2016-04-27 04:15:51

by Shawn Lin

Subject: [PATCH] mmc: sdhci-of-arasan: refactor set_clock callback

commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for
sdhci-of-arasan") introduce phy support for arasan. According to
the vendor's databook, we should make sure the phy is in poweroff
status before we configure the clk stuff. Otherwise it may cause
some IO sample timing issues from the test. And we don't need this
extra operation while running in low perfermance mode since phy
doesn't trigger sampling block.

Signed-off-by: Shawn Lin <[email protected]>
---

drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 2e482b1..20b859e 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -55,8 +55,26 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
return freq;
}

+static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+ bool ctrl_phy = false;
+
+ if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy)))
+ ctrl_phy = true;
+
+ if (ctrl_phy)
+ phy_power_off(sdhci_arasan->phy);
+
+ sdhci_set_clock(host, clock);
+
+ if (ctrl_phy)
+ phy_power_on(sdhci_arasan->phy);
+}
+
static struct sdhci_ops sdhci_arasan_ops = {
- .set_clock = sdhci_set_clock,
+ .set_clock = sdhci_arasan_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.get_timeout_clock = sdhci_arasan_get_timeout_clock,
.set_bus_width = sdhci_set_bus_width,
--
2.3.7

2016-04-28 08:04:02

by Adrian Hunter

Subject: Re: [PATCH] mmc: sdhci-of-arasan: refactor set_clock callback

"refactor" typically means no change in behaviour.
This looks like a fix e.g.
"Fix set_clock when a phy is supported"

On 27/04/16 07:14, Shawn Lin wrote:
> commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for
> sdhci-of-arasan") introduce phy support for arasan. According to
> the vendor's databook, we should make sure the phy is in poweroff
> status before we configure the clk stuff. Otherwise it may cause
> some IO sample timing issues from the test. And we don't need this
> extra operation while running in low perfermance mode since phy

perfermance -> performance

> doesn't trigger sampling block.
>
> Signed-off-by: Shawn Lin <[email protected]>
> ---
>
> drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 2e482b1..20b859e 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -55,8 +55,26 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> return freq;
> }
>
> +static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
> + bool ctrl_phy = false;
> +
> + if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy)))
> + ctrl_phy = true;
> +
> + if (ctrl_phy)
> + phy_power_off(sdhci_arasan->phy);
> +
> + sdhci_set_clock(host, clock);
> +
> + if (ctrl_phy)
> + phy_power_on(sdhci_arasan->phy);
> +}
> +
> static struct sdhci_ops sdhci_arasan_ops = {
> - .set_clock = sdhci_set_clock,
> + .set_clock = sdhci_arasan_set_clock,
> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> .get_timeout_clock = sdhci_arasan_get_timeout_clock,
> .set_bus_width = sdhci_set_bus_width,
>

2016-04-28 08:24:55

by Shawn Lin

Subject: Re: [PATCH] mmc: sdhci-of-arasan: refactor set_clock callback

On 2016/4/28 16:00, Adrian Hunter wrote:
>
> "refactor" typically means no change in behaviour.
> This looks like a fix e.g.
> "Fix set_clock when a phy is supported"

Thanks, will fix it.

>
> On 27/04/16 07:14, Shawn Lin wrote:
>> commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for
>> sdhci-of-arasan") introduce phy support for arasan. According to
>> the vendor's databook, we should make sure the phy is in poweroff
>> status before we configure the clk stuff. Otherwise it may cause
>> some IO sample timing issues from the test. And we don't need this
>> extra operation while running in low perfermance mode since phy
>
> perfermance -> performance

will fix.

>
>> doesn't trigger sampling block.
>>
>> Signed-off-by: Shawn Lin <[email protected]>
>> ---
>>
>> drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++-
>> 1 file changed, 19 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index 2e482b1..20b859e 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -55,8 +55,26 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
>> return freq;
>> }
>>
>> +static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>> +{
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
>> + bool ctrl_phy = false;
>> +
>> + if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy)))
>> + ctrl_phy = true;
>> +
>> + if (ctrl_phy)
>> + phy_power_off(sdhci_arasan->phy);
>> +
>> + sdhci_set_clock(host, clock);
>> +
>> + if (ctrl_phy)
>> + phy_power_on(sdhci_arasan->phy);
>> +}
>> +
>> static struct sdhci_ops sdhci_arasan_ops = {
>> - .set_clock = sdhci_set_clock,
>> + .set_clock = sdhci_arasan_set_clock,
>> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
>> .get_timeout_clock = sdhci_arasan_get_timeout_clock,
>> .set_bus_width = sdhci_set_bus_width,
>>
>
>
>
>


--
Best Regards
Shawn Lin