summaryrefslogtreecommitdiffstats
path: root/Documentation/i2c
diff options
context:
space:
mode:
authorJames Morris <james.l.morris@oracle.com>2014-11-19 21:32:12 +1100
committerJames Morris <james.l.morris@oracle.com>2014-11-19 21:32:12 +1100
commitb10778a00d40b3d9fdaaf5891e802794781ff71c (patch)
tree6ba4cbac86eecedc3f30650e7f764ecf00c83898 /Documentation/i2c
parent594081ee7145cc30a3977cb4e218f81213b63dc5 (diff)
parentbfe01a5ba2490f299e1d2d5508cbbbadd897bbe9 (diff)
Merge commit 'v3.17' into next
Diffstat (limited to 'Documentation/i2c')
-rw-r--r--Documentation/i2c/busses/i2c-i8011
-rw-r--r--Documentation/i2c/dev-interface10
-rw-r--r--Documentation/i2c/i2c-stub23
3 files changed, 23 insertions, 11 deletions
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
index adf5e33e831..e9c803ea306 100644
--- a/Documentation/i2c/busses/i2c-i801
+++ b/Documentation/i2c/busses/i2c-i801
@@ -25,6 +25,7 @@ Supported adapters:
* Intel Avoton (SOC)
* Intel Wellsburg (PCH)
* Intel Coleto Creek (PCH)
+ * Intel Wildcat Point (PCH)
* Intel Wildcat Point-LP (PCH)
* Intel BayTrail (SOC)
Datasheets: Publicly available at the Intel website
diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface
index 3e742ba2553..2ac78ae1039 100644
--- a/Documentation/i2c/dev-interface
+++ b/Documentation/i2c/dev-interface
@@ -57,12 +57,12 @@ Well, you are all set up now. You can now use SMBus commands or plain
I2C to communicate with your device. SMBus commands are preferred if
the device supports them. Both are illustrated below.
- __u8 register = 0x10; /* Device register to access */
+ __u8 reg = 0x10; /* Device register to access */
__s32 res;
char buf[10];
/* Using SMBus commands */
- res = i2c_smbus_read_word_data(file, register);
+ res = i2c_smbus_read_word_data(file, reg);
if (res < 0) {
/* ERROR HANDLING: i2c transaction failed */
} else {
@@ -70,11 +70,11 @@ the device supports them. Both are illustrated below.
}
/* Using I2C Write, equivalent of
- i2c_smbus_write_word_data(file, register, 0x6543) */
- buf[0] = register;
+ i2c_smbus_write_word_data(file, reg, 0x6543) */
+ buf[0] = reg;
buf[1] = 0x43;
buf[2] = 0x65;
- if (write(file, buf, 3) ! =3) {
+ if (write(file, buf, 3) != 3) {
/* ERROR HANDLING: i2c transaction failed */
}
diff --git a/Documentation/i2c/i2c-stub b/Documentation/i2c/i2c-stub
index fa4b669c166..a16924fbd28 100644
--- a/Documentation/i2c/i2c-stub
+++ b/Documentation/i2c/i2c-stub
@@ -2,9 +2,9 @@ MODULE: i2c-stub
DESCRIPTION:
-This module is a very simple fake I2C/SMBus driver. It implements five
+This module is a very simple fake I2C/SMBus driver. It implements six
types of SMBus commands: write quick, (r/w) byte, (r/w) byte data, (r/w)
-word data, and (r/w) I2C block data.
+word data, (r/w) I2C block data, and (r/w) SMBus block data.
You need to provide chip addresses as a module parameter when loading this
driver, which will then only react to SMBus commands to these addresses.
@@ -19,6 +19,14 @@ A pointer register with auto-increment is implemented for all byte
operations. This allows for continuous byte reads like those supported by
EEPROMs, among others.
+SMBus block command support is disabled by default, and must be enabled
+explicitly by setting the respective bits (0x03000000) in the functionality
+module parameter.
+
+SMBus block commands must be written to configure an SMBus command for
+SMBus block operations. Writes can be partial. Block read commands always
+return the number of bytes selected with the largest write so far.
+
The typical use-case is like this:
1. load this module
2. use i2cset (from the i2c-tools project) to pre-load some data
@@ -39,15 +47,18 @@ unsigned long functionality:
value 0x1f0000 would only enable the quick, byte and byte data
commands.
+u8 bank_reg[10]
+u8 bank_mask[10]
+u8 bank_start[10]
+u8 bank_end[10]:
+ Optional bank settings. They tell which bits in which register
+ select the active bank, as well as the range of banked registers.
+
CAVEATS:
If your target driver polls some byte or word waiting for it to change, the
stub could lock it up. Use i2cset to unlock it.
-If the hardware for your driver has banked registers (e.g. Winbond sensors
-chips) this module will not work well - although it could be extended to
-support that pretty easily.
-
If you spam it hard enough, printk can be lossy. This module really wants
something like relayfs.