Re: [PATCH 06/10] phy: Add usb phy support for hi3660 Soc of Hisilicon

From: Kishon Vijay Abraham I
Date: Mon Nov 12 2018 - 04:10:05 EST


Hi,

On 27/10/18 3:28 PM, Yu Chen wrote:
> This driver handles usb phy power on and shutdown for hi3660 Soc of
> Hisilicon.
>
> Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Pengcheng Li <lpc.li@xxxxxxxxxxxxx>
> Cc: Jianguo Sun <sunjianguo1@xxxxxxxxxx>
> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Cc: Jiancheng Xue <xuejiancheng@xxxxxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Binghui Wang <wangbinghui@xxxxxxxxxxxxx>
> Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx>
> ---
> MAINTAINERS | 2 +
> drivers/phy/hisilicon/Kconfig | 10 ++
> drivers/phy/hisilicon/Makefile | 1 +
> drivers/phy/hisilicon/phy-hi3660-usb3.c | 254 ++++++++++++++++++++++++++++++++
> 4 files changed, 267 insertions(+)
> create mode 100644 drivers/phy/hisilicon/phy-hi3660-usb3.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e485449f7811..7adf167588ee 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15294,7 +15294,9 @@ M: Binghui Wang <wangbinghui@xxxxxxxxxxxxx>
> L: linux-usb@xxxxxxxxxxxxxxx
> S: Maintained
> F: Documentation/devicetree/bindings/usb/dwc3-hisi.txt
> +F: Documentation/devicetree/bindings/phy/phy-hi3660-usb3.txt
> F: drivers/usb/dwc3/dwc3-hisi.c
> +F: drivers/phy/hisilicon/phy-hi3660-usb3.c
>
> USB ISP116X DRIVER
> M: Olav Kongas <ok@xxxxxxxxxxxxxx>
> diff --git a/drivers/phy/hisilicon/Kconfig b/drivers/phy/hisilicon/Kconfig
> index b40ee54a1a50..3c142f08987c 100644
> --- a/drivers/phy/hisilicon/Kconfig
> +++ b/drivers/phy/hisilicon/Kconfig
> @@ -12,6 +12,16 @@ config PHY_HI6220_USB
>
> To compile this driver as a module, choose M here.
>
> +config PHY_HI3660_USB
> + tristate "hi3660 USB PHY support"
> + depends on (ARCH_HISI && ARM64) || COMPILE_TEST
> + select GENERIC_PHY
> + select MFD_SYSCON
> + help
> + Enable this to support the HISILICON HI3660 USB PHY.
> +
> + To compile this driver as a module, choose M here.
> +
> config PHY_HISTB_COMBPHY
> tristate "HiSilicon STB SoCs COMBPHY support"
> depends on (ARCH_HISI && ARM64) || COMPILE_TEST
> diff --git a/drivers/phy/hisilicon/Makefile b/drivers/phy/hisilicon/Makefile
> index f662a4fe18d8..75ba64e2faf8 100644
> --- a/drivers/phy/hisilicon/Makefile
> +++ b/drivers/phy/hisilicon/Makefile
> @@ -1,4 +1,5 @@
> obj-$(CONFIG_PHY_HI6220_USB) += phy-hi6220-usb.o
> +obj-$(CONFIG_PHY_HI3660_USB) += phy-hi3660-usb3.o
> obj-$(CONFIG_PHY_HISTB_COMBPHY) += phy-histb-combphy.o
> obj-$(CONFIG_PHY_HISI_INNO_USB2) += phy-hisi-inno-usb2.o
> obj-$(CONFIG_PHY_HIX5HD2_SATA) += phy-hix5hd2-sata.o
> diff --git a/drivers/phy/hisilicon/phy-hi3660-usb3.c b/drivers/phy/hisilicon/phy-hi3660-usb3.c
> new file mode 100644
> index 000000000000..041c542750e2
> --- /dev/null
> +++ b/drivers/phy/hisilicon/phy-hi3660-usb3.c
> @@ -0,0 +1,254 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Phy provider for USB 3.0 controller on HiSilicon 3660 platform
> + *
> + * Copyright (C) 2017-2018 Hilisicon Electronics Co., Ltd.
> + * http://www.huawei.com
> + *
> + * Authors: Yu Chen <chenyu56@xxxxxxxxxx>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */

This license text doesn't have to added explicitly. It should be already
governed by SPDX line.
> +
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/regmap.h>
> +
> +#define PERI_CRG_CLK_EN4 (0x40)
> +#define PERI_CRG_CLK_DIS4 (0x44)
> +#define GT_CLK_USB3OTG_REF BIT(0)
> +#define GT_ACLK_USB3OTG BIT(1)
> +
> +#define PERI_CRG_RSTEN4 (0x90)
> +#define PERI_CRG_RSTDIS4 (0x94)
> +#define IP_RST_USB3OTGPHY_POR BIT(3)
> +#define IP_RST_USB3OTG BIT(5)
> +
> +#define PERI_CRG_ISODIS (0x148)
> +#define USB_REFCLK_ISO_EN BIT(25)
> +
> +#define PCTRL_PERI_CTRL3 (0x10)
> +#define PCTRL_PERI_CTRL3_MSK_START (16)
> +#define USB_TCXO_EN BIT(1)
> +
> +#define PCTRL_PERI_CTRL24 (0x64)
> +#define SC_CLK_USB3PHY_3MUX1_SEL BIT(25)
> +
> +#define USBOTG3_CTRL0 (0x00)
> +#define SC_USB3PHY_ABB_GT_EN BIT(15)
> +
> +#define USBOTG3_CTRL2 (0x08)
> +#define USBOTG3CTRL2_POWERDOWN_HSP BIT(0)
> +#define USBOTG3CTRL2_POWERDOWN_SSP BIT(1)
> +
> +#define USBOTG3_CTRL3 (0x0C)
> +#define USBOTG3_CTRL3_VBUSVLDEXT BIT(6)
> +#define USBOTG3_CTRL3_VBUSVLDEXTSEL BIT(5)
> +
> +#define USBOTG3_CTRL4 (0x10)
> +
> +#define USBOTG3_CTRL7 (0x1c)
> +#define REF_SSP_EN BIT(16)
> +
> +#define HI3660_USB_DEFAULT_PHY_PARAM (0x1c466e3)
> +
> +struct hi3660_priv {
> + struct device *dev;
> + struct regmap *peri_crg;
> + struct regmap *pctrl;
> + struct regmap *otg_bc;
> + u32 eye_diagram_param;
> +
> + u32 peri_crg_offset;
> + u32 pctrl_offset;
> + u32 otg_bc_offset;
> +};
> +
> +static int hi3660_phy_init(struct phy *phy)
> +{
> + struct hi3660_priv *priv = phy_get_drvdata(phy);
> + u32 val, mask;
> + int ret;
> +
> + /* usb refclk iso disable */
> + ret = regmap_write(priv->peri_crg, PERI_CRG_ISODIS, USB_REFCLK_ISO_EN);
> + if (ret)
> + goto out;
> +
> + /* enable usb_tcxo_en */
> + val = USB_TCXO_EN | (USB_TCXO_EN << PCTRL_PERI_CTRL3_MSK_START);
> + ret = regmap_write(priv->pctrl, PCTRL_PERI_CTRL3, val);
> + if (ret)
> + goto out;
> +
> + /* select usbphy clk from abb */
> + mask = SC_CLK_USB3PHY_3MUX1_SEL;

Shouldn't we use clock API's for enabling/selecting clocks?
> + ret = regmap_update_bits(priv->pctrl, PCTRL_PERI_CTRL24, mask, 0);
> + if (ret)
> + goto out;
> +
> + /* assert phy */
> + val = IP_RST_USB3OTGPHY_POR | IP_RST_USB3OTG;
> + ret = regmap_write(priv->peri_crg, PERI_CRG_RSTEN4, val);
> + if (ret)
> + goto out;
> +
> + /* enable phy ref clk */
> + val = SC_USB3PHY_ABB_GT_EN;
> + mask = val;
> + ret = regmap_update_bits(priv->otg_bc, USBOTG3_CTRL0, mask, val);
> + if (ret)
> + goto out;
> +
> + val = REF_SSP_EN;
> + mask = val;
> + ret = regmap_update_bits(priv->otg_bc, USBOTG3_CTRL7, mask, val);
> + if (ret)
> + goto out;
> +
> + /* exit from IDDQ mode */
> + mask = USBOTG3CTRL2_POWERDOWN_HSP | USBOTG3CTRL2_POWERDOWN_SSP;
> + ret = regmap_update_bits(priv->otg_bc, USBOTG3_CTRL2, mask, 0);
> + if (ret)
> + goto out;
> +
> + udelay(100);

Please add a comment for this delay. Does the HW manual states that or it's a
result of experimentation.

Also according to timers/timers-howto.txt, it's preferable to use usleep_range
for 10us - 20ms.
> +
> + /* deassert phy */
> + val = IP_RST_USB3OTGPHY_POR | IP_RST_USB3OTG;
> + ret = regmap_write(priv->peri_crg, PERI_CRG_RSTDIS4, val);
> + if (ret)
> + goto out;
> +
> + usleep_range(10000, 15000);

Add a comment for this delay.
> +
> + /* fake vbus valid signal */
> + val = USBOTG3_CTRL3_VBUSVLDEXT | USBOTG3_CTRL3_VBUSVLDEXTSEL;
> + mask = val;
> + ret = regmap_update_bits(priv->otg_bc, USBOTG3_CTRL3, mask, val);
> + if (ret)
> + goto out;
> +
> + udelay(100);

Same comment here.

Thanks
Kishon