xref: /netbsd-src/sys/dev/i2c/i2c.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: i2c.c,v 1.20 2008/05/04 15:26:29 xtraeme Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: i2c.c,v 1.20 2008/05/04 15:26:29 xtraeme Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/device.h>
44 #include <sys/event.h>
45 #include <sys/conf.h>
46 #include <sys/malloc.h>
47 #include <sys/kthread.h>
48 #include <sys/proc.h>
49 #include <sys/kernel.h>
50 
51 #include <dev/i2c/i2cvar.h>
52 
53 #include "locators.h"
54 
55 struct iic_softc {
56 	i2c_tag_t sc_tag;
57 	int sc_type;
58 };
59 
60 static void	iic_smbus_intr_thread(void *);
61 
62 int
63 iicbus_print(void *aux, const char *pnp)
64 {
65 
66 	if (pnp != NULL)
67 		aprint_normal("iic at %s", pnp);
68 
69 	return (UNCONF);
70 }
71 
72 static int
73 iic_print(void *aux, const char *pnp)
74 {
75 	struct i2c_attach_args *ia = aux;
76 
77 	if (ia->ia_addr != (i2c_addr_t)-1)
78 		aprint_normal(" addr 0x%x", ia->ia_addr);
79 
80 	return (UNCONF);
81 }
82 
83 static int
84 iic_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
85 {
86 	struct iic_softc *sc = device_private(parent);
87 	struct i2c_attach_args ia;
88 
89 	ia.ia_tag = sc->sc_tag;
90 	ia.ia_addr = cf->cf_loc[IICCF_ADDR];
91 	ia.ia_size = cf->cf_loc[IICCF_SIZE];
92 	ia.ia_type = sc->sc_type;
93 
94 	if (config_match(parent, cf, &ia) > 0)
95 		config_attach(parent, cf, &ia, iic_print);
96 
97 	return (0);
98 }
99 
100 static int
101 iic_match(device_t parent, cfdata_t cf, void *aux)
102 {
103 
104 	return (1);
105 }
106 
107 static void
108 iic_attach(device_t parent, device_t self, void *aux)
109 {
110 	struct iic_softc *sc = device_private(self);
111 	struct i2cbus_attach_args *iba = aux;
112 	i2c_tag_t ic;
113 	int rv;
114 
115 	aprint_naive(": I2C bus\n");
116 	aprint_normal(": I2C bus\n");
117 
118 	sc->sc_tag = iba->iba_tag;
119 	sc->sc_type = iba->iba_type;
120 	ic = sc->sc_tag;
121 	ic->ic_devname = device_xname(self);
122 
123 	LIST_INIT(&(sc->sc_tag->ic_list));
124 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
125 
126 	rv = kthread_create(PRI_NONE, 0, NULL, iic_smbus_intr_thread,
127 	    ic, &ic->ic_intr_thread, "%s", ic->ic_devname);
128 	if (rv)
129 		aprint_error_dev(self, "unable to create intr thread\n");
130 
131 #if notyet
132 	if (sc->sc_type == I2C_TYPE_SMBUS) {
133 		int found = 0;
134 		i2c_addr_t addr;
135 		uint8_t cmd = 0, val;
136 
137 		for (addr = 0x0; addr < 0x80; addr++) {
138 			iic_acquire_bus(ic, 0);
139 			if (iic_exec(ic, I2C_OP_READ_WITH_STOP, addr,
140 			    &cmd, 1, &val, 1, 0) == 0) {
141 				if (found == 0)
142 					aprint_normal("%s: devices at",
143 							ic->ic_devname);
144 				found++;
145 				aprint_normal(" 0x%02x", addr);
146 			}
147 			iic_release_bus(ic, 0);
148 		}
149 		if (found == 0)
150 			aprint_normal("%s: no devices found", ic->ic_devname);
151 		aprint_normal("\n");
152 	}
153 #endif
154 
155 	if (!pmf_device_register(self, NULL, NULL))
156 		aprint_error_dev(self, "couldn't establish power handler\n");
157 
158 	/*
159 	 * Attach all i2c devices described in the kernel
160 	 * configuration file.
161 	 */
162 	config_search_ia(iic_search, self, "iic", NULL);
163 }
164 
165 static void
166 iic_smbus_intr_thread(void *aux)
167 {
168 	i2c_tag_t ic;
169 	struct ic_intr_list *il;
170 	int rv;
171 
172 	ic = (i2c_tag_t)aux;
173 	ic->ic_running = 1;
174 	ic->ic_pending = 0;
175 
176 	while (ic->ic_running) {
177 		if (ic->ic_pending == 0)
178 			rv = tsleep(ic, PZERO, "iicintr", hz);
179 		if (ic->ic_pending > 0) {
180 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
181 				(*il->il_intr)(il->il_intrarg);
182 			}
183 			ic->ic_pending--;
184 		}
185 	}
186 
187 	kthread_exit(0);
188 }
189 
190 void *
191 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
192 {
193 	struct ic_intr_list *il;
194 
195 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
196 	if (il == NULL)
197 		return NULL;
198 
199 	il->il_intr = intr;
200 	il->il_intrarg = intrarg;
201 
202 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
203 
204 	return il;
205 }
206 
207 void
208 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
209 {
210 	struct ic_intr_list *il;
211 
212 	il = (struct ic_intr_list *)hdl;
213 
214 	LIST_REMOVE(il, il_next);
215 	free(il, M_DEVBUF);
216 
217 	return;
218 }
219 
220 void *
221 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
222 {
223 	struct ic_intr_list *il;
224 
225 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
226 	if (il == NULL)
227 		return NULL;
228 
229 	il->il_intr = intr;
230 	il->il_intrarg = intrarg;
231 
232 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
233 
234 	return il;
235 }
236 
237 void
238 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
239 {
240 	struct ic_intr_list *il;
241 
242 	il = (struct ic_intr_list *)hdl;
243 
244 	LIST_REMOVE(il, il_next);
245 	free(il, M_DEVBUF);
246 
247 	return;
248 }
249 
250 int
251 iic_smbus_intr(i2c_tag_t ic)
252 {
253 	struct ic_intr_list *il;
254 
255 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
256 		(*il->il_intr)(il->il_intrarg);
257 	}
258 
259 	ic->ic_pending++;
260 	wakeup(ic);
261 
262 	return 1;
263 }
264 
265 CFATTACH_DECL_NEW(iic, sizeof(struct iic_softc),
266     iic_match, iic_attach, NULL, NULL);
267