[PATCH v3 03/36] mmc: msm_sdhci: use modern clock handling

[Caleb Connolly]

On 01/02/2024 08:19, Sumit Garg wrote:
> On Tue, 30 Jan 2024 at 19:35, Caleb Connolly <caleb.connolly at linaro.org> wrote:
>>
>> Use the clk_* helper functions and the correct property name for clocks.
> 
> This still doesn't handle fixed clocks like in case of QCS404, upstream DT says:
> 
>                 sdcc1: mmc at 7804000 {
>                         compatible = "qcom,qcs404-sdhci", "qcom,sdhci-msm-v5";
>                         ...
>                         clocks = <&gcc GCC_SDCC1_AHB_CLK>,
>                                  <&gcc GCC_SDCC1_APPS_CLK>,
>                                  <&xo_board>;
>                         clock-names = "iface", "core", "xo";
>                         ...
>                 };
> 
> Due to that "xo" fixed clock we get:
> 
> MMC:   clk_set_rate(clk=00000000ffaf7348, rate=19200000)
> Unknown clock id 0
> clk_set_rate(clk=00000000ffaf7598, rate=19200000)
> Unknown clock id 0
> clk_set_rate(clk=00000000ffb08868, rate=400000)
> mmc at 7804000: 0

Does MMC work? This doesn't look like a probe failure to me.

But yes this does look odd, somehow qcs404_clk_set_rate() is being
called with clk->id == 0. The xo_board clock uses a different driver so
it can't be that...

Could you try and add some more logging around here? I can't see what
might be causing this.
> 
> -Sumit
> 
>>
>> Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>
>> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
>> ---
>>  drivers/mmc/msm_sdhci.c | 69 ++++++++++++++++++++++++++++++++-----------------
>>  1 file changed, 46 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/mmc/msm_sdhci.c b/drivers/mmc/msm_sdhci.c
>> index 604f9c3ff99c..863e6007a905 100644
>> --- a/drivers/mmc/msm_sdhci.c
>> +++ b/drivers/mmc/msm_sdhci.c
>> @@ -44,6 +44,7 @@ struct msm_sdhc_plat {
>>  struct msm_sdhc {
>>         struct sdhci_host host;
>>         void *base;
>> +       struct clk_bulk clks;
>>  };
>>
>>  struct msm_sdhc_variant_info {
>> @@ -54,36 +55,56 @@ DECLARE_GLOBAL_DATA_PTR;
>>
>>  static int msm_sdc_clk_init(struct udevice *dev)
>>  {
>> -       int node = dev_of_offset(dev);
>> -       uint clk_rate = fdtdec_get_uint(gd->fdt_blob, node, "clock-frequency",
>> -                                       400000);
>> -       uint clkd[2]; /* clk_id and clk_no */
>> -       int clk_offset;
>> -       struct udevice *clk_dev;
>> -       struct clk clk;
>> -       int ret;
>> +       struct msm_sdhc *prv = dev_get_priv(dev);
>> +       ofnode node = dev_ofnode(dev);
>> +       uint clk_rate;
>> +       int ret, i = 0, n_clks;
>> +       const char *clk_name;
>>
>> -       ret = fdtdec_get_int_array(gd->fdt_blob, node, "clock", clkd, 2);
>> +       ret = ofnode_read_u32(node, "clock-frequency", &clk_rate);
>>         if (ret)
>> -               return ret;
>> +               clk_rate = 400000;
>>
>> -       clk_offset = fdt_node_offset_by_phandle(gd->fdt_blob, clkd[0]);
>> -       if (clk_offset < 0)
>> -               return clk_offset;
>> -
>> -       ret = uclass_get_device_by_of_offset(UCLASS_CLK, clk_offset, &clk_dev);
>> -       if (ret)
>> +       ret = clk_get_bulk(dev, &prv->clks);
>> +       if (ret) {
>> +               debug("Couldn't get mmc clocks: %d\n", ret);
>>                 return ret;
>> +       }
>>
>> -       clk.id = clkd[1];
>> -       ret = clk_request(clk_dev, &clk);
>> -       if (ret < 0)
>> +       ret = clk_enable_bulk(&prv->clks);
>> +       if (ret) {
>> +               debug("Couldn't enable mmc clocks: %d\n", ret);
>>                 return ret;
>> +       }
>>
>> -       ret = clk_set_rate(&clk, clk_rate);
>> -       clk_free(&clk);
>> -       if (ret < 0)
>> -               return ret;
>> +       /* If clock-names is unspecified, then the first clock is the core clock */
>> +       if (!ofnode_get_property(node, "clock-names", &n_clks)) {
>> +               if (!clk_set_rate(&prv->clks.clks[0], clk_rate)) {
>> +                       printf("Couldn't set core clock rate: %d\n", ret);
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       /* Find the index of the "core" clock */
>> +       while (i < n_clks) {
>> +               ofnode_read_string_index(node, "clock-names", i, &clk_name);
>> +               if (!strcmp(clk_name, "core"))
>> +                       break;
>> +               i++;
>> +       }
>> +
>> +       if (i >= prv->clks.count) {
>> +               printf("Couldn't find core clock (index %d but only have %d clocks)\n", i,
>> +                      prv->clks.count);
>> +               return -EINVAL;
>> +       }
>> +
>> +       /* The clock is already enabled by the clk_bulk above */
>> +       ret = clk_set_rate(&prv->clks.clks[i], clk_rate);
>> +       if (!ret) {
>> +               printf("Couldn't set core clock rate: %d\n", ret);
>> +               return -EINVAL;
>> +       }
>>
>>         return 0;
>>  }
>> @@ -188,6 +209,8 @@ static int msm_sdc_remove(struct udevice *dev)
>>         if (!var_info->mci_removed)
>>                 writel(0, priv->base + SDCC_MCI_HC_MODE);
>>
>> +       clk_release_bulk(&priv->clks);
>> +
>>         return 0;
>>  }
>>
>>
>> --
>> 2.43.0
>>

-- 
// Caleb (they/them)