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

[Chen-Yu Tsai]

On Mon, Jul 9, 2018 at 12:31 PM, Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
> 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@xxxxxxx>
>> ---
>> 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.
>> +     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@xxxxxxx>
>> + *
>> + * Based on phy-sun9i-usb.c, which is:
>> + *
>> + * Copyright (C) 2014-2015 Chen-Yu Tsai <wens@xxxxxxxx>
>> + *
>> + * Based on code from Allwinner BSP, which is:
>> + *
>> + * Copyright (c) 2010-2015 Allwinner Technology Co., Ltd.
>
> Does the BSP also use GPL license?

Yes they released it under the GPL license. It's still available here:

    https://github.com/allwinner-zh/linux-3.4-sunxi

But is now unmaintained.

ChenYu


>> + */
>> +
>> +#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.
>
> Thanks
> Kishon