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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/Documentation/i2c
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/Documentation/i2c')
-rw-r--r--kernel/Documentation/i2c/busses/i2c-i8013
-rw-r--r--kernel/Documentation/i2c/busses/i2c-parport1
-rw-r--r--kernel/Documentation/i2c/slave-interface34
-rw-r--r--kernel/Documentation/i2c/ten-bit-addresses4
4 files changed, 29 insertions, 13 deletions
diff --git a/kernel/Documentation/i2c/busses/i2c-i801 b/kernel/Documentation/i2c/busses/i2c-i801
index 82f48f774..1bba38dd2 100644
--- a/kernel/Documentation/i2c/busses/i2c-i801
+++ b/kernel/Documentation/i2c/busses/i2c-i801
@@ -30,6 +30,9 @@ Supported adapters:
* Intel BayTrail (SOC)
* Intel Sunrise Point-H (PCH)
* Intel Sunrise Point-LP (PCH)
+ * Intel DNV (SOC)
+ * Intel Broxton (SOC)
+ * Intel Lewisburg (PCH)
Datasheets: Publicly available at the Intel website
On Intel Patsburg and later chipsets, both the normal host SMBus controller
diff --git a/kernel/Documentation/i2c/busses/i2c-parport b/kernel/Documentation/i2c/busses/i2c-parport
index 0e2d17b46..c3dbb3bfd 100644
--- a/kernel/Documentation/i2c/busses/i2c-parport
+++ b/kernel/Documentation/i2c/busses/i2c-parport
@@ -20,6 +20,7 @@ It currently supports the following devices:
* (type=5) Analog Devices evaluation boards: ADM1025, ADM1030, ADM1031
* (type=6) Barco LPT->DVI (K5800236) adapter
* (type=7) One For All JP1 parallel port adapter
+ * (type=8) VCT-jig
These devices use different pinout configurations, so you have to tell
the driver what you have, using the type module parameter. There is no
diff --git a/kernel/Documentation/i2c/slave-interface b/kernel/Documentation/i2c/slave-interface
index b228ca54b..61ed05cd9 100644
--- a/kernel/Documentation/i2c/slave-interface
+++ b/kernel/Documentation/i2c/slave-interface
@@ -3,16 +3,16 @@ Linux I2C slave interface description
by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
-Linux can also be an I2C slave in case I2C controllers have slave support.
-Besides this HW requirement, one also needs a software backend providing the
-actual functionality. An example for this is the slave-eeprom driver, which
-acts as a dual memory driver. While another I2C master on the bus can access it
-like a regular EEPROM, the Linux I2C slave can access the content via sysfs and
-retrieve/provide information as needed. The software backend driver and the I2C
-bus driver communicate via events. Here is a small graph visualizing the data
-flow and the means by which data is transported. The dotted line marks only one
-example. The backend could also use e.g. a character device, be in-kernel
-only, or something completely different:
+Linux can also be an I2C slave if the I2C controller in use has slave
+functionality. For that to work, one needs slave support in the bus driver plus
+a hardware independent software backend providing the actual functionality. An
+example for the latter is the slave-eeprom driver, which acts as a dual memory
+driver. While another I2C master on the bus can access it like a regular
+EEPROM, the Linux I2C slave can access the content via sysfs and handle data as
+needed. The backend driver and the I2C bus driver communicate via events. Here
+is a small graph visualizing the data flow and the means by which data is
+transported. The dotted line marks only one example. The backend could also
+use a character device, be in-kernel only, or something completely different:
e.g. sysfs I2C slave events I/O registers
@@ -31,10 +31,13 @@ User manual
===========
I2C slave backends behave like standard I2C clients. So, you can instantiate
-them as described in the document 'instantiating-devices'. A quick example for
-instantiating the slave-eeprom driver from userspace at address 0x64 on bus 1:
+them as described in the document 'instantiating-devices'. The only difference
+is that i2c slave backends have their own address space. So, you have to add
+0x1000 to the address you would originally request. An example for
+instantiating the slave-eeprom driver from userspace at the 7 bit address 0x64
+on bus 1:
- # echo slave-24c02 0x64 > /sys/bus/i2c/devices/i2c-1/new_device
+ # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device
Each backend should come with separate documentation to describe its specific
behaviour and setup.
@@ -43,6 +46,11 @@ behaviour and setup.
Developer manual
================
+First, the events which are used by the bus driver and the backend will be
+described in detail. After that, some implementation hints for extending bus
+drivers and writing backends will be given.
+
+
I2C slave events
----------------
diff --git a/kernel/Documentation/i2c/ten-bit-addresses b/kernel/Documentation/i2c/ten-bit-addresses
index cdfe13901..7b2d11e53 100644
--- a/kernel/Documentation/i2c/ten-bit-addresses
+++ b/kernel/Documentation/i2c/ten-bit-addresses
@@ -2,6 +2,10 @@ The I2C protocol knows about two kinds of device addresses: normal 7 bit
addresses, and an extended set of 10 bit addresses. The sets of addresses
do not intersect: the 7 bit address 0x10 is not the same as the 10 bit
address 0x10 (though a single device could respond to both of them).
+To avoid ambiguity, the user sees 10 bit addresses mapped to a different
+address space, namely 0xa000-0xa3ff. The leading 0xa (= 10) represents the
+10 bit mode. This is used for creating device names in sysfs. It is also
+needed when instantiating 10 bit devices via the new_device file in sysfs.
I2C messages to and from 10-bit address devices have a different format.
See the I2C specification for the details.