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-rw-r--r--Documentation/i2c/busses/i2c-i8011
-rw-r--r--Documentation/i2c/functionality2
-rw-r--r--Documentation/i2c/i2c-protocol35
3 files changed, 22 insertions, 16 deletions
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
index aaaf069306a..adf5e33e831 100644
--- a/Documentation/i2c/busses/i2c-i801
+++ b/Documentation/i2c/busses/i2c-i801
@@ -26,6 +26,7 @@ Supported adapters:
* Intel Wellsburg (PCH)
* Intel Coleto Creek (PCH)
* Intel Wildcat Point-LP (PCH)
+ * Intel BayTrail (SOC)
Datasheets: Publicly available at the Intel website
On Intel Patsburg and later chipsets, both the normal host SMBus controller
diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
index b0ff2ab596c..4556a3eb87c 100644
--- a/Documentation/i2c/functionality
+++ b/Documentation/i2c/functionality
@@ -46,7 +46,7 @@ A few combinations of the above flags are also defined for your convenience:
and write_block_data commands
I2C_FUNC_SMBUS_I2C_BLOCK Handles the SMBus read_i2c_block_data
and write_i2c_block_data commands
- I2C_FUNC_SMBUS_EMUL Handles all SMBus commands than can be
+ I2C_FUNC_SMBUS_EMUL Handles all SMBus commands that can be
emulated by a real I2C adapter (using
the transparent emulation layer)
diff --git a/Documentation/i2c/i2c-protocol b/Documentation/i2c/i2c-protocol
index 0b3e62d1f77..ff6d6cee6c7 100644
--- a/Documentation/i2c/i2c-protocol
+++ b/Documentation/i2c/i2c-protocol
@@ -6,8 +6,8 @@ Key to symbols
S (1 bit) : Start bit
P (1 bit) : Stop bit
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
-A, NA (1 bit) : Accept and reverse accept bit.
-Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
+A, NA (1 bit) : Accept and reverse accept bit.
+Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to
get a 10 bit I2C address.
Comm (8 bits): Command byte, a data byte which often selects a register on
the device.
@@ -49,11 +49,20 @@ a byte read, followed by a byte write:
Modified transactions
=====================
-The following modifications to the I2C protocol can also be generated,
-with the exception of I2C_M_NOSTART these are usually only needed to
-work around device issues:
+The following modifications to the I2C protocol can also be generated by
+setting these flags for i2c messages. With the exception of I2C_M_NOSTART, they
+are usually only needed to work around device issues:
- Flag I2C_M_NOSTART:
+I2C_M_IGNORE_NAK:
+ Normally message is interrupted immediately if there is [NA] from the
+ client. Setting this flag treats any [NA] as [A], and all of
+ message is sent.
+ These messages may still fail to SCL lo->hi timeout.
+
+I2C_M_NO_RD_ACK:
+ In a read message, master A/NA bit is skipped.
+
+I2C_M_NOSTART:
In a combined transaction, no 'S Addr Wr/Rd [A]' is generated at some
point. For example, setting I2C_M_NOSTART on the second partial message
generates something like:
@@ -67,17 +76,13 @@ work around device issues:
I2C device but may also be used between direction changes by some
rare devices.
- Flags I2C_M_REV_DIR_ADDR
+I2C_M_REV_DIR_ADDR:
This toggles the Rd/Wr flag. That is, if you want to do a write, but
need to emit an Rd instead of a Wr, or vice versa, you set this
flag. For example:
S Addr Rd [A] Data [A] Data [A] ... [A] Data [A] P
- Flags I2C_M_IGNORE_NAK
- Normally message is interrupted immediately if there is [NA] from the
- client. Setting this flag treats any [NA] as [A], and all of
- message is sent.
- These messages may still fail to SCL lo->hi timeout.
-
- Flags I2C_M_NO_RD_ACK
- In a read message, master A/NA bit is skipped.
+I2C_M_STOP:
+ Force a stop condition (P) after the message. Some I2C related protocols
+ like SCCB require that. Normally, you really don't want to get interrupted
+ between the messages of one transfer.