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| author | Romain Baeriswyl <Romain.Baeriswyl@abilis.com> | 2014-01-20 17:43:43 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-03-09 09:29:08 +0100 |
| commit | 6468276b22069d4442aafcd8c59e5d8ccae23f5f (patch) | |
| tree | ed2cc9b10bf940ddc6da148618140b662086f853 /Documentation/devicetree | |
| parent | 5029a22a45056603497c82445db9dd203b050e82 (diff) | |
| download | blackbird-op-linux-6468276b22069d4442aafcd8c59e5d8ccae23f5f.tar.gz blackbird-op-linux-6468276b22069d4442aafcd8c59e5d8ccae23f5f.zip | |
i2c: designware: make SCL and SDA falling time configurable
This patch allows to set independantly SCL and SDA falling times.
The tLOW period is computed by taking into account the SCL falling time.
The tHIGH period is computed by taking into account the SDA falling time.
For instance in case the margin on tLOW is considered too small, it can
be increased by increasing the SCL falling time which is by default set
at 300ns.
The same applies for tHIGH period with the help of SDA falling time.
Signed-off-by: Romain Baeriswyl <romainba@abilis.com>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Acked-by: Shinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-designware.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index 7fd7fa25e9b0..5199b0c8cf7a 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -14,6 +14,12 @@ Optional properties : - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. This option is only supported in hardware blocks version 1.11a or newer. + - i2c-scl-falling-time : should contain the SCL falling time in nanoseconds. + This value which is by default 300ns is used to compute the tLOW period. + + - i2c-sda-falling-time : should contain the SDA falling time in nanoseconds. + This value which is by default 300ns is used to compute the tHIGH period. + Example : i2c@f0000 { @@ -34,4 +40,6 @@ Example : interrupts = <12 1>; clock-frequency = <400000>; i2c-sda-hold-time-ns = <300>; + i2c-sda-falling-time-ns = <300>; + i2c-scl-falling-time-ns = <300>; }; |
