Re: [PATCH] mmc: sdhci-of-arasan: Use standard mmc_clk_phase_map infrastructure

Shawn Lin
2026-03-24T08:34:54Z

Hi Sai

在 2026/03/23 星期一 17:27, Sai Krishna Potthuri 写道:
>
>
>> -----Original Message-----
>> From: Simek, Michal <michal.simek@amd.com>
>> Sent: Thursday, March 19, 2026 3:39 PM
>> To: Shawn Lin <shawn.lin@rock-chips.com>; Ulf Hansson
>> <ulf.hansson@linaro.org>; Potthuri, Sai Krishna
>> <sai.krishna.potthuri@amd.com>
>> Cc: linux-mmc@vger.kernel.org; Adrian Hunter <adrian.hunter@intel.com>;
>> linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH] mmc: sdhci-of-arasan: Use standard
>> mmc_clk_phase_map infrastructure
>>
>> +Sai,
>>
>> On 3/17/26 03:17, Shawn Lin wrote:
>> > Convert the Arasan SDHCI driver to use the mainline standard
>> > mmc_clk_phase_map infrastructure instead of custom clk_phase_in/out
>> > arrays as well as arasan_dt_read_clk_phase().
>> >
>> > The phase values for ZynqMP, Versal, and Versal-NET platforms are
>> > still initialized from the predefined tables, but now follow the
>> > standard phase_map format with valid flag.
>> >
>> > Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>> > ---
>> >
>> >   drivers/mmc/host/sdhci-of-arasan.c | 79
>> +++++++++-----------------------------
>> >   1 file changed, 18 insertions(+), 61 deletions(-)
>> >
>> > diff --git a/drivers/mmc/host/sdhci-of-arasan.c
>> > b/drivers/mmc/host/sdhci-of-arasan.c
>> > index caf9723..b97d27c 100644
>> > --- a/drivers/mmc/host/sdhci-of-arasan.c
>> > +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> > @@ -152,8 +152,7 @@ struct sdhci_arasan_clk_ops {
>> >    * @sdcardclk:        Pointer to normal 'struct clock' for
>> sdcardclk_hw.
>> >    * @sampleclk_hw:    Struct for the clock we might provide to a PHY.
>> >    * @sampleclk:        Pointer to normal 'struct clock' for
>> sampleclk_hw.
>> > - * @clk_phase_in:    Array of Input Clock Phase Delays for all
>> speed modes
>> > - * @clk_phase_out:    Array of Output Clock Phase Delays for all speed
>> modes
>> > + * @phase_map:        Struct for mmc_clk_phase_map provided.
>> >    * @set_clk_delays:    Function pointer for setting Clock Delays
>> >    * @clk_of_data:    Platform specific runtime clock data storage
>> pointer
>> >    */
>> > @@ -162,8 +161,7 @@ struct sdhci_arasan_clk_data {
>> >       struct clk      *sdcardclk;
>> >       struct clk_hw    sampleclk_hw;
>> >       struct clk      *sampleclk;
>> > -    int        clk_phase_in[MMC_TIMING_MMC_HS400 + 1];
>> > -    int        clk_phase_out[MMC_TIMING_MMC_HS400 + 1];
>> > +    struct mmc_clk_phase_map phase_map;
>> >       void        (*set_clk_delays)(struct sdhci_host *host);
>> >       void        *clk_of_data;
>> >   };
>> > @@ -1248,37 +1246,13 @@ static void sdhci_arasan_set_clk_delays(struct
>> sdhci_host *host)
>> >       struct sdhci_arasan_data *sdhci_arasan =
>> sdhci_pltfm_priv(pltfm_host);
>> >       struct sdhci_arasan_clk_data *clk_data = &sdhci_arasan->clk_data;
>> >
>> > -    clk_set_phase(clk_data->sampleclk,
>> > -              clk_data->clk_phase_in[host->timing]);
>> > -    clk_set_phase(clk_data->sdcardclk,
>> > -              clk_data->clk_phase_out[host->timing]);
>> > -}
>> > -
>> > -static void arasan_dt_read_clk_phase(struct device *dev,
>> > -                     struct sdhci_arasan_clk_data *clk_data,
>> > -                     unsigned int timing, const char *prop)
>> > -{
>> > -    struct device_node *np = dev->of_node;
>> > -
>> > -    u32 clk_phase[2] = {0};
>> > -    int ret;
>> > -
>> > -    /*
>> > -     * Read Tap Delay values from DT, if the DT does not contain the
>> > -     * Tap Values then use the pre-defined values.
>> > -     */
>> > -    ret = of_property_read_variable_u32_array(np, prop, &clk_phase[0],
>> > -                          2, 0);
>> > -    if (ret < 0) {
>> > -        dev_dbg(dev, "Using predefined clock phase for %s = %d
>> %d\n",
>> > -            prop, clk_data->clk_phase_in[timing],
>> > -            clk_data->clk_phase_out[timing]);
>> > +    if (!clk_data->phase_map.phase[host->timing].valid)
>> >           return;
>
> This check breaks platforms relying on default phase values. When DT
> properties are absent, mmc_of_parse_timing_phase() sets valid=false,
> which causes sdhci_arasan_set_clk_delays() to skip phase configuration.
>

Ah, you're right, thanks for catching this.

I'll send a v2 patch that removes the validity check in
sdhci_arasan_set_clk_delays().

> Regards
> Sai Krishna
>
>> > -    }
>> >
>> > -    /* The values read are Input and Output Clock Delays in order */
>> > -    clk_data->clk_phase_in[timing] = clk_phase[0];
>> > -    clk_data->clk_phase_out[timing] = clk_phase[1];
>> > +    clk_set_phase(clk_data->sampleclk,
>> > +              clk_data->phase_map.phase[host->timing].in_deg);
>> > +    clk_set_phase(clk_data->sdcardclk,
>> > +              clk_data->phase_map.phase[host->timing].out_deg);
>> >   }
>> >
>> >   /**
>> > @@ -1315,8 +1289,9 @@ static void arasan_dt_parse_clk_phases(struct
>> device *dev,
>> >           }
>> >
>> >           for (i = 0; i <= MMC_TIMING_MMC_HS400; i++) {
>> > -            clk_data->clk_phase_in[i] = zynqmp_iclk_phase[i];
>> > -            clk_data->clk_phase_out[i] = zynqmp_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].in_deg =
>> zynqmp_iclk_phase[i];
>> > +            clk_data->phase_map.phase[i].out_deg =
>> zynqmp_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].valid = true;
>> >           }
>> >       }
>> >
>> > @@ -1327,8 +1302,9 @@ static void arasan_dt_parse_clk_phases(struct
>> device *dev,
>> >               VERSAL_OCLK_PHASE;
>> >
>> >           for (i = 0; i <= MMC_TIMING_MMC_HS400; i++) {
>> > -            clk_data->clk_phase_in[i] = versal_iclk_phase[i];
>> > -            clk_data->clk_phase_out[i] = versal_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].in_deg =
>> versal_iclk_phase[i];
>> > +            clk_data->phase_map.phase[i].out_deg =
>> versal_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].valid = true;
>> >           }
>> >       }
>> >       if (of_device_is_compatible(dev->of_node,
>> "xlnx,versal-net-emmc"))
>> > { @@ -1338,32 +1314,13 @@ static void arasan_dt_parse_clk_phases(struct
>> device *dev,
>> >               VERSAL_NET_EMMC_OCLK_PHASE;
>> >
>> >           for (i = 0; i <= MMC_TIMING_MMC_HS400; i++) {
>> > -            clk_data->clk_phase_in[i] = versal_net_iclk_phase[i];
>> > -            clk_data->clk_phase_out[i] =
>> versal_net_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].in_deg =
>> versal_net_iclk_phase[i];
>> > +            clk_data->phase_map.phase[i].out_deg =
>> versal_net_oclk_phase[i];
>> > +            clk_data->phase_map.phase[i].valid = true;
>> >           }
>> >       }
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_LEGACY,
>> > -                 "clk-phase-legacy");
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS,
>> > -                 "clk-phase-mmc-hs");
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_SD_HS,
>> > -                 "clk-phase-sd-hs");
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR12,
>> > -                 "clk-phase-uhs-sdr12");
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR25,
>> > -                 "clk-phase-uhs-sdr25");
>> > -    arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR50,
>> > -                 "clk-phase-uhs-sdr50");
>> > -    arasan_dt_read_clk_phase(dev, clk_data,
>> MMC_TIMING_UHS_SDR104,
>> > -                 "clk-phase-uhs-sdr104");
>> > -    arasan_dt_read_clk_phase(dev, clk_data,
>> MMC_TIMING_UHS_DDR50,
>> > -                 "clk-phase-uhs-ddr50");
>> > -    arasan_dt_read_clk_phase(dev, clk_data,
>> MMC_TIMING_MMC_DDR52,
>> > -                 "clk-phase-mmc-ddr52");
>> > -    arasan_dt_read_clk_phase(dev, clk_data,
>> MMC_TIMING_MMC_HS200,
>> > -                 "clk-phase-mmc-hs200");
>> > -    arasan_dt_read_clk_phase(dev, clk_data,
>> MMC_TIMING_MMC_HS400,
>> > -                 "clk-phase-mmc-hs400");
>> > +
>> > +    mmc_of_parse_clk_phase(dev, &clk_data->phase_map);
>> >   }
>> >
>> >   static const struct sdhci_pltfm_data sdhci_arasan_pdata = {
>>
>> please take a look at this patch.
>> I was talking to him yesterday and he needs to finish two things
>> before he has
>> time to look at it. That's why please give him some time.
>>
>> Thanks,
>> Michal
>
>