On Thu, 7 Mar 2019 17:29:19 +0200 Stefan Popa <stefan.popa@xxxxxxxxxx> wrote: > Add documentation for optional use of external clock. All devices > supported by this driver can work with an external clock in sync mode. > Another mode, called Pulse Per Second (PPS) is supported only by adis1649x > devices. The mode is selected by using the "clock-names" property. > > The pin which is used as external clock input is selected by using a > custom optional property called "adi,ext-clk-pin". If this field is left > empty, DIO2 is assigned as default external clock input pin. > > Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx> Trivial comments inline... Thanks, Jonathan > --- > .../devicetree/bindings/iio/imu/adi,adis16480.txt | 34 ++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/imu/adi,adis16480.txt b/Documentation/devicetree/bindings/iio/imu/adi,adis16480.txt > index 39ab016..9e2fcd4 100644 > --- a/Documentation/devicetree/bindings/iio/imu/adi,adis16480.txt > +++ b/Documentation/devicetree/bindings/iio/imu/adi,adis16480.txt > @@ -34,6 +34,37 @@ Optional properties: > signal. > - reset-gpios: must be the device tree identifier of the RESET pin. As the line > is active low, it should be marked GPIO_ACTIVE_LOW. > +- clocks: phandle to the external clock. Should be set according to > + "clock-names". > + If this field is left empty, the internal clock is used. > +- clock-names: The name of the external clock to be used. Valid values are: > + * sync: In sync mode, the internal clock is disabled and the frequency > + of the external clock signal establishes therate of data the rate > + collection and processing. See Fig 14 and 15 in the datasheet. > + The clock-frequency must be: > + * 3000 to 4500 Hz for adis1649x devices. > + * 700 to 2400 Hz for adis1648x devices. > + * pps: In Pulse Per Second (PPS) Mode, the rate of data collection and > + production is equal to the product of the external clock > + frequency and the scale factor in the SYNC_SCALE register, see > + Table 154 in the datasheet. > + The clock-frequency must be: > + * 1 to 128 Hz for adis1649x devices. > + * This mode is not supported by adis1648x devices. > + If this field is left empty, the internal clock is used. Should we say that both clocks and clock-names should be empty if that is the intent? > +- adi,ext-clk-pin: The DIOx line to be used as an external clock input. > + Valid values are: > + * DIO1 > + * DIO2 > + * DIO3 > + * DIO4 > + Each DIOx pin supports only one function at a time (data ready line > + selection or external clock input). When a single pin has two > + two assignments, the enable bit for the lower priority function > + automatically resets to zero (disabling the lower priority function). > + Data ready has highest priority. > + If this field is left empty, DIO2 is assigned as default external clock > + input pin. > > Example: > > @@ -46,4 +77,7 @@ Example: > interrupts = <25 IRQF_TRIGGER_FALLING>; > interrupt-parent = <&gpio>; > interrupt-names = "DIO2"; > + clocks = <&adis16495_sync>; > + clock-names = "sync"; > + adi,ext-clk-pin = "DIO1"; > };
