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authorDave Airlie <airlied@redhat.com>2020-07-24 01:28:09 +0300
committerDave Airlie <airlied@redhat.com>2020-07-24 01:48:05 +0300
commit41206a073ceebc517245677a19f52ba6379b33a9 (patch)
tree2fc35aac6abe32b99058ad55b0fc6e4d449d1056 /Documentation/i2c/slave-eeprom-backend.rst
parent206739119508d5ab4b42ab480ff61a7e6cd72d7c (diff)
parentba47d845d715a010f7b51f6f89bae32845e6acb7 (diff)
downloadlinux-41206a073ceebc517245677a19f52ba6379b33a9.tar.xz
Merge v5.8-rc6 into drm-next
I've got a silent conflict + two trees based on fixes to merge. Fixes a silent merge with amdgpu Signed-off-by: Dave Airlie <airlied@redhat.com>
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diff --git a/Documentation/i2c/slave-eeprom-backend.rst b/Documentation/i2c/slave-eeprom-backend.rst
index 0b8cd83698e0..38d951f10302 100644
--- a/Documentation/i2c/slave-eeprom-backend.rst
+++ b/Documentation/i2c/slave-eeprom-backend.rst
@@ -1,14 +1,26 @@
==============================
-Linux I2C slave eeprom backend
+Linux I2C slave EEPROM backend
==============================
-by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
+by Wolfram Sang <wsa@sang-engineering.com> in 2014-20
-This is a proof-of-concept backend which acts like an EEPROM on the connected
-I2C bus. The memory contents can be modified from userspace via this file
-located in sysfs::
+This backend simulates an EEPROM on the connected I2C bus. Its memory contents
+can be accessed from userspace via this file located in sysfs::
/sys/bus/i2c/devices/<device-directory>/slave-eeprom
+The following types are available: 24c02, 24c32, 24c64, and 24c512. Read-only
+variants are also supported. The name needed for instantiating has the form
+'slave-<type>[ro]'. Examples follow:
+
+24c02, read/write, address 0x64:
+ # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device
+
+24c512, read-only, address 0x42:
+ # echo slave-24c512ro 0x1042 > /sys/bus/i2c/devices/i2c-1/new_device
+
+You can also preload data during boot if a device-property named
+'firmware-name' contains a valid filename (DT or ACPI only).
+
As of 2015, Linux doesn't support poll on binary sysfs files, so there is no
notification when another master changed the content.