[PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[Marek Vasut]

Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI
clock enabled after the tuning reset. This is not always necessary.

After the driver performed tuning reset at the end of probe function,
or in the unlikely case that tuning failed during regular operation,
the SDHI clock can be disabled after the tuning reset. The following
set_ios call would reconfigure the clock as needed.

In case of regular set_ios call which requires a tuning reset, keep
the clock enabled or disabled according to the mmc->clk_disable state.

With this in place, the controllers which have not been accessed via
block subsystem after boot are left in quiescent state. However, if an
MMC device is used e.g. for environment storage, that controller would
be accessed during the environment load and left active, including its
clock which would still be generated. This is due to the design of the
MMC subsystem, which does not deinit a controller after it was started
once, the controller is only deinited in case of mmc rescan, or before
OS boot.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Note: To address the part where MMC device has been inited once and
      is never deinited until rescan or OS boot, it would likely be
      necessary to implement something like runtime PM, possibly
      based on the cyclic framework. Basically, keep track of when
      the MMC was accessed last, and if certain time elapsed, deinit
      the MMC. This could also be used to handle card detect polling
      at the same time.
---
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
Cc: Peng Fan <peng.fan@nxp.com>
---
 drivers/mmc/renesas-sdhi.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/renesas-sdhi.c b/drivers/mmc/renesas-sdhi.c
index 8cd501c5f7c..97aaf1e4ec3 100644
--- a/drivers/mmc/renesas-sdhi.c
+++ b/drivers/mmc/renesas-sdhi.c
@@ -318,7 +318,7 @@ static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv)
 		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
 }
 
-static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
+static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv, bool clk_disable)
 {
 	u32 reg;
 
@@ -350,6 +350,12 @@ static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
 	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
+
+	if (clk_disable) {
+		reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
+		reg &= ~TMIO_SD_CLKCTL_SCLKEN;
+		tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
+	}
 }
 
 static int renesas_sdhi_hs400(struct udevice *dev)
@@ -629,7 +635,7 @@ int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
 out:
 	if (ret < 0) {
 		dev_warn(dev, "Tuning procedure failed\n");
-		renesas_sdhi_reset_tuning(priv);
+		renesas_sdhi_reset_tuning(priv, true);
 	}
 
 	return ret;
@@ -668,7 +674,7 @@ static int renesas_sdhi_set_ios(struct udevice *dev)
 	    (mmc->selected_mode != UHS_SDR104) &&
 	    (mmc->selected_mode != MMC_HS_200) &&
 	    (mmc->selected_mode != MMC_HS_400)) {
-		renesas_sdhi_reset_tuning(priv);
+		renesas_sdhi_reset_tuning(priv, mmc->clk_disable);
 	}
 #endif
 
@@ -1095,7 +1101,7 @@ static int renesas_sdhi_probe(struct udevice *dev)
     CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
     CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
 	if (priv->caps & TMIO_SD_CAP_RCAR_UHS)
-		renesas_sdhi_reset_tuning(priv);
+		renesas_sdhi_reset_tuning(priv, true);
 #endif
 	return 0;
 
-- 
2.42.0

RE: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[Jaehoon Chung]

> -----Original Message-----
> From: Marek Vasut <marek.vasut+renesas@mailbox.org>
> Sent: Monday, November 6, 2023 7:43 AM
> To: u-boot@lists.denx.de
> Cc: Marek Vasut <marek.vasut+renesas@mailbox.org>; Jaehoon Chung <jh80.chung@samsung.com>; Nobuhiro
> Iwamatsu <iwamatsu@nigauri.org>; Paul Barker <paul.barker.ct@bp.renesas.com>; Peng Fan
> <peng.fan@nxp.com>
> Subject: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible
> 
> Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI
> clock enabled after the tuning reset. This is not always necessary.
> 
> After the driver performed tuning reset at the end of probe function,
> or in the unlikely case that tuning failed during regular operation,
> the SDHI clock can be disabled after the tuning reset. The following
> set_ios call would reconfigure the clock as needed.
> 
> In case of regular set_ios call which requires a tuning reset, keep
> the clock enabled or disabled according to the mmc->clk_disable state.
> 
> With this in place, the controllers which have not been accessed via
> block subsystem after boot are left in quiescent state. However, if an
> MMC device is used e.g. for environment storage, that controller would
> be accessed during the environment load and left active, including its
> clock which would still be generated. This is due to the design of the
> MMC subsystem, which does not deinit a controller after it was started
> once, the controller is only deinited in case of mmc rescan, or before
> OS boot.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

Best Regards,
Jaehoon Chung

> ---
> Note: To address the part where MMC device has been inited once and
>       is never deinited until rescan or OS boot, it would likely be
>       necessary to implement something like runtime PM, possibly
>       based on the cyclic framework. Basically, keep track of when
>       the MMC was accessed last, and if certain time elapsed, deinit
>       the MMC. This could also be used to handle card detect polling
>       at the same time.
> ---
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
> Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/mmc/renesas-sdhi.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/renesas-sdhi.c b/drivers/mmc/renesas-sdhi.c
> index 8cd501c5f7c..97aaf1e4ec3 100644
> --- a/drivers/mmc/renesas-sdhi.c
> +++ b/drivers/mmc/renesas-sdhi.c
> @@ -318,7 +318,7 @@ static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv)
>  		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
>  }
> 
> -static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
> +static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv, bool clk_disable)
>  {
>  	u32 reg;
> 
> @@ -350,6 +350,12 @@ static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
>  	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
>  	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
>  	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
> +
> +	if (clk_disable) {
> +		reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
> +		reg &= ~TMIO_SD_CLKCTL_SCLKEN;
> +		tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
> +	}
>  }
> 
>  static int renesas_sdhi_hs400(struct udevice *dev)
> @@ -629,7 +635,7 @@ int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
>  out:
>  	if (ret < 0) {
>  		dev_warn(dev, "Tuning procedure failed\n");
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  	}
> 
>  	return ret;
> @@ -668,7 +674,7 @@ static int renesas_sdhi_set_ios(struct udevice *dev)
>  	    (mmc->selected_mode != UHS_SDR104) &&
>  	    (mmc->selected_mode != MMC_HS_200) &&
>  	    (mmc->selected_mode != MMC_HS_400)) {
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, mmc->clk_disable);
>  	}
>  #endif
> 
> @@ -1095,7 +1101,7 @@ static int renesas_sdhi_probe(struct udevice *dev)
>      CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
>      CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>  	if (priv->caps & TMIO_SD_CAP_RCAR_UHS)
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  #endif
>  	return 0;
> 
> --
> 2.42.0

Re: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[Paul Barker]

[-- Attachment #1: Type: text/plain, Size: 4093 bytes --]

On Sun, Nov 05, 2023 at 11:42:45PM +0100, Marek Vasut wrote:
> Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI
> clock enabled after the tuning reset. This is not always necessary.
> 
> After the driver performed tuning reset at the end of probe function,
> or in the unlikely case that tuning failed during regular operation,
> the SDHI clock can be disabled after the tuning reset. The following
> set_ios call would reconfigure the clock as needed.
> 
> In case of regular set_ios call which requires a tuning reset, keep
> the clock enabled or disabled according to the mmc->clk_disable state.
> 
> With this in place, the controllers which have not been accessed via
> block subsystem after boot are left in quiescent state. However, if an
> MMC device is used e.g. for environment storage, that controller would
> be accessed during the environment load and left active, including its
> clock which would still be generated. This is due to the design of the
> MMC subsystem, which does not deinit a controller after it was started
> once, the controller is only deinited in case of mmc rescan, or before
> OS boot.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Note: To address the part where MMC device has been inited once and
>       is never deinited until rescan or OS boot, it would likely be
>       necessary to implement something like runtime PM, possibly
>       based on the cyclic framework. Basically, keep track of when
>       the MMC was accessed last, and if certain time elapsed, deinit
>       the MMC. This could also be used to handle card detect polling
>       at the same time.
> ---
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
> Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/mmc/renesas-sdhi.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/renesas-sdhi.c b/drivers/mmc/renesas-sdhi.c
> index 8cd501c5f7c..97aaf1e4ec3 100644
> --- a/drivers/mmc/renesas-sdhi.c
> +++ b/drivers/mmc/renesas-sdhi.c
> @@ -318,7 +318,7 @@ static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv)
>  		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
>  }
>  
> -static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
> +static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv, bool clk_disable)
>  {
>  	u32 reg;
>  
> @@ -350,6 +350,12 @@ static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
>  	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
>  	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
>  	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
> +
> +	if (clk_disable) {
> +		reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
> +		reg &= ~TMIO_SD_CLKCTL_SCLKEN;
> +		tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
> +	}
>  }
>  
>  static int renesas_sdhi_hs400(struct udevice *dev)
> @@ -629,7 +635,7 @@ int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
>  out:
>  	if (ret < 0) {
>  		dev_warn(dev, "Tuning procedure failed\n");
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  	}
>  
>  	return ret;
> @@ -668,7 +674,7 @@ static int renesas_sdhi_set_ios(struct udevice *dev)
>  	    (mmc->selected_mode != UHS_SDR104) &&
>  	    (mmc->selected_mode != MMC_HS_200) &&
>  	    (mmc->selected_mode != MMC_HS_400)) {
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, mmc->clk_disable);
>  	}
>  #endif
>  
> @@ -1095,7 +1101,7 @@ static int renesas_sdhi_probe(struct udevice *dev)
>      CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
>      CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>  	if (priv->caps & TMIO_SD_CAP_RCAR_UHS)
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  #endif
>  	return 0;

Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Tested-by: Paul Barker <paul.barker.ct@bp.renesas.com>
  (on RZ/G2L SMARC EVK)

Thanks,
Paul

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

RE: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[Yoshihiro Shimoda]

Hello Marek-san,

> From: U-Boot On Behalf Of Marek Vasut, Sent: Monday, November 6, 2023 7:43 AM
> 
> Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI
> clock enabled after the tuning reset. This is not always necessary.
> 
> After the driver performed tuning reset at the end of probe function,
> or in the unlikely case that tuning failed during regular operation,
> the SDHI clock can be disabled after the tuning reset. The following
> set_ios call would reconfigure the clock as needed.
> 
> In case of regular set_ios call which requires a tuning reset, keep
> the clock enabled or disabled according to the mmc->clk_disable state.
> 
> With this in place, the controllers which have not been accessed via
> block subsystem after boot are left in quiescent state. However, if an
> MMC device is used e.g. for environment storage, that controller would
> be accessed during the environment load and left active, including its
> clock which would still be generated. This is due to the design of the
> MMC subsystem, which does not deinit a controller after it was started
> once, the controller is only deinited in case of mmc rescan, or before
> OS boot.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Note: To address the part where MMC device has been inited once and
>       is never deinited until rescan or OS boot, it would likely be
>       necessary to implement something like runtime PM, possibly
>       based on the cyclic framework. Basically, keep track of when
>       the MMC was accessed last, and if certain time elapsed, deinit
>       the MMC. This could also be used to handle card detect polling
>       at the same time.
> ---
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
> Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
> Cc: Peng Fan <peng.fan@nxp.com>

Thank you for the patch! This patch looks good to me. So,

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Also, our outsourcing member tested this patch on R-Car H3 Salvator-XS
And it works without any regression. So,

Tested-by: Thuan Nguyen Hong <thuan.nguyen-hong@banvien.com.vn>

Best regards,
Yoshihiro Shimoda

> ---
>  drivers/mmc/renesas-sdhi.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/renesas-sdhi.c b/drivers/mmc/renesas-sdhi.c
> index 8cd501c5f7c..97aaf1e4ec3 100644
> --- a/drivers/mmc/renesas-sdhi.c
> +++ b/drivers/mmc/renesas-sdhi.c
> @@ -318,7 +318,7 @@ static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv)
>  		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
>  }
> 
> -static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
> +static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv, bool clk_disable)
>  {
>  	u32 reg;
> 
> @@ -350,6 +350,12 @@ static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
>  	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
>  	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
>  	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
> +
> +	if (clk_disable) {
> +		reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
> +		reg &= ~TMIO_SD_CLKCTL_SCLKEN;
> +		tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
> +	}
>  }
> 
>  static int renesas_sdhi_hs400(struct udevice *dev)
> @@ -629,7 +635,7 @@ int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
>  out:
>  	if (ret < 0) {
>  		dev_warn(dev, "Tuning procedure failed\n");
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  	}
> 
>  	return ret;
> @@ -668,7 +674,7 @@ static int renesas_sdhi_set_ios(struct udevice *dev)
>  	    (mmc->selected_mode != UHS_SDR104) &&
>  	    (mmc->selected_mode != MMC_HS_200) &&
>  	    (mmc->selected_mode != MMC_HS_400)) {
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, mmc->clk_disable);
>  	}
>  #endif
> 
> @@ -1095,7 +1101,7 @@ static int renesas_sdhi_probe(struct udevice *dev)
>      CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
>      CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>  	if (priv->caps & TMIO_SD_CAP_RCAR_UHS)
> -		renesas_sdhi_reset_tuning(priv);
> +		renesas_sdhi_reset_tuning(priv, true);
>  #endif
>  	return 0;
> 
> --
> 2.42.0

Re: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible

[Marek Vasut]

On 11/6/23 11:24, Jaehoon Chung wrote:
> 
> 
>> -----Original Message-----
>> From: Marek Vasut <marek.vasut+renesas@mailbox.org>
>> Sent: Monday, November 6, 2023 7:43 AM
>> To: u-boot@lists.denx.de
>> Cc: Marek Vasut <marek.vasut+renesas@mailbox.org>; Jaehoon Chung <jh80.chung@samsung.com>; Nobuhiro
>> Iwamatsu <iwamatsu@nigauri.org>; Paul Barker <paul.barker.ct@bp.renesas.com>; Peng Fan
>> <peng.fan@nxp.com>
>> Subject: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible
>>
>> Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI
>> clock enabled after the tuning reset. This is not always necessary.
>>
>> After the driver performed tuning reset at the end of probe function,
>> or in the unlikely case that tuning failed during regular operation,
>> the SDHI clock can be disabled after the tuning reset. The following
>> set_ios call would reconfigure the clock as needed.
>>
>> In case of regular set_ios call which requires a tuning reset, keep
>> the clock enabled or disabled according to the mmc->clk_disable state.
>>
>> With this in place, the controllers which have not been accessed via
>> block subsystem after boot are left in quiescent state. However, if an
>> MMC device is used e.g. for environment storage, that controller would
>> be accessed during the environment load and left active, including its
>> clock which would still be generated. This is due to the design of the
>> MMC subsystem, which does not deinit a controller after it was started
>> once, the controller is only deinited in case of mmc rescan, or before
>> OS boot.
>>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> 
> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

Thanks. Do you want to take this via mmc tree or shall I take it via sh 
tree ? I wouldn't mind the later, since it is isolated to renesas platforms.