| Message ID | 1515766983-15151-3-git-send-email-claudiu.beznea@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jan 12, 2018 at 04:22:49PM +0200, Claudiu Beznea wrote: > pwm-cells should be at least 2 to provide channel number and period value. > > Cc: Mike Dunn <mikedunn@newsguy.com> > Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> > --- > Documentation/devicetree/bindings/pwm/pxa-pwm.txt | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt > index 5ae9f1e3c338..a0e20edeeebc 100644 > --- a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt > +++ b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt > @@ -10,7 +10,7 @@ Required properties: > Note that one device instance must be created for each PWM that is used, so the > length covers only the register window for one PWM output, not that of the > entire PWM controller. Currently length is 0x10 for all supported devices. > -- #pwm-cells: Should be 1. This cell is used to specify the period in > +- #pwm-cells: Should be 2. This cell is used to specify the period in > nanoseconds. What's the new cell? channel? Does the PXA PWM have more than one channel? If not, then you shouldn't add a cell. Rob
On 20.01.2018 00:30, Rob Herring wrote: > On Fri, Jan 12, 2018 at 04:22:49PM +0200, Claudiu Beznea wrote: >> pwm-cells should be at least 2 to provide channel number and period value. >> >> Cc: Mike Dunn <mikedunn@newsguy.com> >> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> >> --- >> Documentation/devicetree/bindings/pwm/pxa-pwm.txt | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt >> index 5ae9f1e3c338..a0e20edeeebc 100644 >> --- a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt >> +++ b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt >> @@ -10,7 +10,7 @@ Required properties: >> Note that one device instance must be created for each PWM that is used, so the >> length covers only the register window for one PWM output, not that of the >> entire PWM controller. Currently length is 0x10 for all supported devices. >> -- #pwm-cells: Should be 1. This cell is used to specify the period in >> +- #pwm-cells: Should be 2. This cell is used to specify the period in >> nanoseconds. > > What's the new cell? channel? Does the PXA PWM have more than one > channel? If not, then you shouldn't add a cell. The new cell had to be period, to have a generic OF function in the kernel, to parse the pwms bindings for all PWMs, something like pwms=<pwm channel-number pwm-period>. After several discussions on this series, I found that old DT binaries must be compatible with latest kernel version and this series doesn't guarantee this. So I will drop this change in next version. Thank you, Claudiu Beznea > > Rob >
diff --git a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt index 5ae9f1e3c338..a0e20edeeebc 100644 --- a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt +++ b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt @@ -10,7 +10,7 @@ Required properties: Note that one device instance must be created for each PWM that is used, so the length covers only the register window for one PWM output, not that of the entire PWM controller. Currently length is 0x10 for all supported devices. -- #pwm-cells: Should be 1. This cell is used to specify the period in +- #pwm-cells: Should be 2. This cell is used to specify the period in nanoseconds. Example PWM device node: @@ -18,13 +18,13 @@ Example PWM device node: pwm0: pwm@40b00000 { compatible = "marvell,pxa250-pwm"; reg = <0x40b00000 0x10>; - #pwm-cells = <1>; + #pwm-cells = <2>; }; Example PWM client node: backlight { compatible = "pwm-backlight"; - pwms = <&pwm0 5000000>; + pwms = <&pwm0 0 5000000>; ... }
pwm-cells should be at least 2 to provide channel number and period value. Cc: Mike Dunn <mikedunn@newsguy.com> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> --- Documentation/devicetree/bindings/pwm/pxa-pwm.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)