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

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Hi,


On Mon, Apr 14, 2014 at 5:57 PM, Kishon Vijay Abraham I <kishon@xxxxxx> 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@xxxxxxxxxxx>
>> ---
>>  .../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 ?

>> +     help
>> +       Enable USB DRD PHY support for Exynos 5 SoC series.
>> +       This driver provides PHY interface for USB 3.0 DRD controller
>> +       present on Exynos5 SoC series.
>> +
>>  endmenu
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index 2faf78e..31baa0c 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -18,3 +18,4 @@ obj-$(CONFIG_PHY_EXYNOS4210_USB2)   += phy-exynos4210-usb2.o
>>  obj-$(CONFIG_PHY_EXYNOS4X12_USB2)    += phy-exynos4x12-usb2.o
>>  obj-$(CONFIG_PHY_EXYNOS5250_USB2)    += phy-exynos5250-usb2.o
>>  obj-$(CONFIG_PHY_XGENE)                      += phy-xgene.o
>> +obj-$(CONFIG_PHY_EXYNOS5_USBDRD)     += phy-exynos5-usbdrd.o
>> diff --git a/drivers/phy/phy-exynos5-usbdrd.c b/drivers/phy/phy-exynos5-usbdrd.c
>> new file mode 100644
>> index 0000000..ff54a7c
>> --- /dev/null
>> +++ b/drivers/phy/phy-exynos5-usbdrd.c
>> @@ -0,0 +1,668 @@
>> +/*
>> + * Samsung EXYNOS5 SoC series USB DRD PHY driver
>> + *
>> + * Phy provider for USB 3.0 DRD controller on Exynos5 SoC series
>> + *
>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>
> 2014 already ;-)

Yea. :-)
will correct.

>> + * Author: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
> .
> .
> <sniip>
> .
> .
>
>> +
>> +/*
>> + * Sets the pipe3 phy's clk as EXTREFCLK (XXTI) which is internal clock
>> + * from clock core. Further sets multiplier values and spread spectrum
>> + * clock settings for SuperSpeed operations.
>> + */
>> +static unsigned int
>> +exynos5_usbdrd_pipe3_set_refclk(struct phy_usb_instance *inst)
>> +{
>> +     static u32 reg;
>> +     struct exynos5_usbdrd_phy *phy_drd = to_usbdrd_phy(inst);
>> +
>> +     /* restore any previous reference clock settings */
>> +     reg = phy_drd->refclk_reg;
>
> Why don't we just read back from the register instead?

Yes, we can do that too. Will amend it.

>> +
>> +     /* Use EXTREFCLK as ref clock */
>> +     reg &= ~PHYCLKRST_REFCLKSEL_MASK;
>> +     reg |=  PHYCLKRST_REFCLKSEL_EXT_REFCLK;
>> +
>> +     /* FSEL settings corresponding to reference clock */
>> +     reg &= ~PHYCLKRST_FSEL_PIPE_MASK |
>> +             PHYCLKRST_MPLL_MULTIPLIER_MASK |
>> +             PHYCLKRST_SSC_REFCLKSEL_MASK;
>> +     switch (phy_drd->extrefclk) {
>> +     case EXYNOS5_FSEL_50MHZ:
>> +             reg |= (PHYCLKRST_MPLL_MULTIPLIER_50M_REF |
>> +                     PHYCLKRST_SSC_REFCLKSEL(0x00));
>> +             break;
>> +     case EXYNOS5_FSEL_24MHZ:
>> +             reg |= (PHYCLKRST_MPLL_MULTIPLIER_24MHZ_REF |
>> +                     PHYCLKRST_SSC_REFCLKSEL(0x88));
>> +             break;
>> +     case EXYNOS5_FSEL_20MHZ:
>> +             reg |= (PHYCLKRST_MPLL_MULTIPLIER_20MHZ_REF |
>> +                     PHYCLKRST_SSC_REFCLKSEL(0x00));
>> +             break;
>> +     case EXYNOS5_FSEL_19MHZ2:
>> +             reg |= (PHYCLKRST_MPLL_MULTIPLIER_19200KHZ_REF |
>> +                     PHYCLKRST_SSC_REFCLKSEL(0x88));
>> +             break;
>> +     default:
>> +             dev_dbg(phy_drd->dev, "unsupported ref clk\n");
>> +             break;
>> +     }
>> +
>> +     /* save refclk settings for multiple phy inits */
>> +     phy_drd->refclk_reg = reg;
>> +
>> +     return reg;
>> +}
>> +
>> +/*
>> + * Sets the utmi phy's clk as EXTREFCLK (XXTI) which is internal clock
>> + * from clock core. Further sets the FSEL values for HighSpeed operations.
>> + */
>> +static unsigned int
>> +exynos5_usbdrd_utmi_set_refclk(struct phy_usb_instance *inst)
>> +{
>> +     static u32 reg;
>> +     struct exynos5_usbdrd_phy *phy_drd = to_usbdrd_phy(inst);
>> +
>> +     reg = phy_drd->refclk_reg;
>
> same here..
sure

>
> Thanks
> Kishon
> --
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