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,
244 0, itv->card_i2c->radio);
246 sd->grp_id = 1 << idx;
247 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
249 0, itv->card_i2c->demod);
251 sd->grp_id = 1 << idx;
252 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
254 0, itv->card_i2c->tv);
256 sd->grp_id = 1 << idx;
260 if (hw & IVTV_HW_IR_ANY)
261 return ivtv_i2c_new_ir(itv, hw, type, hw_addrs[idx]);
263 /* Is it not an I2C device or one we do not wish to register? */
267 /* It's an I2C device other than an analog tuner or IR chip */
268 if (hw == IVTV_HW_UPD64031A || hw == IVTV_HW_UPD6408X) {
269 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
270 adap, NULL, type, 0, I2C_ADDRS(hw_addrs[idx]));
271 } else if (hw == IVTV_HW_CX25840) {
272 struct cx25840_platform_data pdata;
274 pdata.pvr150_workaround = itv->pvr150_workaround;
275 sd = v4l2_i2c_new_subdev_cfg(&itv->v4l2_dev,
276 adap, NULL, type, 0, &pdata, hw_addrs[idx],
279 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
280 adap, NULL, type, hw_addrs[idx], NULL);
283 sd->grp_id = 1 << idx;
287 struct v4l2_subdev *ivtv_find_hw(struct ivtv *itv, u32 hw)
289 struct v4l2_subdev *result = NULL;
290 struct v4l2_subdev *sd;
292 spin_lock(&itv->v4l2_dev.lock);
293 v4l2_device_for_each_subdev(sd, &itv->v4l2_dev) {
294 if (sd->grp_id == hw) {
299 spin_unlock(&itv->v4l2_dev.lock);
303 /* Set the serial clock line to the desired state */
304 static void ivtv_setscl(struct ivtv *itv, int state)
307 /* write bits are inverted */
308 write_reg(~state, IVTV_REG_I2C_SETSCL_OFFSET);
311 /* Set the serial data line to the desired state */
312 static void ivtv_setsda(struct ivtv *itv, int state)
315 /* write bits are inverted */
316 write_reg(~state & 1, IVTV_REG_I2C_SETSDA_OFFSET);
319 /* Read the serial clock line */
320 static int ivtv_getscl(struct ivtv *itv)
322 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
325 /* Read the serial data line */
326 static int ivtv_getsda(struct ivtv *itv)
328 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
331 /* Implement a short delay by polling the serial clock line */
332 static void ivtv_scldelay(struct ivtv *itv)
336 for (i = 0; i < 5; ++i)
340 /* Wait for the serial clock line to become set to a specific value */
341 static int ivtv_waitscl(struct ivtv *itv, int val)
346 for (i = 0; i < 1000; ++i) {
347 if (ivtv_getscl(itv) == val)
353 /* Wait for the serial data line to become set to a specific value */
354 static int ivtv_waitsda(struct ivtv *itv, int val)
359 for (i = 0; i < 1000; ++i) {
360 if (ivtv_getsda(itv) == val)
366 /* Wait for the slave to issue an ACK */
367 static int ivtv_ack(struct ivtv *itv)
371 if (ivtv_getscl(itv) == 1) {
372 IVTV_DEBUG_HI_I2C("SCL was high starting an ack\n");
374 if (!ivtv_waitscl(itv, 0)) {
375 IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
382 if (!ivtv_waitsda(itv, 0)) {
383 IVTV_DEBUG_I2C("Slave did not ack\n");
387 if (!ivtv_waitscl(itv, 0)) {
388 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
394 /* Write a single byte to the i2c bus and wait for the slave to ACK */
395 static int ivtv_sendbyte(struct ivtv *itv, unsigned char byte)
399 IVTV_DEBUG_HI_I2C("write %x\n",byte);
400 for (i = 0; i < 8; ++i, byte<<=1) {
402 if (!ivtv_waitscl(itv, 0)) {
403 IVTV_DEBUG_I2C("Error setting SCL low\n");
407 ivtv_setsda(itv, bit);
408 if (!ivtv_waitsda(itv, bit)) {
409 IVTV_DEBUG_I2C("Error setting SDA\n");
413 if (!ivtv_waitscl(itv, 1)) {
414 IVTV_DEBUG_I2C("Slave not ready for bit\n");
419 if (!ivtv_waitscl(itv, 0)) {
420 IVTV_DEBUG_I2C("Error setting SCL low\n");
423 return ivtv_ack(itv);
426 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
428 static int ivtv_readbyte(struct ivtv *itv, unsigned char *byte, int nack)
436 for (i = 0; i < 8; ++i) {
440 if (!ivtv_waitscl(itv, 1)) {
441 IVTV_DEBUG_I2C("Error setting SCL high\n");
444 *byte = ((*byte)<<1)|ivtv_getsda(itv);
448 ivtv_setsda(itv, nack);
454 IVTV_DEBUG_HI_I2C("read %x\n",*byte);
458 /* Issue a start condition on the i2c bus to alert slaves to prepare for
460 static int ivtv_start(struct ivtv *itv)
464 sda = ivtv_getsda(itv);
466 IVTV_DEBUG_HI_I2C("SDA was low at start\n");
468 if (!ivtv_waitsda(itv, 1)) {
469 IVTV_DEBUG_I2C("SDA stuck low\n");
473 if (ivtv_getscl(itv) != 1) {
475 if (!ivtv_waitscl(itv, 1)) {
476 IVTV_DEBUG_I2C("SCL stuck low at start\n");
485 /* Issue a stop condition on the i2c bus to release it */
486 static int ivtv_stop(struct ivtv *itv)
490 if (ivtv_getscl(itv) != 0) {
491 IVTV_DEBUG_HI_I2C("SCL not low when stopping\n");
493 if (!ivtv_waitscl(itv, 0)) {
494 IVTV_DEBUG_I2C("SCL could not be set low\n");
500 if (!ivtv_waitscl(itv, 1)) {
501 IVTV_DEBUG_I2C("SCL could not be set high\n");
506 if (!ivtv_waitsda(itv, 1)) {
507 IVTV_DEBUG_I2C("resetting I2C\n");
508 for (i = 0; i < 16; ++i) {
515 ivtv_waitsda(itv, 1);
521 /* Write a message to the given i2c slave. do_stop may be 0 to prevent
522 issuing the i2c stop condition (when following with a read) */
523 static int ivtv_write(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len, int do_stop)
525 int retry, ret = -EREMOTEIO;
528 for (retry = 0; ret != 0 && retry < 8; ++retry) {
529 ret = ivtv_start(itv);
532 ret = ivtv_sendbyte(itv, addr<<1);
533 for (i = 0; ret == 0 && i < len; ++i)
534 ret = ivtv_sendbyte(itv, data[i]);
536 if (ret != 0 || do_stop) {
541 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr);
545 /* Read data from the given i2c slave. A stop condition is always issued. */
546 static int ivtv_read(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len)
548 int retry, ret = -EREMOTEIO;
551 for (retry = 0; ret != 0 && retry < 8; ++retry) {
552 ret = ivtv_start(itv);
554 ret = ivtv_sendbyte(itv, (addr << 1) | 1);
555 for (i = 0; ret == 0 && i < len; ++i) {
556 ret = ivtv_readbyte(itv, &data[i], i == len - 1);
561 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr);
565 /* Kernel i2c transfer implementation. Takes a number of messages to be read
566 or written. If a read follows a write, this will occur without an
567 intervening stop condition */
568 static int ivtv_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
570 struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
571 struct ivtv *itv = to_ivtv(v4l2_dev);
575 mutex_lock(&itv->i2c_bus_lock);
576 for (i = retval = 0; retval == 0 && i < num; i++) {
577 if (msgs[i].flags & I2C_M_RD)
578 retval = ivtv_read(itv, msgs[i].addr, msgs[i].buf, msgs[i].len);
580 /* if followed by a read, don't stop */
581 int stop = !(i + 1 < num && msgs[i + 1].flags == I2C_M_RD);
583 retval = ivtv_write(itv, msgs[i].addr, msgs[i].buf, msgs[i].len, stop);
586 mutex_unlock(&itv->i2c_bus_lock);
587 return retval ? retval : num;
590 /* Kernel i2c capabilities */
591 static u32 ivtv_functionality(struct i2c_adapter *adap)
593 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
596 static struct i2c_algorithm ivtv_algo = {
597 .master_xfer = ivtv_xfer,
598 .functionality = ivtv_functionality,
601 /* template for our-bit banger */
602 static struct i2c_adapter ivtv_i2c_adap_hw_template = {
603 .name = "ivtv i2c driver",
605 .algo_data = NULL, /* filled from template */
606 .owner = THIS_MODULE,
609 static void ivtv_setscl_old(void *data, int state)
611 struct ivtv *itv = (struct ivtv *)data;
614 itv->i2c_state |= 0x01;
616 itv->i2c_state &= ~0x01;
619 /* write bits are inverted */
620 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSCL_OFFSET);
623 static void ivtv_setsda_old(void *data, int state)
625 struct ivtv *itv = (struct ivtv *)data;
628 itv->i2c_state |= 0x01;
630 itv->i2c_state &= ~0x01;
633 /* write bits are inverted */
634 write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSDA_OFFSET);
637 static int ivtv_getscl_old(void *data)
639 struct ivtv *itv = (struct ivtv *)data;
641 return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
644 static int ivtv_getsda_old(void *data)
646 struct ivtv *itv = (struct ivtv *)data;
648 return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
651 /* template for i2c-bit-algo */
652 static struct i2c_adapter ivtv_i2c_adap_template = {
653 .name = "ivtv i2c driver",
654 .algo = NULL, /* set by i2c-algo-bit */
655 .algo_data = NULL, /* filled from template */
656 .owner = THIS_MODULE,
659 #define IVTV_ALGO_BIT_TIMEOUT (2) /* seconds */
661 static const struct i2c_algo_bit_data ivtv_i2c_algo_template = {
662 .setsda = ivtv_setsda_old,
663 .setscl = ivtv_setscl_old,
664 .getsda = ivtv_getsda_old,
665 .getscl = ivtv_getscl_old,
666 .udelay = IVTV_DEFAULT_I2C_CLOCK_PERIOD / 2, /* microseconds */
667 .timeout = IVTV_ALGO_BIT_TIMEOUT * HZ, /* jiffies */
670 static struct i2c_client ivtv_i2c_client_template = {
671 .name = "ivtv internal",
674 /* init + register i2c adapter */
675 int init_ivtv_i2c(struct ivtv *itv)
679 IVTV_DEBUG_I2C("i2c init\n");
681 /* Sanity checks for the I2C hardware arrays. They must be the
684 if (ARRAY_SIZE(hw_devicenames) != ARRAY_SIZE(hw_addrs)) {
685 IVTV_ERR("Mismatched I2C hardware arrays\n");
688 if (itv->options.newi2c > 0) {
689 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_hw_template,
690 sizeof(struct i2c_adapter));
692 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_template,
693 sizeof(struct i2c_adapter));
694 memcpy(&itv->i2c_algo, &ivtv_i2c_algo_template,
695 sizeof(struct i2c_algo_bit_data));
697 itv->i2c_algo.udelay = itv->options.i2c_clock_period / 2;
698 itv->i2c_algo.data = itv;
699 itv->i2c_adap.algo_data = &itv->i2c_algo;
701 sprintf(itv->i2c_adap.name + strlen(itv->i2c_adap.name), " #%d",
703 i2c_set_adapdata(&itv->i2c_adap, &itv->v4l2_dev);
705 memcpy(&itv->i2c_client, &ivtv_i2c_client_template,
706 sizeof(struct i2c_client));
707 itv->i2c_client.adapter = &itv->i2c_adap;
708 itv->i2c_adap.dev.parent = &itv->pdev->dev;
710 IVTV_DEBUG_I2C("setting scl and sda to 1\n");
714 if (itv->options.newi2c > 0)
715 retval = i2c_add_adapter(&itv->i2c_adap);
717 retval = i2c_bit_add_bus(&itv->i2c_adap);
722 void exit_ivtv_i2c(struct ivtv *itv)
724 IVTV_DEBUG_I2C("i2c exit\n");
726 i2c_del_adapter(&itv->i2c_adap);