[PATCH v2] clk: exynos4: Fix wrong clock for Exynos4x12 ADC

Tomasz Figa tomasz.figa at gmail.com
Sun Jul 5 22:12:04 PDT 2015

2015-07-06 13:03 GMT+09:00 Krzysztof Kozlowski <k.kozlowski at samsung.com>:
> 2015-06-12 14:46 GMT+09:00 Javier Martinez Canillas <javier at dowhile0.org>:
>> Hello Krzysztof,
>> On Fri, Jun 12, 2015 at 3:53 AM, Krzysztof Kozlowski
>> <k.kozlowski at samsung.com> wrote:
>>> The TSADC gate clock was used in Exynos4x12 DTSI for exynos-adc driver.
>>> However TSADC is present only on Exynos4210 so on Trats2 board (with
>>> Exynos4412 SoC) the exynos-adc driver could not be probed:
>>>    ERROR: could not get clock /adc at 126C0000:adc(0)
>>>    exynos-adc 126c0000.adc: failed getting clock, err = -2
>>>    exynos-adc: probe of 126c0000.adc failed with error -2
>>> Instead on Exynos4x12 SoCs the main clock used by Analog to Digital
>>> Converter is located in different register and it is named in datasheet
>>> as PCLK_ADC. Regardless of the name the purpose of this PCLK_ADC clock
>>> is the same as purpose of TSADC from Exynos4210.
>>> The patch adds gate clock for Exynos4x12 using the proper register so
>>> backward compatibility is preserved. This fixes the probe of exynos-adc
>>> driver on Exynos4x12 boards and allows accessing sensors connected to it
>>> on Trats2 board (ntc,ncp15wb473 AP and battery thermistors).
>>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
>>> Cc: <stable at vger.kernel.org>
>>> Fixes: c63c57433003 ("ARM: dts: Add ADC's dt data to read raw data for exynos4x12")
>>> Link: https://lkml.org/lkml/2015/6/11/85
>>> ---
>>> Changes since v1:
>>> 1. After discussion on LKML this solution was chosen because it smaller,
>>>    simpler, self-contained (one patch to fix issue) and maintains backward
>>>    compatibility. Thanks to Javier Martinez Canillas and Tomasz Figa for
>>>    valuable comments.
>>> 2. Dropped patch 2/2 because now it is not needed. The clock id "TSADC"
>>>    will be used on all Exynos4 boards.
>>> 3. Added CC-stable.
>>> ---
>>>  drivers/clk/samsung/clk-exynos4.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>> Patch looks good to me.
>> Reviewed-by: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
> Hi Tomasz and Sylwester,
> Any comments on this version of patch?
> Tomasz, you gave me comments on previous version. Are their satisfied?

Acked-by: Tomasz Figa <tomasz.figa at gmail.com>

Thanks for pinging.

Best regards,

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