Re: [PATCH v3 10/12] watchdog: s3c2410: Support separate source clock

From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To: Sam Protsenko <semen.protsenko@linaro.org>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Rob Herring <robh+dt@kernel.org>
Cc: linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH v3 10/12] watchdog: s3c2410: Support separate source clock
Date: Mon, 8 Nov 2021 14:24:28 +0100	[thread overview]
Message-ID: <f1a28b8f-c27d-19ae-a993-3fbe614d17b3@canonical.com> (raw)
In-Reply-To: <20211107202943.8859-11-semen.protsenko@linaro.org>

On 07/11/2021 21:29, Sam Protsenko wrote:
> Right now all devices supported in the driver have the single clock: it
> acts simultaneously as a bus clock (providing register interface
> clocking) and source clock (driving watchdog counter). Some newer Exynos
> chips, like Exynos850, have two separate clocks for that. In that case
> two clocks will be passed to the driver from the resource provider, e.g.
> Device Tree. Provide necessary infrastructure to support that case:
>   - use source clock's rate for all timer related calculations
>   - use bus clock to gate/ungate the register interface
> 
> All devices that use the single clock are kept intact: if only one clock
> is passed from Device Tree, it will be used for both purposes as before.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
> Changes in v3:
>   - Removed has_src_clk field: clk framework can handle NULL clk; added
>     s3c2410wdt_get_freq() function instead, to figure out which clock to
>     use for getting the rate
> 
> Changes in v2:
>   - Reworded commit message to be more formal
>   - Used separate "has_src_clk" trait to tell if source clock is present
>   - Renamed clock variables to match their purpose
>   - Removed caching source clock rate, obtaining it in place each time
>     instead
>   - Renamed err labels for more consistency
> 
>  drivers/watchdog/s3c2410_wdt.c | 56 +++++++++++++++++++++++++---------
>  1 file changed, 41 insertions(+), 15 deletions(-)
> 


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>


Best regards,
Krzysztof