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authorLinus Torvalds <torvalds@linux-foundation.org>2011-11-23 12:50:05 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-23 12:50:05 -0500
commit5907c5f8adbd0bb7ab69124520304e5b25c8eb5e (patch)
treec3e1bc99f41c74b369293c74a1752e57e538f706
parent0a2c986557b964453f8deeaf56f6d88bf3e65e92 (diff)
parenteff245c82f115059648cdce95dd68bb940f2b006 (diff)
Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: i2c: Make i2cdev_notifier_call static i2c: Delete ANY_I2C_BUS i2c: Fix device name for 10-bit slave address i2c-algo-bit: Generate correct i2c address sequence for 10-bit target
-rw-r--r--Documentation/i2c/ten-bit-addresses36
-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c4
-rw-r--r--drivers/i2c/i2c-core.c4
-rw-r--r--drivers/i2c/i2c-dev.c2
-rw-r--r--include/linux/i2c.h3
5 files changed, 25 insertions, 24 deletions
diff --git a/Documentation/i2c/ten-bit-addresses b/Documentation/i2c/ten-bit-addresses
index e9890709c508..cdfe13901b99 100644
--- a/Documentation/i2c/ten-bit-addresses
+++ b/Documentation/i2c/ten-bit-addresses
@@ -1,22 +1,24 @@
1The I2C protocol knows about two kinds of device addresses: normal 7 bit 1The I2C protocol knows about two kinds of device addresses: normal 7 bit
2addresses, and an extended set of 10 bit addresses. The sets of addresses 2addresses, and an extended set of 10 bit addresses. The sets of addresses
3do not intersect: the 7 bit address 0x10 is not the same as the 10 bit 3do not intersect: the 7 bit address 0x10 is not the same as the 10 bit
4address 0x10 (though a single device could respond to both of them). You 4address 0x10 (though a single device could respond to both of them).
5select a 10 bit address by adding an extra byte after the address
6byte:
7 S Addr7 Rd/Wr ....
8becomes
9 S 11110 Addr10 Rd/Wr
10S is the start bit, Rd/Wr the read/write bit, and if you count the number
11of bits, you will see the there are 8 after the S bit for 7 bit addresses,
12and 16 after the S bit for 10 bit addresses.
13 5
14WARNING! The current 10 bit address support is EXPERIMENTAL. There are 6I2C messages to and from 10-bit address devices have a different format.
15several places in the code that will cause SEVERE PROBLEMS with 10 bit 7See the I2C specification for the details.
16addresses, even though there is some basic handling and hooks. Also,
17almost no supported adapter handles the 10 bit addresses correctly.
18 8
19As soon as a real 10 bit address device is spotted 'in the wild', we 9The current 10 bit address support is minimal. It should work, however
20can and will add proper support. Right now, 10 bit address devices 10you can expect some problems along the way:
21are defined by the I2C protocol, but we have never seen a single device 11* Not all bus drivers support 10-bit addresses. Some don't because the
22which supports them. 12 hardware doesn't support them (SMBus doesn't require 10-bit address
13 support for example), some don't because nobody bothered adding the
14 code (or it's there but not working properly.) Software implementation
15 (i2c-algo-bit) is known to work.
16* Some optional features do not support 10-bit addresses. This is the
17 case of automatic detection and instantiation of devices by their,
18 drivers, for example.
19* Many user-space packages (for example i2c-tools) lack support for
20 10-bit addresses.
21
22Note that 10-bit address devices are still pretty rare, so the limitations
23listed above could stay for a long time, maybe even forever if nobody
24needs them to be fixed.
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 85584a547c25..525c7345fa0b 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -488,7 +488,7 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
488 488
489 if (flags & I2C_M_TEN) { 489 if (flags & I2C_M_TEN) {
490 /* a ten bit address */ 490 /* a ten bit address */
491 addr = 0xf0 | ((msg->addr >> 7) & 0x03); 491 addr = 0xf0 | ((msg->addr >> 7) & 0x06);
492 bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); 492 bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr);
493 /* try extended address code...*/ 493 /* try extended address code...*/
494 ret = try_address(i2c_adap, addr, retries); 494 ret = try_address(i2c_adap, addr, retries);
@@ -498,7 +498,7 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
498 return -ENXIO; 498 return -ENXIO;
499 } 499 }
500 /* the remaining 8 bit address */ 500 /* the remaining 8 bit address */
501 ret = i2c_outb(i2c_adap, msg->addr & 0x7f); 501 ret = i2c_outb(i2c_adap, msg->addr & 0xff);
502 if ((ret != 1) && !nak_ok) { 502 if ((ret != 1) && !nak_ok) {
503 /* the chip did not ack / xmission error occurred */ 503 /* the chip did not ack / xmission error occurred */
504 dev_err(&i2c_adap->dev, "died at 2nd address code\n"); 504 dev_err(&i2c_adap->dev, "died at 2nd address code\n");
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 131079a3e292..1e5606185b4f 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -539,8 +539,10 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
539 client->dev.type = &i2c_client_type; 539 client->dev.type = &i2c_client_type;
540 client->dev.of_node = info->of_node; 540 client->dev.of_node = info->of_node;
541 541
542 /* For 10-bit clients, add an arbitrary offset to avoid collisions */
542 dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), 543 dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
543 client->addr); 544 client->addr | ((client->flags & I2C_CLIENT_TEN)
545 ? 0xa000 : 0));
544 status = device_register(&client->dev); 546 status = device_register(&client->dev);
545 if (status) 547 if (status)
546 goto out_err; 548 goto out_err;
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index c90ce50b619f..57a45ce84b2d 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -579,7 +579,7 @@ static int i2cdev_detach_adapter(struct device *dev, void *dummy)
579 return 0; 579 return 0;
580} 580}
581 581
582int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, 582static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
583 void *data) 583 void *data)
584{ 584{
585 struct device *dev = data; 585 struct device *dev = data;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index a81bf6d23b3e..07d103a06d64 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -432,9 +432,6 @@ void i2c_unlock_adapter(struct i2c_adapter *);
432/* Internal numbers to terminate lists */ 432/* Internal numbers to terminate lists */
433#define I2C_CLIENT_END 0xfffeU 433#define I2C_CLIENT_END 0xfffeU
434 434
435/* The numbers to use to set I2C bus address */
436#define ANY_I2C_BUS 0xffff
437
438/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 435/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
439#define I2C_ADDRS(addr, addrs...) \ 436#define I2C_ADDRS(addr, addrs...) \
440 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 437 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })