 200msec/200msec etc.
155		 */
156		case 'f':
157			if (s[1] >= '1' && s[1] <= '9')
158				i = s[1] - '1';
159			else
160				i = 0;
161			sbuf_printf(sb, "%c%c", 'A' + i, 'a' + i);
162			break;
163		/*
164		 * Digits, flashes out numbers.
165		 * 'd12' becomes -__________-_-______________________________
166		 */
167		case 'd':
168			for(s++; *s; s++) {
169				if (!isdigit(*s))
170					continue;
171				i = *s - '0';
172				if (i == 0)
173					i = 10;
174				for (; i > 1; i--)
175					sbuf_cat(sb, "Aa");
176				sbuf_cat(sb, "Aj");
177			}
178			sbuf_cat(sb, "jj");
179			break;
180		/*
181		 * String, roll your own.
182		 * 'a-j' gives "off" for n/10 sec.
183		 * 'A-J' gives "on" for n/10 sec.
184		 * no delay before repeat
185		 * 'sAaAbBa' becomes _-_--__-
186		 */
187		case 's':
188			for(s++; *s; s++) {
189				if ((*s >= 'a' && *s <= 'j') ||
190				    (*s >= 'A' && *s <= 'J') ||
191				    *s == 'U' || *s <= 'u' ||
192					*s == '.')
193					sbuf_bcat(sb, s, 1);
194			}
195			break;
196		/*
197		 * Morse.
198		 * '.' becomes _-
199		 * '-' becomes _---
200		 * ' ' becomes __
201		 * '\n' becomes ____
202		 * 1sec pause between repeats
203		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
204		 */
205		case 'm':
206			for(s++; *s; s++) {
207				if (*s == '.')
208					sbuf_cat(sb, "aA");
209				else if (*s == '-')
210					sbuf_cat(sb, "aC");
211				else if (*s == ' ')
212					sbuf_cat(sb, "b");
213				else if (*s == '\n')
214					sbuf_cat(sb, "d");
215			}
216			sbuf_cat(sb, "j");
217			break;
218		default:
219			sbuf_delete(sb);
220			free(s2, M_DEVBUF);
221			return (EINVAL);
222	}
223	sbuf_finish(sb);
224	free(s2, M_DEVBUF);
225	if (sbuf_overflowed(sb)) {
226		sbuf_delete(sb);
227		return (ENOMEM);
228	}
229	if (sbuf_len(sb) == 0) {
230		sbuf_delete(sb);
231		return (0);
232	}
233
234	return (led_state(dev, sb, 0));
235}
236
237static struct cdevsw led_cdevsw = {
238	.d_version =	D_VERSION,
239	.d_write =	led_write,
240	.d_name =	"LED",
241};
242
243struct cdev *
244led_create(led_t *func, void *priv, char const *name)
245{
246
247	return (led_create_state(func, priv, name, 0));
248}
249struct cdev *
250led_create_state(led_t *func, void *priv, char const *name, int state)
251{
252	struct ledsc	*sc;
253
254	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
255
256	sx_xlock(&led_sx);
257	sc->unit = alloc_unr(led_unit);
258	sc->private = priv;
259	sc->func = func;
260	sc->dev = make_dev(&led_cdevsw, sc->unit,
261	    UID_ROOT, GID_WHEEL, 0600, "led/%s", name);
262	sx_xunlock(&led_sx);
263
264	mtx_lock(&led_mtx);
265	sc->dev->si_drv1 = sc;
266	if (LIST_EMPTY(&led_list))
267		callout_reset(&led_ch, hz / 10, led_timeout, NULL);
268	LIST_INSERT_HEAD(&led_list, sc, list);
269	sc->func(sc->private, state != 0);
270	mtx_unlock(&led_mtx);
271
272	return (sc->dev);
273}
274
275void
276led_destroy(struct cdev *dev)
277{
278	struct ledsc *sc;
279
280	mtx_lock(&led_mtx);
281	sc = dev->si_drv1;
282	dev->si_drv1 = NULL;
283
284	LIST_REMOVE(sc, list);
285	if (LIST_EMPTY(&led_list))
286		callout_stop(&led_ch);
287	mtx_unlock(&led_mtx);
288
289	sx_xlock(&led_sx);
290	free_unr(led_unit, sc->unit);
291	destroy_dev(dev);
292	if (sc->spec != NULL)
293		sbuf_delete(sc->spec);
294	free(sc, M_LED);
295	sx_xunlock(&led_sx);
296}
297
298static void
299led_drvinit(void *unused)
300{
301
302	led_unit = new_unrhdr(0, INT_MAX, NULL);
303	mtx_init(&led_mtx, "LED mtx", NULL, MTX_DEF);
304	sx_init(&led_sx, "LED sx");
305	callout_init(&led_ch, CALLOUT_MPSAFE);
306}
307
308SYSINIT(leddev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, led_drvinit, NULL);
309