[PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

Some controllers can have internal mechanism to inform the SW that it
is ready for voltage switching. For such controllers, changing voltage
before the HW is ready can result in various issues.

During setup/cleanup of host, check whether regulator enable/disable
was already done by platform driver.

Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..ea7ce1d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3616,6 +3616,7 @@ int sdhci_setup_host(struct sdhci_host *host)
 	unsigned int override_timeout_clk;
 	u32 max_clk;
 	int ret;
+	bool enable_vqmmc = false;
 
 	WARN_ON(host == NULL);
 	if (host == NULL)
@@ -3629,9 +3630,12 @@ int sdhci_setup_host(struct sdhci_host *host)
 	 * the host can take the appropriate action if regulators are not
 	 * available.
 	 */
-	ret = mmc_regulator_get_supply(mmc);
-	if (ret)
-		return ret;
+	if (!mmc->supply.vqmmc) {
+		ret = mmc_regulator_get_supply(mmc);
+		if (ret)
+			return ret;
+		enable_vqmmc  = true;
+	}
 
 	DBG("Version:   0x%08x | Present:  0x%08x\n",
 	    sdhci_readw(host, SDHCI_HOST_VERSION),
@@ -3880,7 +3884,15 @@ int sdhci_setup_host(struct sdhci_host *host)
 		mmc->caps |= MMC_CAP_NEEDS_POLL;
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
-		ret = regulator_enable(mmc->supply.vqmmc);
+		if (enable_vqmmc) {
+			ret = regulator_enable(mmc->supply.vqmmc);
+			if (ret) {
+				pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
+					mmc_hostname(mmc), ret);
+				mmc->supply.vqmmc = ERR_PTR(-EINVAL);
+			}
+			host->vqmmc_enabled = !ret;
+		}
 
 		/* If vqmmc provides no 1.8V signalling, then there's no UHS */
 		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
@@ -3893,12 +3905,6 @@ int sdhci_setup_host(struct sdhci_host *host)
 		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
 						    3600000))
 			host->flags &= ~SDHCI_SIGNALING_330;
-
-		if (ret) {
-			pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
-				mmc_hostname(mmc), ret);
-			mmc->supply.vqmmc = ERR_PTR(-EINVAL);
-		}
 	}
 
 	if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
@@ -4136,7 +4142,7 @@ int sdhci_setup_host(struct sdhci_host *host)
 	return 0;
 
 unreg:
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 undma:
 	if (host->align_buffer)
@@ -4154,7 +4160,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
 {
 	struct mmc_host *mmc = host->mmc;
 
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 
 	if (host->align_buffer)
@@ -4287,7 +4293,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 
 	tasklet_kill(&host->finish_tasklet);
 
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 
 	if (host->align_buffer)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index b001cf4..3c28152 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -524,6 +524,7 @@ struct sdhci_host {
 	bool pending_reset;	/* Cmd/data reset is pending */
 	bool irq_wake_enabled;	/* IRQ wakeup is enabled */
 	bool v4_mode;		/* Host Version 4 Enable */
+	bool vqmmc_enabled;	/* Vqmmc is enabled */
 
 	struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];	/* Requests done */
 	struct mmc_command *cmd;	/* Current command */
-- 
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.

[PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

Some controllers can have internal mechanism to inform the SW that it
is ready for voltage switching. For such controllers, changing voltage
before the HW is ready can result in various issues.

During setup/cleanup of host, check whether regulator enable/disable
was already done by platform driver.

Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 99bdae5..ea7ce1d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3616,6 +3616,7 @@ int sdhci_setup_host(struct sdhci_host *host)
 	unsigned int override_timeout_clk;
 	u32 max_clk;
 	int ret;
+	bool enable_vqmmc = false;
 
 	WARN_ON(host == NULL);
 	if (host == NULL)
@@ -3629,9 +3630,12 @@ int sdhci_setup_host(struct sdhci_host *host)
 	 * the host can take the appropriate action if regulators are not
 	 * available.
 	 */
-	ret = mmc_regulator_get_supply(mmc);
-	if (ret)
-		return ret;
+	if (!mmc->supply.vqmmc) {
+		ret = mmc_regulator_get_supply(mmc);
+		if (ret)
+			return ret;
+		enable_vqmmc  = true;
+	}
 
 	DBG("Version:   0x%08x | Present:  0x%08x\n",
 	    sdhci_readw(host, SDHCI_HOST_VERSION),
@@ -3880,7 +3884,15 @@ int sdhci_setup_host(struct sdhci_host *host)
 		mmc->caps |= MMC_CAP_NEEDS_POLL;
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {
-		ret = regulator_enable(mmc->supply.vqmmc);
+		if (enable_vqmmc) {
+			ret = regulator_enable(mmc->supply.vqmmc);
+			if (ret) {
+				pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
+					mmc_hostname(mmc), ret);
+				mmc->supply.vqmmc = ERR_PTR(-EINVAL);
+			}
+			host->vqmmc_enabled = !ret;
+		}
 
 		/* If vqmmc provides no 1.8V signalling, then there's no UHS */
 		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
@@ -3893,12 +3905,6 @@ int sdhci_setup_host(struct sdhci_host *host)
 		if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
 						    3600000))
 			host->flags &= ~SDHCI_SIGNALING_330;
-
-		if (ret) {
-			pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
-				mmc_hostname(mmc), ret);
-			mmc->supply.vqmmc = ERR_PTR(-EINVAL);
-		}
 	}
 
 	if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
@@ -4136,7 +4142,7 @@ int sdhci_setup_host(struct sdhci_host *host)
 	return 0;
 
 unreg:
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 undma:
 	if (host->align_buffer)
@@ -4154,7 +4160,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
 {
 	struct mmc_host *mmc = host->mmc;
 
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 
 	if (host->align_buffer)
@@ -4287,7 +4293,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 
 	tasklet_kill(&host->finish_tasklet);
 
-	if (!IS_ERR(mmc->supply.vqmmc))
+	if (host->vqmmc_enabled)
 		regulator_disable(mmc->supply.vqmmc);
 
 	if (host->align_buffer)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index b001cf4..3c28152 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -524,6 +524,7 @@ struct sdhci_host {
 	bool pending_reset;	/* Cmd/data reset is pending */
 	bool irq_wake_enabled;	/* IRQ wakeup is enabled */
 	bool v4_mode;		/* Host Version 4 Enable */
+	bool vqmmc_enabled;	/* Vqmmc is enabled */
 
 	struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];	/* Requests done */
 	struct mmc_command *cmd;	/* Current command */
-- 
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.

Re: [PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Evan Green]

On Mon, Oct 8, 2018 at 6:22 AM Veerabhadrarao Badiganti
<vbadigan@codeaurora.org> wrote:
>
> From: Vijay Viswanath <vviswana@codeaurora.org>
>
> Some controllers can have internal mechanism to inform the SW that it
> is ready for voltage switching. For such controllers, changing voltage
> before the HW is ready can result in various issues.
>
> During setup/cleanup of host, check whether regulator enable/disable
> was already done by platform driver.
>
> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>  drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
>  drivers/mmc/host/sdhci.h |  1 +
>  2 files changed, 20 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..ea7ce1d 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3616,6 +3616,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>         unsigned int override_timeout_clk;
>         u32 max_clk;
>         int ret;
> +       bool enable_vqmmc = false;
>
>         WARN_ON(host == NULL);
>         if (host == NULL)
> @@ -3629,9 +3630,12 @@ int sdhci_setup_host(struct sdhci_host *host)
>          * the host can take the appropriate action if regulators are not
>          * available.
>          */
> -       ret = mmc_regulator_get_supply(mmc);
> -       if (ret)
> -               return ret;
> +       if (!mmc->supply.vqmmc) {
> +               ret = mmc_regulator_get_supply(mmc);
> +               if (ret)
> +                       return ret;
> +               enable_vqmmc  = true;
> +       }

Did you not like my suggestion in the previous patch of changing
mmc_regulator_get_supply to only get supplies that were not set
previously? What you have here is almost the same, except you've got
this weird coupling where if vqmmc is already present, you implicitly
skip looking at vmmc entirely (since mmc_regulator_get_supply does
more than just get vqmmc).

>
>         DBG("Version:   0x%08x | Present:  0x%08x\n",
>             sdhci_readw(host, SDHCI_HOST_VERSION),
> @@ -3880,7 +3884,15 @@ int sdhci_setup_host(struct sdhci_host *host)
>                 mmc->caps |= MMC_CAP_NEEDS_POLL;
>
>         if (!IS_ERR(mmc->supply.vqmmc)) {
> -               ret = regulator_enable(mmc->supply.vqmmc);
> +               if (enable_vqmmc) {
> +                       ret = regulator_enable(mmc->supply.vqmmc);
> +                       if (ret) {
> +                               pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
> +                                       mmc_hostname(mmc), ret);
> +                               mmc->supply.vqmmc = ERR_PTR(-EINVAL);
> +                       }
> +                       host->vqmmc_enabled = !ret;
> +               }
>
>                 /* If vqmmc provides no 1.8V signalling, then there's no UHS */
>                 if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
> @@ -3893,12 +3905,6 @@ int sdhci_setup_host(struct sdhci_host *host)
>                 if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
>                                                     3600000))
>                         host->flags &= ~SDHCI_SIGNALING_330;
> -
> -               if (ret) {
> -                       pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
> -                               mmc_hostname(mmc), ret);
> -                       mmc->supply.vqmmc = ERR_PTR(-EINVAL);
> -               }
>         }
>
>         if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
> @@ -4136,7 +4142,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>         return 0;
>
>  unreg:
> -       if (!IS_ERR(mmc->supply.vqmmc))
> +       if (host->vqmmc_enabled)
>                 regulator_disable(mmc->supply.vqmmc);
>  undma:
>         if (host->align_buffer)
> @@ -4154,7 +4160,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
>  {
>         struct mmc_host *mmc = host->mmc;
>
> -       if (!IS_ERR(mmc->supply.vqmmc))
> +       if (host->vqmmc_enabled)
>                 regulator_disable(mmc->supply.vqmmc);
>
>         if (host->align_buffer)
> @@ -4287,7 +4293,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
>
>         tasklet_kill(&host->finish_tasklet);
>
> -       if (!IS_ERR(mmc->supply.vqmmc))
> +       if (host->vqmmc_enabled)
>                 regulator_disable(mmc->supply.vqmmc);
>
>         if (host->align_buffer)
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index b001cf4..3c28152 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -524,6 +524,7 @@ struct sdhci_host {
>         bool pending_reset;     /* Cmd/data reset is pending */
>         bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>         bool v4_mode;           /* Host Version 4 Enable */
> +       bool vqmmc_enabled;     /* Vqmmc is enabled */

I still don't love this, since it doesn't mean what it says. Everyone
else that has a vqmmc_enabled member uses it to actually mean "vqmmc
is enabled", but this doesn't mean that. For example, you don't clear
this when you disable the regulator in patch 3, so this would be set
even if the regulator is disabled, and you don't set it when sdhci
enables the regulator, so the regulator is on when this flag is not
set.

At the very least, I think a rename is in order. I'm struggling with
the rename, since
"vqmmc_pltfrm_enable_but_feel_free_to_call_set_voltage_anywhere" is
too long. I guess vqmmc_pltfrm_enabled is the best I've got for now.

>
>         struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
>         struct mmc_command *cmd;        /* Current command */
> --
> 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.
>

Re: [PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Veerabhadrarao Badiganti]

On 10/17/2018 3:39 AM, Evan Green wrote:
> On Mon, Oct 8, 2018 at 6:22 AM Veerabhadrarao Badiganti
> <vbadigan@codeaurora.org> wrote:
>> From: Vijay Viswanath <vviswana@codeaurora.org>
>>
>> Some controllers can have internal mechanism to inform the SW that it
>> is ready for voltage switching. For such controllers, changing voltage
>> before the HW is ready can result in various issues.
>>
>> During setup/cleanup of host, check whether regulator enable/disable
>> was already done by platform driver.
>>
>> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
>> ---
>>   drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
>>   drivers/mmc/host/sdhci.h |  1 +
>>   2 files changed, 20 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 99bdae5..ea7ce1d 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3616,6 +3616,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>>          unsigned int override_timeout_clk;
>>          u32 max_clk;
>>          int ret;
>> +       bool enable_vqmmc = false;
>>
>>          WARN_ON(host == NULL);
>>          if (host == NULL)
>> @@ -3629,9 +3630,12 @@ int sdhci_setup_host(struct sdhci_host *host)
>>           * the host can take the appropriate action if regulators are not
>>           * available.
>>           */
>> -       ret = mmc_regulator_get_supply(mmc);
>> -       if (ret)
>> -               return ret;
>> +       if (!mmc->supply.vqmmc) {
>> +               ret = mmc_regulator_get_supply(mmc);
>> +               if (ret)
>> +                       return ret;
>> +               enable_vqmmc  = true;
>> +       }
> Did you not like my suggestion in the previous patch of changing
> mmc_regulator_get_supply to only get supplies that were not set
> previously? What you have here is almost the same, except you've got
> this weird coupling where if vqmmc is already present, you implicitly
> skip looking at vmmc entirely (since mmc_regulator_get_supply does
> more than just get vqmmc).

sure. Will update mmc_regulator_get_supply() as you suggested.

>>          DBG("Version:   0x%08x | Present:  0x%08x\n",
>>              sdhci_readw(host, SDHCI_HOST_VERSION),
>> @@ -3880,7 +3884,15 @@ int sdhci_setup_host(struct sdhci_host *host)
>>                  mmc->caps |= MMC_CAP_NEEDS_POLL;
>>
>>          if (!IS_ERR(mmc->supply.vqmmc)) {
>> -               ret = regulator_enable(mmc->supply.vqmmc);
>> +               if (enable_vqmmc) {
>> +                       ret = regulator_enable(mmc->supply.vqmmc);
>> +                       if (ret) {
>> +                               pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
>> +                                       mmc_hostname(mmc), ret);
>> +                               mmc->supply.vqmmc = ERR_PTR(-EINVAL);
>> +                       }
>> +                       host->vqmmc_enabled = !ret;
>> +               }
>>
>>                  /* If vqmmc provides no 1.8V signalling, then there's no UHS */
>>                  if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
>> @@ -3893,12 +3905,6 @@ int sdhci_setup_host(struct sdhci_host *host)
>>                  if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
>>                                                      3600000))
>>                          host->flags &= ~SDHCI_SIGNALING_330;
>> -
>> -               if (ret) {
>> -                       pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
>> -                               mmc_hostname(mmc), ret);
>> -                       mmc->supply.vqmmc = ERR_PTR(-EINVAL);
>> -               }
>>          }
>>
>>          if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
>> @@ -4136,7 +4142,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>>          return 0;
>>
>>   unreg:
>> -       if (!IS_ERR(mmc->supply.vqmmc))
>> +       if (host->vqmmc_enabled)
>>                  regulator_disable(mmc->supply.vqmmc);
>>   undma:
>>          if (host->align_buffer)
>> @@ -4154,7 +4160,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
>>   {
>>          struct mmc_host *mmc = host->mmc;
>>
>> -       if (!IS_ERR(mmc->supply.vqmmc))
>> +       if (host->vqmmc_enabled)
>>                  regulator_disable(mmc->supply.vqmmc);
>>
>>          if (host->align_buffer)
>> @@ -4287,7 +4293,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
>>
>>          tasklet_kill(&host->finish_tasklet);
>>
>> -       if (!IS_ERR(mmc->supply.vqmmc))
>> +       if (host->vqmmc_enabled)
>>                  regulator_disable(mmc->supply.vqmmc);
>>
>>          if (host->align_buffer)
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index b001cf4..3c28152 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -524,6 +524,7 @@ struct sdhci_host {
>>          bool pending_reset;     /* Cmd/data reset is pending */
>>          bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>>          bool v4_mode;           /* Host Version 4 Enable */
>> +       bool vqmmc_enabled;     /* Vqmmc is enabled */
> I still don't love this, since it doesn't mean what it says. Everyone
> else that has a vqmmc_enabled member uses it to actually mean "vqmmc
> is enabled", but this doesn't mean that. For example, you don't clear
> this when you disable the regulator in patch 3, so this would be set
> even if the regulator is disabled, and you don't set it when sdhci
> enables the regulator, so the regulator is on when this flag is not
> set.
>
> At the very least, I think a rename is in order. I'm struggling with
> the rename, since
> "vqmmc_pltfrm_enable_but_feel_free_to_call_set_voltage_anywhere" is
> too long. I guess vqmmc_pltfrm_enabled is the best I've got for now.

Sure. Will rename it.

>>          struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests done */
>>          struct mmc_command *cmd;        /* Current command */
>> --
>> 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.
>>

Re: [PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Veerabhadrarao Badiganti]

On 11/12/2018 10:49 PM, Veerabhadrarao Badiganti wrote:
>
> On 10/17/2018 3:39 AM, Evan Green wrote:
>> On Mon, Oct 8, 2018 at 6:22 AM Veerabhadrarao Badiganti
>> <vbadigan@codeaurora.org> wrote:
>>> From: Vijay Viswanath <vviswana@codeaurora.org>
>>>
>>> Some controllers can have internal mechanism to inform the SW that it
>>> is ready for voltage switching. For such controllers, changing voltage
>>> before the HW is ready can result in various issues.
>>>
>>> During setup/cleanup of host, check whether regulator enable/disable
>>> was already done by platform driver.
>>>
>>> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
>>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
>>> ---
>>>   drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
>>>   drivers/mmc/host/sdhci.h |  1 +
>>>   2 files changed, 20 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 99bdae5..ea7ce1d 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -3616,6 +3616,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>          unsigned int override_timeout_clk;
>>>          u32 max_clk;
>>>          int ret;
>>> +       bool enable_vqmmc = false;
>>>
>>>          WARN_ON(host == NULL);
>>>          if (host == NULL)
>>> @@ -3629,9 +3630,12 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>           * the host can take the appropriate action if regulators 
>>> are not
>>>           * available.
>>>           */
>>> -       ret = mmc_regulator_get_supply(mmc);
>>> -       if (ret)
>>> -               return ret;
>>> +       if (!mmc->supply.vqmmc) {
>>> +               ret = mmc_regulator_get_supply(mmc);
>>> +               if (ret)
>>> +                       return ret;
>>> +               enable_vqmmc  = true;
>>> +       }
>> Did you not like my suggestion in the previous patch of changing
>> mmc_regulator_get_supply to only get supplies that were not set
>> previously? What you have here is almost the same, except you've got
>> this weird coupling where if vqmmc is already present, you implicitly
>> skip looking at vmmc entirely (since mmc_regulator_get_supply does
>> more than just get vqmmc).
>
> sure. Will update mmc_regulator_get_supply() as you suggested.
>
>>>          DBG("Version:   0x%08x | Present:  0x%08x\n",
>>>              sdhci_readw(host, SDHCI_HOST_VERSION),
>>> @@ -3880,7 +3884,15 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>                  mmc->caps |= MMC_CAP_NEEDS_POLL;
>>>
>>>          if (!IS_ERR(mmc->supply.vqmmc)) {
>>> -               ret = regulator_enable(mmc->supply.vqmmc);
>>> +               if (enable_vqmmc) {
>>> +                       ret = regulator_enable(mmc->supply.vqmmc);
>>> +                       if (ret) {
>>> +                               pr_warn("%s: Failed to enable vqmmc 
>>> regulator: %d\n",
>>> +                                       mmc_hostname(mmc), ret);
>>> +                               mmc->supply.vqmmc = ERR_PTR(-EINVAL);
>>> +                       }
>>> +                       host->vqmmc_enabled = !ret;
>>> +               }
>>>
>>>                  /* If vqmmc provides no 1.8V signalling, then 
>>> there's no UHS */
>>>                  if 
>>> (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
>>> @@ -3893,12 +3905,6 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>                  if 
>>> (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
>>>                                                      3600000))
>>>                          host->flags &= ~SDHCI_SIGNALING_330;
>>> -
>>> -               if (ret) {
>>> -                       pr_warn("%s: Failed to enable vqmmc 
>>> regulator: %d\n",
>>> -                               mmc_hostname(mmc), ret);
>>> -                       mmc->supply.vqmmc = ERR_PTR(-EINVAL);
>>> -               }
>>>          }
>>>
>>>          if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
>>> @@ -4136,7 +4142,7 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>          return 0;
>>>
>>>   unreg:
>>> -       if (!IS_ERR(mmc->supply.vqmmc))
>>> +       if (host->vqmmc_enabled)
>>>                  regulator_disable(mmc->supply.vqmmc);
>>>   undma:
>>>          if (host->align_buffer)
>>> @@ -4154,7 +4160,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
>>>   {
>>>          struct mmc_host *mmc = host->mmc;
>>>
>>> -       if (!IS_ERR(mmc->supply.vqmmc))
>>> +       if (host->vqmmc_enabled)
>>>                  regulator_disable(mmc->supply.vqmmc);
>>>
>>>          if (host->align_buffer)
>>> @@ -4287,7 +4293,7 @@ void sdhci_remove_host(struct sdhci_host 
>>> *host, int dead)
>>>
>>>          tasklet_kill(&host->finish_tasklet);
>>>
>>> -       if (!IS_ERR(mmc->supply.vqmmc))
>>> +       if (host->vqmmc_enabled)
>>>                  regulator_disable(mmc->supply.vqmmc);
>>>
>>>          if (host->align_buffer)
>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>> index b001cf4..3c28152 100644
>>> --- a/drivers/mmc/host/sdhci.h
>>> +++ b/drivers/mmc/host/sdhci.h
>>> @@ -524,6 +524,7 @@ struct sdhci_host {
>>>          bool pending_reset;     /* Cmd/data reset is pending */
>>>          bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>>>          bool v4_mode;           /* Host Version 4 Enable */
>>> +       bool vqmmc_enabled;     /* Vqmmc is enabled */
>> I still don't love this, since it doesn't mean what it says. Everyone
>> else that has a vqmmc_enabled member uses it to actually mean "vqmmc
>> is enabled", but this doesn't mean that. For example, you don't clear
>> this when you disable the regulator in patch 3, so this would be set
>> even if the regulator is disabled, and you don't set it when sdhci
>> enables the regulator, so the regulator is on when this flag is not
>> set.
>>
Hi Evan

This flag is meant to say "disable vqmmc *only* if it is enabled by host 
driver (sdhci_host)".
If host driver doesn't enable vqmmc (enabled by platfrm driver) or if it 
fails to enable it, then don't call disable vqmmc.

Agree with you, the present name is not conveying its purpose.
It must be something like "vqmmc_enabled_by_host".

Please let me know if you have any suggestions on this name.


>> At the very least, I think a rename is in order. I'm struggling with
>> the rename, since
>> "vqmmc_pltfrm_enable_but_feel_free_to_call_set_voltage_anywhere" is
>> too long. I guess vqmmc_pltfrm_enabled is the best I've got for now.
>
> Sure. Will rename it.
>
>>>          struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];  /* Requests 
>>> done */
>>>          struct mmc_command *cmd;        /* Current command */
>>> -- 
>>> 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.
>>>
>

Re: [PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Evan Green]

On Wed, Nov 14, 2018 at 6:36 AM Veerabhadrarao Badiganti
<vbadigan@codeaurora.org> wrote:
>
> >>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> >>> index b001cf4..3c28152 100644
> >>> --- a/drivers/mmc/host/sdhci.h
> >>> +++ b/drivers/mmc/host/sdhci.h
> >>> @@ -524,6 +524,7 @@ struct sdhci_host {
> >>>          bool pending_reset;     /* Cmd/data reset is pending */
> >>>          bool irq_wake_enabled;  /* IRQ wakeup is enabled */
> >>>          bool v4_mode;           /* Host Version 4 Enable */
> >>> +       bool vqmmc_enabled;     /* Vqmmc is enabled */
> >> I still don't love this, since it doesn't mean what it says. Everyone
> >> else that has a vqmmc_enabled member uses it to actually mean "vqmmc
> >> is enabled", but this doesn't mean that. For example, you don't clear
> >> this when you disable the regulator in patch 3, so this would be set
> >> even if the regulator is disabled, and you don't set it when sdhci
> >> enables the regulator, so the regulator is on when this flag is not
> >> set.
> >>
> Hi Evan
>
> This flag is meant to say "disable vqmmc *only* if it is enabled by host
> driver (sdhci_host)".
> If host driver doesn't enable vqmmc (enabled by platfrm driver) or if it
> fails to enable it, then don't call disable vqmmc.
>
> Agree with you, the present name is not conveying its purpose.
> It must be something like "vqmmc_enabled_by_host".
>
> Please let me know if you have any suggestions on this name.

Yeah. Maybe vqmmc_pltfrm_controlled? Or vqmmc_enabled_by_platfrm as
you suggested?
-Evan

Re: [PATCH V3 1/3] mmc: sdhci: Allow platform controlled voltage switching

[Adrian Hunter]

On 16/11/18 1:17 AM, Evan Green wrote:
> On Wed, Nov 14, 2018 at 6:36 AM Veerabhadrarao Badiganti
> <vbadigan@codeaurora.org> wrote:
>>
>>>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>>>> index b001cf4..3c28152 100644
>>>>> --- a/drivers/mmc/host/sdhci.h
>>>>> +++ b/drivers/mmc/host/sdhci.h
>>>>> @@ -524,6 +524,7 @@ struct sdhci_host {
>>>>>          bool pending_reset;     /* Cmd/data reset is pending */
>>>>>          bool irq_wake_enabled;  /* IRQ wakeup is enabled */
>>>>>          bool v4_mode;           /* Host Version 4 Enable */
>>>>> +       bool vqmmc_enabled;     /* Vqmmc is enabled */
>>>> I still don't love this, since it doesn't mean what it says. Everyone
>>>> else that has a vqmmc_enabled member uses it to actually mean "vqmmc
>>>> is enabled", but this doesn't mean that. For example, you don't clear
>>>> this when you disable the regulator in patch 3, so this would be set
>>>> even if the regulator is disabled, and you don't set it when sdhci
>>>> enables the regulator, so the regulator is on when this flag is not
>>>> set.
>>>>
>> Hi Evan
>>
>> This flag is meant to say "disable vqmmc *only* if it is enabled by host
>> driver (sdhci_host)".
>> If host driver doesn't enable vqmmc (enabled by platfrm driver) or if it
>> fails to enable it, then don't call disable vqmmc.
>>
>> Agree with you, the present name is not conveying its purpose.
>> It must be something like "vqmmc_enabled_by_host".
>>
>> Please let me know if you have any suggestions on this name.
> 
> Yeah. Maybe vqmmc_pltfrm_controlled? Or vqmmc_enabled_by_platfrm as
> you suggested?

"pltfrm" doesn't mean anything here.  Just change the comment "vqmmc enabled
in sdhci.c"

[PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

The load a particular sdhc controller should request from a regulator
is device specific and hence each device should individually vote for
the required load.

Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 502b3b8..cb22178 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -25,6 +25,10 @@ Required properties:
 	"xo"	- TCXO clock (optional)
 	"cal"	- reference clock for RCLK delay calibration (optional)
 	"sleep"	- sleep clock for RCLK delay calibration (optional)
+- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
+					BUS_OFF states in power irq. Should be specified in
+					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
+					Units uA.
 
 Example:
 
@@ -36,7 +40,9 @@ Example:
 		non-removable;
 
 		vmmc-supply = <&pm8941_l20>;
+		qcom,vmmc-current-level-microamp = <200 570000>;
 		vqmmc-supply = <&pm8941_s3>;
+		qcom,vqmmc-current-level-microamp = <200 325000>;
 
 		pinctrl-names = "default";
 		pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
@@ -53,7 +59,9 @@ Example:
 		cd-gpios = <&msmgpio 62 0x1>;
 
 		vmmc-supply = <&pm8941_l21>;
+		qcom,vmmc-current-level-microamp = <200 800000>;
 		vqmmc-supply = <&pm8941_l13>;
+		qcom,vqmmc-current-level-microamp = <200 22000>;
 
 		pinctrl-names = "default";
 		pinctrl-0 = <&sdc2_clk &sdc2_cmd &sdc2_data>;
-- 
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.

[PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

The load a particular sdhc controller should request from a regulator
is device specific and hence each device should individually vote for
the required load.

Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 502b3b8..cb22178 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -25,6 +25,10 @@ Required properties:
 	"xo"	- TCXO clock (optional)
 	"cal"	- reference clock for RCLK delay calibration (optional)
 	"sleep"	- sleep clock for RCLK delay calibration (optional)
+- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
+					BUS_OFF states in power irq. Should be specified in
+					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
+					Units uA.
 
 Example:
 
@@ -36,7 +40,9 @@ Example:
 		non-removable;
 
 		vmmc-supply = <&pm8941_l20>;
+		qcom,vmmc-current-level-microamp = <200 570000>;
 		vqmmc-supply = <&pm8941_s3>;
+		qcom,vqmmc-current-level-microamp = <200 325000>;
 
 		pinctrl-names = "default";
 		pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
@@ -53,7 +59,9 @@ Example:
 		cd-gpios = <&msmgpio 62 0x1>;
 
 		vmmc-supply = <&pm8941_l21>;
+		qcom,vmmc-current-level-microamp = <200 800000>;
 		vqmmc-supply = <&pm8941_l13>;
+		qcom,vqmmc-current-level-microamp = <200 22000>;
 
 		pinctrl-names = "default";
 		pinctrl-0 = <&sdc2_clk &sdc2_cmd &sdc2_data>;
-- 
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.

Re: [PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Rob Herring]

On Mon, Oct 08, 2018 at 06:48:58PM +0530, Veerabhadrarao Badiganti wrote:
> From: Vijay Viswanath <vviswana@codeaurora.org>
> 
> The load a particular sdhc controller should request from a regulator
> is device specific and hence each device should individually vote for
> the required load.
> 
> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>  Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> index 502b3b8..cb22178 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> @@ -25,6 +25,10 @@ Required properties:
>  	"xo"	- TCXO clock (optional)
>  	"cal"	- reference clock for RCLK delay calibration (optional)
>  	"sleep"	- sleep clock for RCLK delay calibration (optional)
> +- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
> +					BUS_OFF states in power irq. Should be specified in
> +					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
> +					Units uA.

Seems like something that should be common?

Re: [PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Rob Herring]

On Mon, Oct 08, 2018 at 06:48:58PM +0530, Veerabhadrarao Badiganti wrote:
> From: Vijay Viswanath <vviswana@codeaurora.org>
> 
> The load a particular sdhc controller should request from a regulator
> is device specific and hence each device should individually vote for
> the required load.
> 
> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>  Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> index 502b3b8..cb22178 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> @@ -25,6 +25,10 @@ Required properties:
>  	"xo"	- TCXO clock (optional)
>  	"cal"	- reference clock for RCLK delay calibration (optional)
>  	"sleep"	- sleep clock for RCLK delay calibration (optional)
> +- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
> +					BUS_OFF states in power irq. Should be specified in
> +					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
> +					Units uA.

Seems like something that should be common?

Re: [PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Veerabhadrarao Badiganti]

On 10/12/2018 8:25 PM, Rob Herring wrote:
> On Mon, Oct 08, 2018 at 06:48:58PM +0530, Veerabhadrarao Badiganti wrote:
>> From: Vijay Viswanath <vviswana@codeaurora.org>
>>
>> The load a particular sdhc controller should request from a regulator
>> is device specific and hence each device should individually vote for
>> the required load.
>>
>> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
>> ---
>>   Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> index 502b3b8..cb22178 100644
>> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> @@ -25,6 +25,10 @@ Required properties:
>>   	"xo"	- TCXO clock (optional)
>>   	"cal"	- reference clock for RCLK delay calibration (optional)
>>   	"sleep"	- sleep clock for RCLK delay calibration (optional)
>> +- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
>> +					BUS_OFF states in power irq. Should be specified in
>> +					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
>> +					Units uA.
> Seems like something that should be common?

Hi Rob,
Can you please little elaborate your comment?
Do mean this should be common for all vendors, not specific to qcom-mmc?


Thanks,
Veera

Re: [PATCH V3 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values

[Veerabhadrarao Badiganti]

On 10/12/2018 8:25 PM, Rob Herring wrote:
> On Mon, Oct 08, 2018 at 06:48:58PM +0530, Veerabhadrarao Badiganti wrote:
>> From: Vijay Viswanath <vviswana@codeaurora.org>
>>
>> The load a particular sdhc controller should request from a regulator
>> is device specific and hence each device should individually vote for
>> the required load.
>>
>> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
>> ---
>>   Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> index 502b3b8..cb22178 100644
>> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> @@ -25,6 +25,10 @@ Required properties:
>>   	"xo"	- TCXO clock (optional)
>>   	"cal"	- reference clock for RCLK delay calibration (optional)
>>   	"sleep"	- sleep clock for RCLK delay calibration (optional)
>> +- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
>> +					BUS_OFF states in power irq. Should be specified in
>> +					pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
>> +					Units uA.
> Seems like something that should be common?

Hi Rob,
Can you please little elaborate your comment?
Do mean this should be common for all vendors, not specific to qcom-mmc?


Thanks,
Veera

[PATCH V3 3/3] mmc: sdhci-msm: Use internal voltage control

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

Some sdhci-msm controllers require that voltage switching be done after
the HW is ready for it. The HW informs its readiness through power irq.
The voltage switching should happen only then.

Use the quirk for internal voltage switching and then control the
voltage switching using power irq.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 drivers/mmc/host/sdhci-msm.c | 212 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 204 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 3cc8bfe..6918e70 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -43,7 +43,9 @@
 #define CORE_PWRCTL_IO_LOW	BIT(2)
 #define CORE_PWRCTL_IO_HIGH	BIT(3)
 #define CORE_PWRCTL_BUS_SUCCESS BIT(0)
+#define CORE_PWRCTL_BUS_FAIL    BIT(1)
 #define CORE_PWRCTL_IO_SUCCESS	BIT(2)
+#define CORE_PWRCTL_IO_FAIL     BIT(3)
 #define REQ_BUS_OFF		BIT(0)
 #define REQ_BUS_ON		BIT(1)
 #define REQ_IO_LOW		BIT(2)
@@ -258,6 +260,10 @@ struct sdhci_msm_host {
 	bool mci_removed;
 	const struct sdhci_msm_variant_ops *var_ops;
 	const struct sdhci_msm_offset *offset;
+	bool vmmc_load;
+	u32 vmmc_level[2];
+	bool vqmmc_load;
+	u32 vqmmc_level[2];
 };
 
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
@@ -1211,6 +1217,74 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
 		sdhci_msm_hs400(host, &mmc->ios);
 }
 
+static int sdhci_msm_set_vmmc(struct sdhci_msm_host *msm_host,
+			      struct mmc_host *mmc, int level)
+{
+	int load = msm_host->vmmc_level[level];
+	int ret;
+
+	if (IS_ERR(mmc->supply.vmmc))
+		return 0;
+
+	if (msm_host->vmmc_load) {
+		ret = regulator_set_load(mmc->supply.vmmc, load);
+		if (ret)
+			goto out;
+	}
+
+	ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, mmc->ios.vdd);
+out:
+	if (ret)
+		pr_err("%s: vmmc set load/ocr failed: %d\n",
+				mmc_hostname(mmc), ret);
+
+	return ret;
+}
+
+static int sdhci_msm_set_vqmmc(struct sdhci_msm_host *msm_host,
+			      struct mmc_host *mmc, int level)
+{
+	int load = msm_host->vqmmc_level[level];
+	int ret;
+	struct mmc_ios ios;
+
+	if (IS_ERR(mmc->supply.vqmmc))
+		return 0;
+
+	if (msm_host->vqmmc_load) {
+		ret = regulator_set_load(mmc->supply.vqmmc, load);
+		if (ret)
+			goto out;
+	}
+
+	/*
+	 * The IO voltage regulator may not always support a voltage close to
+	 * vdd. Set IO voltage based on capability of the regulator.
+	 */
+	if (level) {
+		if (msm_host->caps_0 & CORE_3_0V_SUPPORT)
+			ios.signal_voltage = MMC_SIGNAL_VOLTAGE_330;
+		else if (msm_host->caps_0 & CORE_1_8V_SUPPORT)
+			ios.signal_voltage = MMC_SIGNAL_VOLTAGE_180;
+		if (msm_host->caps_0 & CORE_VOLT_SUPPORT) {
+			pr_debug("%s: %s: setting signal voltage: %d\n",
+					mmc_hostname(mmc), __func__,
+					ios.signal_voltage);
+			ret = mmc_regulator_set_vqmmc(mmc, &ios);
+			if (ret)
+				goto out;
+		}
+		ret = regulator_enable(mmc->supply.vqmmc);
+	} else {
+		ret = regulator_disable(mmc->supply.vqmmc);
+	}
+out:
+	if (ret)
+		pr_err("%s: vqmmc failed: %d\n", mmc_hostname(mmc), ret);
+
+	return ret;
+}
+
 static inline void sdhci_msm_init_pwr_irq_wait(struct sdhci_msm_host *msm_host)
 {
 	init_waitqueue_head(&msm_host->pwr_irq_wait);
@@ -1314,8 +1388,9 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct mmc_host *mmc = host->mmc;
 	u32 irq_status, irq_ack = 0;
-	int retry = 10;
+	int retry = 10, ret = 0;
 	u32 pwr_state = 0, io_level = 0;
 	u32 config;
 	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
@@ -1351,14 +1426,35 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 
 	/* Handle BUS ON/OFF*/
 	if (irq_status & CORE_PWRCTL_BUS_ON) {
-		pwr_state = REQ_BUS_ON;
-		io_level = REQ_IO_HIGH;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		ret = sdhci_msm_set_vmmc(msm_host, mmc, 1);
+		if (!ret)
+			ret = sdhci_msm_set_vqmmc(msm_host, mmc, 1);
+
+		if (!ret) {
+			pwr_state = REQ_BUS_ON;
+			io_level = REQ_IO_HIGH;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+			sdhci_msm_set_vmmc(msm_host, mmc, 0);
+		}
 	}
 	if (irq_status & CORE_PWRCTL_BUS_OFF) {
-		pwr_state = REQ_BUS_OFF;
-		io_level = REQ_IO_LOW;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		ret = sdhci_msm_set_vmmc(msm_host, mmc, 0);
+		if (!ret)
+			ret = sdhci_msm_set_vqmmc(msm_host, mmc, 0);
+
+		if (!ret) {
+			pwr_state = REQ_BUS_OFF;
+			io_level = REQ_IO_LOW;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+		}
 	}
 	/* Handle IO LOW/HIGH */
 	if (irq_status & CORE_PWRCTL_IO_LOW) {
@@ -1370,6 +1466,15 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 		irq_ack |= CORE_PWRCTL_IO_SUCCESS;
 	}
 
+	if (io_level && !IS_ERR(mmc->supply.vqmmc) && !pwr_state) {
+		ret = mmc_regulator_set_vqmmc(mmc, &mmc->ios);
+		if (ret)
+			pr_err("%s: IO_level setting failed(%d). signal_voltage: %d, vdd: %d irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret,
+					mmc->ios.signal_voltage, mmc->ios.vdd,
+					irq_status);
+	}
+
 	/*
 	 * The driver has to acknowledge the interrupt, switch voltages and
 	 * report back if it succeded or not to this register. The voltage
@@ -1605,6 +1710,91 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
 }
 
+static int sdhci_msm_register_vreg(struct sdhci_msm_host *msm_host)
+{
+	int ret = 0;
+
+	ret = mmc_regulator_get_supply(msm_host->mmc);
+	if (ret)
+		return ret;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"qcom,vmmc-current-level-microamp",
+			msm_host->vmmc_level, 2) >= 0)
+		msm_host->vmmc_load = true;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"qcom,vqmmc-current-level-microamp",
+			msm_host->vqmmc_level, 2) >= 0)
+		msm_host->vqmmc_load = true;
+
+	sdhci_msm_set_regulator_caps(msm_host);
+
+	return 0;
+
+}
+
+static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
+				      struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 ctrl;
+
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (host->version < SDHCI_SPEC_300)
+		return 0;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		if (!(host->flags & SDHCI_SIGNALING_330))
+			return -EINVAL;
+		/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
+		ctrl &= ~SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 3.3V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (!(ctrl & SDHCI_CTRL_VDD_180))
+			return 0;
+
+		pr_warn("%s: 3.3V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_180:
+		if (!(host->flags & SDHCI_SIGNALING_180))
+			return -EINVAL;
+
+		/*
+		 * Enable 1.8V Signal Enable in the Host Control2
+		 * register
+		 */
+		ctrl |= SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 1.8V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (ctrl & SDHCI_CTRL_VDD_180)
+			return 0;
+
+		pr_warn("%s: 1.8V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_120:
+		if (!(host->flags & SDHCI_SIGNALING_120))
+			return -EINVAL;
+		return 0;
+	default:
+		/* No signal voltage switch required */
+		return 0;
+	}
+
+}
+
 static const struct sdhci_msm_variant_ops mci_var_ops = {
 	.msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
 	.msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
@@ -1644,6 +1834,7 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	.set_uhs_signaling = sdhci_msm_set_uhs_signaling,
 	.write_w = sdhci_msm_writew,
 	.write_b = sdhci_msm_writeb,
+	.set_power = sdhci_set_power_noreg,
 };
 
 static const struct sdhci_pltfm_data sdhci_msm_pdata = {
@@ -1818,6 +2009,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 				msm_offset->core_vendor_spec_capabilities0);
 	}
 
+	ret = sdhci_msm_register_vreg(msm_host);
+	if (ret)
+		goto clk_disable;
+
 	/*
 	 * Power on reset state may trigger power irq if previous status of
 	 * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq
@@ -1862,11 +2057,12 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 					 MSM_MMC_AUTOSUSPEND_DELAY_MS);
 	pm_runtime_use_autosuspend(&pdev->dev);
 
+	host->mmc_host_ops.start_signal_voltage_switch =
+		sdhci_msm_start_signal_voltage_switch;
 	host->mmc_host_ops.execute_tuning = sdhci_msm_execute_tuning;
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
-	sdhci_msm_set_regulator_caps(msm_host);
 
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);
-- 
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.

[PATCH V3 3/3] mmc: sdhci-msm: Use internal voltage control

[Veerabhadrarao Badiganti]

From: Vijay Viswanath <vviswana@codeaurora.org>

Some sdhci-msm controllers require that voltage switching be done after
the HW is ready for it. The HW informs its readiness through power irq.
The voltage switching should happen only then.

Use the quirk for internal voltage switching and then control the
voltage switching using power irq.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
 drivers/mmc/host/sdhci-msm.c | 212 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 204 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 3cc8bfe..6918e70 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -43,7 +43,9 @@
 #define CORE_PWRCTL_IO_LOW	BIT(2)
 #define CORE_PWRCTL_IO_HIGH	BIT(3)
 #define CORE_PWRCTL_BUS_SUCCESS BIT(0)
+#define CORE_PWRCTL_BUS_FAIL    BIT(1)
 #define CORE_PWRCTL_IO_SUCCESS	BIT(2)
+#define CORE_PWRCTL_IO_FAIL     BIT(3)
 #define REQ_BUS_OFF		BIT(0)
 #define REQ_BUS_ON		BIT(1)
 #define REQ_IO_LOW		BIT(2)
@@ -258,6 +260,10 @@ struct sdhci_msm_host {
 	bool mci_removed;
 	const struct sdhci_msm_variant_ops *var_ops;
 	const struct sdhci_msm_offset *offset;
+	bool vmmc_load;
+	u32 vmmc_level[2];
+	bool vqmmc_load;
+	u32 vqmmc_level[2];
 };
 
 static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
@@ -1211,6 +1217,74 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
 		sdhci_msm_hs400(host, &mmc->ios);
 }
 
+static int sdhci_msm_set_vmmc(struct sdhci_msm_host *msm_host,
+			      struct mmc_host *mmc, int level)
+{
+	int load = msm_host->vmmc_level[level];
+	int ret;
+
+	if (IS_ERR(mmc->supply.vmmc))
+		return 0;
+
+	if (msm_host->vmmc_load) {
+		ret = regulator_set_load(mmc->supply.vmmc, load);
+		if (ret)
+			goto out;
+	}
+
+	ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, mmc->ios.vdd);
+out:
+	if (ret)
+		pr_err("%s: vmmc set load/ocr failed: %d\n",
+				mmc_hostname(mmc), ret);
+
+	return ret;
+}
+
+static int sdhci_msm_set_vqmmc(struct sdhci_msm_host *msm_host,
+			      struct mmc_host *mmc, int level)
+{
+	int load = msm_host->vqmmc_level[level];
+	int ret;
+	struct mmc_ios ios;
+
+	if (IS_ERR(mmc->supply.vqmmc))
+		return 0;
+
+	if (msm_host->vqmmc_load) {
+		ret = regulator_set_load(mmc->supply.vqmmc, load);
+		if (ret)
+			goto out;
+	}
+
+	/*
+	 * The IO voltage regulator may not always support a voltage close to
+	 * vdd. Set IO voltage based on capability of the regulator.
+	 */
+	if (level) {
+		if (msm_host->caps_0 & CORE_3_0V_SUPPORT)
+			ios.signal_voltage = MMC_SIGNAL_VOLTAGE_330;
+		else if (msm_host->caps_0 & CORE_1_8V_SUPPORT)
+			ios.signal_voltage = MMC_SIGNAL_VOLTAGE_180;
+		if (msm_host->caps_0 & CORE_VOLT_SUPPORT) {
+			pr_debug("%s: %s: setting signal voltage: %d\n",
+					mmc_hostname(mmc), __func__,
+					ios.signal_voltage);
+			ret = mmc_regulator_set_vqmmc(mmc, &ios);
+			if (ret)
+				goto out;
+		}
+		ret = regulator_enable(mmc->supply.vqmmc);
+	} else {
+		ret = regulator_disable(mmc->supply.vqmmc);
+	}
+out:
+	if (ret)
+		pr_err("%s: vqmmc failed: %d\n", mmc_hostname(mmc), ret);
+
+	return ret;
+}
+
 static inline void sdhci_msm_init_pwr_irq_wait(struct sdhci_msm_host *msm_host)
 {
 	init_waitqueue_head(&msm_host->pwr_irq_wait);
@@ -1314,8 +1388,9 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct mmc_host *mmc = host->mmc;
 	u32 irq_status, irq_ack = 0;
-	int retry = 10;
+	int retry = 10, ret = 0;
 	u32 pwr_state = 0, io_level = 0;
 	u32 config;
 	const struct sdhci_msm_offset *msm_offset = msm_host->offset;
@@ -1351,14 +1426,35 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 
 	/* Handle BUS ON/OFF*/
 	if (irq_status & CORE_PWRCTL_BUS_ON) {
-		pwr_state = REQ_BUS_ON;
-		io_level = REQ_IO_HIGH;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		ret = sdhci_msm_set_vmmc(msm_host, mmc, 1);
+		if (!ret)
+			ret = sdhci_msm_set_vqmmc(msm_host, mmc, 1);
+
+		if (!ret) {
+			pwr_state = REQ_BUS_ON;
+			io_level = REQ_IO_HIGH;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+			sdhci_msm_set_vmmc(msm_host, mmc, 0);
+		}
 	}
 	if (irq_status & CORE_PWRCTL_BUS_OFF) {
-		pwr_state = REQ_BUS_OFF;
-		io_level = REQ_IO_LOW;
-		irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		ret = sdhci_msm_set_vmmc(msm_host, mmc, 0);
+		if (!ret)
+			ret = sdhci_msm_set_vqmmc(msm_host, mmc, 0);
+
+		if (!ret) {
+			pwr_state = REQ_BUS_OFF;
+			io_level = REQ_IO_LOW;
+			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+		} else {
+			pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret, irq_status);
+			irq_ack |= CORE_PWRCTL_BUS_FAIL;
+		}
 	}
 	/* Handle IO LOW/HIGH */
 	if (irq_status & CORE_PWRCTL_IO_LOW) {
@@ -1370,6 +1466,15 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
 		irq_ack |= CORE_PWRCTL_IO_SUCCESS;
 	}
 
+	if (io_level && !IS_ERR(mmc->supply.vqmmc) && !pwr_state) {
+		ret = mmc_regulator_set_vqmmc(mmc, &mmc->ios);
+		if (ret)
+			pr_err("%s: IO_level setting failed(%d). signal_voltage: %d, vdd: %d irq_status: 0x%08x\n",
+					mmc_hostname(mmc), ret,
+					mmc->ios.signal_voltage, mmc->ios.vdd,
+					irq_status);
+	}
+
 	/*
 	 * The driver has to acknowledge the interrupt, switch voltages and
 	 * report back if it succeded or not to this register. The voltage
@@ -1605,6 +1710,91 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
 }
 
+static int sdhci_msm_register_vreg(struct sdhci_msm_host *msm_host)
+{
+	int ret = 0;
+
+	ret = mmc_regulator_get_supply(msm_host->mmc);
+	if (ret)
+		return ret;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"qcom,vmmc-current-level-microamp",
+			msm_host->vmmc_level, 2) >= 0)
+		msm_host->vmmc_load = true;
+	if (device_property_read_u32_array(&msm_host->pdev->dev,
+			"qcom,vqmmc-current-level-microamp",
+			msm_host->vqmmc_level, 2) >= 0)
+		msm_host->vqmmc_load = true;
+
+	sdhci_msm_set_regulator_caps(msm_host);
+
+	return 0;
+
+}
+
+static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc,
+				      struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 ctrl;
+
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (host->version < SDHCI_SPEC_300)
+		return 0;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		if (!(host->flags & SDHCI_SIGNALING_330))
+			return -EINVAL;
+		/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
+		ctrl &= ~SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 3.3V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (!(ctrl & SDHCI_CTRL_VDD_180))
+			return 0;
+
+		pr_warn("%s: 3.3V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_180:
+		if (!(host->flags & SDHCI_SIGNALING_180))
+			return -EINVAL;
+
+		/*
+		 * Enable 1.8V Signal Enable in the Host Control2
+		 * register
+		 */
+		ctrl |= SDHCI_CTRL_VDD_180;
+		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+		/* 1.8V regulator output should be stable within 5 ms */
+		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+		if (ctrl & SDHCI_CTRL_VDD_180)
+			return 0;
+
+		pr_warn("%s: 1.8V regulator output did not became stable\n",
+			mmc_hostname(mmc));
+
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_120:
+		if (!(host->flags & SDHCI_SIGNALING_120))
+			return -EINVAL;
+		return 0;
+	default:
+		/* No signal voltage switch required */
+		return 0;
+	}
+
+}
+
 static const struct sdhci_msm_variant_ops mci_var_ops = {
 	.msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
 	.msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
@@ -1644,6 +1834,7 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	.set_uhs_signaling = sdhci_msm_set_uhs_signaling,
 	.write_w = sdhci_msm_writew,
 	.write_b = sdhci_msm_writeb,
+	.set_power = sdhci_set_power_noreg,
 };
 
 static const struct sdhci_pltfm_data sdhci_msm_pdata = {
@@ -1818,6 +2009,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 				msm_offset->core_vendor_spec_capabilities0);
 	}
 
+	ret = sdhci_msm_register_vreg(msm_host);
+	if (ret)
+		goto clk_disable;
+
 	/*
 	 * Power on reset state may trigger power irq if previous status of
 	 * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq
@@ -1862,11 +2057,12 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 					 MSM_MMC_AUTOSUSPEND_DELAY_MS);
 	pm_runtime_use_autosuspend(&pdev->dev);
 
+	host->mmc_host_ops.start_signal_voltage_switch =
+		sdhci_msm_start_signal_voltage_switch;
 	host->mmc_host_ops.execute_tuning = sdhci_msm_execute_tuning;
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
-	sdhci_msm_set_regulator_caps(msm_host);
 
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);
-- 
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Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.