Re: [PATCH v2 0/4] Add support for Exynos clock output configuration
From: Tomasz Figa
Date: Wed Jul 09 2014 - 12:54:23 EST
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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