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_CX25840_I2C_ADDR 0x44
84 #define IVTV_SAA7115_I2C_ADDR 0x21
85 #define IVTV_SAA7127_I2C_ADDR 0x44
86 #define IVTV_SAA717x_I2C_ADDR 0x21
87 #define IVTV_MSP3400_I2C_ADDR 0x40
88 #define IVTV_HAUPPAUGE_I2C_ADDR 0x50
89 #define IVTV_WM8739_I2C_ADDR 0x1a
90 #define IVTV_WM8775_I2C_ADDR 0x1b
91 #define IVTV_TEA5767_I2C_ADDR 0x60
92 #define IVTV_UPD64031A_I2C_ADDR 0x12
93 #define IVTV_UPD64083_I2C_ADDR 0x5c
94 #define IVTV_TDA985X_I2C_ADDR 0x5b
96 /* This array should match the IVTV_HW_ defines */
97 static const u8 hw_driverids
[] = {
100 I2C_DRIVERID_SAA7127
,
101 I2C_DRIVERID_MSP3400
,
104 I2C_DRIVERID_CS53L32A
,
105 I2C_DRIVERID_TVEEPROM
,
106 I2C_DRIVERID_SAA711X
,
107 I2C_DRIVERID_TVAUDIO
,
108 I2C_DRIVERID_UPD64031A
,
109 I2C_DRIVERID_UPD64083
,
110 I2C_DRIVERID_SAA717X
,
112 I2C_DRIVERID_VP27SMPX
,
113 0 /* IVTV_HW_GPIO dummy driver ID */
116 /* This array should match the IVTV_HW_ defines */
117 static const char * const hw_drivernames
[] = {
136 static int attach_inform(struct i2c_client
*client
)
138 struct ivtv
*itv
= (struct ivtv
*)i2c_get_adapdata(client
->adapter
);
141 IVTV_DEBUG_I2C("i2c client attach\n");
142 for (i
= 0; i
< I2C_CLIENTS_MAX
; i
++) {
143 if (itv
->i2c_clients
[i
] == NULL
) {
144 itv
->i2c_clients
[i
] = client
;
148 if (i
== I2C_CLIENTS_MAX
) {
149 IVTV_ERR("Insufficient room for new I2C client\n");
154 static int detach_inform(struct i2c_client
*client
)
157 struct ivtv
*itv
= (struct ivtv
*)i2c_get_adapdata(client
->adapter
);
159 IVTV_DEBUG_I2C("i2c client detach\n");
160 for (i
= 0; i
< I2C_CLIENTS_MAX
; i
++) {
161 if (itv
->i2c_clients
[i
] == client
) {
162 itv
->i2c_clients
[i
] = NULL
;
166 IVTV_DEBUG_I2C("i2c detach [client=%s,%s]\n",
167 client
->name
, (i
< I2C_CLIENTS_MAX
) ? "ok" : "failed");
172 /* Set the serial clock line to the desired state */
173 static void ivtv_setscl(struct ivtv
*itv
, int state
)
176 /* write bits are inverted */
177 write_reg(~state
, IVTV_REG_I2C_SETSCL_OFFSET
);
180 /* Set the serial data line to the desired state */
181 static void ivtv_setsda(struct ivtv
*itv
, int state
)
184 /* write bits are inverted */
185 write_reg(~state
& 1, IVTV_REG_I2C_SETSDA_OFFSET
);
188 /* Read the serial clock line */
189 static int ivtv_getscl(struct ivtv
*itv
)
191 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET
) & 1;
194 /* Read the serial data line */
195 static int ivtv_getsda(struct ivtv
*itv
)
197 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET
) & 1;
200 /* Implement a short delay by polling the serial clock line */
201 static void ivtv_scldelay(struct ivtv
*itv
)
205 for (i
= 0; i
< 5; ++i
)
209 /* Wait for the serial clock line to become set to a specific value */
210 static int ivtv_waitscl(struct ivtv
*itv
, int val
)
215 for (i
= 0; i
< 1000; ++i
) {
216 if (ivtv_getscl(itv
) == val
)
222 /* Wait for the serial data line to become set to a specific value */
223 static int ivtv_waitsda(struct ivtv
*itv
, int val
)
228 for (i
= 0; i
< 1000; ++i
) {
229 if (ivtv_getsda(itv
) == val
)
235 /* Wait for the slave to issue an ACK */
236 static int ivtv_ack(struct ivtv
*itv
)
240 if (ivtv_getscl(itv
) == 1) {
241 IVTV_DEBUG_HI_I2C("SCL was high starting an ack\n");
243 if (!ivtv_waitscl(itv
, 0)) {
244 IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
251 if (!ivtv_waitsda(itv
, 0)) {
252 IVTV_DEBUG_I2C("Slave did not ack\n");
256 if (!ivtv_waitscl(itv
, 0)) {
257 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
263 /* Write a single byte to the i2c bus and wait for the slave to ACK */
264 static int ivtv_sendbyte(struct ivtv
*itv
, unsigned char byte
)
268 IVTV_DEBUG_HI_I2C("write %x\n",byte
);
269 for (i
= 0; i
< 8; ++i
, byte
<<=1) {
271 if (!ivtv_waitscl(itv
, 0)) {
272 IVTV_DEBUG_I2C("Error setting SCL low\n");
276 ivtv_setsda(itv
, bit
);
277 if (!ivtv_waitsda(itv
, bit
)) {
278 IVTV_DEBUG_I2C("Error setting SDA\n");
282 if (!ivtv_waitscl(itv
, 1)) {
283 IVTV_DEBUG_I2C("Slave not ready for bit\n");
288 if (!ivtv_waitscl(itv
, 0)) {
289 IVTV_DEBUG_I2C("Error setting SCL low\n");
292 return ivtv_ack(itv
);
295 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
297 static int ivtv_readbyte(struct ivtv
*itv
, unsigned char *byte
, int nack
)
305 for (i
= 0; i
< 8; ++i
) {
309 if (!ivtv_waitscl(itv
, 1)) {
310 IVTV_DEBUG_I2C("Error setting SCL high\n");
313 *byte
= ((*byte
)<<1)|ivtv_getsda(itv
);
317 ivtv_setsda(itv
, nack
);
323 IVTV_DEBUG_HI_I2C("read %x\n",*byte
);
327 /* Issue a start condition on the i2c bus to alert slaves to prepare for
329 static int ivtv_start(struct ivtv
*itv
)
333 sda
= ivtv_getsda(itv
);
335 IVTV_DEBUG_HI_I2C("SDA was low at start\n");
337 if (!ivtv_waitsda(itv
, 1)) {
338 IVTV_DEBUG_I2C("SDA stuck low\n");
342 if (ivtv_getscl(itv
) != 1) {
344 if (!ivtv_waitscl(itv
, 1)) {
345 IVTV_DEBUG_I2C("SCL stuck low at start\n");
354 /* Issue a stop condition on the i2c bus to release it */
355 static int ivtv_stop(struct ivtv
*itv
)
359 if (ivtv_getscl(itv
) != 0) {
360 IVTV_DEBUG_HI_I2C("SCL not low when stopping\n");
362 if (!ivtv_waitscl(itv
, 0)) {
363 IVTV_DEBUG_I2C("SCL could not be set low\n");
369 if (!ivtv_waitscl(itv
, 1)) {
370 IVTV_DEBUG_I2C("SCL could not be set high\n");
375 if (!ivtv_waitsda(itv
, 1)) {
376 IVTV_DEBUG_I2C("resetting I2C\n");
377 for (i
= 0; i
< 16; ++i
) {
384 ivtv_waitsda(itv
, 1);
390 /* Write a message to the given i2c slave. do_stop may be 0 to prevent
391 issuing the i2c stop condition (when following with a read) */
392 static int ivtv_write(struct ivtv
*itv
, unsigned char addr
, unsigned char *data
, u32 len
, int do_stop
)
394 int retry
, ret
= -EREMOTEIO
;
397 for (retry
= 0; ret
!= 0 && retry
< 8; ++retry
) {
398 ret
= ivtv_start(itv
);
401 ret
= ivtv_sendbyte(itv
, addr
<<1);
402 for (i
= 0; ret
== 0 && i
< len
; ++i
)
403 ret
= ivtv_sendbyte(itv
, data
[i
]);
405 if (ret
!= 0 || do_stop
) {
410 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr
);
414 /* Read data from the given i2c slave. A stop condition is always issued. */
415 static int ivtv_read(struct ivtv
*itv
, unsigned char addr
, unsigned char *data
, u32 len
)
417 int retry
, ret
= -EREMOTEIO
;
420 for (retry
= 0; ret
!= 0 && retry
< 8; ++retry
) {
421 ret
= ivtv_start(itv
);
423 ret
= ivtv_sendbyte(itv
, (addr
<< 1) | 1);
424 for (i
= 0; ret
== 0 && i
< len
; ++i
) {
425 ret
= ivtv_readbyte(itv
, &data
[i
], i
== len
- 1);
430 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr
);
434 /* Kernel i2c transfer implementation. Takes a number of messages to be read
435 or written. If a read follows a write, this will occur without an
436 intervening stop condition */
437 static int ivtv_xfer(struct i2c_adapter
*i2c_adap
, struct i2c_msg
*msgs
, int num
)
439 struct ivtv
*itv
= i2c_get_adapdata(i2c_adap
);
443 mutex_lock(&itv
->i2c_bus_lock
);
444 for (i
= retval
= 0; retval
== 0 && i
< num
; i
++) {
445 if (msgs
[i
].flags
& I2C_M_RD
)
446 retval
= ivtv_read(itv
, msgs
[i
].addr
, msgs
[i
].buf
, msgs
[i
].len
);
448 /* if followed by a read, don't stop */
449 int stop
= !(i
+ 1 < num
&& msgs
[i
+ 1].flags
== I2C_M_RD
);
451 retval
= ivtv_write(itv
, msgs
[i
].addr
, msgs
[i
].buf
, msgs
[i
].len
, stop
);
454 mutex_unlock(&itv
->i2c_bus_lock
);
455 return retval
? retval
: num
;
458 /* Kernel i2c capabilities */
459 static u32
ivtv_functionality(struct i2c_adapter
*adap
)
461 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
;
464 static struct i2c_algorithm ivtv_algo
= {
465 .master_xfer
= ivtv_xfer
,
466 .functionality
= ivtv_functionality
,
469 /* template for our-bit banger */
470 static struct i2c_adapter ivtv_i2c_adap_hw_template
= {
471 .name
= "ivtv i2c driver",
472 .id
= I2C_HW_B_CX2341X
,
474 .algo_data
= NULL
, /* filled from template */
475 .client_register
= attach_inform
,
476 .client_unregister
= detach_inform
,
477 .owner
= THIS_MODULE
,
478 #ifdef I2C_ADAP_CLASS_TV_ANALOG
479 .class = I2C_ADAP_CLASS_TV_ANALOG
,
483 static void ivtv_setscl_old(void *data
, int state
)
485 struct ivtv
*itv
= (struct ivtv
*)data
;
488 itv
->i2c_state
|= 0x01;
490 itv
->i2c_state
&= ~0x01;
493 /* write bits are inverted */
494 write_reg(~itv
->i2c_state
, IVTV_REG_I2C_SETSCL_OFFSET
);
497 static void ivtv_setsda_old(void *data
, int state
)
499 struct ivtv
*itv
= (struct ivtv
*)data
;
502 itv
->i2c_state
|= 0x01;
504 itv
->i2c_state
&= ~0x01;
507 /* write bits are inverted */
508 write_reg(~itv
->i2c_state
, IVTV_REG_I2C_SETSDA_OFFSET
);
511 static int ivtv_getscl_old(void *data
)
513 struct ivtv
*itv
= (struct ivtv
*)data
;
515 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET
) & 1;
518 static int ivtv_getsda_old(void *data
)
520 struct ivtv
*itv
= (struct ivtv
*)data
;
522 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET
) & 1;
525 /* template for i2c-bit-algo */
526 static struct i2c_adapter ivtv_i2c_adap_template
= {
527 .name
= "ivtv i2c driver",
528 .id
= I2C_HW_B_CX2341X
, /* algo-bit is OR'd with this */
529 .algo
= NULL
, /* set by i2c-algo-bit */
530 .algo_data
= NULL
, /* filled from template */
531 .client_register
= attach_inform
,
532 .client_unregister
= detach_inform
,
533 .owner
= THIS_MODULE
,
534 #ifdef I2C_ADAP_CLASS_TV_ANALOG
535 .class = I2C_ADAP_CLASS_TV_ANALOG
,
539 static struct i2c_algo_bit_data ivtv_i2c_algo_template
= {
541 ivtv_setsda_old
, /* setsda function */
542 ivtv_setscl_old
, /* " */
543 ivtv_getsda_old
, /* " */
544 ivtv_getscl_old
, /* " */
549 static struct i2c_client ivtv_i2c_client_template
= {
550 .name
= "ivtv internal",
553 int ivtv_call_i2c_client(struct ivtv
*itv
, int addr
, unsigned int cmd
, void *arg
)
555 struct i2c_client
*client
;
559 IVTV_DEBUG_I2C("call_i2c_client addr=%02x\n", addr
);
560 for (i
= 0; i
< I2C_CLIENTS_MAX
; i
++) {
561 client
= itv
->i2c_clients
[i
];
562 if (client
== NULL
) {
565 if (client
->driver
->command
== NULL
) {
568 if (addr
== client
->addr
) {
569 retval
= client
->driver
->command(client
, cmd
, arg
);
573 if (cmd
!= VIDIOC_G_CHIP_IDENT
)
574 IVTV_ERR("i2c addr 0x%02x not found for command 0x%x\n", addr
, cmd
);
578 /* Find the i2c device based on the driver ID and return
579 its i2c address or -ENODEV if no matching device was found. */
580 static int ivtv_i2c_id_addr(struct ivtv
*itv
, u32 id
)
582 struct i2c_client
*client
;
583 int retval
= -ENODEV
;
586 for (i
= 0; i
< I2C_CLIENTS_MAX
; i
++) {
587 client
= itv
->i2c_clients
[i
];
590 if (id
== client
->driver
->id
) {
591 retval
= client
->addr
;
598 /* Find the i2c device name matching the DRIVERID */
599 static const char *ivtv_i2c_id_name(u32 id
)
603 for (i
= 0; i
< ARRAY_SIZE(hw_driverids
); i
++)
604 if (hw_driverids
[i
] == id
)
605 return hw_drivernames
[i
];
606 return "unknown device";
609 /* Find the i2c device name matching the IVTV_HW_ flag */
610 static const char *ivtv_i2c_hw_name(u32 hw
)
614 for (i
= 0; i
< ARRAY_SIZE(hw_driverids
); i
++)
616 return hw_drivernames
[i
];
617 return "unknown device";
620 /* Find the i2c device matching the IVTV_HW_ flag and return
621 its i2c address or -ENODEV if no matching device was found. */
622 int ivtv_i2c_hw_addr(struct ivtv
*itv
, u32 hw
)
626 for (i
= 0; i
< ARRAY_SIZE(hw_driverids
); i
++)
628 return ivtv_i2c_id_addr(itv
, hw_driverids
[i
]);
632 /* Calls i2c device based on IVTV_HW_ flag. If hw == 0, then do nothing.
633 If hw == IVTV_HW_GPIO then call the gpio handler. */
634 int ivtv_i2c_hw(struct ivtv
*itv
, u32 hw
, unsigned int cmd
, void *arg
)
638 if (hw
== IVTV_HW_GPIO
)
639 return ivtv_gpio(itv
, cmd
, arg
);
643 addr
= ivtv_i2c_hw_addr(itv
, hw
);
645 IVTV_ERR("i2c hardware 0x%08x (%s) not found for command 0x%x\n",
646 hw
, ivtv_i2c_hw_name(hw
), cmd
);
649 return ivtv_call_i2c_client(itv
, addr
, cmd
, arg
);
652 /* Calls i2c device based on I2C driver ID. */
653 int ivtv_i2c_id(struct ivtv
*itv
, u32 id
, unsigned int cmd
, void *arg
)
657 addr
= ivtv_i2c_id_addr(itv
, id
);
659 if (cmd
!= VIDIOC_G_CHIP_IDENT
)
660 IVTV_ERR("i2c ID 0x%08x (%s) not found for command 0x%x\n",
661 id
, ivtv_i2c_id_name(id
), cmd
);
664 return ivtv_call_i2c_client(itv
, addr
, cmd
, arg
);
667 int ivtv_cx25840(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
669 return ivtv_call_i2c_client(itv
, IVTV_CX25840_I2C_ADDR
, cmd
, arg
);
672 int ivtv_saa7115(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
674 return ivtv_call_i2c_client(itv
, IVTV_SAA7115_I2C_ADDR
, cmd
, arg
);
677 int ivtv_saa7127(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
679 return ivtv_call_i2c_client(itv
, IVTV_SAA7127_I2C_ADDR
, cmd
, arg
);
682 int ivtv_saa717x(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
684 return ivtv_call_i2c_client(itv
, IVTV_SAA717x_I2C_ADDR
, cmd
, arg
);
687 int ivtv_upd64031a(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
689 return ivtv_call_i2c_client(itv
, IVTV_UPD64031A_I2C_ADDR
, cmd
, arg
);
692 int ivtv_upd64083(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
694 return ivtv_call_i2c_client(itv
, IVTV_UPD64083_I2C_ADDR
, cmd
, arg
);
697 /* broadcast cmd for all I2C clients and for the gpio subsystem */
698 void ivtv_call_i2c_clients(struct ivtv
*itv
, unsigned int cmd
, void *arg
)
700 if (itv
->i2c_adap
.algo
== NULL
) {
701 IVTV_ERR("Adapter is not set");
704 i2c_clients_command(&itv
->i2c_adap
, cmd
, arg
);
705 if (itv
->hw_flags
& IVTV_HW_GPIO
)
706 ivtv_gpio(itv
, cmd
, arg
);
709 /* init + register i2c algo-bit adapter */
710 int __devinit
init_ivtv_i2c(struct ivtv
*itv
)
712 IVTV_DEBUG_I2C("i2c init\n");
714 if (itv
->options
.newi2c
> 0) {
715 memcpy(&itv
->i2c_adap
, &ivtv_i2c_adap_hw_template
,
716 sizeof(struct i2c_adapter
));
718 memcpy(&itv
->i2c_adap
, &ivtv_i2c_adap_template
,
719 sizeof(struct i2c_adapter
));
720 memcpy(&itv
->i2c_algo
, &ivtv_i2c_algo_template
,
721 sizeof(struct i2c_algo_bit_data
));
722 itv
->i2c_algo
.data
= itv
;
723 itv
->i2c_adap
.algo_data
= &itv
->i2c_algo
;
726 sprintf(itv
->i2c_adap
.name
+ strlen(itv
->i2c_adap
.name
), " #%d",
728 i2c_set_adapdata(&itv
->i2c_adap
, itv
);
730 memcpy(&itv
->i2c_client
, &ivtv_i2c_client_template
,
731 sizeof(struct i2c_client
));
732 itv
->i2c_client
.adapter
= &itv
->i2c_adap
;
733 itv
->i2c_adap
.dev
.parent
= &itv
->dev
->dev
;
735 IVTV_DEBUG_I2C("setting scl and sda to 1\n");
739 if (itv
->options
.newi2c
> 0)
740 return i2c_add_adapter(&itv
->i2c_adap
);
742 return i2c_bit_add_bus(&itv
->i2c_adap
);
745 void __devexit
exit_ivtv_i2c(struct ivtv
*itv
)
747 IVTV_DEBUG_I2C("i2c exit\n");
749 i2c_del_adapter(&itv
->i2c_adap
);