On Wed, Jul 25, 2018 at 1:04 PM Marcus Folkesson <marcus.folkesson@xxxxxxxxx> wrote: > > Hello Rob, > > Thank you for the review. > > On Wed, Jul 25, 2018 at 11:51:17AM -0600, Rob Herring wrote: > > On Tue, Jul 24, 2018 at 08:30:03PM +0200, Marcus Folkesson wrote: > > > MCP3911 is a dual channel Analog Front End (AFE) containing two > > > synchronous sampling delta-sigma Analog-to-Digital Converters (ADC). > > > > > > Signed-off-by: Marcus Folkesson <marcus.folkesson@xxxxxxxxx> > > > Signed-off-by: Kent Gustavsson <kent@xxxxxxxxxx> > > > --- > > > > > > Notes: > > > v2: > > > - drop channel width > > > - drop `external_vref` > > > - replace `external-clock` with proper clock bindings > > > > > > .../devicetree/bindings/iio/adc/mcp3911.txt | 28 ++++++++++++++++++++++ > > > 1 file changed, 28 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/iio/adc/mcp3911.txt > > > > > > diff --git a/Documentation/devicetree/bindings/iio/adc/mcp3911.txt b/Documentation/devicetree/bindings/iio/adc/mcp3911.txt > > > new file mode 100644 > > > index 000000000000..af5472f51a84 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/iio/adc/mcp3911.txt > > > @@ -0,0 +1,28 @@ > > > +* Microchip MCP3911 Dual channel analog front end (ADC) > > > + > > > +Required properties: > > > + - compatible: Should be "microchip,mcp3911" > > > + - reg: SPI chip select number for the device > > > + > > > +Recommended properties: > > > + - spi-max-frequency: Definition as per > > > + Documentation/devicetree/bindings/spi/spi-bus.txt. > > > + Max frequency for this chip is 20MHz. > > > + > > > +Optional properties: > > > + - device-addr: Device address when multiple MCP3911 chips are present on the > > > + same SPI bus. Valid values are 0-3. Defaults to 0. > > > > Isn't this the reg value? > > > > The reg value defines which chip select the chip hangs on. > The chip has support to connect up to four chips on the same SPI bus, > including the same chip select signal. > > The chips are separated by the device-addr as it is part of the > communication protocol. Okay, seems pretty specific to this chip. Just add a vendor prefix. > When reading the description for device-addr, I agree that it fits well > for the reg property as well.. Except that reg format is already defined for SPI devices, so it's going to have to be separate property. > > > + - vref-supply: Phandle to the external reference voltage supply. > > > + - clocks: Phandle and clock identifier (see clock-names) > > > + - clock-names: "adc_clk" for the ADC (sampling) clock > > > > Datasheet calls this clki (or mclk internally). Or just drop clock-names > > as it is pointless > > when there is only 1 clock. > > I will drop the clock-names, thanks! > > > > > Also DR handling as an IRQ is missing. > > I have considered using the DR signal, but as we not support buffering > yet I did not see any point in using it. For the binding it doesn't matter if a particular driver uses it or not. If it's connected in a h/w design it should be in DT. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
