Re: [PATCH v3 2/3] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan

[Shawn Lin]

On 2015/10/20 15:30, Michal Simek wrote:
> Hi,
>
> On 10/20/2015 09:05 AM, Shawn Lin wrote:
> > This patch adds Generic PHY access for sdhci-of-arasan. Driver
> > can get PHY handler from dt-binding, and power-on/init the PHY.
> > Also we add pm ops for PHY here if CONFIG_PM_SLEEP is enabled.
> > Currently, it's just mandatory for arasan,sdhci-5.1.
> >
> > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> >
> > Serise-changes: 3
> > - remove phy_init/exit for suspend/resume
> > - adjust phy_int/power_on seq to make code more reasonable
> > - simplify suspend/resume_phy
> >
> > Serise-changes: 2
> > - Keep phy as a mandatory requirement for arasan,sdhci-5.1
> >
> > ---
> >
> > Changes in v2: None
> >
> >   drivers/mmc/host/sdhci-of-arasan.c | 87 ++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 87 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> > index 75379cb..85bd0f9d 100644
> > --- a/drivers/mmc/host/sdhci-of-arasan.c
> > +++ b/drivers/mmc/host/sdhci-of-arasan.c
> > @@ -21,6 +21,7 @@
> >
> >   #include <linux/module.h>
> >   #include <linux/of_device.h>
> > +#include <linux/phy/phy.h>
> >   #include "sdhci-pltfm.h"
> >
> >   #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
> > @@ -35,6 +36,7 @@
> >    */
> >   struct sdhci_arasan_data {
> >   	struct clk	*clk_ahb;
> > +	struct phy	*phy;
> >   };
> >
> >   static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> > @@ -70,6 +72,42 @@ static struct sdhci_pltfm_data sdhci_arasan_pdata = {
> >
> >   #ifdef CONFIG_PM_SLEEP
> >   /**
> > +  * sdhci_arasan_suspend_phy - Suspend phy method for the driver
> > +  * @phy:        Handler of phy structure
> > +  * Returns 0 on success and error value on error
> > +  *
> > +  * Put the phy in a deactive state.
> > +  */
>
> This is not kernel-doc format.
> Try this and fix it.
>
> ./scripts/kernel-doc -man -v drivers/mmc/host/sdhci-of-arasan.c > /dev/null

okay, I will try to fix it.

> > +static int sdhci_arasan_suspend_phy(struct phy *phy)
> > +{
> > +	int ret = 0;
> > +
> > +	ret = phy_power_off(phy);
> > +	if (ret)
> > +		phy_power_on(phy);
>
> I am curious about this logic. If power_off fails I would expect that
> phy could still have power_on. Or not?

That depends. From "ret", I cannot tell the failure type, whether it's 
caused by *real power off fail* or by other generic phy stuff.

So, I think it's better to power_on it again if we can't guarantee phy's 
state. ïï

> Thanks,
> Michal


--
Best Regards
Shawn Lin

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/