xref: /freebsd/sys/dev/led/led.c (revision 7773002178c8dbc52b44e4d705f07706409af8e4)
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 
25 struct ledsc {
26 	LIST_ENTRY(ledsc)	list;
27 	void			*private;
28 	led_t			*func;
29 	dev_t			dev;
30 	struct sbuf		*spec;
31 	char			*str;
32 	char			*ptr;
33 	int			count;
34 };
35 
36 static unsigned next_minor;
37 static struct mtx led_mtx;
38 static LIST_HEAD(, ledsc) led_list = LIST_HEAD_INITIALIZER(&led_list);
39 
40 MALLOC_DEFINE(M_LED, "LED", "LED driver");
41 
42 static void
43 led_timeout(void *p)
44 {
45 	struct ledsc	*sc;
46 
47 	mtx_lock(&led_mtx);
48 	LIST_FOREACH(sc, &led_list, list) {
49 		if (sc->ptr == NULL)
50 			continue;
51 		if (sc->count > 0) {
52 			sc->count--;
53 			continue;
54 		}
55 		sc->func(sc->private, sc->ptr[0] >= 'a' ? 1 : 0);
56 		sc->count = sc->ptr[0] & 0xf;
57 		if (*(++sc->ptr) == '\0')
58 			sc->ptr = sc->str;
59 	}
60 	mtx_unlock(&led_mtx);
61 	timeout(led_timeout, p, hz / 10);
62 	return;
63 }
64 
65 static int
66 led_write(dev_t dev, struct uio *uio, int ioflag)
67 {
68 	int error;
69 	char *s;
70 	struct ledsc *sc;
71 	struct sbuf *sb;
72 	struct sbuf *sb2;
73 	int i;
74 
75 	sc = dev->si_drv1;
76 
77 	if (uio->uio_resid > 512)
78 		return (EINVAL);
79 	s = malloc(uio->uio_resid + 1, M_DEVBUF, M_WAITOK);
80 	if (s == NULL)
81 		return (ENOMEM);
82 	s[uio->uio_resid] = '\0';
83 	error = uiomove(s, uio->uio_resid, uio);
84 	if (error) {
85 		free(s, M_DEVBUF);
86 		return (error);
87 	}
88 
89 	/*
90 	 * Handle "on" and "off" immediately so people can flash really
91 	 * fast from userland if they want to
92 	 */
93 	if (*s == '0' || *s == '1') {
94 		mtx_lock(&led_mtx);
95 		sb2 = sc->spec;
96 		sc->spec = NULL;
97 		sc->str = NULL;
98 		sc->ptr = NULL;
99 		sc->count = 0;
100 		sc->func(sc->private, *s & 1);
101 		mtx_unlock(&led_mtx);
102 		if (sb2 != NULL)
103 			sbuf_delete(sb2);
104 		free(s, M_DEVBUF);
105 		return(0);
106 	}
107 
108 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
109 	if (sb == NULL) {
110 		free(s, M_DEVBUF);
111 		return (ENOMEM);
112 	}
113 
114 	switch(s[0]) {
115 		/*
116 		 * Flash, default is 100msec/100msec.
117 		 * 'f2' sets 200msec/200msec etc.
118 		 */
119 		case 'f':
120 			if (s[1] >= '1' && s[1] <= '9')
121 				i = s[1] - '1';
122 			else
123 				i = 0;
124 			sbuf_printf(sb, "%c%c", 'a' + i, 'A' + i);
125 			break;
126 		/*
127 		 * Digits, flashes out numbers.
128 		 * 'd12' becomes -__________-_-______________________________
129 		 */
130 		case 'd':
131 			for(s++; *s; s++) {
132 				if (!isdigit(*s))
133 					continue;
134 				i = *s - '0';
135 				if (i == 0)
136 					i = 10;
137 				for (; i > 1; i--)
138 					sbuf_cat(sb, "aA");
139 				sbuf_cat(sb, "aJ");
140 			}
141 			sbuf_cat(sb, "JJ");
142 			break;
143 		/*
144 		 * String, roll your own.
145 		 * 'A-J' gives "off" for n/10 sec.
146 		 * 'a-j' gives "on" for n/10 sec.
147 		 * no delay before repeat
148 		 * 'sAaAbBa' becomes _-_--__-
149 		 */
150 		case 's':
151 			for(s++; *s; s++) {
152 				if ((*s & 0x0f) > 10)
153 					continue;
154 				if ((*s & 0xf0) < ' ')
155 					continue;
156 				sbuf_bcat(sb, s, 1);
157 			}
158 			break;
159 		/*
160 		 * Morse.
161 		 * '.' becomes _-
162 		 * '-' becomes _---
163 		 * ' ' becomes __
164 		 * '\n' becomes ____
165 		 * 1sec pause between repeats
166 		 * '... --- ...' -> _-_-_-___---_---_---___-_-_-__________
167 		 */
168 		case 'm':
169 			for(s++; *s; s++) {
170 				if (*s == '.')
171 					sbuf_cat(sb, "Aa");
172 				else if (*s == '-')
173 					sbuf_cat(sb, "Ac");
174 				else if (*s == ' ')
175 					sbuf_cat(sb, "B");
176 				else if (*s == '\n')
177 					sbuf_cat(sb, "D");
178 			}
179 			sbuf_cat(sb, "J");
180 			break;
181 		default:
182 			break;
183 	}
184 	sbuf_finish(sb);
185 	free(s, M_DEVBUF);
186 	if (sbuf_overflowed(sb)) {
187 		sbuf_delete(sb);
188 		return (ENOMEM);
189 	}
190 	if (sbuf_len(sb) == 0) {
191 		sbuf_delete(sb);
192 		return (0);
193 	}
194 
195 	mtx_lock(&led_mtx);
196 	sb2 = sc->spec;
197 	sc->spec = sb;
198 	sc->str = sbuf_data(sb);
199 	sc->ptr = sc->str;
200 	sc->count = 0;
201 	mtx_unlock(&led_mtx);
202 	if (sb2 != NULL)
203 		sbuf_delete(sb2);
204 	return(0);
205 }
206 
207 static struct cdevsw led_cdevsw = {
208         .d_write =      led_write,
209         .d_name =       "LED",
210 };
211 
212 dev_t
213 led_create(led_t *func, void *priv, char const *name)
214 {
215 	struct ledsc	*sc;
216 	struct sbuf *sb;
217 
218 	if (next_minor == 0) {
219 		mtx_init(&led_mtx, "LED mtx", MTX_DEF, 0);
220 		timeout(led_timeout, NULL, hz / 10);
221 	}
222 
223 	sb = sbuf_new(NULL, NULL, SPECNAMELEN, SBUF_FIXEDLEN);
224 	if (sb == NULL)
225 		return (NODEV);
226 	sbuf_cpy(sb, "led/");
227 	sbuf_cat(sb, name);
228 	sbuf_finish(sb);
229 	if (sbuf_overflowed(sb)) {
230 		sbuf_delete(sb);
231 		return (NODEV);
232 	}
233 
234 	sc = malloc(sizeof *sc, M_LED, M_WAITOK | M_ZERO);
235 	sc->private = priv;
236 	sc->func = func;
237 	sc->dev = make_dev(&led_cdevsw, unit2minor(next_minor),
238 	    UID_ROOT, GID_WHEEL, 0600, sbuf_data(sb));
239 	sc->dev->si_drv1 = sc;
240 	next_minor++;
241 	sbuf_delete(sb);
242 	mtx_lock(&led_mtx);
243 	LIST_INSERT_HEAD(&led_list, sc, list);
244 	mtx_unlock(&led_mtx);
245 	return (sc->dev);
246 }
247 
248 void
249 led_destroy(dev_t dev)
250 {
251 	struct ledsc *sc;
252 
253 	sc = dev->si_drv1;
254 	mtx_lock(&led_mtx);
255 	LIST_REMOVE(sc, list);
256 	mtx_unlock(&led_mtx);
257 	sbuf_delete(sc->spec);
258 	destroy_dev(dev);
259 	free(sc, M_LED);
260 }
261