Loading...
1/*
2 * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
3 *
4 * Copyright (C) 1995-1997 Simon G. Vogl
5 * 1998-2000 Hans Berglund
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
18 * Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
19 * <mbailey@littlefeet-inc.com>
20 *
21 * Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
22 * messages, proper stop/repstart signaling during receive, added detect code
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/delay.h>
28#include <linux/errno.h>
29#include <linux/i2c.h>
30#include <linux/i2c-algo-pcf.h>
31#include "i2c-algo-pcf.h"
32
33
34#define DEB2(x) if (i2c_debug >= 2) x
35#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
36#define DEBPROTO(x) if (i2c_debug >= 9) x;
37 /* debug the protocol by showing transferred bits */
38#define DEF_TIMEOUT 16
39
40/*
41 * module parameters:
42 */
43static int i2c_debug;
44
45/* setting states on the bus with the right timing: */
46
47#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
48#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
49#define get_own(adap) adap->getown(adap->data)
50#define get_clock(adap) adap->getclock(adap->data)
51#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
52#define i2c_inb(adap) adap->getpcf(adap->data, 0)
53
54/* other auxiliary functions */
55
56static void i2c_start(struct i2c_algo_pcf_data *adap)
57{
58 DEBPROTO(printk(KERN_DEBUG "S "));
59 set_pcf(adap, 1, I2C_PCF_START);
60}
61
62static void i2c_repstart(struct i2c_algo_pcf_data *adap)
63{
64 DEBPROTO(printk(" Sr "));
65 set_pcf(adap, 1, I2C_PCF_REPSTART);
66}
67
68static void i2c_stop(struct i2c_algo_pcf_data *adap)
69{
70 DEBPROTO(printk("P\n"));
71 set_pcf(adap, 1, I2C_PCF_STOP);
72}
73
74static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
75{
76 DEB2(printk(KERN_INFO
77 "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
78 *status));
79 /*
80 * Cleanup from LAB -- reset and enable ESO.
81 * This resets the PCF8584; since we've lost the bus, no
82 * further attempts should be made by callers to clean up
83 * (no i2c_stop() etc.)
84 */
85 set_pcf(adap, 1, I2C_PCF_PIN);
86 set_pcf(adap, 1, I2C_PCF_ESO);
87 /*
88 * We pause for a time period sufficient for any running
89 * I2C transaction to complete -- the arbitration logic won't
90 * work properly until the next START is seen.
91 * It is assumed the bus driver or client has set a proper value.
92 *
93 * REVISIT: should probably use msleep instead of mdelay if we
94 * know we can sleep.
95 */
96 if (adap->lab_mdelay)
97 mdelay(adap->lab_mdelay);
98
99 DEB2(printk(KERN_INFO
100 "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
101 get_pcf(adap, 1)));
102}
103
104static int wait_for_bb(struct i2c_algo_pcf_data *adap)
105{
106
107 int timeout = DEF_TIMEOUT;
108 int status;
109
110 status = get_pcf(adap, 1);
111
112 while (!(status & I2C_PCF_BB) && --timeout) {
113 udelay(100); /* wait for 100 us */
114 status = get_pcf(adap, 1);
115 }
116
117 if (timeout == 0) {
118 printk(KERN_ERR "Timeout waiting for Bus Busy\n");
119 return -ETIMEDOUT;
120 }
121
122 return 0;
123}
124
125static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
126{
127
128 int timeout = DEF_TIMEOUT;
129
130 *status = get_pcf(adap, 1);
131
132 while ((*status & I2C_PCF_PIN) && --timeout) {
133 adap->waitforpin(adap->data);
134 *status = get_pcf(adap, 1);
135 }
136 if (*status & I2C_PCF_LAB) {
137 handle_lab(adap, status);
138 return -EINTR;
139 }
140
141 if (timeout == 0)
142 return -ETIMEDOUT;
143
144 return 0;
145}
146
147/*
148 * This should perform the 'PCF8584 initialization sequence' as described
149 * in the Philips IC12 data book (1995, Aug 29).
150 * There should be a 30 clock cycle wait after reset, I assume this
151 * has been fulfilled.
152 * There should be a delay at the end equal to the longest I2C message
153 * to synchronize the BB-bit (in multimaster systems). How long is
154 * this? I assume 1 second is always long enough.
155 *
156 * vdovikin: added detect code for PCF8584
157 */
158static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
159{
160 unsigned char temp;
161
162 DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
163 get_pcf(adap, 1)));
164
165 /* S1=0x80: S0 selected, serial interface off */
166 set_pcf(adap, 1, I2C_PCF_PIN);
167 /*
168 * check to see S1 now used as R/W ctrl -
169 * PCF8584 does that when ESO is zero
170 */
171 if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
172 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
173 return -ENXIO; /* definitely not PCF8584 */
174 }
175
176 /* load own address in S0, effective address is (own << 1) */
177 i2c_outb(adap, get_own(adap));
178 /* check it's really written */
179 if ((temp = i2c_inb(adap)) != get_own(adap)) {
180 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
181 return -ENXIO;
182 }
183
184 /* S1=0xA0, next byte in S2 */
185 set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
186 /* check to see S2 now selected */
187 if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
188 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
189 return -ENXIO;
190 }
191
192 /* load clock register S2 */
193 i2c_outb(adap, get_clock(adap));
194 /* check it's really written, the only 5 lowest bits does matter */
195 if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
196 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
197 return -ENXIO;
198 }
199
200 /* Enable serial interface, idle, S0 selected */
201 set_pcf(adap, 1, I2C_PCF_IDLE);
202
203 /* check to see PCF is really idled and we can access status register */
204 if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
205 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
206 return -ENXIO;
207 }
208
209 printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
210
211 return 0;
212}
213
214static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
215 int count, int last)
216{
217 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
218 int wrcount, status, timeout;
219
220 for (wrcount=0; wrcount<count; ++wrcount) {
221 DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
222 buf[wrcount] & 0xff));
223 i2c_outb(adap, buf[wrcount]);
224 timeout = wait_for_pin(adap, &status);
225 if (timeout) {
226 if (timeout == -EINTR)
227 return -EINTR; /* arbitration lost */
228
229 i2c_stop(adap);
230 dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
231 return -EREMOTEIO; /* got a better one ?? */
232 }
233 if (status & I2C_PCF_LRB) {
234 i2c_stop(adap);
235 dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
236 return -EREMOTEIO; /* got a better one ?? */
237 }
238 }
239 if (last)
240 i2c_stop(adap);
241 else
242 i2c_repstart(adap);
243
244 return wrcount;
245}
246
247static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
248 int count, int last)
249{
250 int i, status;
251 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
252 int wfp;
253
254 /* increment number of bytes to read by one -- read dummy byte */
255 for (i = 0; i <= count; i++) {
256
257 if ((wfp = wait_for_pin(adap, &status))) {
258 if (wfp == -EINTR)
259 return -EINTR; /* arbitration lost */
260
261 i2c_stop(adap);
262 dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
263 return -1;
264 }
265
266 if ((status & I2C_PCF_LRB) && (i != count)) {
267 i2c_stop(adap);
268 dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
269 return -1;
270 }
271
272 if (i == count - 1) {
273 set_pcf(adap, 1, I2C_PCF_ESO);
274 } else if (i == count) {
275 if (last)
276 i2c_stop(adap);
277 else
278 i2c_repstart(adap);
279 }
280
281 if (i)
282 buf[i - 1] = i2c_inb(adap);
283 else
284 i2c_inb(adap); /* dummy read */
285 }
286
287 return i - 1;
288}
289
290
291static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
292 struct i2c_msg *msg)
293{
294 unsigned short flags = msg->flags;
295 unsigned char addr;
296
297 addr = msg->addr << 1;
298 if (flags & I2C_M_RD)
299 addr |= 1;
300 if (flags & I2C_M_REV_DIR_ADDR)
301 addr ^= 1;
302 i2c_outb(adap, addr);
303
304 return 0;
305}
306
307static int pcf_xfer(struct i2c_adapter *i2c_adap,
308 struct i2c_msg *msgs,
309 int num)
310{
311 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
312 struct i2c_msg *pmsg;
313 int i;
314 int ret=0, timeout, status;
315
316 if (adap->xfer_begin)
317 adap->xfer_begin(adap->data);
318
319 /* Check for bus busy */
320 timeout = wait_for_bb(adap);
321 if (timeout) {
322 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
323 "Timeout waiting for BB in pcf_xfer\n");)
324 i = -EIO;
325 goto out;
326 }
327
328 for (i = 0;ret >= 0 && i < num; i++) {
329 pmsg = &msgs[i];
330
331 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
332 pmsg->flags & I2C_M_RD ? "read" : "write",
333 pmsg->len, pmsg->addr, i + 1, num);)
334
335 ret = pcf_doAddress(adap, pmsg);
336
337 /* Send START */
338 if (i == 0)
339 i2c_start(adap);
340
341 /* Wait for PIN (pending interrupt NOT) */
342 timeout = wait_for_pin(adap, &status);
343 if (timeout) {
344 if (timeout == -EINTR) {
345 /* arbitration lost */
346 i = -EINTR;
347 goto out;
348 }
349 i2c_stop(adap);
350 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
351 "for PIN(1) in pcf_xfer\n");)
352 i = -EREMOTEIO;
353 goto out;
354 }
355
356 /* Check LRB (last rcvd bit - slave ack) */
357 if (status & I2C_PCF_LRB) {
358 i2c_stop(adap);
359 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
360 i = -EREMOTEIO;
361 goto out;
362 }
363
364 DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
365 i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
366
367 if (pmsg->flags & I2C_M_RD) {
368 ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
369 (i + 1 == num));
370
371 if (ret != pmsg->len) {
372 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
373 "only read %d bytes.\n",ret));
374 } else {
375 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
376 }
377 } else {
378 ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
379 (i + 1 == num));
380
381 if (ret != pmsg->len) {
382 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
383 "only wrote %d bytes.\n",ret));
384 } else {
385 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
386 }
387 }
388 }
389
390out:
391 if (adap->xfer_end)
392 adap->xfer_end(adap->data);
393 return i;
394}
395
396static u32 pcf_func(struct i2c_adapter *adap)
397{
398 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
399 I2C_FUNC_PROTOCOL_MANGLING;
400}
401
402/* exported algorithm data: */
403static const struct i2c_algorithm pcf_algo = {
404 .master_xfer = pcf_xfer,
405 .functionality = pcf_func,
406};
407
408/*
409 * registering functions to load algorithms at runtime
410 */
411int i2c_pcf_add_bus(struct i2c_adapter *adap)
412{
413 struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
414 int rval;
415
416 DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
417
418 /* register new adapter to i2c module... */
419 adap->algo = &pcf_algo;
420
421 if ((rval = pcf_init_8584(pcf_adap)))
422 return rval;
423
424 rval = i2c_add_adapter(adap);
425
426 return rval;
427}
428EXPORT_SYMBOL(i2c_pcf_add_bus);
429
430MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
431MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
432MODULE_LICENSE("GPL");
433
434module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
435MODULE_PARM_DESC(i2c_debug,
436 "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
1/*
2 * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
3 *
4 * Copyright (C) 1995-1997 Simon G. Vogl
5 * 1998-2000 Hans Berglund
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
20 * MA 02110-1301 USA.
21 *
22 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
23 * Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
24 * <mbailey@littlefeet-inc.com>
25 *
26 * Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
27 * messages, proper stop/repstart signaling during receive, added detect code
28 */
29
30#include <linux/kernel.h>
31#include <linux/module.h>
32#include <linux/delay.h>
33#include <linux/init.h>
34#include <linux/errno.h>
35#include <linux/i2c.h>
36#include <linux/i2c-algo-pcf.h>
37#include "i2c-algo-pcf.h"
38
39
40#define DEB2(x) if (i2c_debug >= 2) x
41#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
42#define DEBPROTO(x) if (i2c_debug >= 9) x;
43 /* debug the protocol by showing transferred bits */
44#define DEF_TIMEOUT 16
45
46/*
47 * module parameters:
48 */
49static int i2c_debug;
50
51/* setting states on the bus with the right timing: */
52
53#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
54#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
55#define get_own(adap) adap->getown(adap->data)
56#define get_clock(adap) adap->getclock(adap->data)
57#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
58#define i2c_inb(adap) adap->getpcf(adap->data, 0)
59
60/* other auxiliary functions */
61
62static void i2c_start(struct i2c_algo_pcf_data *adap)
63{
64 DEBPROTO(printk(KERN_DEBUG "S "));
65 set_pcf(adap, 1, I2C_PCF_START);
66}
67
68static void i2c_repstart(struct i2c_algo_pcf_data *adap)
69{
70 DEBPROTO(printk(" Sr "));
71 set_pcf(adap, 1, I2C_PCF_REPSTART);
72}
73
74static void i2c_stop(struct i2c_algo_pcf_data *adap)
75{
76 DEBPROTO(printk("P\n"));
77 set_pcf(adap, 1, I2C_PCF_STOP);
78}
79
80static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
81{
82 DEB2(printk(KERN_INFO
83 "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
84 *status));
85 /*
86 * Cleanup from LAB -- reset and enable ESO.
87 * This resets the PCF8584; since we've lost the bus, no
88 * further attempts should be made by callers to clean up
89 * (no i2c_stop() etc.)
90 */
91 set_pcf(adap, 1, I2C_PCF_PIN);
92 set_pcf(adap, 1, I2C_PCF_ESO);
93 /*
94 * We pause for a time period sufficient for any running
95 * I2C transaction to complete -- the arbitration logic won't
96 * work properly until the next START is seen.
97 * It is assumed the bus driver or client has set a proper value.
98 *
99 * REVISIT: should probably use msleep instead of mdelay if we
100 * know we can sleep.
101 */
102 if (adap->lab_mdelay)
103 mdelay(adap->lab_mdelay);
104
105 DEB2(printk(KERN_INFO
106 "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
107 get_pcf(adap, 1)));
108}
109
110static int wait_for_bb(struct i2c_algo_pcf_data *adap)
111{
112
113 int timeout = DEF_TIMEOUT;
114 int status;
115
116 status = get_pcf(adap, 1);
117
118 while (!(status & I2C_PCF_BB) && --timeout) {
119 udelay(100); /* wait for 100 us */
120 status = get_pcf(adap, 1);
121 }
122
123 if (timeout == 0) {
124 printk(KERN_ERR "Timeout waiting for Bus Busy\n");
125 return -ETIMEDOUT;
126 }
127
128 return 0;
129}
130
131static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
132{
133
134 int timeout = DEF_TIMEOUT;
135
136 *status = get_pcf(adap, 1);
137
138 while ((*status & I2C_PCF_PIN) && --timeout) {
139 adap->waitforpin(adap->data);
140 *status = get_pcf(adap, 1);
141 }
142 if (*status & I2C_PCF_LAB) {
143 handle_lab(adap, status);
144 return -EINTR;
145 }
146
147 if (timeout == 0)
148 return -ETIMEDOUT;
149
150 return 0;
151}
152
153/*
154 * This should perform the 'PCF8584 initialization sequence' as described
155 * in the Philips IC12 data book (1995, Aug 29).
156 * There should be a 30 clock cycle wait after reset, I assume this
157 * has been fulfilled.
158 * There should be a delay at the end equal to the longest I2C message
159 * to synchronize the BB-bit (in multimaster systems). How long is
160 * this? I assume 1 second is always long enough.
161 *
162 * vdovikin: added detect code for PCF8584
163 */
164static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
165{
166 unsigned char temp;
167
168 DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
169 get_pcf(adap, 1)));
170
171 /* S1=0x80: S0 selected, serial interface off */
172 set_pcf(adap, 1, I2C_PCF_PIN);
173 /*
174 * check to see S1 now used as R/W ctrl -
175 * PCF8584 does that when ESO is zero
176 */
177 if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
178 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
179 return -ENXIO; /* definitely not PCF8584 */
180 }
181
182 /* load own address in S0, effective address is (own << 1) */
183 i2c_outb(adap, get_own(adap));
184 /* check it's really written */
185 if ((temp = i2c_inb(adap)) != get_own(adap)) {
186 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
187 return -ENXIO;
188 }
189
190 /* S1=0xA0, next byte in S2 */
191 set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
192 /* check to see S2 now selected */
193 if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
194 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
195 return -ENXIO;
196 }
197
198 /* load clock register S2 */
199 i2c_outb(adap, get_clock(adap));
200 /* check it's really written, the only 5 lowest bits does matter */
201 if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
202 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
203 return -ENXIO;
204 }
205
206 /* Enable serial interface, idle, S0 selected */
207 set_pcf(adap, 1, I2C_PCF_IDLE);
208
209 /* check to see PCF is really idled and we can access status register */
210 if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
211 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
212 return -ENXIO;
213 }
214
215 printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
216
217 return 0;
218}
219
220static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
221 int count, int last)
222{
223 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
224 int wrcount, status, timeout;
225
226 for (wrcount=0; wrcount<count; ++wrcount) {
227 DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
228 buf[wrcount] & 0xff));
229 i2c_outb(adap, buf[wrcount]);
230 timeout = wait_for_pin(adap, &status);
231 if (timeout) {
232 if (timeout == -EINTR)
233 return -EINTR; /* arbitration lost */
234
235 i2c_stop(adap);
236 dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
237 return -EREMOTEIO; /* got a better one ?? */
238 }
239 if (status & I2C_PCF_LRB) {
240 i2c_stop(adap);
241 dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
242 return -EREMOTEIO; /* got a better one ?? */
243 }
244 }
245 if (last)
246 i2c_stop(adap);
247 else
248 i2c_repstart(adap);
249
250 return wrcount;
251}
252
253static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
254 int count, int last)
255{
256 int i, status;
257 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
258 int wfp;
259
260 /* increment number of bytes to read by one -- read dummy byte */
261 for (i = 0; i <= count; i++) {
262
263 if ((wfp = wait_for_pin(adap, &status))) {
264 if (wfp == -EINTR)
265 return -EINTR; /* arbitration lost */
266
267 i2c_stop(adap);
268 dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
269 return -1;
270 }
271
272 if ((status & I2C_PCF_LRB) && (i != count)) {
273 i2c_stop(adap);
274 dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
275 return -1;
276 }
277
278 if (i == count - 1) {
279 set_pcf(adap, 1, I2C_PCF_ESO);
280 } else if (i == count) {
281 if (last)
282 i2c_stop(adap);
283 else
284 i2c_repstart(adap);
285 }
286
287 if (i)
288 buf[i - 1] = i2c_inb(adap);
289 else
290 i2c_inb(adap); /* dummy read */
291 }
292
293 return i - 1;
294}
295
296
297static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
298 struct i2c_msg *msg)
299{
300 unsigned short flags = msg->flags;
301 unsigned char addr;
302
303 addr = msg->addr << 1;
304 if (flags & I2C_M_RD)
305 addr |= 1;
306 if (flags & I2C_M_REV_DIR_ADDR)
307 addr ^= 1;
308 i2c_outb(adap, addr);
309
310 return 0;
311}
312
313static int pcf_xfer(struct i2c_adapter *i2c_adap,
314 struct i2c_msg *msgs,
315 int num)
316{
317 struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
318 struct i2c_msg *pmsg;
319 int i;
320 int ret=0, timeout, status;
321
322 if (adap->xfer_begin)
323 adap->xfer_begin(adap->data);
324
325 /* Check for bus busy */
326 timeout = wait_for_bb(adap);
327 if (timeout) {
328 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
329 "Timeout waiting for BB in pcf_xfer\n");)
330 i = -EIO;
331 goto out;
332 }
333
334 for (i = 0;ret >= 0 && i < num; i++) {
335 pmsg = &msgs[i];
336
337 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
338 pmsg->flags & I2C_M_RD ? "read" : "write",
339 pmsg->len, pmsg->addr, i + 1, num);)
340
341 ret = pcf_doAddress(adap, pmsg);
342
343 /* Send START */
344 if (i == 0)
345 i2c_start(adap);
346
347 /* Wait for PIN (pending interrupt NOT) */
348 timeout = wait_for_pin(adap, &status);
349 if (timeout) {
350 if (timeout == -EINTR) {
351 /* arbitration lost */
352 i = -EINTR;
353 goto out;
354 }
355 i2c_stop(adap);
356 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
357 "for PIN(1) in pcf_xfer\n");)
358 i = -EREMOTEIO;
359 goto out;
360 }
361
362 /* Check LRB (last rcvd bit - slave ack) */
363 if (status & I2C_PCF_LRB) {
364 i2c_stop(adap);
365 DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
366 i = -EREMOTEIO;
367 goto out;
368 }
369
370 DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
371 i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
372
373 if (pmsg->flags & I2C_M_RD) {
374 ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
375 (i + 1 == num));
376
377 if (ret != pmsg->len) {
378 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
379 "only read %d bytes.\n",ret));
380 } else {
381 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
382 }
383 } else {
384 ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
385 (i + 1 == num));
386
387 if (ret != pmsg->len) {
388 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
389 "only wrote %d bytes.\n",ret));
390 } else {
391 DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
392 }
393 }
394 }
395
396out:
397 if (adap->xfer_end)
398 adap->xfer_end(adap->data);
399 return i;
400}
401
402static u32 pcf_func(struct i2c_adapter *adap)
403{
404 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
405 I2C_FUNC_PROTOCOL_MANGLING;
406}
407
408/* exported algorithm data: */
409static const struct i2c_algorithm pcf_algo = {
410 .master_xfer = pcf_xfer,
411 .functionality = pcf_func,
412};
413
414/*
415 * registering functions to load algorithms at runtime
416 */
417int i2c_pcf_add_bus(struct i2c_adapter *adap)
418{
419 struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
420 int rval;
421
422 DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
423
424 /* register new adapter to i2c module... */
425 adap->algo = &pcf_algo;
426
427 if ((rval = pcf_init_8584(pcf_adap)))
428 return rval;
429
430 rval = i2c_add_adapter(adap);
431
432 return rval;
433}
434EXPORT_SYMBOL(i2c_pcf_add_bus);
435
436MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
437MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
438MODULE_LICENSE("GPL");
439
440module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
441MODULE_PARM_DESC(i2c_debug,
442 "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");