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

From: Kishon Vijay Abraham I
Date: Mon Apr 14 2014 - 08:28:38 EST


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.
> + 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 ;-)
> + * 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?
> +
> + /* 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..

Thanks
Kishon
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