| Message ID | 1377019903-14614-2-git-send-email-t.figa@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/20/2013 11:31 AM, Tomasz Figa wrote: > PWM driver consumes at least one and up to three clocks, which need to be > specified in device tree when used. This patch updates bindings > documentation to add information about clocks. > diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt > +- clock-names: should contain all following required clock names: > + - "timers" - PWM base clock used to generate PWM signals, > + and any subset of following optional clock names: > + - "pwm-tclk0" - first external PWM clock source, > + - "pwm-tclk1" - second external PWM clock source. > + Note that not all IP variants allow using all external clock sources. > + Refer to SoC documentation to learn which clock source configurations > + are available. It might be nice to explicitly enumerate which variants (or rather, I suppose which exact compatible values) support which optional clocks. However, I suppose it's fine to just say "go read the HW manual" instead. So, this patch, Acked-by: Stephen Warren <swarren@nvidia.com> (although this patch isn't backwards-compatible since before now, DT nodes didn't need to provide any entries in clocks)
On Tuesday 20 of August 2013 14:34:30 Stephen Warren wrote: > On 08/20/2013 11:31 AM, Tomasz Figa wrote: > > PWM driver consumes at least one and up to three clocks, which need to > > be specified in device tree when used. This patch updates bindings > > documentation to add information about clocks. > > > > diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt > > b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt > > > > +- clock-names: should contain all following required clock names: > > + - "timers" - PWM base clock used to generate PWM signals, > > + and any subset of following optional clock names: > > + - "pwm-tclk0" - first external PWM clock source, > > + - "pwm-tclk1" - second external PWM clock source. > > + Note that not all IP variants allow using all external clock > > sources. + Refer to SoC documentation to learn which clock source > > configurations + are available. > > It might be nice to explicitly enumerate which variants (or rather, I > suppose which exact compatible values) support which optional clocks. > However, I suppose it's fine to just say "go read the HW manual" > instead. I don't have enough information about some of the variants, so I decided to put it this way, instead of making an incomplete list or speculating about things. > So, this patch, > Acked-by: Stephen Warren <swarren@nvidia.com> Thanks. > (although this patch isn't backwards-compatible since before now, DT > nodes didn't need to provide any entries in clocks) The thing is that the clocks were supposed to be there from the beginning, but in a hurry I forgot to specify them in original bindings documentation and things were running over compatibility clkdev aliases anyway, so nobody (including me) noticed. Best regards, Tomasz
diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt index 4caa1a7..d61fccd 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt @@ -19,6 +19,16 @@ Required properties: - reg: base address and size of register area - interrupts: list of timer interrupts (one interrupt per timer, starting at timer 0) +- clock-names: should contain all following required clock names: + - "timers" - PWM base clock used to generate PWM signals, + and any subset of following optional clock names: + - "pwm-tclk0" - first external PWM clock source, + - "pwm-tclk1" - second external PWM clock source. + Note that not all IP variants allow using all external clock sources. + Refer to SoC documentation to learn which clock source configurations + are available. +- clocks: should contain clock specifiers of all clocks, which input names + have been specified in clock-names property, in same order. - #pwm-cells: should be 3. See pwm.txt in this directory for a description of the cells format. The only third cell flag supported by this binding is PWM_POLARITY_INVERTED. @@ -34,6 +44,8 @@ Example: reg = <0x7f006000 0x1000>; interrupt-parent = <&vic0>; interrupts = <23>, <24>, <25>, <27>, <28>; + clocks = <&clock 67>; + clock-names = "timers"; samsung,pwm-outputs = <0>, <1>; #pwm-cells = <3>; }