From: dinguyen@opensource.altera.com (Dinh Nguyen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: socfpga: dts: Add a ciu clock node for sdmmc
Date: Mon, 13 Apr 2015 10:05:53 -0500 [thread overview]
Message-ID: <552BDB51.70903@opensource.altera.com> (raw)
In-Reply-To: <73wq1g30ua.fsf@unicorn.hi.pengutronix.de>
Hi Steffen,
On 04/13/2015 03:10 AM, Steffen Trumtrar wrote:
>
> Hi!
>
> dinguyen at opensource.altera.com writes:
>> From: Dinh Nguyen <dinguyen@opensource.altera.com>
>>
>> The CIU(Card Interface Unit) clock is used by the dw_mmc IP to clock an SD
>> card. The ciu_clk is the sdmmc_clk passed through a fixed divider of 4. This patch
>> adds the ciu_clk node and makes the sdmmc_clk it's parent.
>>
>> Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
>> ---
>> arch/arm/boot/dts/socfpga.dtsi | 10 +++++++++-
>> 1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
>> index d9176e6..25418ee 100644
>> --- a/arch/arm/boot/dts/socfpga.dtsi
>> +++ b/arch/arm/boot/dts/socfpga.dtsi
>> @@ -451,6 +451,14 @@
>> clk-phase = <0 135>;
>> };
>>
>> + ciu_clk: ciu_clk {
>> + #clock-cells = <0>;
>> + compatible = "altr,socfpga-gate-clk";
>> + clocks = <&sdmmc_clk>;
>> + clk-gate = <0xa0 8>;
>> + fixed-divider = <4>;
>> + };
>> +
>
> Hm, is this correct? The clk-gate at 0xa0 is for the SDMMC_CLK, no?
> Also, maybe the clock should be named "sdmmc_clk_divided" like in the
> datasheet, so it is easier to find.
>
Well, I didn't want to go down the path of defining a new clock that is
just a fork of the sdmmc_clk, so I just defined it as a gate-clock. I
think ultimately the gating of the sdmmc_clk is being done.
I can rename it to sdmmc_clk_divided.
Dinh
next prev parent reply other threads:[~2015-04-13 15:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-10 20:56 [PATCH] ARM: socfpga: dts: Add a ciu clock node for sdmmc dinguyen at opensource.altera.com
2015-04-13 8:10 ` Steffen Trumtrar
2015-04-13 15:05 ` Dinh Nguyen [this message]
2015-04-13 23:44 ` Doug Anderson
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