Hi, On 11/01/2023 13:44, Siddharth Vadapalli wrote: > The CPTS driver is capable of configuring GENFy (Periodic Signal Generator > Function) present in the CPTS module, to generate periodic output signals > with a custom time period. In order to generate a PPS signal on the GENFy > output, the device-tree property "ti,pps" has to be used. The "ti,pps" > property is used to declare the mapping between the CPTS HWx_TS_PUSH > (Hardware Timestamp trigger) input and the GENFy output that is configured > to generate a PPS signal. The mapping is of the form: > <x-1 y> > where the value x corresponds to HWx_TS_PUSH input (1-based indexing) and > the value y corresponds to GENFy (0-based indexing). You mean there is no HWx_TX_PUSH0 pin? so user needs to use 0 for HWx_TX_PUSH1 pin? Can you please define macros for HWx_TS_PUSH and GENFy so we avoid human error with this different indexing methods? DT should contain the name exactly in hardware. So if pin is called HWx_TX_PUSH1 in hardware then DT should contain HWx_TX_PUSH(1). > > To verify that the signal is a PPS signal, the GENFy output signal is fed > into the CPTS HWx_TS_PUSH input, which generates a timestamp event on the > rising edge of the GENFy signal. The GENFy output signal can be routed to > the HWx_TS_PUSH input by using the Time Sync Router. This is done by > mentioning the mapping between the GENFy output and the HWx_TS_PUSH input > within the "timesync_router" device-tree node. > > The Input Sources to the Time Sync Router are documented at: [1] > The Output Destinations of the Time Sync Router are documented at: [2] > > The PPS signal can be verified using testptp and ppstest tools as follows: > # ./testptp -d /dev/ptp0 -P 1 > pps for system time request okay > # ./ppstest /dev/pps0 > trying PPS source "/dev/pps0" > found PPS source "/dev/pps0" > ok, found 1 source(s), now start fetching data... > source 0 - assert 48.000000013, sequence: 8 - clear 0.000000000, sequence: 0 > source 0 - assert 49.000000013, sequence: 9 - clear 0.000000000, sequence: 0 > source 0 - assert 50.000000013, sequence: 10 - clear 0.000000000, sequence: 0 > > Add an example in the device-tree, enabling PPS generation on GENF1. The > HW3_TS_PUSH Timestamp trigger input is used to verify the PPS signal. > > [1] > Link: https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am62x/interrupt_cfg.html#timesync-event-router0-interrupt-router-input-sources > [2] > Link: https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am62x/interrupt_cfg.html#timesync-event-router0-interrupt-router-output-destinations > > Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx> > --- > arch/arm64/boot/dts/ti/k3-am625-sk.dts | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/arch/arm64/boot/dts/ti/k3-am625-sk.dts b/arch/arm64/boot/dts/ti/k3-am625-sk.dts > index 4f179b146cab..962a922cc94b 100644 > --- a/arch/arm64/boot/dts/ti/k3-am625-sk.dts > +++ b/arch/arm64/boot/dts/ti/k3-am625-sk.dts > @@ -366,6 +366,10 @@ &cpsw3g { > pinctrl-names = "default"; > pinctrl-0 = <&main_rgmii1_pins_default > &main_rgmii2_pins_default>; > + > + cpts@3d000 { > + ti,pps = <2 1>; > + }; > }; > > &cpsw_port1 { > @@ -464,3 +468,19 @@ partition@3fc0000 { > }; > }; > }; > + > +#define TS_OFFSET(pa, val) (0x4+(pa)*4) (0x10000 | val) Should this go in ./include/dt-bindings/pinctrl/k3.h ? That way every board DT file doesn't have to define it. The name should be made more platform specific. e.g. K3_TS_OFFSET if it is the same for all K3 platforms. If not then please add Platform name instead of K3. > + > +×ync_router { > + status = "okay"; > + pinctrl-names = "default"; > + pinctrl-0 = <&cpsw_cpts>; > + > + /* Example of the timesync routing */ > + cpsw_cpts: cpsw-cpts { > + pinctrl-single,pins = < > + /* pps [cpsw cpts genf1] in17 -> out12 [cpsw cpts hw3_push] */ > + TS_OFFSET(12, 17) > + >; > + }; > +}; cheers, -roger
