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mmc: sdhci: Allow platform controlled voltage switching

PATCH In review Veerabhadrarao Badiganti 4 participants 10 messages Oct 8, 2018 – Nov 16, 2018 1 message not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]

#1 lore raw

PATCH v3 1/3 mmc: sdhci: Allow platform controlled voltage switching

From: Vijay Viswanath <[email protected]>

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.

---
 drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 20 insertions(+), 13 deletions(-)
drivers/mmc/host/sdhci.c +19 -13
index 99bdae5..ea7ce1d 100644
@@ -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)
drivers/mmc/host/sdhci.h +1 -0
index b001cf4..3c28152 100644
@@ -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 */
Signature · 2 lines
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.
#2 lore raw
Quoted 32 lines · Veerabhadrarao Badiganti

From: Vijay Viswanath <[email protected]>

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.

---
 drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 20 insertions(+), 13 deletions(-)
drivers/mmc/host/sdhci.c +1 -0
index 99bdae5..ea7ce1d 100644
@@ -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.

drivers/mmc/host/sdhci.c int sdhci_setup_host(struct sdhci_host *host) · line 3638

Quoted 10 lines
drivers/mmc/host/sdhci.c +6 -3
         */
-       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).

Quoted 65 lines
drivers/mmc/host/sdhci.c +12 -10
        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)
drivers/mmc/host/sdhci.h +0 -0
index b001cf4..3c28152 100644

drivers/mmc/host/sdhci.h struct sdhci_host { · line 527

Quoted 4 lines
drivers/mmc/host/sdhci.h +1 -0
@@ -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.

Quoted 7 lines
drivers/mmc/host/sdhci.h +0 -1
        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.

#3 lore raw
Quoted 41 lines · Evan Green
Quoted 39 lines · Veerabhadrarao Badiganti

From: Vijay Viswanath <[email protected]>

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.

---
  drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
  drivers/mmc/host/sdhci.h |  1 +
  2 files changed, 20 insertions(+), 13 deletions(-)
drivers/mmc/host/sdhci.c +5 -3
index 99bdae5..ea7ce1d 100644
@@ -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;
Quoted 8 lines

drivers/mmc/host/sdhci.c int sdhci_setup_host(struct sdhci_host *host) · line 3638

Quoted 2 lines
drivers/mmc/host/sdhci.c +2 -0
+               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.

Quoted 76 lines
Quoted 64 lines
drivers/mmc/host/sdhci.c +12 -10
         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)
drivers/mmc/host/sdhci.h +0 -0
index b001cf4..3c28152 100644

drivers/mmc/host/sdhci.h struct sdhci_host { · line 527

Quoted 4 lines
drivers/mmc/host/sdhci.h +1 -0
@@ -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.

Quoted 4 lines

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.

Quoted 6 lines
Quoted 6 lines
drivers/mmc/host/sdhci.h +0 -1
         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.

#4 lore raw
Quoted 52 lines · Veerabhadrarao Badiganti
Quoted 41 lines · Evan Green
Quoted 39 lines · Veerabhadrarao Badiganti

From: Vijay Viswanath <[email protected]>

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.

---
  drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++------------- drivers/mmc/host/sdhci.h |  1 +

  2 files changed, 20 insertions(+), 13 deletions(-)
drivers/mmc/host/sdhci.c +5 -3
index 99bdae5..ea7ce1d 100644
@@ -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;
Quoted 8 lines

drivers/mmc/host/sdhci.c int sdhci_setup_host(struct sdhci_host *host) · line 3638

Quoted 2 lines
drivers/mmc/host/sdhci.c +2 -0
+               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).

Quoted 81 lines

sure. Will update mmc_regulator_get_supply() as you suggested.

Quoted 79 lines
Quoted 67 lines
drivers/mmc/host/sdhci.c +9 -1
          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,

drivers/mmc/host/sdhci.c +0 -6
@@ -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) {

drivers/mmc/host/sdhci.c +0 -0
@@ -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)

drivers/mmc/host/sdhci.c +2 -2
@@ -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)

drivers/mmc/host/sdhci.h +0 -0
index b001cf4..3c28152 100644
@@ -524,6 +524,7 @@ struct sdhci_host {
Quoted 4 lines

         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.

Quoted 14 lines
Quoted 4 lines

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.

Quoted 6 lines
Quoted 6 lines

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

Signature · 2 lines
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.
#5 lore raw
Quoted 25 lines · Veerabhadrarao Badiganti
Quoted 10 lines
Quoted 10 lines
Quoted 10 lines
drivers/mmc/host/sdhci.h +1 -0
index b001cf4..3c28152 100644
@@ -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 */
Quoted 8 lines
Quoted 8 lines

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.

Quoted 4 lines

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

maintainer
#6 lore raw
Quoted 27 lines · Evan Green
Quoted 25 lines · Veerabhadrarao Badiganti
Quoted 10 lines
Quoted 10 lines
Quoted 10 lines
drivers/mmc/host/sdhci.h +1 -0
index b001cf4..3c28152 100644
@@ -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 */
Quoted 8 lines
Quoted 8 lines

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.

Quoted 7 lines
Quoted 4 lines

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"

#7 lore raw

PATCH v3 2/3 dt-bindings: mmc: sdhci-msm: Add entries for passing load values

In reply to a message not in the archive

From: Vijay Viswanath <[email protected]>

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.

---
 Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
 1 file changed, 8 insertions(+)
Documentation/devicetree/bindings/mmc/sdhci-msm.txt +8 -0
index 502b3b8..cb22178 100644
@@ -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>;
Signature · 2 lines
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.
maintainer
#8 lore raw

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

Quoted 17 lines · Veerabhadrarao Badiganti

From: Vijay Viswanath <[email protected]>

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.

---
 Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
 1 file changed, 8 insertions(+)
Documentation/devicetree/bindings/mmc/sdhci-msm.txt +0 -0
index 502b3b8..cb22178 100644

Documentation/devicetree/bindings/mmc/sdhci-msm.txt Required properties: · line 31

Quoted 7 lines
Documentation/devicetree/bindings/mmc/sdhci-msm.txt +4 -0
@@ -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?

#9 lore raw

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

Quoted 13 lines · Rob Herring
Quoted 12 lines · Veerabhadrarao Badiganti

From: Vijay Viswanath <[email protected]>

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.

---
  Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 8 ++++++++
  1 file changed, 8 insertions(+)
Quoted 13 lines

Documentation/devicetree/bindings/mmc/sdhci-msm.txt Required properties: · line 31

Quoted 12 lines
Documentation/devicetree/bindings/mmc/sdhci-msm.txt +4 -0
index 502b3b8..cb22178 100644
@@ -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

#10 lore raw

PATCH v3 3/3 mmc: sdhci-msm: Use internal voltage control

In reply to a message not in the archive

From: Vijay Viswanath <[email protected]>

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.

---
 drivers/mmc/host/sdhci-msm.c | 212 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 204 insertions(+), 8 deletions(-)
drivers/mmc/host/sdhci-msm.c +204 -8
index 3cc8bfe..6918e70 100644
@@ -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);
Signature · 2 lines
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.