| Message ID | 1568189911-31641-3-git-send-email-eugen.hristev@microchip.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | i2c: add support for filters | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | warning | "total: 0 errors, 1 warnings, 24 lines checked" |
On Wed, Sep 11, 2019 at 08:24:20AM +0000, Eugen.Hristev@microchip.com wrote: > From: Eugen Hristev <eugen.hristev@microchip.com> > > Some i2c controllers have a built-in digital or analog filter. > This is specifically required depending on the hardware PCB/board. > Some controllers also allow specifying the maximum width of the > spikes that can be filtered for digital filter. The width length can be > specified in nanoseconds. > Analog filters can be configured to have a cutoff frequency (low-pass filter). > This frequency can be specified in Hz. > Added an optional property for such types of analog filters. > > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> > --- > Documentation/devicetree/bindings/i2c/i2c.txt | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) Reviewed-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt index 44efafd..9a53df4 100644 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ b/Documentation/devicetree/bindings/i2c/i2c.txt @@ -55,6 +55,24 @@ wants to support one of the below features, it should adapt the bindings below. Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C specification. +- i2c-analog-filter + Enable analog filter for i2c lines. + +- i2c-digital-filter + Enable digital filter for i2c lines. + +- i2c-digital-filter-width-ns + Width of spikes which can be filtered by digital filter + (i2c-digital-filter). This width is specified in nanoseconds. + +- i2c-analog-filter-cutoff-frequency + Frequency that the analog filter (i2c-analog-filter) uses to distinguish + which signal to filter. Signal with higher frequency than specified will + be filtered out. Only lower frequency will pass (this is applicable to + a low-pass analog filter). Typical value should be above the normal + i2c bus clock frequency (clock-frequency). + Specified in Hz. + - interrupts interrupts used by the device.