[PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Shawn Lin]

Currently the get_timeout_clock callabck doesn't clearly
have a statment that it needs the variant drivers to return
the timeout clock rate in KHz if the SDHCI_TIMEOUT_CLK_UNIT
isn't present, otherwise the variant drivers should return it
in KHz. So actually sdhci-of-arasan return the wrong value found
by Anssi[1]. It's also very likely that further variant drivers which
are going to use this callback will be confused by this situation.
Given the fact that modem sdhci variant hosts are very prone to get
the timeout clock from common clock framework(actuall the only three
users did that), it's more nature to return the value in Hz and we
make a explicit comment there. Then we put the unit conversion inside
the sdhci core. Thus will improve the code and prevent further misues.

[1]: https://patchwork.kernel.org/patch/9569431/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v4:
- rebased on -next
- add Masahiro's ack for sdhci-cadence

Changes in v3:
- squash all the patches into one to keep bisectability
- fix wrong return value of sdhci-cadence
- slight improve the condition check to avoid the complaint of
  checkpatch

Changes in v2:
- fix the comment and make it return in Hz

 drivers/mmc/host/sdhci-cadence.c   |  4 ++--
 drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
 drivers/mmc/host/sdhci.c           | 16 +++++++++-------
 drivers/mmc/host/sdhci.h           |  1 +
 4 files changed, 13 insertions(+), 25 deletions(-)

diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index 316cfec..7baeeaf 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
 {
 	/*
 	 * Cadence's spec says the Timeout Clock Frequency is the same as the
-	 * Base Clock Frequency.  Divide it by 1000 to return a value in kHz.
+	 * Base Clock Frequency.
 	 */
-	return host->max_clk / 1000;
+	return host->max_clk;
 }
 
 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 1cfd7f9..c52f153 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
 	return ret;
 }
 
-static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
-{
-	unsigned long freq;
-	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
-
-	/* SDHCI timeout clock is in kHz */
-	freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
-
-	/* or in MHz */
-	if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
-		freq = DIV_ROUND_UP(freq, 1000);
-
-	return freq;
-}
-
 static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
 static struct sdhci_ops sdhci_arasan_ops = {
 	.set_clock = sdhci_arasan_set_clock,
 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
-	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
+	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
 	.set_bus_width = sdhci_set_bus_width,
 	.reset = sdhci_arasan_reset,
 	.set_uhs_signaling = sdhci_set_uhs_signaling,
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6fdd7a7..f73494e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
 	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
 		host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
 					SDHCI_TIMEOUT_CLK_SHIFT;
+
+		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
+			host->timeout_clk *= 1000;
+
 		if (host->timeout_clk == 0) {
-			if (host->ops->get_timeout_clock) {
-				host->timeout_clk =
-					host->ops->get_timeout_clock(host);
-			} else {
+			if (unlikely(!host->ops->get_timeout_clock)) {
 				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
 					mmc_hostname(mmc));
 				ret = -ENODEV;
 				goto undma;
 			}
-		}
 
-		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
-			host->timeout_clk *= 1000;
+			host->timeout_clk =
+				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
+					     1000);
+		}
 
 		if (override_timeout_clk)
 			host->timeout_clk = override_timeout_clk;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index edf3adf..27c252c 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -547,6 +547,7 @@ struct sdhci_ops {
 	int		(*enable_dma)(struct sdhci_host *host);
 	unsigned int	(*get_max_clock)(struct sdhci_host *host);
 	unsigned int	(*get_min_clock)(struct sdhci_host *host);
+	/* get_timeout_clock should return clk rate in unit of Hz */
 	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
 	unsigned int	(*get_max_timeout_count)(struct sdhci_host *host);
 	void		(*set_timeout)(struct sdhci_host *host,
-- 
1.9.1

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Jisheng Zhang]

On Thu, 16 Mar 2017 09:20:51 +0800 Shawn Lin wrote:

> Currently the get_timeout_clock callabck doesn't clearly
> have a statment that it needs the variant drivers to return
> the timeout clock rate in KHz if the SDHCI_TIMEOUT_CLK_UNIT
> isn't present, otherwise the variant drivers should return it
> in KHz. So actually sdhci-of-arasan return the wrong value found
> by Anssi[1]. It's also very likely that further variant drivers which
> are going to use this callback will be confused by this situation.
> Given the fact that modem sdhci variant hosts are very prone to get
> the timeout clock from common clock framework(actuall the only three
> users did that), it's more nature to return the value in Hz and we
> make a explicit comment there. Then we put the unit conversion inside
> the sdhci core. Thus will improve the code and prevent further misues.
> 
> [1]: https://patchwork.kernel.org/patch/9569431/

I think we need a blank line here

> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>

This blank line need to be removed.

> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v4:
> - rebased on -next
> - add Masahiro's ack for sdhci-cadence
> 
> Changes in v3:
> - squash all the patches into one to keep bisectability
> - fix wrong return value of sdhci-cadence
> - slight improve the condition check to avoid the complaint of
>   checkpatch
> 
> Changes in v2:
> - fix the comment and make it return in Hz
> 
>  drivers/mmc/host/sdhci-cadence.c   |  4 ++--
>  drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
>  drivers/mmc/host/sdhci.c           | 16 +++++++++-------
>  drivers/mmc/host/sdhci.h           |  1 +
>  4 files changed, 13 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> index 316cfec..7baeeaf 100644
> --- a/drivers/mmc/host/sdhci-cadence.c
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
>  {
>  	/*
>  	 * Cadence's spec says the Timeout Clock Frequency is the same as the
> -	 * Base Clock Frequency.  Divide it by 1000 to return a value in kHz.
> +	 * Base Clock Frequency.
>  	 */
> -	return host->max_clk / 1000;
> +	return host->max_clk;
>  }
>  
>  static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 1cfd7f9..c52f153 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
>  	return ret;
>  }
>  
> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> -{
> -	unsigned long freq;
> -	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> -
> -	/* SDHCI timeout clock is in kHz */
> -	freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
> -
> -	/* or in MHz */
> -	if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> -		freq = DIV_ROUND_UP(freq, 1000);
> -
> -	return freq;
> -}
> -
>  static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
>  static struct sdhci_ops sdhci_arasan_ops = {
>  	.set_clock = sdhci_arasan_set_clock,
>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
> -	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
> +	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
>  	.set_bus_width = sdhci_set_bus_width,
>  	.reset = sdhci_arasan_reset,
>  	.set_uhs_signaling = sdhci_set_uhs_signaling,
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6fdd7a7..f73494e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
>  	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
>  		host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
>  					SDHCI_TIMEOUT_CLK_SHIFT;
> +
> +		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> +			host->timeout_clk *= 1000;
> +
>  		if (host->timeout_clk == 0) {
> -			if (host->ops->get_timeout_clock) {
> -				host->timeout_clk =
> -					host->ops->get_timeout_clock(host);
> -			} else {
> +			if (unlikely(!host->ops->get_timeout_clock)) {
>  				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
>  					mmc_hostname(mmc));
>  				ret = -ENODEV;
>  				goto undma;
>  			}
> -		}
>  
> -		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> -			host->timeout_clk *= 1000;
> +			host->timeout_clk =
> +				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
> +					     1000);
> +		}
>  
>  		if (override_timeout_clk)
>  			host->timeout_clk = override_timeout_clk;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index edf3adf..27c252c 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -547,6 +547,7 @@ struct sdhci_ops {
>  	int		(*enable_dma)(struct sdhci_host *host);
>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
> +	/* get_timeout_clock should return clk rate in unit of Hz */
>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_max_timeout_count)(struct sdhci_host *host);
>  	void		(*set_timeout)(struct sdhci_host *host,

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Shawn Lin]

On 2017/3/16 13:25, Jisheng Zhang wrote:
> On Thu, 16 Mar 2017 09:20:51 +0800 Shawn Lin wrote:
>
>> Currently the get_timeout_clock callabck doesn't clearly
>> have a statment that it needs the variant drivers to return
>> the timeout clock rate in KHz if the SDHCI_TIMEOUT_CLK_UNIT
>> isn't present, otherwise the variant drivers should return it
>> in KHz. So actually sdhci-of-arasan return the wrong value found
>> by Anssi[1]. It's also very likely that further variant drivers which
>> are going to use this callback will be confused by this situation.
>> Given the fact that modem sdhci variant hosts are very prone to get
>> the timeout clock from common clock framework(actuall the only three
>> users did that), it's more nature to return the value in Hz and we
>> make a explicit comment there. Then we put the unit conversion inside
>> the sdhci core. Thus will improve the code and prevent further misues.
>>
>> [1]: https://patchwork.kernel.org/patch/9569431/
>
> I think we need a blank line here
>
>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
>> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>
>
> This blank line need to be removed.

okay, thanks.

Should I respin v5 or maybe Ulf could help amend these two
when applied if there is no other issues?

>
>> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>> Changes in v4:
>> - rebased on -next
>> - add Masahiro's ack for sdhci-cadence
>>
>> Changes in v3:
>> - squash all the patches into one to keep bisectability
>> - fix wrong return value of sdhci-cadence
>> - slight improve the condition check to avoid the complaint of
>>   checkpatch
>>
>> Changes in v2:
>> - fix the comment and make it return in Hz
>>
>>  drivers/mmc/host/sdhci-cadence.c   |  4 ++--
>>  drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
>>  drivers/mmc/host/sdhci.c           | 16 +++++++++-------
>>  drivers/mmc/host/sdhci.h           |  1 +
>>  4 files changed, 13 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
>> index 316cfec..7baeeaf 100644
>> --- a/drivers/mmc/host/sdhci-cadence.c
>> +++ b/drivers/mmc/host/sdhci-cadence.c
>> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
>>  {
>>  	/*
>>  	 * Cadence's spec says the Timeout Clock Frequency is the same as the
>> -	 * Base Clock Frequency.  Divide it by 1000 to return a value in kHz.
>> +	 * Base Clock Frequency.
>>  	 */
>> -	return host->max_clk / 1000;
>> +	return host->max_clk;
>>  }
>>
>>  static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index 1cfd7f9..c52f153 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
>>  	return ret;
>>  }
>>
>> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
>> -{
>> -	unsigned long freq;
>> -	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> -
>> -	/* SDHCI timeout clock is in kHz */
>> -	freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
>> -
>> -	/* or in MHz */
>> -	if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> -		freq = DIV_ROUND_UP(freq, 1000);
>> -
>> -	return freq;
>> -}
>> -
>>  static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
>>  static struct sdhci_ops sdhci_arasan_ops = {
>>  	.set_clock = sdhci_arasan_set_clock,
>>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
>> -	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
>> +	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
>>  	.set_bus_width = sdhci_set_bus_width,
>>  	.reset = sdhci_arasan_reset,
>>  	.set_uhs_signaling = sdhci_set_uhs_signaling,
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 6fdd7a7..f73494e 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
>>  	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
>>  		host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
>>  					SDHCI_TIMEOUT_CLK_SHIFT;
>> +
>> +		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> +			host->timeout_clk *= 1000;
>> +
>>  		if (host->timeout_clk == 0) {
>> -			if (host->ops->get_timeout_clock) {
>> -				host->timeout_clk =
>> -					host->ops->get_timeout_clock(host);
>> -			} else {
>> +			if (unlikely(!host->ops->get_timeout_clock)) {
>>  				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
>>  					mmc_hostname(mmc));
>>  				ret = -ENODEV;
>>  				goto undma;
>>  			}
>> -		}
>>
>> -		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> -			host->timeout_clk *= 1000;
>> +			host->timeout_clk =
>> +				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
>> +					     1000);
>> +		}
>>
>>  		if (override_timeout_clk)
>>  			host->timeout_clk = override_timeout_clk;
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index edf3adf..27c252c 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -547,6 +547,7 @@ struct sdhci_ops {
>>  	int		(*enable_dma)(struct sdhci_host *host);
>>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
>> +	/* get_timeout_clock should return clk rate in unit of Hz */
>>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
>>  	unsigned int	(*get_max_timeout_count)(struct sdhci_host *host);
>>  	void		(*set_timeout)(struct sdhci_host *host,
>
>
>
>


-- 
Best Regards
Shawn Lin

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Adrian Hunter]

On 16/03/17 03:20, Shawn Lin wrote:
> Currently the get_timeout_clock callabck doesn't clearly

callabck -> callback

> have a statment that it needs the variant drivers to return

statment -> statement

> the timeout clock rate in KHz if the SDHCI_TIMEOUT_CLK_UNIT

KHz -> kHz

> isn't present, otherwise the variant drivers should return it
> in KHz. So actually sdhci-of-arasan return the wrong value found

KHz -> MHz


> by Anssi[1]. It's also very likely that further variant drivers which
> are going to use this callback will be confused by this situation.
> Given the fact that modem sdhci variant hosts are very prone to get

modem -> modern

> the timeout clock from common clock framework(actuall the only three

framework( -> framework (

actuall -> actually


> users did that), it's more nature to return the value in Hz and we

nature -> natural

> make a explicit comment there. Then we put the unit conversion inside
> the sdhci core. Thus will improve the code and prevent further misues.

misues -> misuses

> 
> [1]: https://patchwork.kernel.org/patch/9569431/

+ blank line

> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> 

- blank line

> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v4:
> - rebased on -next
> - add Masahiro's ack for sdhci-cadence
> 
> Changes in v3:
> - squash all the patches into one to keep bisectability
> - fix wrong return value of sdhci-cadence
> - slight improve the condition check to avoid the complaint of
>   checkpatch
> 
> Changes in v2:
> - fix the comment and make it return in Hz
> 
>  drivers/mmc/host/sdhci-cadence.c   |  4 ++--
>  drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
>  drivers/mmc/host/sdhci.c           | 16 +++++++++-------
>  drivers/mmc/host/sdhci.h           |  1 +
>  4 files changed, 13 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> index 316cfec..7baeeaf 100644
> --- a/drivers/mmc/host/sdhci-cadence.c
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
>  {
>  	/*
>  	 * Cadence's spec says the Timeout Clock Frequency is the same as the
> -	 * Base Clock Frequency.  Divide it by 1000 to return a value in kHz.
> +	 * Base Clock Frequency.
>  	 */
> -	return host->max_clk / 1000;
> +	return host->max_clk;
>  }
>  
>  static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 1cfd7f9..c52f153 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
>  	return ret;
>  }
>  
> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> -{
> -	unsigned long freq;
> -	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> -
> -	/* SDHCI timeout clock is in kHz */
> -	freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
> -
> -	/* or in MHz */
> -	if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> -		freq = DIV_ROUND_UP(freq, 1000);
> -
> -	return freq;
> -}
> -
>  static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
>  static struct sdhci_ops sdhci_arasan_ops = {
>  	.set_clock = sdhci_arasan_set_clock,
>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
> -	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
> +	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
>  	.set_bus_width = sdhci_set_bus_width,
>  	.reset = sdhci_arasan_reset,
>  	.set_uhs_signaling = sdhci_set_uhs_signaling,
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6fdd7a7..f73494e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
>  	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
>  		host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
>  					SDHCI_TIMEOUT_CLK_SHIFT;
> +
> +		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> +			host->timeout_clk *= 1000;
> +
>  		if (host->timeout_clk == 0) {
> -			if (host->ops->get_timeout_clock) {
> -				host->timeout_clk =
> -					host->ops->get_timeout_clock(host);
> -			} else {
> +			if (unlikely(!host->ops->get_timeout_clock)) {

This is not a CPU hot path, so I don't want to use 'likely' or 'unlikely'.

>  				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
>  					mmc_hostname(mmc));
>  				ret = -ENODEV;
>  				goto undma;
>  			}
> -		}
>  
> -		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> -			host->timeout_clk *= 1000;
> +			host->timeout_clk =
> +				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
> +					     1000);
> +		}
>  
>  		if (override_timeout_clk)
>  			host->timeout_clk = override_timeout_clk;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index edf3adf..27c252c 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -547,6 +547,7 @@ struct sdhci_ops {
>  	int		(*enable_dma)(struct sdhci_host *host);
>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
> +	/* get_timeout_clock should return clk rate in unit of Hz */
>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_max_timeout_count)(struct sdhci_host *host);
>  	void		(*set_timeout)(struct sdhci_host *host,
> 

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Masahiro Yamada]

Hi Shawn,


>
>> users did that), it's more nature to return the value in Hz and we
>
> nature -> natural
>
>> make a explicit comment there. Then we put the unit conversion inside

While you are at it,

a explicit -> an explicit



>> the sdhci core. Thus will improve the code and prevent further misues.
>
> misues -> misuses
>
>>
>> [1]: https://patchwork.kernel.org/patch/9569431/
>
> + blank line
>
>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
>> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>


When applied, my Cc can be dropped
because I had already given Acked-by.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Shawn Lin]

On 2017/3/16 16:46, Masahiro Yamada wrote:
> Hi Shawn,
>
>
>>
>>> users did that), it's more nature to return the value in Hz and we
>>
>> nature -> natural
>>
>>> make a explicit comment there. Then we put the unit conversion inside
>
> While you are at it,
>
> a explicit -> an explicit
>
>

Okay, thanks.

>
>>> the sdhci core. Thus will improve the code and prevent further misues.
>>
>> misues -> misuses
>>
>>>
>>> [1]: https://patchwork.kernel.org/patch/9569431/
>>
>> + blank line
>>
>>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>>> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
>>> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
>
>
> When applied, my Cc can be dropped
> because I had already given Acked-by.

will remove it. Thanks.

>
>


-- 
Best Regards
Shawn Lin

Re: [PATCH v4] mmc: sdhci: clarify the get_timeout_clock callback

[Shawn Lin]

On 2017/3/16 16:31, Adrian Hunter wrote:
> On 16/03/17 03:20, Shawn Lin wrote:
>> Currently the get_timeout_clock callabck doesn't clearly
>
> callabck -> callback
>
>> have a statment that it needs the variant drivers to return
>
> statment -> statement
>
>> the timeout clock rate in KHz if the SDHCI_TIMEOUT_CLK_UNIT
>
> KHz -> kHz
>
>> isn't present, otherwise the variant drivers should return it
>> in KHz. So actually sdhci-of-arasan return the wrong value found
>
> KHz -> MHz
>
>
>> by Anssi[1]. It's also very likely that further variant drivers which
>> are going to use this callback will be confused by this situation.
>> Given the fact that modem sdhci variant hosts are very prone to get
>
> modem -> modern
>
>> the timeout clock from common clock framework(actuall the only three
>
> framework( -> framework (
>
> actuall -> actually
>
>
>> users did that), it's more nature to return the value in Hz and we
>
> nature -> natural
>
>> make a explicit comment there. Then we put the unit conversion inside
>> the sdhci core. Thus will improve the code and prevent further misues.
>
> misues -> misuses
>
>>
>> [1]: https://patchwork.kernel.org/patch/9569431/
>
> + blank line
>
>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
>> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>
>
> - blank line
>
>> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>> Changes in v4:
>> - rebased on -next
>> - add Masahiro's ack for sdhci-cadence
>>
>> Changes in v3:
>> - squash all the patches into one to keep bisectability
>> - fix wrong return value of sdhci-cadence
>> - slight improve the condition check to avoid the complaint of
>>   checkpatch
>>
>> Changes in v2:
>> - fix the comment and make it return in Hz
>>
>>  drivers/mmc/host/sdhci-cadence.c   |  4 ++--
>>  drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
>>  drivers/mmc/host/sdhci.c           | 16 +++++++++-------
>>  drivers/mmc/host/sdhci.h           |  1 +
>>  4 files changed, 13 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
>> index 316cfec..7baeeaf 100644
>> --- a/drivers/mmc/host/sdhci-cadence.c
>> +++ b/drivers/mmc/host/sdhci-cadence.c
>> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
>>  {
>>  	/*
>>  	 * Cadence's spec says the Timeout Clock Frequency is the same as the
>> -	 * Base Clock Frequency.  Divide it by 1000 to return a value in kHz.
>> +	 * Base Clock Frequency.
>>  	 */
>> -	return host->max_clk / 1000;
>> +	return host->max_clk;
>>  }
>>
>>  static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index 1cfd7f9..c52f153 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
>>  	return ret;
>>  }
>>
>> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
>> -{
>> -	unsigned long freq;
>> -	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> -
>> -	/* SDHCI timeout clock is in kHz */
>> -	freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
>> -
>> -	/* or in MHz */
>> -	if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> -		freq = DIV_ROUND_UP(freq, 1000);
>> -
>> -	return freq;
>> -}
>> -
>>  static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
>>  static struct sdhci_ops sdhci_arasan_ops = {
>>  	.set_clock = sdhci_arasan_set_clock,
>>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
>> -	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
>> +	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
>>  	.set_bus_width = sdhci_set_bus_width,
>>  	.reset = sdhci_arasan_reset,
>>  	.set_uhs_signaling = sdhci_set_uhs_signaling,
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 6fdd7a7..f73494e 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
>>  	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
>>  		host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
>>  					SDHCI_TIMEOUT_CLK_SHIFT;
>> +
>> +		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> +			host->timeout_clk *= 1000;
>> +
>>  		if (host->timeout_clk == 0) {
>> -			if (host->ops->get_timeout_clock) {
>> -				host->timeout_clk =
>> -					host->ops->get_timeout_clock(host);
>> -			} else {
>> +			if (unlikely(!host->ops->get_timeout_clock)) {
>
> This is not a CPU hot path, so I don't want to use 'likely' or 'unlikely'.

will remove this and fix all the typo. :)

>
>>  				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
>>  					mmc_hostname(mmc));
>>  				ret = -ENODEV;
>>  				goto undma;
>>  			}
>> -		}
>>
>> -		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> -			host->timeout_clk *= 1000;
>> +			host->timeout_clk =
>> +				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
>> +					     1000);
>> +		}
>>
>>  		if (override_timeout_clk)
>>  			host->timeout_clk = override_timeout_clk;
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index edf3adf..27c252c 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -547,6 +547,7 @@ struct sdhci_ops {
>>  	int		(*enable_dma)(struct sdhci_host *host);
>>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
>> +	/* get_timeout_clock should return clk rate in unit of Hz */
>>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
>>  	unsigned int	(*get_max_timeout_count)(struct sdhci_host *host);
>>  	void		(*set_timeout)(struct sdhci_host *host,
>>
>
>
>
>


-- 
Best Regards
Shawn Lin