diff mbox series

[V2,2/2] mmc: sdhci-msm: Re-initialize DLL if MCLK is gated dynamically

Message ID 1539005138-32560-3-git-send-email-vbadigan@codeaurora.org (mailing list archive)
State New, archived
Headers show
Series Re-initialize DLL when MCLK is gated dynamically | expand

Commit Message

Veerabhadrarao Badiganti Oct. 8, 2018, 1:25 p.m. UTC
On few SDHCI-MSM controllers, the host controller's clock tuning
circuit may go out of sync if controller clocks are gated which
eventually will result in data CRC, command CRC/timeout errors.
To overcome this h/w limitation, the DLL needs to be re-initialized
and restored with its old settings once clocks are ungated.

Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 drivers/mmc/host/sdhci-msm.c | 67 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 65 insertions(+), 2 deletions(-)

Comments

Evan Green Oct. 16, 2018, 10:28 p.m. UTC | #1
On Mon, Oct 8, 2018 at 6:26 AM Veerabhadrarao Badiganti
<vbadigan@codeaurora.org> wrote:
>
> On few SDHCI-MSM controllers, the host controller's clock tuning
> circuit may go out of sync if controller clocks are gated which
> eventually will result in data CRC, command CRC/timeout errors.
> To overcome this h/w limitation, the DLL needs to be re-initialized
> and restored with its old settings once clocks are ungated.
>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>  drivers/mmc/host/sdhci-msm.c | 67 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 65 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 6918e70..1eb70c0 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -234,6 +234,7 @@ struct sdhci_msm_variant_ops {
>   */
>  struct sdhci_msm_variant_info {
>         bool mci_removed;
> +       bool uses_sdcdc10;

What does that flag mean? Couldn't this just be called something like
restore_dll_config?

>         const struct sdhci_msm_variant_ops *var_ops;
>         const struct sdhci_msm_offset *offset;
>  };
> @@ -264,6 +265,8 @@ struct sdhci_msm_host {
>         u32 vmmc_level[2];
>         bool vqmmc_load;
>         u32 vqmmc_level[2];
> +       bool uses_sdcdc10_dll;
> +       bool restore_sdr_dll_cfg;

restore_sdr_dll_cfg appears to not be used.

>  };
>
>  static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
> @@ -1031,6 +1034,36 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>         return ret;
>  }
>
> +static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
> +{
> +       struct mmc_ios ios = host->mmc->ios;
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +       int ret;
> +
> +       /*
> +        * SDR DLL comes into picure only if clock frequency is greater than
> +        * 100MHz. And its needed only for SDR104, HS200 and HS400 cards.
> +        * Its not needed for HS400es cards.
> +        */
> +       if (host->clock <= CORE_FREQ_100MHZ ||
> +           !(ios.timing == MMC_TIMING_MMC_HS400 ||
> +           ios.timing == MMC_TIMING_MMC_HS200 ||
> +           ios.timing == MMC_TIMING_UHS_SDR104) ||
> +           ios.enhanced_strobe)
> +               return 0;
> +
> +       /* Reset the tuning block */
> +       ret = msm_init_cm_dll(host);

Is this reinit required? It's kind of meaty.

> +       if (ret)
> +               return ret;
> +
> +       /* Restore the tuning block */
> +       ret = msm_config_cm_dll_phase(host, msm_host->saved_tuning_phase);
> +
> +       return ret;
> +}
> +
>  static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  {
>         struct sdhci_host *host = mmc_priv(mmc);
> @@ -1075,7 +1108,6 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>                 if (rc)
>                         return rc;
>
> -               msm_host->saved_tuning_phase = phase;
>                 rc = mmc_send_tuning(mmc, opcode, NULL);
>                 if (!rc) {
>                         /* Tuning is successful at this tuning point */
> @@ -1100,6 +1132,7 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>                 rc = msm_config_cm_dll_phase(host, phase);
>                 if (rc)
>                         return rc;
> +               msm_host->saved_tuning_phase = phase;
>                 dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
>                          mmc_hostname(mmc), phase);
>         } else {
> @@ -1807,19 +1840,39 @@ static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
>
>  static const struct sdhci_msm_variant_info sdhci_msm_mci_var = {
>         .mci_removed = false,
> +       .uses_sdcdc10 = false,
> +       .var_ops = &mci_var_ops,
> +       .offset = &sdhci_msm_mci_offset,
> +};
> +
> +static const struct sdhci_msm_variant_info sdhci_msm_mci_sdcdc10_var = {
> +       .mci_removed = false,
> +       .uses_sdcdc10 = true,
>         .var_ops = &mci_var_ops,
>         .offset = &sdhci_msm_mci_offset,
>  };
>
>  static const struct sdhci_msm_variant_info sdhci_msm_v5_var = {
>         .mci_removed = true,
> +       .uses_sdcdc10 = false,
> +       .var_ops = &v5_var_ops,
> +       .offset = &sdhci_msm_v5_offset,
> +};
> +
> +static const struct sdhci_msm_variant_info sdhci_msm_v5_sdcdc10_var = {
> +       .mci_removed = true,
> +       .uses_sdcdc10 = true,
>         .var_ops = &v5_var_ops,
>         .offset = &sdhci_msm_v5_offset,
>  };
>
>  static const struct of_device_id sdhci_msm_dt_match[] = {
>         {.compatible = "qcom,sdhci-msm-v4", .data = &sdhci_msm_mci_var},
> +       {.compatible = "qcom,sdhci-msm-v4-sdcdc10",
> +                                           .data = &sdhci_msm_mci_sdcdc10_var},
>         {.compatible = "qcom,sdhci-msm-v5", .data = &sdhci_msm_v5_var},
> +       {.compatible = "qcom,sdhci-msm-v5-sdcdc10",
> +                                           .data = &sdhci_msm_v5_sdcdc10_var},
>         {},
>  };
>
> @@ -1880,6 +1933,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>         var_info = of_device_get_match_data(&pdev->dev);
>
>         msm_host->mci_removed = var_info->mci_removed;
> +       msm_host->uses_sdcdc10_dll = var_info->uses_sdcdc10;
>         msm_host->var_ops = var_info->var_ops;
>         msm_host->offset = var_info->offset;
>
> @@ -2124,9 +2178,18 @@ static int sdhci_msm_runtime_resume(struct device *dev)
>         struct sdhci_host *host = dev_get_drvdata(dev);
>         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>         struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +       int ret;
>
> -       return clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
> +       ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
>                                        msm_host->bulk_clks);

It might be nicer to just put an if (ret) return ret; here, instead of
rolling it into the next conditional.

> +       /*
> +        * Whenever core-clock is gated dynamically, it's needed to
> +        * restore the SDR DLL settings when the clock is ungated.
> +        */
> +       if (!ret && msm_host->uses_sdcdc10_dll && msm_host->clk_rate)
> +               ret = sdhci_msm_restore_sdr_dll_config(host);
> +
> +       return ret;
>  }
>  #endif
>
> --
> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
>
Veerabhadrarao Badiganti Oct. 23, 2018, 12:13 p.m. UTC | #2
On 10/17/2018 3:58 AM, Evan Green wrote:
> On Mon, Oct 8, 2018 at 6:26 AM Veerabhadrarao Badiganti
> <vbadigan@codeaurora.org> wrote:
>> On few SDHCI-MSM controllers, the host controller's clock tuning
>> circuit may go out of sync if controller clocks are gated which
>> eventually will result in data CRC, command CRC/timeout errors.
>> To overcome this h/w limitation, the DLL needs to be re-initialized
>> and restored with its old settings once clocks are ungated.
>>
>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
>> ---
>>   drivers/mmc/host/sdhci-msm.c | 67 ++++++++++++++++++++++++++++++++++++++++++--
>>   1 file changed, 65 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 6918e70..1eb70c0 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -234,6 +234,7 @@ struct sdhci_msm_variant_ops {
>>    */
>>   struct sdhci_msm_variant_info {
>>          bool mci_removed;
>> +       bool uses_sdcdc10;
> What does that flag mean? Couldn't this just be called something like
> restore_dll_config?

'sdcdc10' is the DLL code-name that is being used in SDHC controller on 
SDM845.
I should have named it as uses_sdcdc10_dll.
I will update the name to be more meaningful.

>
>>          const struct sdhci_msm_variant_ops *var_ops;
>>          const struct sdhci_msm_offset *offset;
>>   };
>> @@ -264,6 +265,8 @@ struct sdhci_msm_host {
>>          u32 vmmc_level[2];
>>          bool vqmmc_load;
>>          u32 vqmmc_level[2];
>> +       bool uses_sdcdc10_dll;
>> +       bool restore_sdr_dll_cfg;
> restore_sdr_dll_cfg appears to not be used.

Yes, this needs to be removed, will remove it. Thanks for pointing.

>>   };
>>
>>   static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>> @@ -1031,6 +1034,36 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
>>          return ret;
>>   }
>>
>> +static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
>> +{
>> +       struct mmc_ios ios = host->mmc->ios;
>> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +       int ret;
>> +
>> +       /*
>> +        * SDR DLL comes into picure only if clock frequency is greater than
>> +        * 100MHz. And its needed only for SDR104, HS200 and HS400 cards.
>> +        * Its not needed for HS400es cards.
>> +        */
>> +       if (host->clock <= CORE_FREQ_100MHZ ||
>> +           !(ios.timing == MMC_TIMING_MMC_HS400 ||
>> +           ios.timing == MMC_TIMING_MMC_HS200 ||
>> +           ios.timing == MMC_TIMING_UHS_SDR104) ||
>> +           ios.enhanced_strobe)
>> +               return 0;
>> +
>> +       /* Reset the tuning block */
>> +       ret = msm_init_cm_dll(host);
> Is this reinit required? It's kind of meaty.

DLL re-initialization is very-much needed.
Its as per DLL h/w team instructions to support sdcdc10 DLL (10nm DLL)

>> +       if (ret)
>> +               return ret;
>> +
>> +       /* Restore the tuning block */
>> +       ret = msm_config_cm_dll_phase(host, msm_host->saved_tuning_phase);
>> +
>> +       return ret;
>> +}
>> +
>>   static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>   {
>>          struct sdhci_host *host = mmc_priv(mmc);
>> @@ -1075,7 +1108,6 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>                  if (rc)
>>                          return rc;
>>
>> -               msm_host->saved_tuning_phase = phase;
>>                  rc = mmc_send_tuning(mmc, opcode, NULL);
>>                  if (!rc) {
>>                          /* Tuning is successful at this tuning point */
>> @@ -1100,6 +1132,7 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>                  rc = msm_config_cm_dll_phase(host, phase);
>>                  if (rc)
>>                          return rc;
>> +               msm_host->saved_tuning_phase = phase;
>>                  dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
>>                           mmc_hostname(mmc), phase);
>>          } else {
>> @@ -1807,19 +1840,39 @@ static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
>>
>>   static const struct sdhci_msm_variant_info sdhci_msm_mci_var = {
>>          .mci_removed = false,
>> +       .uses_sdcdc10 = false,
>> +       .var_ops = &mci_var_ops,
>> +       .offset = &sdhci_msm_mci_offset,
>> +};
>> +
>> +static const struct sdhci_msm_variant_info sdhci_msm_mci_sdcdc10_var = {
>> +       .mci_removed = false,
>> +       .uses_sdcdc10 = true,
>>          .var_ops = &mci_var_ops,
>>          .offset = &sdhci_msm_mci_offset,
>>   };
>>
>>   static const struct sdhci_msm_variant_info sdhci_msm_v5_var = {
>>          .mci_removed = true,
>> +       .uses_sdcdc10 = false,
>> +       .var_ops = &v5_var_ops,
>> +       .offset = &sdhci_msm_v5_offset,
>> +};
>> +
>> +static const struct sdhci_msm_variant_info sdhci_msm_v5_sdcdc10_var = {
>> +       .mci_removed = true,
>> +       .uses_sdcdc10 = true,
>>          .var_ops = &v5_var_ops,
>>          .offset = &sdhci_msm_v5_offset,
>>   };
>>
>>   static const struct of_device_id sdhci_msm_dt_match[] = {
>>          {.compatible = "qcom,sdhci-msm-v4", .data = &sdhci_msm_mci_var},
>> +       {.compatible = "qcom,sdhci-msm-v4-sdcdc10",
>> +                                           .data = &sdhci_msm_mci_sdcdc10_var},
>>          {.compatible = "qcom,sdhci-msm-v5", .data = &sdhci_msm_v5_var},
>> +       {.compatible = "qcom,sdhci-msm-v5-sdcdc10",
>> +                                           .data = &sdhci_msm_v5_sdcdc10_var},
>>          {},
>>   };
>>
>> @@ -1880,6 +1933,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>>          var_info = of_device_get_match_data(&pdev->dev);
>>
>>          msm_host->mci_removed = var_info->mci_removed;
>> +       msm_host->uses_sdcdc10_dll = var_info->uses_sdcdc10;
>>          msm_host->var_ops = var_info->var_ops;
>>          msm_host->offset = var_info->offset;
>>
>> @@ -2124,9 +2178,18 @@ static int sdhci_msm_runtime_resume(struct device *dev)
>>          struct sdhci_host *host = dev_get_drvdata(dev);
>>          struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>          struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> +       int ret;
>>
>> -       return clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
>> +       ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
>>                                         msm_host->bulk_clks);
> It might be nicer to just put an if (ret) return ret; here, instead of
> rolling it into the next conditional.

Sure. Will update it.

>
>> +       /*
>> +        * Whenever core-clock is gated dynamically, it's needed to
>> +        * restore the SDR DLL settings when the clock is ungated.
>> +        */
>> +       if (!ret && msm_host->uses_sdcdc10_dll && msm_host->clk_rate)
>> +               ret = sdhci_msm_restore_sdr_dll_config(host);
>> +
>> +       return ret;
>>   }
>>   #endif
>>
>> --
>> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
>>
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 6918e70..1eb70c0 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -234,6 +234,7 @@  struct sdhci_msm_variant_ops {
  */
 struct sdhci_msm_variant_info {
 	bool mci_removed;
+	bool uses_sdcdc10;
 	const struct sdhci_msm_variant_ops *var_ops;
 	const struct sdhci_msm_offset *offset;
 };
@@ -264,6 +265,8 @@  struct sdhci_msm_host {
 	u32 vmmc_level[2];
 	bool vqmmc_load;
 	u32 vqmmc_level[2];
+	bool uses_sdcdc10_dll;
+	bool restore_sdr_dll_cfg;
 };
 
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
@@ -1031,6 +1034,36 @@  static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host)
 	return ret;
 }
 
+static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host)
+{
+	struct mmc_ios ios = host->mmc->ios;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	int ret;
+
+	/*
+	 * SDR DLL comes into picure only if clock frequency is greater than
+	 * 100MHz. And its needed only for SDR104, HS200 and HS400 cards.
+	 * Its not needed for HS400es cards.
+	 */
+	if (host->clock <= CORE_FREQ_100MHZ ||
+	    !(ios.timing == MMC_TIMING_MMC_HS400 ||
+	    ios.timing == MMC_TIMING_MMC_HS200 ||
+	    ios.timing == MMC_TIMING_UHS_SDR104) ||
+	    ios.enhanced_strobe)
+		return 0;
+
+	/* Reset the tuning block */
+	ret = msm_init_cm_dll(host);
+	if (ret)
+		return ret;
+
+	/* Restore the tuning block */
+	ret = msm_config_cm_dll_phase(host, msm_host->saved_tuning_phase);
+
+	return ret;
+}
+
 static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
@@ -1075,7 +1108,6 @@  static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		if (rc)
 			return rc;
 
-		msm_host->saved_tuning_phase = phase;
 		rc = mmc_send_tuning(mmc, opcode, NULL);
 		if (!rc) {
 			/* Tuning is successful at this tuning point */
@@ -1100,6 +1132,7 @@  static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		rc = msm_config_cm_dll_phase(host, phase);
 		if (rc)
 			return rc;
+		msm_host->saved_tuning_phase = phase;
 		dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
 			 mmc_hostname(mmc), phase);
 	} else {
@@ -1807,19 +1840,39 @@  static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
 
 static const struct sdhci_msm_variant_info sdhci_msm_mci_var = {
 	.mci_removed = false,
+	.uses_sdcdc10 = false,
+	.var_ops = &mci_var_ops,
+	.offset = &sdhci_msm_mci_offset,
+};
+
+static const struct sdhci_msm_variant_info sdhci_msm_mci_sdcdc10_var = {
+	.mci_removed = false,
+	.uses_sdcdc10 = true,
 	.var_ops = &mci_var_ops,
 	.offset = &sdhci_msm_mci_offset,
 };
 
 static const struct sdhci_msm_variant_info sdhci_msm_v5_var = {
 	.mci_removed = true,
+	.uses_sdcdc10 = false,
+	.var_ops = &v5_var_ops,
+	.offset = &sdhci_msm_v5_offset,
+};
+
+static const struct sdhci_msm_variant_info sdhci_msm_v5_sdcdc10_var = {
+	.mci_removed = true,
+	.uses_sdcdc10 = true,
 	.var_ops = &v5_var_ops,
 	.offset = &sdhci_msm_v5_offset,
 };
 
 static const struct of_device_id sdhci_msm_dt_match[] = {
 	{.compatible = "qcom,sdhci-msm-v4", .data = &sdhci_msm_mci_var},
+	{.compatible = "qcom,sdhci-msm-v4-sdcdc10",
+					    .data = &sdhci_msm_mci_sdcdc10_var},
 	{.compatible = "qcom,sdhci-msm-v5", .data = &sdhci_msm_v5_var},
+	{.compatible = "qcom,sdhci-msm-v5-sdcdc10",
+					    .data = &sdhci_msm_v5_sdcdc10_var},
 	{},
 };
 
@@ -1880,6 +1933,7 @@  static int sdhci_msm_probe(struct platform_device *pdev)
 	var_info = of_device_get_match_data(&pdev->dev);
 
 	msm_host->mci_removed = var_info->mci_removed;
+	msm_host->uses_sdcdc10_dll = var_info->uses_sdcdc10;
 	msm_host->var_ops = var_info->var_ops;
 	msm_host->offset = var_info->offset;
 
@@ -2124,9 +2178,18 @@  static int sdhci_msm_runtime_resume(struct device *dev)
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	int ret;
 
-	return clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
 				       msm_host->bulk_clks);
+	/*
+	 * Whenever core-clock is gated dynamically, it's needed to
+	 * restore the SDR DLL settings when the clock is ungated.
+	 */
+	if (!ret && msm_host->uses_sdcdc10_dll && msm_host->clk_rate)
+		ret = sdhci_msm_restore_sdr_dll_config(host);
+
+	return ret;
 }
 #endif