From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ritesh Harjani Subject: Re: [PATCH v5 03/12] mmc: sdhci-msm: add pltfm_data support to get clk-rates from DT Date: Tue, 11 Oct 2016 14:36:19 +0530 Message-ID: <9db96ae7-9a5e-1494-2371-e5b346a08155@codeaurora.org> References: <1475678440-3525-1-git-send-email-riteshh@codeaurora.org> <1475678440-3525-4-git-send-email-riteshh@codeaurora.org> <20161010125738.GA26940@rob-hp-laptop> <1a7f9c09-70a6-da2a-ca84-78a0331e3b4d@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org To: Rob Herring Cc: Ulf Hansson , "linux-mmc@vger.kernel.org" , Adrian Hunter , Shawn Lin , David Brown , Andy Gross , "devicetree@vger.kernel.org" , linux-arm-msm , georgi.djakov@linaro.org, alex.lemberg@sandisk.com, mateusz.nowak@intel.com, Yuliy.Izrailov@sandisk.com, asutoshd@codeaurora.org, David Griego , Sahitya Tummala , venkatg@codeaurora.org, Stephen Boyd , Bjorn Andersson , pramod.gurav@linaro.org List-Id: linux-arm-msm@vger.kernel.org Hi Rob On 10/11/2016 12:59 AM, Rob Herring wrote: > On Mon, Oct 10, 2016 at 11:07 AM, Ritesh Harjani wrote: >> Hi Rob, >> >> Thanks for review. >> >> On 10/10/2016 6:27 PM, Rob Herring wrote: >>> >>> On Wed, Oct 05, 2016 at 08:10:31PM +0530, Ritesh Harjani wrote: >>>> >>>> This adds support for sdhc-msm controllers to get supported >>>> clk-rates from DT. sdhci-msm would need it's own set_clock >>>> ops to be implemented. For this, supported clk-rates needs >>>> to be populated in sdhci_msm_pltfm_data. >>>> >>>> Signed-off-by: Ritesh Harjani >>>> --- >>>> .../devicetree/bindings/mmc/sdhci-msm.txt | 1 + >>>> drivers/mmc/host/sdhci-msm.c | 48 >>>> ++++++++++++++++++++++ >>>> 2 files changed, 49 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt >>>> b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt >>>> index 485483a..6a83b38 100644 >>>> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt >>>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt >>>> @@ -17,6 +17,7 @@ Required properties: >>>> "iface" - Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) >>>> (required) >>>> "core" - SDC MMC clock (MCLK) (required) >>>> "bus" - SDCC bus voter clock (optional) >>>> +- clk-rates: Array of supported GCC clock frequencies for sdhc, Units - >>>> Hz. >>> >>> >>> Why can't some combination of assigned-clock-rates and querying the >>> clock provider for rates be used here? >> >> From what I understood, assigned-clock-rates would only work for setting >> some default clock rates for certain clocks by calling >> of_clk_set_defaults. >> >> Whereas the requirement here is - >> That since SDHC msm directly controls the clk(core clock) at source, it's >> sdhci-msm driver needs to know the supported clk-rates by the underlying >> platform to configure the nearest floor value supported on this platform >> (when the request arrives from the core layer to switch the clock). > > Why does clk_round_rate not work for you? That will round down to the > nearest frequency supported. clk_round_rate will round off to nearest supported "ceil" frequency. But we require nearest rounded off "floor" frequency. > >> Hence the table of clk-rates is provided for sdhci-msm. >> >>> >>> Minimally this would need unit suffix and either be made common or have >>> a vendor prefix. >> >> Sure will this work in that case - "qcom-clk-rates" > > "qcom,clk-rates", but I'm not yet convinced this is right. > > Rob > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >