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/ir-kbd-i2c.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 #ifndef I2C_ADAP_CLASS_TV_ANALOG
78 #define I2C_ADAP_CLASS_TV_ANALOG I2C_CLASS_TV_ANALOG
79 #endif /* I2C_ADAP_CLASS_TV_ANALOG */
81 #define IVTV_CS53L32A_I2C_ADDR 0x11
82 #define IVTV_CX25840_I2C_ADDR 0x44
83 #define IVTV_SAA7115_I2C_ADDR 0x21
84 #define IVTV_SAA7127_I2C_ADDR 0x44
85 #define IVTV_SAA717x_I2C_ADDR 0x21
86 #define IVTV_MSP3400_I2C_ADDR 0x40
87 #define IVTV_HAUPPAUGE_I2C_ADDR 0x50
88 #define IVTV_WM8739_I2C_ADDR 0x1a
89 #define IVTV_WM8775_I2C_ADDR 0x1b
90 #define IVTV_TEA5767_I2C_ADDR 0x60
91 #define IVTV_UPD64031A_I2C_ADDR 0x12
92 #define IVTV_UPD64083_I2C_ADDR 0x5c
93 #define IVTV_TDA985X_I2C_ADDR 0x5b
95 /* This array should match the IVTV_HW_ defines */
96 static const u8 hw_driverids[] = {
100 I2C_DRIVERID_MSP3400,
103 I2C_DRIVERID_CS53L32A,
104 I2C_DRIVERID_TVEEPROM,
105 I2C_DRIVERID_SAA711X,
106 I2C_DRIVERID_TVAUDIO,
107 I2C_DRIVERID_UPD64031A,
108 I2C_DRIVERID_UPD64083,
109 I2C_DRIVERID_SAA717X,
111 0 /* IVTV_HW_GPIO dummy driver ID */
114 /* This array should match the IVTV_HW_ defines */
115 static const char * const hw_drivernames[] = {
133 static int attach_inform(struct i2c_client *client)
135 struct ivtv *itv = (struct ivtv *)i2c_get_adapdata(client->adapter);
138 IVTV_DEBUG_I2C("i2c client attach\n");
139 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
140 if (itv->i2c_clients[i] == NULL) {
141 itv->i2c_clients[i] = client;
145 if (i == I2C_CLIENTS_MAX) {
146 IVTV_ERR("insufficient room for new I2C client!\n");
151 static int detach_inform(struct i2c_client *client)
154 struct ivtv *itv = (struct ivtv *)i2c_get_adapdata(client->adapter);
156 IVTV_DEBUG_I2C("i2c client detach\n");
157 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
158 if (itv->i2c_clients[i] == client) {
159 itv->i2c_clients[i] = NULL;
163 IVTV_DEBUG_I2C("i2c detach [client=%s,%s]\n",
164 client->name, (i < I2C_CLIENTS_MAX) ? "ok" : "failed");
169 /* Set the serial clock line to the desired state */
170 static void ivtv_setscl(struct ivtv *itv, int state)
173 /* write bits are inverted */
174 write_reg(~state, IVTV_REG_I2C_SETSCL_OFFSET);
177 /* Set the serial data line to the desired state */
178 static void ivtv_setsda(struct ivtv *itv, int state)
181 /* write bits are inverted */
182 write_reg(~state & 1, IVTV_REG_I2C_SETSDA_OFFSET);
185 /* Read the serial clock line */
186 static int ivtv_getscl(struct ivtv *itv)
188 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
191 /* Read the serial data line */
192 static int ivtv_getsda(struct ivtv *itv)
194 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
197 /* Implement a short delay by polling the serial clock line */
198 static void ivtv_scldelay(struct ivtv *itv)
202 for (i = 0; i < 5; ++i)
206 /* Wait for the serial clock line to become set to a specific value */
207 static int ivtv_waitscl(struct ivtv *itv, int val)
212 for (i = 0; i < 1000; ++i) {
213 if (ivtv_getscl(itv) == val)
219 /* Wait for the serial data line to become set to a specific value */
220 static int ivtv_waitsda(struct ivtv *itv, int val)
225 for (i = 0; i < 1000; ++i) {
226 if (ivtv_getsda(itv) == val)
232 /* Wait for the slave to issue an ACK */
233 static int ivtv_ack(struct ivtv *itv)
237 if (ivtv_getscl(itv) == 1) {
238 IVTV_DEBUG_I2C("SCL was high starting an ack\n");
240 if (!ivtv_waitscl(itv, 0)) {
241 IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
248 if (!ivtv_waitsda(itv, 0)) {
249 IVTV_DEBUG_I2C("Slave did not ack\n");
253 if (!ivtv_waitscl(itv, 0)) {
254 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
260 /* Write a single byte to the i2c bus and wait for the slave to ACK */
261 static int ivtv_sendbyte(struct ivtv *itv, unsigned char byte)
265 IVTV_DEBUG_I2C("write %x\n",byte);
266 for (i = 0; i < 8; ++i, byte<<=1) {
268 if (!ivtv_waitscl(itv, 0)) {
269 IVTV_DEBUG_I2C("Error setting SCL low\n");
273 ivtv_setsda(itv, bit);
274 if (!ivtv_waitsda(itv, bit)) {
275 IVTV_DEBUG_I2C("Error setting SDA\n");
279 if (!ivtv_waitscl(itv, 1)) {
280 IVTV_DEBUG_I2C("Slave not ready for bit\n");
285 if (!ivtv_waitscl(itv, 0)) {
286 IVTV_DEBUG_I2C("Error setting SCL low\n");
289 return ivtv_ack(itv);
292 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
294 static int ivtv_readbyte(struct ivtv *itv, unsigned char *byte, int nack)
302 for (i = 0; i < 8; ++i) {
306 if (!ivtv_waitscl(itv, 1)) {
307 IVTV_DEBUG_I2C("Error setting SCL high\n");
310 *byte = ((*byte)<<1)|ivtv_getsda(itv);
314 ivtv_setsda(itv, nack);
320 IVTV_DEBUG_I2C("read %x\n",*byte);
324 /* Issue a start condition on the i2c bus to alert slaves to prepare for
326 static int ivtv_start(struct ivtv *itv)
330 sda = ivtv_getsda(itv);
332 IVTV_DEBUG_I2C("SDA was low at start\n");
334 if (!ivtv_waitsda(itv, 1)) {
335 IVTV_DEBUG_I2C("SDA stuck low\n");
339 if (ivtv_getscl(itv) != 1) {
341 if (!ivtv_waitscl(itv, 1)) {
342 IVTV_DEBUG_I2C("SCL stuck low at start\n");
351 /* Issue a stop condition on the i2c bus to release it */
352 static int ivtv_stop(struct ivtv *itv)
356 if (ivtv_getscl(itv) != 0) {
357 IVTV_DEBUG_I2C("SCL not low when stopping\n");
359 if (!ivtv_waitscl(itv, 0)) {
360 IVTV_DEBUG_I2C("SCL could not be set low\n");
366 if (!ivtv_waitscl(itv, 1)) {
367 IVTV_DEBUG_I2C("SCL could not be set high\n");
372 if (!ivtv_waitsda(itv, 1)) {
373 IVTV_DEBUG_I2C("resetting I2C\n");
374 for (i = 0; i < 16; ++i) {
381 ivtv_waitsda(itv, 1);
387 /* Write a message to the given i2c slave. do_stop may be 0 to prevent
388 issuing the i2c stop condition (when following with a read) */
389 static int ivtv_write(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len, int do_stop)
391 int retry, ret = -EREMOTEIO;
394 for (retry = 0; ret != 0 && retry < 8; ++retry) {
395 ret = ivtv_start(itv);
398 ret = ivtv_sendbyte(itv, addr<<1);
399 for (i = 0; ret == 0 && i < len; ++i)
400 ret = ivtv_sendbyte(itv, data[i]);
402 if (ret != 0 || do_stop) {
407 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr);
411 /* Read data from the given i2c slave. A stop condition is always issued. */
412 static int ivtv_read(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len)
414 int retry, ret = -EREMOTEIO;
417 for (retry = 0; ret != 0 && retry < 8; ++retry) {
418 ret = ivtv_start(itv);
420 ret = ivtv_sendbyte(itv, (addr << 1) | 1);
421 for (i = 0; ret == 0 && i < len; ++i) {
422 ret = ivtv_readbyte(itv, &data[i], i == len - 1);
427 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr);
431 /* Kernel i2c transfer implementation. Takes a number of messages to be read
432 or written. If a read follows a write, this will occur without an
433 intervening stop condition */
434 static int ivtv_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
436 struct ivtv *itv = i2c_get_adapdata(i2c_adap);
440 mutex_lock(&itv->i2c_bus_lock);
441 for (i = retval = 0; retval == 0 && i < num; i++) {
442 if (msgs[i].flags & I2C_M_RD)
443 retval = ivtv_read(itv, msgs[i].addr, msgs[i].buf, msgs[i].len);
445 /* if followed by a read, don't stop */
446 int stop = !(i + 1 < num && msgs[i + 1].flags == I2C_M_RD);
448 retval = ivtv_write(itv, msgs[i].addr, msgs[i].buf, msgs[i].len, stop);
451 mutex_unlock(&itv->i2c_bus_lock);
452 return retval ? retval : num;
455 /* Kernel i2c capabilities */
456 static u32 ivtv_functionality(struct i2c_adapter *adap)
458 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
461 static struct i2c_algorithm ivtv_algo = {
462 .master_xfer = ivtv_xfer,
463 .functionality = ivtv_functionality,
466 /* template for our-bit banger */
467 static struct i2c_adapter ivtv_i2c_adap_hw_template = {
468 .name = "ivtv i2c driver",
469 .id = I2C_HW_B_CX2341X,
471 .algo_data = NULL, /* filled from template */
472 .client_register = attach_inform,
473 .client_unregister = detach_inform,
474 .owner = THIS_MODULE,
475 #ifdef I2C_ADAP_CLASS_TV_ANALOG
476 .class = I2C_ADAP_CLASS_TV_ANALOG,
480 static void ivtv_setscl_old(void *data, int state)
482 struct ivtv *itv = (struct ivtv *)data;
485 itv->i2c_state |= 0x01;
487 itv->i2c_state &= ~0x01;
490 /* write bits are inverted */
491 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSCL_OFFSET);
494 static void ivtv_setsda_old(void *data, int state)
496 struct ivtv *itv = (struct ivtv *)data;
499 itv->i2c_state |= 0x01;
501 itv->i2c_state &= ~0x01;
504 /* write bits are inverted */
505 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSDA_OFFSET);
508 static int ivtv_getscl_old(void *data)
510 struct ivtv *itv = (struct ivtv *)data;
512 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
515 static int ivtv_getsda_old(void *data)
517 struct ivtv *itv = (struct ivtv *)data;
519 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
522 /* template for i2c-bit-algo */
523 static struct i2c_adapter ivtv_i2c_adap_template = {
524 .name = "ivtv i2c driver",
525 .id = I2C_HW_B_CX2341X, /* algo-bit is OR'd with this */
526 .algo = NULL, /* set by i2c-algo-bit */
527 .algo_data = NULL, /* filled from template */
528 .client_register = attach_inform,
529 .client_unregister = detach_inform,
530 .owner = THIS_MODULE,
531 #ifdef I2C_ADAP_CLASS_TV_ANALOG
532 .class = I2C_ADAP_CLASS_TV_ANALOG,
536 static struct i2c_algo_bit_data ivtv_i2c_algo_template = {
538 ivtv_setsda_old, /* setsda function */
539 ivtv_setscl_old, /* " */
540 ivtv_getsda_old, /* " */
541 ivtv_getscl_old, /* " */
546 static struct i2c_client ivtv_i2c_client_template = {
547 .name = "ivtv internal use only",
550 int ivtv_call_i2c_client(struct ivtv *itv, int addr, unsigned int cmd, void *arg)
552 struct i2c_client *client;
556 IVTV_DEBUG_I2C("call_i2c_client addr=%02x\n", addr);
557 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
558 client = itv->i2c_clients[i];
559 if (client == NULL) {
562 if (client->driver->command == NULL) {
565 if (addr == client->addr) {
566 retval = client->driver->command(client, cmd, arg);
570 if (cmd != VIDIOC_G_CHIP_IDENT)
571 IVTV_ERR("i2c addr 0x%02x not found for command 0x%x!\n", addr, cmd);
575 /* Find the i2c device based on the driver ID and return
576 its i2c address or -ENODEV if no matching device was found. */
577 int ivtv_i2c_id_addr(struct ivtv *itv, u32 id)
579 struct i2c_client *client;
580 int retval = -ENODEV;
583 for (i = 0; i < I2C_CLIENTS_MAX; i++) {
584 client = itv->i2c_clients[i];
587 if (id == client->driver->id) {
588 retval = client->addr;
595 /* Find the i2c device name matching the DRIVERID */
596 static const char *ivtv_i2c_id_name(u32 id)
600 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
601 if (hw_driverids[i] == id)
602 return hw_drivernames[i];
603 return "unknown device";
606 /* Find the i2c device name matching the IVTV_HW_ flag */
607 static const char *ivtv_i2c_hw_name(u32 hw)
611 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
613 return hw_drivernames[i];
614 return "unknown device";
617 /* Find the i2c device matching the IVTV_HW_ flag and return
618 its i2c address or -ENODEV if no matching device was found. */
619 int ivtv_i2c_hw_addr(struct ivtv *itv, u32 hw)
623 for (i = 0; i < ARRAY_SIZE(hw_driverids); i++)
625 return ivtv_i2c_id_addr(itv, hw_driverids[i]);
629 /* Calls i2c device based on IVTV_HW_ flag. If hw == 0, then do nothing.
630 If hw == IVTV_HW_GPIO then call the gpio handler. */
631 int ivtv_i2c_hw(struct ivtv *itv, u32 hw, unsigned int cmd, void *arg)
635 if (hw == IVTV_HW_GPIO)
636 return ivtv_gpio(itv, cmd, arg);
640 addr = ivtv_i2c_hw_addr(itv, hw);
642 IVTV_ERR("i2c hardware 0x%08x (%s) not found for command 0x%x!\n",
643 hw, ivtv_i2c_hw_name(hw), cmd);
646 return ivtv_call_i2c_client(itv, addr, cmd, arg);
649 /* Calls i2c device based on I2C driver ID. */
650 int ivtv_i2c_id(struct ivtv *itv, u32 id, unsigned int cmd, void *arg)
654 addr = ivtv_i2c_id_addr(itv, id);
656 if (cmd != VIDIOC_G_CHIP_IDENT)
657 IVTV_ERR("i2c ID 0x%08x (%s) not found for command 0x%x!\n",
658 id, ivtv_i2c_id_name(id), cmd);
661 return ivtv_call_i2c_client(itv, addr, cmd, arg);
664 int ivtv_cx25840(struct ivtv *itv, unsigned int cmd, void *arg)
666 return ivtv_call_i2c_client(itv, IVTV_CX25840_I2C_ADDR, cmd, arg);
669 int ivtv_saa7115(struct ivtv *itv, unsigned int cmd, void *arg)
671 return ivtv_call_i2c_client(itv, IVTV_SAA7115_I2C_ADDR, cmd, arg);
674 int ivtv_saa7127(struct ivtv *itv, unsigned int cmd, void *arg)
676 return ivtv_call_i2c_client(itv, IVTV_SAA7127_I2C_ADDR, cmd, arg);
679 int ivtv_saa717x(struct ivtv *itv, unsigned int cmd, void *arg)
681 return ivtv_call_i2c_client(itv, IVTV_SAA717x_I2C_ADDR, cmd, arg);
684 int ivtv_msp34xx(struct ivtv *itv, unsigned int cmd, void *arg)
686 return ivtv_call_i2c_client(itv, IVTV_MSP3400_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 __devinit 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 __devexit exit_ivtv_i2c(struct ivtv *itv)
749 IVTV_DEBUG_I2C("i2c exit\n");
751 i2c_del_adapter(&itv->i2c_adap);