[PATCH v2 0/4] Add support for Exynos clock output configuration

Tomasz Figa t.figa at samsung.com
Wed Jul 9 09:53:27 PDT 2014


Kukjin,

On 24.06.2014 18:08, Tomasz Figa wrote:
> On all Exynos SoCs there is a dedicated CLKOUT pin that allows many of
> internal SoC clocks to be output from the SoC. The hardware structure
> of CLKOUT related clocks looks as follows:
> 
> 	CMU	|---> clock0 --------->	|	PMU	|
> 		|			|		|
>     several	|---> clock1 ---------> |	mux	|
>     muxes	|			|	+	|---> CLKOUT
>     dividers	|       ...		|	gate	|
>     and gates	|			|		|
> 		|---> clockN ---------> |		|
> 
> Since the block responsible for handling the pin is PMU, not CMU,
> a separate driver, that binds to PMU node is required and acquires
> all input clocks by standard DT clock look-up. This way we don't need
> any cross-IP block drivers and cross-driver register sharing or
> nodes for fake devices.
> 
> To represent the PMU mux/gate clock, generic composite clock is registered.
> 
> Tested on Odroid U3, with HSIC/USB hub using CLKOUT as reference clock,
> with some additional patches.
> 
> Changes since v1:
> (http://www.spinics.net/lists/arm-kernel/msg333276.html)
>  - rebased onto next-20140624,
>  - fixed #clock-cells values in exynos5250.dtsi and exynos5420.dtsi,
>  - temporarily removed ISP CLKOUT clocks on Exynos4x12, until ISP clock
>    domain handling gets fixed in Exynos4 clock driver.
> Changes since RFC v1:
> (https://lkml.org/lkml/2014/5/15/506)
>  - rebased onto v5 of "Enable usbphy and hsotg for exynos4" series and
>    current HEAD of samsung-clk tree,
>  - added handling of suspend/resume in the driver,
>  - added missing CPU clocks on Exynos4,
>  - added CLK_SET_RATE_PARENT to CMU CLKOUT gates on Exynos4,
>  - fixed bit field width on Exynos4,
>  - added CLKOUT CMU registers of Exynos4 to save/restore list,
>  - added CLK_SET_RATE_PARENT and CLK_SET_RATE_NO_REPARENT to clkout clock,
>  - changed the binding to use 1-cell clock specifier to allow extension
>    with further PMU clocks in future, if needed.
> 
> Tomasz Figa (4):
>   clk: samsung: exynos4: Add missing CPU/DMC clock hierarchy
>   clk: samsung: exynos4: Add CLKOUT clock hierarchy
>   clk: samsung: Add driver to control CLKOUT line on Exynos SoCs
>   ARM: dts: exynos: Update PMU node with CLKOUT related data
> 
>  .../devicetree/bindings/arm/samsung/pmu.txt        |  30 ++++
>  arch/arm/boot/dts/exynos4210.dtsi                  |  10 ++
>  arch/arm/boot/dts/exynos4x12.dtsi                  |   7 +
>  arch/arm/boot/dts/exynos5250.dtsi                  |   3 +
>  arch/arm/boot/dts/exynos5420.dtsi                  |   3 +
>  drivers/clk/samsung/Makefile                       |   1 +
>  drivers/clk/samsung/clk-exynos-clkout.c            | 153 +++++++++++++++++++
>  drivers/clk/samsung/clk-exynos4.c                  | 166 ++++++++++++++++++++-
>  include/dt-bindings/clock/exynos4.h                |   5 +
>  9 files changed, 374 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/clk/samsung/clk-exynos-clkout.c
> 

Is there any progress with consulting this with hardware guys? Could I
have your Ack for this series, so I could put it in my tree and let
other patches base on it (especially on patches 1 and 2)? Thanks in advance.

Best regards,
Tomasz



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