Re: [PATCH V4 1/5] phy: Add new Exynos5 USB 3.0 PHY driver

[Kishon Vijay Abraham I <kishon@ti.com>]

On Monday 14 April 2014 06:12 PM, Vivek Gautam wrote:
> Hi,
> 
> 
> On Mon, Apr 14, 2014 at 5:57 PM, Kishon Vijay Abraham I <kishon@ti.com> wrote:
>> Hi,
>>
>> On Tuesday 08 April 2014 08:06 PM, Vivek Gautam wrote:
>>> Add a new driver for the USB 3.0 PHY on Exynos5 series of SoCs.
>>> The new driver uses the generic PHY framework and will interact
>>> with DWC3 controller present on Exynos5 series of SoCs.
>>> Thereby, removing old phy-samsung-usb3 driver and related code
>>> used untill now which was based on usb/phy framework.
>>>
>>> Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
>>> ---
>>>  .../devicetree/bindings/phy/samsung-phy.txt        |   42 ++
>>>  drivers/phy/Kconfig                                |   11 +
>>>  drivers/phy/Makefile                               |    1 +
>>>  drivers/phy/phy-exynos5-usbdrd.c                   |  668 ++++++++++++++++++++
>>>  4 files changed, 722 insertions(+)
>>>  create mode 100644 drivers/phy/phy-exynos5-usbdrd.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/phy/samsung-phy.txt b/Documentation/devicetree/bindings/phy/samsung-phy.txt
>>> index 28f9edb..6d99ba9 100644
>>> --- a/Documentation/devicetree/bindings/phy/samsung-phy.txt
>>> +++ b/Documentation/devicetree/bindings/phy/samsung-phy.txt
>>> @@ -74,3 +74,45 @@ phy-consumer@12340000 {
>>>
>>>  Refer to DT bindings documentation of particular PHY consumer devices for more
>>>  information about required PHYs and the way of specification.
>>> +
>>> +Samsung Exynos5 SoC series USB DRD PHY controller
>>> +--------------------------------------------------
>>> +
>>> +Required properties:
>>> +- compatible : Should be set to one of the following supported values:
>>> +     - "samsung,exynos5250-usbdrd-phy" - for exynos5250 SoC,
>>> +     - "samsung,exynos5420-usbdrd-phy" - for exynos5420 SoC.
>>> +- reg : Register offset and length of USB DRD PHY register set;
>>> +- clocks: Clock IDs array as required by the controller
>>> +- clock-names: names of clocks correseponding to IDs in the clock property;
>>> +            Required clocks:
>>> +     - phy: main PHY clock (same as USB DRD controller i.e. DWC3 IP clock),
>>> +            used for register access.
>>> +     - ref: PHY's reference clock (usually crystal clock), associated by
>>> +            phy name, used to determine bit values for clock settings
>>> +            register.
>>> +     Additional clock required for Exynos5420:
>>> +     - usb30_sclk_100m: Additional special clock used for PHY operation
>>> +                        depicted as 'sclk_usbphy30' in CMU of Exynos5420.
>>> +- samsung,syscon-phandle: phandle for syscon interface, which is used to
>>> +                       control pmu registers for power isolation.
>>> +- samsung,pmu-offset: phy power control register offset to pmu-system-controller
>>> +                   base.
>>> +- #phy-cells : from the generic PHY bindings, must be 1;
>>> +
>>> +For "samsung,exynos5250-usbdrd-phy" and "samsung,exynos5420-usbdrd-phy"
>>> +compatible PHYs, the second cell in the PHY specifier identifies the
>>> +PHY id, which is interpreted as follows:
>>> +  0 - UTMI+ type phy,
>>> +  1 - PIPE3 type phy,
>>> +
>>> +Example:
>>> +     usb3_phy: usbphy@12100000 {
>>> +             compatible = "samsung,exynos5250-usbdrd-phy";
>>> +             reg = <0x12100000 0x100>;
>>> +             clocks = <&clock 286>, <&clock 1>;
>>> +             clock-names = "phy", "usb3phy_refclk";
>>> +             samsung,syscon-phandle = <&pmu_syscon>;
>>> +             samsung,pmu-offset = <0x704>;
>>> +             #phy-cells = <1>;
>>> +     };
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index 8d3c49c..d955a05 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -166,4 +166,15 @@ config PHY_XGENE
>>>       help
>>>         This option enables support for APM X-Gene SoC multi-purpose PHY.
>>>
>>> +config PHY_EXYNOS5_USBDRD
>>> +     tristate "Exynos5 SoC series USB DRD PHY driver"
>>> +     depends on ARCH_EXYNOS5 && OF
>>> +     depends on HAS_IOMEM
>>> +     select GENERIC_PHY
>>> +     select MFD_SYSCON
>>
>> Lets try to avoid select in Kconfig. We've got enough problems with that.
> 
> I hope you meant with "select MFD_SYSCON".
> We are referencing the syscon for accessing pmu reg, for which we need
> this config to be selected.
> Other Exynos phy drivers also need this config and for that they have
> selected this.
> 
> Do you want me to do it any other way ?

depends on is one option.

Thanks
Kishon