1 /*-
2 * Copyright (c) 1998 Nicolas Souchu
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/dev/iicbus/iiconf.c,v 1.19 2008/08/23 07:38:00 imp Exp $
27 * $DragonFly: src/sys/bus/iicbus/iiconf.c,v 1.5 2005/06/02 20:40:36 dillon Exp $
28 *
29 */
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/module.h>
34 #include <sys/bus.h>
35 #include <sys/thread2.h>
36
37 #include <bus/iicbus/iiconf.h>
38 #include <bus/iicbus/iicbus.h>
39 #include "iicbus_if.h"
40
41 /*
42 * iicbus_intr()
43 */
44 void
iicbus_intr(device_t bus,int event,char * buf)45 iicbus_intr(device_t bus, int event, char *buf)
46 {
47 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
48
49 /* call owner's intr routine */
50 if (sc->owner)
51 IICBUS_INTR(sc->owner, event, buf);
52
53 return;
54 }
55
56 static int
iicbus_poll(struct iicbus_softc * sc,int how)57 iicbus_poll(struct iicbus_softc *sc, int how)
58 {
59 int error;
60
61 switch (how) {
62 case IIC_WAIT | IIC_INTR:
63 error = tsleep(sc, PCATCH, "iicreq", 0);
64 break;
65
66 case IIC_WAIT | IIC_NOINTR:
67 error = tsleep(sc, 0, "iicreq", 0);
68 break;
69
70 default:
71 return (EWOULDBLOCK);
72 break;
73 }
74
75 return (error);
76 }
77
78 /*
79 * iicbus_request_bus()
80 *
81 * Allocate the device to perform transfers.
82 *
83 * how : IIC_WAIT or IIC_DONTWAIT
84 */
85 int
iicbus_request_bus(device_t bus,device_t dev,int how)86 iicbus_request_bus(device_t bus, device_t dev, int how)
87 {
88 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
89 int error = 0;
90
91 /* first, ask the underlying layers if the request is ok */
92 do {
93 error = IICBUS_CALLBACK(device_get_parent(bus),
94 IIC_REQUEST_BUS, (caddr_t)&how);
95 if (error)
96 error = iicbus_poll(sc, how);
97 } while (error == EWOULDBLOCK);
98
99 while (!error) {
100 crit_enter();
101 if (sc->owner && sc->owner != dev) {
102 crit_exit();
103 error = iicbus_poll(sc, how);
104 } else {
105 sc->owner = dev;
106 crit_exit();
107 return (0);
108 }
109
110 /* free any allocated resource */
111 if (error)
112 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
113 (caddr_t)&how);
114 }
115
116 return (error);
117 }
118
119 /*
120 * iicbus_release_bus()
121 *
122 * Release the device allocated with iicbus_request_dev()
123 */
124 int
iicbus_release_bus(device_t bus,device_t dev)125 iicbus_release_bus(device_t bus, device_t dev)
126 {
127 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
128 int error;
129
130 /* first, ask the underlying layers if the release is ok */
131 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
132
133 if (error)
134 return (error);
135
136 crit_enter();
137 if (sc->owner != dev) {
138 crit_exit();
139 return (EACCES);
140 }
141 sc->owner = NULL;
142 crit_exit();
143
144 /* wakeup waiting processes */
145 wakeup(sc);
146
147 return (0);
148 }
149
150 /*
151 * iicbus_started()
152 *
153 * Test if the iicbus is started by the controller
154 */
155 int
iicbus_started(device_t bus)156 iicbus_started(device_t bus)
157 {
158 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
159
160 return (sc->started);
161 }
162
163 /*
164 * iicbus_start()
165 *
166 * Send start condition to the slave addressed by 'slave'
167 */
168 int
iicbus_start(device_t bus,u_char slave,int timeout)169 iicbus_start(device_t bus, u_char slave, int timeout)
170 {
171 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
172 int error = 0;
173
174 if (sc->started)
175 return (EINVAL); /* bus already started */
176
177 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
178 sc->started = slave;
179 else
180 sc->started = 0;
181
182 return (error);
183 }
184
185 /*
186 * iicbus_repeated_start()
187 *
188 * Send start condition to the slave addressed by 'slave'
189 */
190 int
iicbus_repeated_start(device_t bus,u_char slave,int timeout)191 iicbus_repeated_start(device_t bus, u_char slave, int timeout)
192 {
193 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
194 int error = 0;
195
196 if (!sc->started)
197 return (EINVAL); /* bus should have been already started */
198
199 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
200 sc->started = slave;
201 else
202 sc->started = 0;
203
204 return (error);
205 }
206
207 /*
208 * iicbus_stop()
209 *
210 * Send stop condition to the bus
211 */
212 int
iicbus_stop(device_t bus)213 iicbus_stop(device_t bus)
214 {
215 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
216 int error = 0;
217
218 if (!sc->started)
219 return (EINVAL); /* bus not started */
220
221 error = IICBUS_STOP(device_get_parent(bus));
222
223 /* refuse any further access */
224 sc->started = 0;
225
226 return (error);
227 }
228
229 /*
230 * iicbus_write()
231 *
232 * Write a block of data to the slave previously started by
233 * iicbus_start() call
234 */
235 int
iicbus_write(device_t bus,const char * buf,int len,int * sent,int timeout)236 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
237 {
238 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
239
240 /* a slave must have been started with the appropriate address */
241 if (!sc->started || (sc->started & LSB))
242 return (EINVAL);
243
244 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
245 }
246
247 /*
248 * iicbus_read()
249 *
250 * Read a block of data from the slave previously started by
251 * iicbus_read() call
252 */
253 int
iicbus_read(device_t bus,char * buf,int len,int * read,int last,int delay)254 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
255 {
256 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
257
258 /* a slave must have been started with the appropriate address */
259 if (!sc->started || !(sc->started & LSB))
260 return (EINVAL);
261
262 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
263 }
264
265 /*
266 * iicbus_write_byte()
267 *
268 * Write a byte to the slave previously started by iicbus_start() call
269 */
270 int
iicbus_write_byte(device_t bus,char byte,int timeout)271 iicbus_write_byte(device_t bus, char byte, int timeout)
272 {
273 char data = byte;
274 int sent;
275
276 return (iicbus_write(bus, &data, 1, &sent, timeout));
277 }
278
279 /*
280 * iicbus_read_byte()
281 *
282 * Read a byte from the slave previously started by iicbus_start() call
283 */
284 int
iicbus_read_byte(device_t bus,char * byte,int timeout)285 iicbus_read_byte(device_t bus, char *byte, int timeout)
286 {
287 int read;
288
289 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
290 }
291
292 /*
293 * iicbus_block_write()
294 *
295 * Write a block of data to slave ; start/stop protocol managed
296 */
297 int
iicbus_block_write(device_t bus,u_char slave,char * buf,int len,int * sent)298 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
299 {
300 u_char addr = slave & ~LSB;
301 int error;
302
303 if ((error = iicbus_start(bus, addr, 0)))
304 return (error);
305
306 error = iicbus_write(bus, buf, len, sent, 0);
307
308 iicbus_stop(bus);
309
310 return (error);
311 }
312
313 /*
314 * iicbus_block_read()
315 *
316 * Read a block of data from slave ; start/stop protocol managed
317 */
318 int
iicbus_block_read(device_t bus,u_char slave,char * buf,int len,int * read)319 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
320 {
321 u_char addr = slave | LSB;
322 int error;
323
324 if ((error = iicbus_start(bus, addr, 0)))
325 return (error);
326
327 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
328
329 iicbus_stop(bus);
330
331 return (error);
332 }
333
334 /*
335 * iicbus_transfer()
336 *
337 * Do an aribtrary number of transfers on the iicbus. We pass these
338 * raw requests to the bridge driver. If the bridge driver supports
339 * them directly, then it manages all the details. If not, it can use
340 * the helper function iicbus_transfer_gen() which will do the
341 * transfers at a low level.
342 *
343 * Pointers passed in as part of iic_msg must be kernel pointers.
344 * Callers that have user addresses to manage must do so on their own.
345 */
346 int
iicbus_transfer(device_t bus,struct iic_msg * msgs,uint32_t nmsgs)347 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
348 {
349 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
350 }
351
352 /*
353 * Generic version of iicbus_transfer that calls the appropriate
354 * routines to accomplish this. See note above about acceptable
355 * buffer addresses.
356 */
357 int
iicbus_transfer_gen(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)358 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
359 {
360 int i, error, lenread, lenwrote, nkid;
361 device_t *children, bus;
362
363 if ((error = device_get_children(dev, &children, &nkid)) != 0)
364 return (error);
365 if (nkid != 1) {
366 kfree(children, M_TEMP);
367 return (EIO);
368 }
369 bus = children[0];
370 kfree(children, M_TEMP);
371 for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
372 if (msgs[i].flags & IIC_M_RD)
373 error = iicbus_block_read(bus, msgs[i].slave,
374 msgs[i].buf, msgs[i].len, &lenread);
375 else
376 error = iicbus_block_write(bus, msgs[i].slave,
377 msgs[i].buf, msgs[i].len, &lenwrote);
378 }
379 return (error);
380 }
381