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"
67 #include <media/ir-kbd-i2c.h>
69 /* i2c implementation for cx23415/6 chip, ivtv project.
70 * Author: Kevin Thayer (nufan_wfk at yahoo.com)
73 #define IVTV_REG_I2C_SETSCL_OFFSET 0x7000
74 #define IVTV_REG_I2C_SETSDA_OFFSET 0x7004
75 #define IVTV_REG_I2C_GETSCL_OFFSET 0x7008
76 #define IVTV_REG_I2C_GETSDA_OFFSET 0x700c
78 #ifndef I2C_ADAP_CLASS_TV_ANALOG
79 #define I2C_ADAP_CLASS_TV_ANALOG I2C_CLASS_TV_ANALOG
80 #endif /* I2C_ADAP_CLASS_TV_ANALOG */
82 #define IVTV_CS53L32A_I2C_ADDR 0x11
83 #define IVTV_M52790_I2C_ADDR 0x48
84 #define IVTV_CX25840_I2C_ADDR 0x44
85 #define IVTV_SAA7115_I2C_ADDR 0x21
86 #define IVTV_SAA7127_I2C_ADDR 0x44
87 #define IVTV_SAA717x_I2C_ADDR 0x21
88 #define IVTV_MSP3400_I2C_ADDR 0x40
89 #define IVTV_HAUPPAUGE_I2C_ADDR 0x50
90 #define IVTV_WM8739_I2C_ADDR 0x1a
91 #define IVTV_WM8775_I2C_ADDR 0x1b
92 #define IVTV_TEA5767_I2C_ADDR 0x60
93 #define IVTV_UPD64031A_I2C_ADDR 0x12
94 #define IVTV_UPD64083_I2C_ADDR 0x5c
95 #define IVTV_TDA985X_I2C_ADDR 0x5b
97 /* This array should match the IVTV_HW_ defines */
98 static const u8 hw_driverids[] = {
100 I2C_DRIVERID_SAA711X,
101 I2C_DRIVERID_SAA7127,
102 I2C_DRIVERID_MSP3400,
105 I2C_DRIVERID_CS53L32A,
106 I2C_DRIVERID_TVEEPROM,
107 I2C_DRIVERID_SAA711X,
108 I2C_DRIVERID_TVAUDIO,
109 I2C_DRIVERID_UPD64031A,
110 I2C_DRIVERID_UPD64083,
111 I2C_DRIVERID_SAA717X,
113 I2C_DRIVERID_VP27SMPX,
115 0 /* IVTV_HW_GPIO dummy driver ID */
118 /* This array should match the IVTV_HW_ defines */
119 static const char * const hw_drivernames[] = {
139 static int attach_inform(struct i2c_client *client)
141 struct ivtv *itv = (struct ivtv *)i2c_get_adapdata(client->adapter);
144 IVTV_DEBUG_I2C("i2c client attach\n");
145 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
146 if (itv->i2c_clients[i] == NULL) {
147 itv->i2c_clients[i] = client;
151 if (i == I2C_CLIENTS_MAX) {
152 IVTV_ERR("Insufficient room for new I2C client\n");
157 static int detach_inform(struct i2c_client *client)
160 struct ivtv *itv = (struct ivtv *)i2c_get_adapdata(client->adapter);
162 IVTV_DEBUG_I2C("i2c client detach\n");
163 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
164 if (itv->i2c_clients[i] == client) {
165 itv->i2c_clients[i] = NULL;
169 IVTV_DEBUG_I2C("i2c detach [client=%s,%s]\n",
170 client->name, (i < I2C_CLIENTS_MAX) ? "ok" : "failed");
175 /* Set the serial clock line to the desired state */
176 static void ivtv_setscl(struct ivtv *itv, int state)
179 /* write bits are inverted */
180 write_reg(~state, IVTV_REG_I2C_SETSCL_OFFSET);
183 /* Set the serial data line to the desired state */
184 static void ivtv_setsda(struct ivtv *itv, int state)
187 /* write bits are inverted */
188 write_reg(~state & 1, IVTV_REG_I2C_SETSDA_OFFSET);
191 /* Read the serial clock line */
192 static int ivtv_getscl(struct ivtv *itv)
194 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
197 /* Read the serial data line */
198 static int ivtv_getsda(struct ivtv *itv)
200 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
203 /* Implement a short delay by polling the serial clock line */
204 static void ivtv_scldelay(struct ivtv *itv)
208 for (i = 0; i < 5; ++i)
212 /* Wait for the serial clock line to become set to a specific value */
213 static int ivtv_waitscl(struct ivtv *itv, int val)
218 for (i = 0; i < 1000; ++i) {
219 if (ivtv_getscl(itv) == val)
225 /* Wait for the serial data line to become set to a specific value */
226 static int ivtv_waitsda(struct ivtv *itv, int val)
231 for (i = 0; i < 1000; ++i) {
232 if (ivtv_getsda(itv) == val)
238 /* Wait for the slave to issue an ACK */
239 static int ivtv_ack(struct ivtv *itv)
243 if (ivtv_getscl(itv) == 1) {
244 IVTV_DEBUG_HI_I2C("SCL was high starting an ack\n");
246 if (!ivtv_waitscl(itv, 0)) {
247 IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
254 if (!ivtv_waitsda(itv, 0)) {
255 IVTV_DEBUG_I2C("Slave did not ack\n");
259 if (!ivtv_waitscl(itv, 0)) {
260 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
266 /* Write a single byte to the i2c bus and wait for the slave to ACK */
267 static int ivtv_sendbyte(struct ivtv *itv, unsigned char byte)
271 IVTV_DEBUG_HI_I2C("write %x\n",byte);
272 for (i = 0; i < 8; ++i, byte<<=1) {
274 if (!ivtv_waitscl(itv, 0)) {
275 IVTV_DEBUG_I2C("Error setting SCL low\n");
279 ivtv_setsda(itv, bit);
280 if (!ivtv_waitsda(itv, bit)) {
281 IVTV_DEBUG_I2C("Error setting SDA\n");
285 if (!ivtv_waitscl(itv, 1)) {
286 IVTV_DEBUG_I2C("Slave not ready for bit\n");
291 if (!ivtv_waitscl(itv, 0)) {
292 IVTV_DEBUG_I2C("Error setting SCL low\n");
295 return ivtv_ack(itv);
298 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
300 static int ivtv_readbyte(struct ivtv *itv, unsigned char *byte, int nack)
308 for (i = 0; i < 8; ++i) {
312 if (!ivtv_waitscl(itv, 1)) {
313 IVTV_DEBUG_I2C("Error setting SCL high\n");
316 *byte = ((*byte)<<1)|ivtv_getsda(itv);
320 ivtv_setsda(itv, nack);
326 IVTV_DEBUG_HI_I2C("read %x\n",*byte);
330 /* Issue a start condition on the i2c bus to alert slaves to prepare for
332 static int ivtv_start(struct ivtv *itv)
336 sda = ivtv_getsda(itv);
338 IVTV_DEBUG_HI_I2C("SDA was low at start\n");
340 if (!ivtv_waitsda(itv, 1)) {
341 IVTV_DEBUG_I2C("SDA stuck low\n");
345 if (ivtv_getscl(itv) != 1) {
347 if (!ivtv_waitscl(itv, 1)) {
348 IVTV_DEBUG_I2C("SCL stuck low at start\n");
357 /* Issue a stop condition on the i2c bus to release it */
358 static int ivtv_stop(struct ivtv *itv)
362 if (ivtv_getscl(itv) != 0) {
363 IVTV_DEBUG_HI_I2C("SCL not low when stopping\n");
365 if (!ivtv_waitscl(itv, 0)) {
366 IVTV_DEBUG_I2C("SCL could not be set low\n");
372 if (!ivtv_waitscl(itv, 1)) {
373 IVTV_DEBUG_I2C("SCL could not be set high\n");
378 if (!ivtv_waitsda(itv, 1)) {
379 IVTV_DEBUG_I2C("resetting I2C\n");
380 for (i = 0; i < 16; ++i) {
387 ivtv_waitsda(itv, 1);
393 /* Write a message to the given i2c slave. do_stop may be 0 to prevent
394 issuing the i2c stop condition (when following with a read) */
395 static int ivtv_write(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len, int do_stop)
397 int retry, ret = -EREMOTEIO;
400 for (retry = 0; ret != 0 && retry < 8; ++retry) {
401 ret = ivtv_start(itv);
404 ret = ivtv_sendbyte(itv, addr<<1);
405 for (i = 0; ret == 0 && i < len; ++i)
406 ret = ivtv_sendbyte(itv, data[i]);
408 if (ret != 0 || do_stop) {
413 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr);
417 /* Read data from the given i2c slave. A stop condition is always issued. */
418 static int ivtv_read(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len)
420 int retry, ret = -EREMOTEIO;
423 for (retry = 0; ret != 0 && retry < 8; ++retry) {
424 ret = ivtv_start(itv);
426 ret = ivtv_sendbyte(itv, (addr << 1) | 1);
427 for (i = 0; ret == 0 && i < len; ++i) {
428 ret = ivtv_readbyte(itv, &data[i], i == len - 1);
433 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr);
437 /* Kernel i2c transfer implementation. Takes a number of messages to be read
438 or written. If a read follows a write, this will occur without an
439 intervening stop condition */
440 static int ivtv_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
442 struct ivtv *itv = i2c_get_adapdata(i2c_adap);
446 mutex_lock(&itv->i2c_bus_lock);
447 for (i = retval = 0; retval == 0 && i < num; i++) {
448 if (msgs[i].flags & I2C_M_RD)
449 retval = ivtv_read(itv, msgs[i].addr, msgs[i].buf, msgs[i].len);
451 /* if followed by a read, don't stop */
452 int stop = !(i + 1 < num && msgs[i + 1].flags == I2C_M_RD);
454 retval = ivtv_write(itv, msgs[i].addr, msgs[i].buf, msgs[i].len, stop);
457 mutex_unlock(&itv->i2c_bus_lock);
458 return retval ? retval : num;
461 /* Kernel i2c capabilities */
462 static u32 ivtv_functionality(struct i2c_adapter *adap)
464 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
467 static struct i2c_algorithm ivtv_algo = {
468 .master_xfer = ivtv_xfer,
469 .functionality = ivtv_functionality,
472 /* template for our-bit banger */
473 static struct i2c_adapter ivtv_i2c_adap_hw_template = {
474 .name = "ivtv i2c driver",
475 .id = I2C_HW_B_CX2341X,
477 .algo_data = NULL, /* filled from template */
478 .client_register = attach_inform,
479 .client_unregister = detach_inform,
480 .owner = THIS_MODULE,
481 #ifdef I2C_ADAP_CLASS_TV_ANALOG
482 .class = I2C_ADAP_CLASS_TV_ANALOG,
486 static void ivtv_setscl_old(void *data, int state)
488 struct ivtv *itv = (struct ivtv *)data;
491 itv->i2c_state |= 0x01;
493 itv->i2c_state &= ~0x01;
496 /* write bits are inverted */
497 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSCL_OFFSET);
500 static void ivtv_setsda_old(void *data, int state)
502 struct ivtv *itv = (struct ivtv *)data;
505 itv->i2c_state |= 0x01;
507 itv->i2c_state &= ~0x01;
510 /* write bits are inverted */
511 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSDA_OFFSET);
514 static int ivtv_getscl_old(void *data)
516 struct ivtv *itv = (struct ivtv *)data;
518 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
521 static int ivtv_getsda_old(void *data)
523 struct ivtv *itv = (struct ivtv *)data;
525 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
528 /* template for i2c-bit-algo */
529 static struct i2c_adapter ivtv_i2c_adap_template = {
530 .name = "ivtv i2c driver",
531 .id = I2C_HW_B_CX2341X, /* algo-bit is OR'd with this */
532 .algo = NULL, /* set by i2c-algo-bit */
533 .algo_data = NULL, /* filled from template */
534 .client_register = attach_inform,
535 .client_unregister = detach_inform,
536 .owner = THIS_MODULE,
537 #ifdef I2C_ADAP_CLASS_TV_ANALOG
538 .class = I2C_ADAP_CLASS_TV_ANALOG,
542 static const struct i2c_algo_bit_data ivtv_i2c_algo_template = {
543 .setsda = ivtv_setsda_old,
544 .setscl = ivtv_setscl_old,
545 .getsda = ivtv_getsda_old,
546 .getscl = ivtv_getscl_old,
551 static struct i2c_client ivtv_i2c_client_template = {
552 .name = "ivtv internal",
555 int ivtv_call_i2c_client(struct ivtv *itv, int addr, unsigned int cmd, void *arg)
557 struct i2c_client *client;
561 IVTV_DEBUG_I2C("call_i2c_client addr=%02x\n", addr);
562 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
563 client = itv->i2c_clients[i];
564 if (client == NULL) {
567 if (client->driver->command == NULL) {
570 if (addr == client->addr) {
571 retval = client->driver->command(client, cmd, arg);
575 if (cmd != VIDIOC_G_CHIP_IDENT)
576 IVTV_ERR("i2c addr 0x%02x not found for command 0x%x\n", addr, cmd);
580 /* Find the i2c device based on the driver ID and return
581 its i2c address or -ENODEV if no matching device was found. */
582 static int ivtv_i2c_id_addr(struct ivtv *itv, u32 id)
584 struct i2c_client *client;
585 int retval = -ENODEV;
588 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
589 client = itv->i2c_clients[i];
592 if (id == client->driver->id) {
593 retval = client->addr;
600 /* Find the i2c device name matching the DRIVERID */
601 static const char *ivtv_i2c_id_name(u32 id)
605 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
606 if (hw_driverids[i] == id)
607 return hw_drivernames[i];
608 return "unknown device";
611 /* Find the i2c device name matching the IVTV_HW_ flag */
612 static const char *ivtv_i2c_hw_name(u32 hw)
616 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
618 return hw_drivernames[i];
619 return "unknown device";
622 /* Find the i2c device matching the IVTV_HW_ flag and return
623 its i2c address or -ENODEV if no matching device was found. */
624 int ivtv_i2c_hw_addr(struct ivtv *itv, u32 hw)
628 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
630 return ivtv_i2c_id_addr(itv, hw_driverids[i]);
634 /* Calls i2c device based on IVTV_HW_ flag. If hw == 0, then do nothing.
635 If hw == IVTV_HW_GPIO then call the gpio handler. */
636 int ivtv_i2c_hw(struct ivtv *itv, u32 hw, unsigned int cmd, void *arg)
640 if (hw == IVTV_HW_GPIO)
641 return ivtv_gpio(itv, cmd, arg);
645 addr = ivtv_i2c_hw_addr(itv, hw);
647 IVTV_ERR("i2c hardware 0x%08x (%s) not found for command 0x%x\n",
648 hw, ivtv_i2c_hw_name(hw), cmd);
651 return ivtv_call_i2c_client(itv, addr, cmd, arg);
654 /* Calls i2c device based on I2C driver ID. */
655 int ivtv_i2c_id(struct ivtv *itv, u32 id, unsigned int cmd, void *arg)
659 addr = ivtv_i2c_id_addr(itv, id);
661 if (cmd != VIDIOC_G_CHIP_IDENT)
662 IVTV_ERR("i2c ID 0x%08x (%s) not found for command 0x%x\n",
663 id, ivtv_i2c_id_name(id), cmd);
666 return ivtv_call_i2c_client(itv, addr, cmd, arg);
669 int ivtv_cx25840(struct ivtv *itv, unsigned int cmd, void *arg)
671 return ivtv_call_i2c_client(itv, IVTV_CX25840_I2C_ADDR, cmd, arg);
674 int ivtv_saa7115(struct ivtv *itv, unsigned int cmd, void *arg)
676 return ivtv_call_i2c_client(itv, IVTV_SAA7115_I2C_ADDR, cmd, arg);
679 int ivtv_saa7127(struct ivtv *itv, unsigned int cmd, void *arg)
681 return ivtv_call_i2c_client(itv, IVTV_SAA7127_I2C_ADDR, cmd, arg);
684 int ivtv_saa717x(struct ivtv *itv, unsigned int cmd, void *arg)
686 return ivtv_call_i2c_client(itv, IVTV_SAA717x_I2C_ADDR, cmd, arg);
689 int ivtv_upd64031a(struct ivtv *itv, unsigned int cmd, void *arg)
691 return ivtv_call_i2c_client(itv, IVTV_UPD64031A_I2C_ADDR, cmd, arg);
694 int ivtv_upd64083(struct ivtv *itv, unsigned int cmd, void *arg)
696 return ivtv_call_i2c_client(itv, IVTV_UPD64083_I2C_ADDR, cmd, arg);
699 /* broadcast cmd for all I2C clients and for the gpio subsystem */
700 void ivtv_call_i2c_clients(struct ivtv *itv, unsigned int cmd, void *arg)
702 if (itv->i2c_adap.algo == NULL) {
703 IVTV_ERR("Adapter is not set");
706 i2c_clients_command(&itv->i2c_adap, cmd, arg);
707 if (itv->hw_flags & IVTV_HW_GPIO)
708 ivtv_gpio(itv, cmd, arg);
711 /* init + register i2c algo-bit adapter */
712 int init_ivtv_i2c(struct ivtv *itv)
714 IVTV_DEBUG_I2C("i2c init\n");
716 if (itv->options.newi2c > 0) {
717 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_hw_template,
718 sizeof(struct i2c_adapter));
720 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_template,
721 sizeof(struct i2c_adapter));
722 memcpy(&itv->i2c_algo, &ivtv_i2c_algo_template,
723 sizeof(struct i2c_algo_bit_data));
724 itv->i2c_algo.data = itv;
725 itv->i2c_adap.algo_data = &itv->i2c_algo;
728 sprintf(itv->i2c_adap.name + strlen(itv->i2c_adap.name), " #%d",
730 i2c_set_adapdata(&itv->i2c_adap, itv);
732 memcpy(&itv->i2c_client, &ivtv_i2c_client_template,
733 sizeof(struct i2c_client));
734 itv->i2c_client.adapter = &itv->i2c_adap;
735 itv->i2c_adap.dev.parent = &itv->dev->dev;
737 IVTV_DEBUG_I2C("setting scl and sda to 1\n");
741 if (itv->options.newi2c > 0)
742 return i2c_add_adapter(&itv->i2c_adap);
744 return i2c_bit_add_bus(&itv->i2c_adap);
747 void exit_ivtv_i2c(struct ivtv *itv)
749 IVTV_DEBUG_I2C("i2c exit\n");
751 i2c_del_adapter(&itv->i2c_adap);