Re: [linux-sunxi] Re: [PATCH v2 7/9] phy: allwinner: add phy driver for USB3 PHY on Allwinner H6 SoC

[Icenowy Zheng <icenowy@aosc.io>]

在 2018-07-09一的 10:01 +0530，'Kishon Vijay Abraham I' via linux-sunxi写道：
> Hi,
> 
> On Friday 06 July 2018 09:08 PM, Icenowy Zheng wrote:
> > Allwinner H6 SoC contains a USB3 PHY (with USB2 DP/DM lines also
> > controlled).
> > 
> > Add a driver for it.
> > 
> > The register operations in this driver is mainly extracted from the
> > BSP
> > USB3 driver.
> > 
> > Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> > ---
> > Changes in v2:
> > - Splitted out the DT binding.
> > 
> >  drivers/phy/allwinner/Kconfig           |  13 ++
> >  drivers/phy/allwinner/Makefile          |   1 +
> >  drivers/phy/allwinner/phy-sun50i-usb3.c | 194
> > ++++++++++++++++++++++++
> >  3 files changed, 208 insertions(+)
> >  create mode 100644 drivers/phy/allwinner/phy-sun50i-usb3.c
> > 
> > diff --git a/drivers/phy/allwinner/Kconfig
> > b/drivers/phy/allwinner/Kconfig
> > index cdc1e745ba47..cf373bcee034 100644
> > --- a/drivers/phy/allwinner/Kconfig
> > +++ b/drivers/phy/allwinner/Kconfig
> > @@ -29,3 +29,16 @@ config PHY_SUN9I_USB
> >  	  sun9i SoCs.
> >  
> >  	  This driver controls each individual USB 2 host PHY.
> > +
> > +config PHY_SUN50I_USB3
> > +	tristate "Allwinner sun50i SoC USB3 PHY driver"
> > +	depends on ARCH_SUNXI && HAS_IOMEM && OF
> > +	depends on RESET_CONTROLLER
> > +	depends on USB_SUPPORT
> > +	select USB_COMMON
> 
> Doesn't look like this driver depends on USB_SUPPORT.

Yes, it doesn't depend on USB_SUPPORT; however, it's a USB PHY.

> > +	select GENERIC_PHY
> > +	help
> > +	  Enable this to support the USB3.0-capable transceiver
> > that is
> > +	  part of some Allwinner sun50i SoCs.
> > +
> > +	  This driver controls each individual USB 2+3 host PHY
> > combo.
> > diff --git a/drivers/phy/allwinner/Makefile
> > b/drivers/phy/allwinner/Makefile
> > index 8605529c01a1..a8d01e9073c2 100644
> > --- a/drivers/phy/allwinner/Makefile
> > +++ b/drivers/phy/allwinner/Makefile
> > @@ -1,2 +1,3 @@
> >  obj-$(CONFIG_PHY_SUN4I_USB)		+= phy-sun4i-usb.o
> >  obj-$(CONFIG_PHY_SUN9I_USB)		+= phy-sun9i-usb.o
> > +obj-$(CONFIG_PHY_SUN50I_USB3)		+= phy-sun50i-usb3.o
> > diff --git a/drivers/phy/allwinner/phy-sun50i-usb3.c
> > b/drivers/phy/allwinner/phy-sun50i-usb3.c
> > new file mode 100644
> > index 000000000000..226c99c2d664
> > --- /dev/null
> > +++ b/drivers/phy/allwinner/phy-sun50i-usb3.c
> > @@ -0,0 +1,194 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Allwinner sun50i(H6) USB 3.0 phy driver
> > + *
> > + * Copyright (C) 2017 Icenowy Zheng <icenowy@aosc.io>
> > + *
> > + * Based on phy-sun9i-usb.c, which is:
> > + *
> > + * Copyright (C) 2014-2015 Chen-Yu Tsai <wens@csie.org>
> > + *
> > + * Based on code from Allwinner BSP, which is:
> > + *
> > + * Copyright (c) 2010-2015 Allwinner Technology Co., Ltd.
> 
> Does the BSP also use GPL license?

See [1].

[1] https://github.com/Allwinner-Homlet/H6-BSP4.9-linux/blob/master/dri
vers/usb/host/xhci_sunxi.c

> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/phy/phy.h>
> > +#include <linux/usb/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +
> > +/* Interface Status and Control Registers */
> > +#define SUNXI_ISCR			0x00
> > +#define SUNXI_PIPE_CLOCK_CONTROL	0x14
> > +#define SUNXI_PHY_TUNE_LOW		0x18
> > +#define SUNXI_PHY_TUNE_HIGH		0x1c
> > +#define SUNXI_PHY_EXTERNAL_CONTROL	0x20
> > +
> > +/* USB2.0 Interface Status and Control Register */
> > +#define SUNXI_ISCR_FORCE_VBUS		(3 << 12)
> > +
> > +/* PIPE Clock Control Register */
> > +#define SUNXI_PCC_PIPE_CLK_OPEN		(1 << 6)
> > +
> > +/* PHY External Control Register */
> > +#define SUNXI_PEC_EXTERN_VBUS		(3 << 1)
> > +#define SUNXI_PEC_SSC_EN		(1 << 24)
> > +#define SUNXI_PEC_REF_SSP_EN		(1 << 26)
> > +
> > +/* PHY Tune High Register */
> > +#define SUNXI_TX_DEEMPH_3P5DB(n)	((n) << 19)
> > +#define SUNXI_TX_DEEMPH_3P5DB_MASK	GENMASK(24, 19)
> > +#define SUNXI_TX_DEEMPH_6DB(n)		((n) << 13)
> > +#define SUNXI_TX_DEEMPH_6GB_MASK	GENMASK(18, 13)
> > +#define SUNXI_TX_SWING_FULL(n)		((n) << 6)
> > +#define SUNXI_TX_SWING_FULL_MASK	GENMASK(12, 6)
> > +#define SUNXI_LOS_BIAS(n)		((n) << 3)
> > +#define SUNXI_LOS_BIAS_MASK		GENMASK(5, 3)
> > +#define SUNXI_TXVBOOSTLVL(n)		((n) << 0)
> > +#define SUNXI_TXVBOOSTLVL_MASK		GENMASK(0, 2)
> > +
> > +struct sun50i_usb3_phy {
> > +	struct phy *phy;
> > +	void __iomem *regs;
> > +	struct reset_control *reset;
> > +	struct clk *clk;
> > +};
> > +
> > +static void sun50i_usb3_phy_open(struct sun50i_usb3_phy *phy)
> > +{
> > +	u32 val;
> > +
> > +	val = readl(phy->regs + SUNXI_PHY_EXTERNAL_CONTROL);
> > +	val |= SUNXI_PEC_EXTERN_VBUS;
> > +	val |= SUNXI_PEC_SSC_EN | SUNXI_PEC_REF_SSP_EN;
> > +	writel(val, phy->regs + SUNXI_PHY_EXTERNAL_CONTROL);
> > +
> > +	val = readl(phy->regs + SUNXI_PIPE_CLOCK_CONTROL);
> > +	val |= SUNXI_PCC_PIPE_CLK_OPEN;
> > +	writel(val, phy->regs + SUNXI_PIPE_CLOCK_CONTROL);
> > +
> > +	val = readl(phy->regs + SUNXI_ISCR);
> > +	val |= SUNXI_ISCR_FORCE_VBUS;
> > +	writel(val, phy->regs + SUNXI_ISCR);
> > +
> > +	/*
> > +	 * All the magic numbers written to the
> > PHY_TUNE_{LOW_HIGH}
> > +	 * registers are directly taken from the BSP USB3 driver
> > from
> > +	 * Allwiner.
> 
> %s/Allwiner/Allwinner/
> > +	 */
> > +	writel(0x0047fc87, phy->regs + SUNXI_PHY_TUNE_LOW);
> 
> PHY_TUNE_LOW should also configure individual parameters like how
> you've done
> below for PHY_TUNE_HIGH.

Sorry the BSP doesn't contain any macros on it, only a comment says "It
is set 0x0047fc87 on bare-metal."

> 
> Thanks
> Kishon
>