3 Copyright (C) 2003-2004 Kevin Thayer <nufan_wfk at yahoo.com>
4 Copyright (C) 2005-2007 Hans Verkuil <hverkuil@xs4all.nl>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 This file includes an i2c implementation that was reverse engineered
23 from the Hauppauge windows driver. Older ivtv versions used i2c-algo-bit,
24 which whilst fine under most circumstances, had trouble with the Zilog
25 CPU on the PVR-150 which handles IR functions (occasional inability to
26 communicate with the chip until it was reset) and also with the i2c
27 bus being completely unreachable when multiple PVR cards were present.
29 The implementation is very similar to i2c-algo-bit, but there are enough
30 subtle differences that the two are hard to merge. The general strategy
31 employed by i2c-algo-bit is to use udelay() to implement the timing
32 when putting out bits on the scl/sda lines. The general strategy taken
33 here is to poll the lines for state changes (see ivtv_waitscl and
34 ivtv_waitsda). In addition there are small delays at various locations
35 which poll the SCL line 5 times (ivtv_scldelay). I would guess that
36 since this is memory mapped I/O that the length of those delays is tied
37 to the PCI bus clock. There is some extra code to do with recovery
38 and retries. Since it is not known what causes the actual i2c problems
39 in the first place, the only goal if one was to attempt to use
40 i2c-algo-bit would be to try to make it follow the same code path.
41 This would be a lot of work, and I'm also not convinced that it would
42 provide a generic benefit to i2c-algo-bit. Therefore consider this
43 an engineering solution -- not pretty, but it works.
45 Some more general comments about what we are doing:
47 The i2c bus is a 2 wire serial bus, with clock (SCL) and data (SDA)
48 lines. To communicate on the bus (as a master, we don't act as a slave),
49 we first initiate a start condition (ivtv_start). We then write the
50 address of the device that we want to communicate with, along with a flag
51 that indicates whether this is a read or a write. The slave then issues
52 an ACK signal (ivtv_ack), which tells us that it is ready for reading /
53 writing. We then proceed with reading or writing (ivtv_read/ivtv_write),
54 and finally issue a stop condition (ivtv_stop) to make the bus available
57 There is an additional form of transaction where a write may be
58 immediately followed by a read. In this case, there is no intervening
59 stop condition. (Only the msp3400 chip uses this method of data transfer).
62 #include "ivtv-driver.h"
63 #include "ivtv-cards.h"
64 #include "ivtv-gpio.h"
66 #include <media/cx25840.h>
68 /* i2c implementation for cx23415/6 chip, ivtv project.
69 * Author: Kevin Thayer (nufan_wfk at yahoo.com)
72 #define IVTV_REG_I2C_SETSCL_OFFSET 0x7000
73 #define IVTV_REG_I2C_SETSDA_OFFSET 0x7004
74 #define IVTV_REG_I2C_GETSCL_OFFSET 0x7008
75 #define IVTV_REG_I2C_GETSDA_OFFSET 0x700c
77 #define IVTV_CS53L32A_I2C_ADDR 0x11
78 #define IVTV_M52790_I2C_ADDR 0x48
79 #define IVTV_CX25840_I2C_ADDR 0x44
80 #define IVTV_SAA7115_I2C_ADDR 0x21
81 #define IVTV_SAA7127_I2C_ADDR 0x44
82 #define IVTV_SAA717x_I2C_ADDR 0x21
83 #define IVTV_MSP3400_I2C_ADDR 0x40
84 #define IVTV_HAUPPAUGE_I2C_ADDR 0x50
85 #define IVTV_WM8739_I2C_ADDR 0x1a
86 #define IVTV_WM8775_I2C_ADDR 0x1b
87 #define IVTV_TEA5767_I2C_ADDR 0x60
88 #define IVTV_UPD64031A_I2C_ADDR 0x12
89 #define IVTV_UPD64083_I2C_ADDR 0x5c
90 #define IVTV_VP27SMPX_I2C_ADDR 0x5b
91 #define IVTV_M52790_I2C_ADDR 0x48
92 #define IVTV_AVERMEDIA_IR_RX_I2C_ADDR 0x40
93 #define IVTV_HAUP_EXT_IR_RX_I2C_ADDR 0x1a
94 #define IVTV_HAUP_INT_IR_RX_I2C_ADDR 0x18
95 #define IVTV_Z8F0811_IR_TX_I2C_ADDR 0x70
96 #define IVTV_Z8F0811_IR_RX_I2C_ADDR 0x71
98 /* This array should match the IVTV_HW_ defines */
99 static const u8 hw_addrs[] = {
100 IVTV_CX25840_I2C_ADDR,
101 IVTV_SAA7115_I2C_ADDR,
102 IVTV_SAA7127_I2C_ADDR,
103 IVTV_MSP3400_I2C_ADDR,
105 IVTV_WM8775_I2C_ADDR,
106 IVTV_CS53L32A_I2C_ADDR,
108 IVTV_SAA7115_I2C_ADDR,
109 IVTV_UPD64031A_I2C_ADDR,
110 IVTV_UPD64083_I2C_ADDR,
111 IVTV_SAA717x_I2C_ADDR,
112 IVTV_WM8739_I2C_ADDR,
113 IVTV_VP27SMPX_I2C_ADDR,
114 IVTV_M52790_I2C_ADDR,
115 0, /* IVTV_HW_GPIO dummy driver ID */
116 IVTV_AVERMEDIA_IR_RX_I2C_ADDR, /* IVTV_HW_I2C_IR_RX_AVER */
117 IVTV_HAUP_EXT_IR_RX_I2C_ADDR, /* IVTV_HW_I2C_IR_RX_HAUP_EXT */
118 IVTV_HAUP_INT_IR_RX_I2C_ADDR, /* IVTV_HW_I2C_IR_RX_HAUP_INT */
119 IVTV_Z8F0811_IR_TX_I2C_ADDR, /* IVTV_HW_Z8F0811_IR_TX_HAUP */
120 IVTV_Z8F0811_IR_RX_I2C_ADDR, /* IVTV_HW_Z8F0811_IR_RX_HAUP */
123 /* This array should match the IVTV_HW_ defines */
124 static const char * const hw_devicenames[] = {
127 "saa7127_auto", /* saa7127 or saa7129 */
141 "ir_video", /* IVTV_HW_I2C_IR_RX_AVER */
142 "ir_video", /* IVTV_HW_I2C_IR_RX_HAUP_EXT */
143 "ir_video", /* IVTV_HW_I2C_IR_RX_HAUP_INT */
144 "ir_tx_z8f0811_haup", /* IVTV_HW_Z8F0811_IR_TX_HAUP */
145 "ir_rx_z8f0811_haup", /* IVTV_HW_Z8F0811_IR_RX_HAUP */
148 static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
150 struct i2c_board_info info;
151 struct i2c_adapter *adap = &itv->i2c_adap;
152 struct IR_i2c_init_data *init_data = &itv->ir_i2c_init_data;
153 unsigned short addr_list[2] = { addr, I2C_CLIENT_END };
155 /* Only allow one IR transmitter to be registered per board */
156 if (hw & IVTV_HW_IR_TX_ANY) {
157 if (itv->hw_flags & IVTV_HW_IR_TX_ANY)
159 memset(&info, 0, sizeof(struct i2c_board_info));
160 strlcpy(info.type, type, I2C_NAME_SIZE);
161 return i2c_new_probed_device(adap, &info, addr_list, NULL)
165 /* Only allow one IR receiver to be registered per board */
166 if (itv->hw_flags & IVTV_HW_IR_RX_ANY)
169 /* Our default information for ir-kbd-i2c.c to use */
171 case IVTV_HW_I2C_IR_RX_AVER:
172 init_data->ir_codes = RC_MAP_AVERMEDIA_CARDBUS;
173 init_data->internal_get_key_func =
174 IR_KBD_GET_KEY_AVERMEDIA_CARDBUS;
175 init_data->type = IR_TYPE_OTHER;
176 init_data->name = "AVerMedia AVerTV card";
178 case IVTV_HW_I2C_IR_RX_HAUP_EXT:
179 case IVTV_HW_I2C_IR_RX_HAUP_INT:
180 /* Default to old black remote */
181 init_data->ir_codes = RC_MAP_RC5_TV;
182 init_data->internal_get_key_func = IR_KBD_GET_KEY_HAUP;
183 init_data->type = IR_TYPE_RC5;
184 init_data->name = itv->card_name;
186 case IVTV_HW_Z8F0811_IR_RX_HAUP:
187 /* Default to grey remote */
188 init_data->ir_codes = RC_MAP_HAUPPAUGE_NEW;
189 init_data->internal_get_key_func = IR_KBD_GET_KEY_HAUP_XVR;
190 init_data->type = IR_TYPE_RC5;
191 init_data->name = itv->card_name;
195 memset(&info, 0, sizeof(struct i2c_board_info));
196 info.platform_data = init_data;
197 strlcpy(info.type, type, I2C_NAME_SIZE);
199 return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
203 /* Instantiate the IR receiver device using probing -- undesirable */
204 struct i2c_client *ivtv_i2c_new_ir_legacy(struct ivtv *itv)
206 struct i2c_board_info info;
208 * The external IR receiver is at i2c address 0x34.
209 * The internal IR receiver is at i2c address 0x30.
211 * In theory, both can be fitted, and Hauppauge suggests an external
212 * overrides an internal. That's why we probe 0x1a (~0x34) first. CB
214 * Some of these addresses we probe may collide with other i2c address
215 * allocations, so this function must be called after all other i2c
216 * devices we care about are registered.
218 const unsigned short addr_list[] = {
219 0x1a, /* Hauppauge IR external - collides with WM8739 */
220 0x18, /* Hauppauge IR internal */
221 0x71, /* Hauppauge IR (PVR150) */
222 0x6b, /* Adaptec IR */
226 memset(&info, 0, sizeof(struct i2c_board_info));
227 strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
228 return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list, NULL);
231 int ivtv_i2c_register(struct ivtv *itv, unsigned idx)
233 struct v4l2_subdev *sd;
234 struct i2c_adapter *adap = &itv->i2c_adap;
235 const char *type = hw_devicenames[idx];
238 if (idx >= ARRAY_SIZE(hw_addrs))
240 if (hw == IVTV_HW_TUNER) {
241 /* special tuner handling */
242 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
243 itv->card_i2c->radio);
245 sd->grp_id = 1 << idx;
246 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
247 itv->card_i2c->demod);
249 sd->grp_id = 1 << idx;
250 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
253 sd->grp_id = 1 << idx;
257 if (hw & IVTV_HW_IR_ANY)
258 return ivtv_i2c_new_ir(itv, hw, type, hw_addrs[idx]);
260 /* Is it not an I2C device or one we do not wish to register? */
264 /* It's an I2C device other than an analog tuner or IR chip */
265 if (hw == IVTV_HW_UPD64031A || hw == IVTV_HW_UPD6408X) {
266 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
267 adap, type, 0, I2C_ADDRS(hw_addrs[idx]));
268 } else if (hw == IVTV_HW_CX25840) {
269 struct cx25840_platform_data pdata;
271 pdata.pvr150_workaround = itv->pvr150_workaround;
272 sd = v4l2_i2c_new_subdev_cfg(&itv->v4l2_dev,
273 adap, type, 0, &pdata, hw_addrs[idx], NULL);
275 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
276 adap, type, hw_addrs[idx], NULL);
279 sd->grp_id = 1 << idx;
283 struct v4l2_subdev *ivtv_find_hw(struct ivtv *itv, u32 hw)
285 struct v4l2_subdev *result = NULL;
286 struct v4l2_subdev *sd;
288 spin_lock(&itv->v4l2_dev.lock);
289 v4l2_device_for_each_subdev(sd, &itv->v4l2_dev) {
290 if (sd->grp_id == hw) {
295 spin_unlock(&itv->v4l2_dev.lock);
299 /* Set the serial clock line to the desired state */
300 static void ivtv_setscl(struct ivtv *itv, int state)
303 /* write bits are inverted */
304 write_reg(~state, IVTV_REG_I2C_SETSCL_OFFSET);
307 /* Set the serial data line to the desired state */
308 static void ivtv_setsda(struct ivtv *itv, int state)
311 /* write bits are inverted */
312 write_reg(~state & 1, IVTV_REG_I2C_SETSDA_OFFSET);
315 /* Read the serial clock line */
316 static int ivtv_getscl(struct ivtv *itv)
318 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
321 /* Read the serial data line */
322 static int ivtv_getsda(struct ivtv *itv)
324 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
327 /* Implement a short delay by polling the serial clock line */
328 static void ivtv_scldelay(struct ivtv *itv)
332 for (i = 0; i < 5; ++i)
336 /* Wait for the serial clock line to become set to a specific value */
337 static int ivtv_waitscl(struct ivtv *itv, int val)
342 for (i = 0; i < 1000; ++i) {
343 if (ivtv_getscl(itv) == val)
349 /* Wait for the serial data line to become set to a specific value */
350 static int ivtv_waitsda(struct ivtv *itv, int val)
355 for (i = 0; i < 1000; ++i) {
356 if (ivtv_getsda(itv) == val)
362 /* Wait for the slave to issue an ACK */
363 static int ivtv_ack(struct ivtv *itv)
367 if (ivtv_getscl(itv) == 1) {
368 IVTV_DEBUG_HI_I2C("SCL was high starting an ack\n");
370 if (!ivtv_waitscl(itv, 0)) {
371 IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
378 if (!ivtv_waitsda(itv, 0)) {
379 IVTV_DEBUG_I2C("Slave did not ack\n");
383 if (!ivtv_waitscl(itv, 0)) {
384 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
390 /* Write a single byte to the i2c bus and wait for the slave to ACK */
391 static int ivtv_sendbyte(struct ivtv *itv, unsigned char byte)
395 IVTV_DEBUG_HI_I2C("write %x\n",byte);
396 for (i = 0; i < 8; ++i, byte<<=1) {
398 if (!ivtv_waitscl(itv, 0)) {
399 IVTV_DEBUG_I2C("Error setting SCL low\n");
403 ivtv_setsda(itv, bit);
404 if (!ivtv_waitsda(itv, bit)) {
405 IVTV_DEBUG_I2C("Error setting SDA\n");
409 if (!ivtv_waitscl(itv, 1)) {
410 IVTV_DEBUG_I2C("Slave not ready for bit\n");
415 if (!ivtv_waitscl(itv, 0)) {
416 IVTV_DEBUG_I2C("Error setting SCL low\n");
419 return ivtv_ack(itv);
422 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
424 static int ivtv_readbyte(struct ivtv *itv, unsigned char *byte, int nack)
432 for (i = 0; i < 8; ++i) {
436 if (!ivtv_waitscl(itv, 1)) {
437 IVTV_DEBUG_I2C("Error setting SCL high\n");
440 *byte = ((*byte)<<1)|ivtv_getsda(itv);
444 ivtv_setsda(itv, nack);
450 IVTV_DEBUG_HI_I2C("read %x\n",*byte);
454 /* Issue a start condition on the i2c bus to alert slaves to prepare for
456 static int ivtv_start(struct ivtv *itv)
460 sda = ivtv_getsda(itv);
462 IVTV_DEBUG_HI_I2C("SDA was low at start\n");
464 if (!ivtv_waitsda(itv, 1)) {
465 IVTV_DEBUG_I2C("SDA stuck low\n");
469 if (ivtv_getscl(itv) != 1) {
471 if (!ivtv_waitscl(itv, 1)) {
472 IVTV_DEBUG_I2C("SCL stuck low at start\n");
481 /* Issue a stop condition on the i2c bus to release it */
482 static int ivtv_stop(struct ivtv *itv)
486 if (ivtv_getscl(itv) != 0) {
487 IVTV_DEBUG_HI_I2C("SCL not low when stopping\n");
489 if (!ivtv_waitscl(itv, 0)) {
490 IVTV_DEBUG_I2C("SCL could not be set low\n");
496 if (!ivtv_waitscl(itv, 1)) {
497 IVTV_DEBUG_I2C("SCL could not be set high\n");
502 if (!ivtv_waitsda(itv, 1)) {
503 IVTV_DEBUG_I2C("resetting I2C\n");
504 for (i = 0; i < 16; ++i) {
511 ivtv_waitsda(itv, 1);
517 /* Write a message to the given i2c slave. do_stop may be 0 to prevent
518 issuing the i2c stop condition (when following with a read) */
519 static int ivtv_write(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len, int do_stop)
521 int retry, ret = -EREMOTEIO;
524 for (retry = 0; ret != 0 && retry < 8; ++retry) {
525 ret = ivtv_start(itv);
528 ret = ivtv_sendbyte(itv, addr<<1);
529 for (i = 0; ret == 0 && i < len; ++i)
530 ret = ivtv_sendbyte(itv, data[i]);
532 if (ret != 0 || do_stop) {
537 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr);
541 /* Read data from the given i2c slave. A stop condition is always issued. */
542 static int ivtv_read(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len)
544 int retry, ret = -EREMOTEIO;
547 for (retry = 0; ret != 0 && retry < 8; ++retry) {
548 ret = ivtv_start(itv);
550 ret = ivtv_sendbyte(itv, (addr << 1) | 1);
551 for (i = 0; ret == 0 && i < len; ++i) {
552 ret = ivtv_readbyte(itv, &data[i], i == len - 1);
557 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr);
561 /* Kernel i2c transfer implementation. Takes a number of messages to be read
562 or written. If a read follows a write, this will occur without an
563 intervening stop condition */
564 static int ivtv_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
566 struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
567 struct ivtv *itv = to_ivtv(v4l2_dev);
571 mutex_lock(&itv->i2c_bus_lock);
572 for (i = retval = 0; retval == 0 && i < num; i++) {
573 if (msgs[i].flags & I2C_M_RD)
574 retval = ivtv_read(itv, msgs[i].addr, msgs[i].buf, msgs[i].len);
576 /* if followed by a read, don't stop */
577 int stop = !(i + 1 < num && msgs[i + 1].flags == I2C_M_RD);
579 retval = ivtv_write(itv, msgs[i].addr, msgs[i].buf, msgs[i].len, stop);
582 mutex_unlock(&itv->i2c_bus_lock);
583 return retval ? retval : num;
586 /* Kernel i2c capabilities */
587 static u32 ivtv_functionality(struct i2c_adapter *adap)
589 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
592 static struct i2c_algorithm ivtv_algo = {
593 .master_xfer = ivtv_xfer,
594 .functionality = ivtv_functionality,
597 /* template for our-bit banger */
598 static struct i2c_adapter ivtv_i2c_adap_hw_template = {
599 .name = "ivtv i2c driver",
601 .algo_data = NULL, /* filled from template */
602 .owner = THIS_MODULE,
605 static void ivtv_setscl_old(void *data, int state)
607 struct ivtv *itv = (struct ivtv *)data;
610 itv->i2c_state |= 0x01;
612 itv->i2c_state &= ~0x01;
615 /* write bits are inverted */
616 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSCL_OFFSET);
619 static void ivtv_setsda_old(void *data, int state)
621 struct ivtv *itv = (struct ivtv *)data;
624 itv->i2c_state |= 0x01;
626 itv->i2c_state &= ~0x01;
629 /* write bits are inverted */
630 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSDA_OFFSET);
633 static int ivtv_getscl_old(void *data)
635 struct ivtv *itv = (struct ivtv *)data;
637 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
640 static int ivtv_getsda_old(void *data)
642 struct ivtv *itv = (struct ivtv *)data;
644 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
647 /* template for i2c-bit-algo */
648 static struct i2c_adapter ivtv_i2c_adap_template = {
649 .name = "ivtv i2c driver",
650 .algo = NULL, /* set by i2c-algo-bit */
651 .algo_data = NULL, /* filled from template */
652 .owner = THIS_MODULE,
655 #define IVTV_ALGO_BIT_TIMEOUT (2) /* seconds */
657 static const struct i2c_algo_bit_data ivtv_i2c_algo_template = {
658 .setsda = ivtv_setsda_old,
659 .setscl = ivtv_setscl_old,
660 .getsda = ivtv_getsda_old,
661 .getscl = ivtv_getscl_old,
662 .udelay = IVTV_DEFAULT_I2C_CLOCK_PERIOD / 2, /* microseconds */
663 .timeout = IVTV_ALGO_BIT_TIMEOUT * HZ, /* jiffies */
666 static struct i2c_client ivtv_i2c_client_template = {
667 .name = "ivtv internal",
670 /* init + register i2c adapter */
671 int init_ivtv_i2c(struct ivtv *itv)
675 IVTV_DEBUG_I2C("i2c init\n");
677 /* Sanity checks for the I2C hardware arrays. They must be the
680 if (ARRAY_SIZE(hw_devicenames) != ARRAY_SIZE(hw_addrs)) {
681 IVTV_ERR("Mismatched I2C hardware arrays\n");
684 if (itv->options.newi2c > 0) {
685 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_hw_template,
686 sizeof(struct i2c_adapter));
688 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_template,
689 sizeof(struct i2c_adapter));
690 memcpy(&itv->i2c_algo, &ivtv_i2c_algo_template,
691 sizeof(struct i2c_algo_bit_data));
693 itv->i2c_algo.udelay = itv->options.i2c_clock_period / 2;
694 itv->i2c_algo.data = itv;
695 itv->i2c_adap.algo_data = &itv->i2c_algo;
697 sprintf(itv->i2c_adap.name + strlen(itv->i2c_adap.name), " #%d",
699 i2c_set_adapdata(&itv->i2c_adap, &itv->v4l2_dev);
701 memcpy(&itv->i2c_client, &ivtv_i2c_client_template,
702 sizeof(struct i2c_client));
703 itv->i2c_client.adapter = &itv->i2c_adap;
704 itv->i2c_adap.dev.parent = &itv->pdev->dev;
706 IVTV_DEBUG_I2C("setting scl and sda to 1\n");
710 if (itv->options.newi2c > 0)
711 retval = i2c_add_adapter(&itv->i2c_adap);
713 retval = i2c_bit_add_bus(&itv->i2c_adap);
718 void exit_ivtv_i2c(struct ivtv *itv)
720 IVTV_DEBUG_I2C("i2c exit\n");
722 i2c_del_adapter(&itv->i2c_adap);