[PATCH 1/3] ahci: exynos: add ahci sata support on Exynos platform

[Yuvaraj Kumar]

On Fri, Oct 4, 2013 at 6:03 AM, Jingoo Han <jg1.han at samsung.com> wrote:
> On Thursday, October 03, 2013 8:32 PM, Bartlomiej Zolnierkiewicz wrote:
>> On Tuesday, October 01, 2013 12:03:01 PM Yuvaraj Kumar C D wrote:
>> > Exynos5250 contains one Synopsys AHCI SATA controller.The avalaible
>> > ahci_platform driver is not sufficient to handle the AHCI PHY and PHY
>> > clock related initialization.
>> >
>> > This patch adds exynos specific ahci sata driver,contained the exynos
>> > specific initialized codes, re-use the generic ahci_platform driver, and
>> > keep the generic ahci_platform driver clean as much as possible.
>> >
>> > This patch depends on the below patch
>> >     [1].drivers: phy: add generic PHY framework
>> >             by Kishon Vijay Abraham I<kishon at ti.com>
>> >
>> > Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd at samsung.com>
>> > ---
>> >  drivers/ata/Kconfig       |    9 ++
>> >  drivers/ata/Makefile      |    1 +
>> >  drivers/ata/ahci_exynos.c |  226 +++++++++++++++++++++++++++++++++++++++++++++
>> >  3 files changed, 236 insertions(+)
>> >  create mode 100644 drivers/ata/ahci_exynos.c
>> >
>
>
> [.....]
>
>> > +   priv->phy = devm_phy_get(dev , "sata-phy");
>> > +   if (IS_ERR(priv->phy))
>> > +           return PTR_ERR(priv->phy);
>
> [.....]
>
>> Also please take a look at the following patch:
>>
>> https://lkml.org/lkml/2013/9/19/173
>>
>> it adds PHY support to ahci_platform driver, maybe it can be used
>> for your needs as well.
>
> I also agree with Bartlomiej Zolnierkiewicz's opinion.
> 'ahci_exynos.c' just calls PHY API, without any additional control
> for Exynos AHCI IP.
In addition to PHY handling,it also deals with the special clock
sclk_sata which is not dealt in ahci_platform.c(certainly exynos
specific).

Morever there is a wrapper driver to handle the platform specific
things for the sata.Please refer the  patch[1]
[1]ata: ti_sata: Add Texas Instruments SATA Wrapper driver
https://lkml.org/lkml/2013/9/19/166

[2]ahci_imx: add ahci sata support on imx platforms

I think, if we have platform specific driver like ahci_xxx.c , it
would be better to handle the sata PHY in ahci_xxx.c so that we can
retain and re-use the ahci_platform.c as it is.

Further comments will be much appreciated.

>
> Best regards,
> Jingoo Han
>
>>
>> > +   ret = phy_init(priv->phy);
>> > +   if (ret < 0) {
>> > +                   dev_err(dev, "failed to init SATA PHY\n");
>> > +                   return ret;
>> > +   }
>> > +
>