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authorJean-Michel Hautbois <jhautbois@gmail.com>2016-01-31 16:33:00 +0100
committerWolfram Sang <wsa@the-dreams.de>2016-06-13 22:32:09 +0200
commit0f614d834bccd3537881c5d0933803b407ce3283 (patch)
tree78e72c00ab33827c5d4dff25f3f0ff9c17100753 /Documentation
parentLinux 4.7-rc3 (diff)
downloadlinux-0f614d834bccd3537881c5d0933803b407ce3283.tar.xz
linux-0f614d834bccd3537881c5d0933803b407ce3283.zip
i2c: Add generic support passing secondary devices addresses
Some I2C devices have multiple addresses assigned, for example each address corresponding to a different internal register map page of the device. So far drivers which need support for this have handled this with a driver specific and non-generic implementation, e.g. passing the additional address via platform data. This patch provides a new helper function called i2c_new_secondary_device() which is intended to provide a generic way to get the secondary address as well as instantiate a struct i2c_client for the secondary address. The function expects a pointer to the primary i2c_client, a name for the secondary address and an optional default address. The name is used as a handle to specify which secondary address to get. The default address is used as a fallback in case no secondary address was explicitly specified. In case no secondary address and no default address were specified the function returns NULL. For now the function only supports look-up of the secondary address from devicetree, but it can be extended in the future to for example support board files and/or ACPI. Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@veo-labs.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
index c8d977ed847f..f31b2ad1552b 100644
--- a/Documentation/devicetree/bindings/i2c/i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c.txt
@@ -62,6 +62,13 @@ wants to support one of the below features, it should adapt the bindings below.
- wakeup-source
device can be used as a wakeup source.
+- reg
+ I2C slave addresses
+
+- reg-names
+ Names of map programmable addresses.
+ It can contain any map needing another address than default one.
+
Binding may contain optional "interrupts" property, describing interrupts
used by the device. I2C core will assign "irq" interrupt (or the very first
interrupt if not using interrupt names) as primary interrupt for the slave.