diff mbox

[v3,2/7] bindings: spi-samsung: document the clocks and the clock-name property

Message ID 1468317736-18841-3-git-send-email-andi.shyti@samsung.com (mailing list archive)
State Not Applicable, archived
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Commit Message

Andi Shyti July 12, 2016, 10:02 a.m. UTC
These two properties were not documented but used in the spi
dts. Add the related documentation.

Suggested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Michael Turquette <mturquette@baylibre.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
 Documentation/devicetree/bindings/spi/spi-samsung.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Rob Herring (Arm) July 16, 2016, 8:30 p.m. UTC | #1
On Tue, Jul 12, 2016 at 07:02:11PM +0900, Andi Shyti wrote:
> These two properties were not documented but used in the spi
> dts. Add the related documentation.
> 
> Suggested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> Reviewed-by: Michael Turquette <mturquette@baylibre.com>
> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> ---
>  Documentation/devicetree/bindings/spi/spi-samsung.txt | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
> index 57d5539..f45c6eb 100644
> --- a/Documentation/devicetree/bindings/spi/spi-samsung.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
> @@ -24,6 +24,15 @@ Required SoC Specific Properties:
>  - dma-names: Names for the dma channels. There must be at least one channel
>    named "tx" for transmit and named "rx" for receive.
>  
> +- clocks: specifies the clock IDs provided to the SPI controller; they are
> +  required for interacting with the controller itself, for synchronizing the bus
> +  and as I/O clock (the latter is required by exynos5433 and exynos7).
> +
> +- clock-names: string names of the clocks in the 'clocks' property; for all the
> +  the devices the names must be "spi", "spi_busclkN" (where N is determined by
> +  "samsung,spi-src-clk"), while Exynos5433 should specify a third clock

This sounds like you are describing the configuration of the clocks, not 
the connections. The binding here should list clocks for all possible 
vaules of N as those are all the input clocks to the block.

> +  "spi_ioclk" for the I/O clock.
> +
>  Required Board Specific Properties:
>  
>  - #address-cells: should be 1.
> -- 
> 2.8.1
> 
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On 07/16/2016 10:30 PM, Rob Herring wrote:
>> diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt 
>> b/Documentation/devicetree/bindings/spi/spi-samsung.txt
>> > index 57d5539..f45c6eb 100644
>> > --- a/Documentation/devicetree/bindings/spi/spi-samsung.txt
>> > +++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
>> > @@ -24,6 +24,15 @@ Required SoC Specific Properties:
>> >  - dma-names: Names for the dma channels. There must be at least one channel
>> >    named "tx" for transmit and named "rx" for receive.
>> >  
>> > +- clocks: specifies the clock IDs provided to the SPI controller; they are
>> > +  required for interacting with the controller itself, for synchronizing the bus
>> > +  and as I/O clock (the latter is required by exynos5433 and exynos7).
>> > +
>> > +- clock-names: string names of the clocks in the 'clocks' property; for all the
>> > +  the devices the names must be "spi", "spi_busclkN" (where N is determined by
>> > +  "samsung,spi-src-clk"), while Exynos5433 should specify a third clock
>
> This sounds like you are describing the configuration of the clocks, not 
> the connections. The binding here should list clocks for all possible 
> vaules of N as those are all the input clocks to the block.
> 
>> > +  "spi_ioclk" for the I/O clock.

I agree we should list all possible spi_busclkN, I must admit  I might
have introduced some confusion by suggesting wording for clock-names 
similar to the above while discussing those things internally.  Afterwards 
I came to a similar conclusion all possible input clocks should be listed
These will differ depending  on the compatible.  I checked in documentation 
of most of related SoCs and for "samsung,s3c6410-spi" or older compatibles 
possible N is 0..2 (PCLK, USBCLK, PLL clock), for "samsung,s5pv210-spi" 
and newer possible N is 0 (SCLK_SPI).  

It's important to have all the input clocks listed so we have a list 
of parent clocks to the SPI controller's internal clocks, should we 
ever decide to model them with the clk API.

--
Thanks, 
Sylwester
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
index 57d5539..f45c6eb 100644
--- a/Documentation/devicetree/bindings/spi/spi-samsung.txt
+++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
@@ -24,6 +24,15 @@  Required SoC Specific Properties:
 - dma-names: Names for the dma channels. There must be at least one channel
   named "tx" for transmit and named "rx" for receive.
 
+- clocks: specifies the clock IDs provided to the SPI controller; they are
+  required for interacting with the controller itself, for synchronizing the bus
+  and as I/O clock (the latter is required by exynos5433 and exynos7).
+
+- clock-names: string names of the clocks in the 'clocks' property; for all the
+  the devices the names must be "spi", "spi_busclkN" (where N is determined by
+  "samsung,spi-src-clk"), while Exynos5433 should specify a third clock
+  "spi_ioclk" for the I/O clock.
+
 Required Board Specific Properties:
 
 - #address-cells: should be 1.