Re: [PATCH v2 3/5] USB: phy: convert usb_phy_generic logic to use a faux device

Peter Chen
2025-02-05T10:19:26Z

On 25-02-04 12:09:15, Greg Kroah-Hartman wrote:
> The usb_phy_generic code was creating a "fake" platform device to pass
> around in different places. Instead of doing that, use the faux bus
> instead as that is what is really wanted here.

Hi Greg,

As far as I know, there are some platforms use the device-tree to get
the system resource (eg, clock, reset, regular) for this driver.
We may not use fake bus for this driver.

$grep -rn "usb-nop-xceiv" arch/arm64/boot/dts/*

arch/arm64/boot/dts/altera/socfpga_stratix10.dtsi:649: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/freescale/imx8mm.dtsi:275: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/freescale/imx8mm.dtsi:285: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/freescale/imx93.dtsi:238: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/freescale/imx93.dtsi:245: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/freescale/imx8mn.dtsi:1321: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/intel/socfpga_agilex.dtsi:149: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/intel/socfpga_agilex5.dtsi:133: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9132-db.dtsi:30: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9132-db.dtsi:44: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9131-db.dtsi:33: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/armada-3720-db.dts:43: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9130-crb.dtsi:49: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9130-crb.dtsi:53: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9130-db.dtsi:52: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/cn9130-db.dtsi:66: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/armada-8040-db.dts:53: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/armada-8040-db.dts:67: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/ac5-98dx35xx-rd.dts:36: compatible = "usb-nop-xceiv";
arch/arm64/boot/dts/marvell/armada-3720-espressobin-ultra.dts:39: compatible = "usb-nop-xceiv";

Peter

>
> Site note, this fixes a bug in the mpfs driver where the incorrect
> pointer was being passed to usb_phy_generic_unregister(), odd that no
> one ever hit this in the past.
>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> v2: no change
>
> drivers/usb/chipidea/ci_hdrc_pci.c | 2 +-
> drivers/usb/dwc2/pci.c | 4 ++--
> drivers/usb/musb/mediatek.c | 4 ++--
> drivers/usb/musb/mpfs.c | 4 ++--
> drivers/usb/musb/tusb6010.c | 2 +-
> drivers/usb/phy/phy-generic.c | 9 ++++-----
> include/linux/usb/usb_phy_generic.h | 9 +++++----
> 7 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/usb/chipidea/ci_hdrc_pci.c b/drivers/usb/chipidea/ci_hdrc_pci.c
> index d63479e1ad10..63511ea30d6e 100644
> --- a/drivers/usb/chipidea/ci_hdrc_pci.c
> +++ b/drivers/usb/chipidea/ci_hdrc_pci.c
> @@ -20,7 +20,7 @@
>
> struct ci_hdrc_pci {
> struct platform_device *ci;
> - struct platform_device *phy;
> + struct faux_device *phy;
> };
>
> /******************************************************************************
> diff --git a/drivers/usb/dwc2/pci.c b/drivers/usb/dwc2/pci.c
> index f3a1e4232a31..8cb50620aa55 100644
> --- a/drivers/usb/dwc2/pci.c
> +++ b/drivers/usb/dwc2/pci.c
> @@ -30,7 +30,7 @@ static const char dwc2_driver_name[] = "dwc2-pci";
>
> struct dwc2_pci_glue {
> struct platform_device *dwc2;
> - struct platform_device *phy;
> + struct faux_device *phy;
> };
>
> /**
> @@ -53,7 +53,7 @@ static int dwc2_pci_probe(struct pci_dev *pci,
> {
> struct resource res[2];
> struct platform_device *dwc2;
> - struct platform_device *phy;
> + struct faux_device *phy;
> int ret;
> struct device *dev = &pci->dev;
> struct dwc2_pci_glue *glue;
> diff --git a/drivers/usb/musb/mediatek.c b/drivers/usb/musb/mediatek.c
> index aa988d74b58d..995bab88506a 100644
> --- a/drivers/usb/musb/mediatek.c
> +++ b/drivers/usb/musb/mediatek.c
> @@ -43,7 +43,7 @@ struct mtk_glue {
> struct device *dev;
> struct musb *musb;
> struct platform_device *musb_pdev;
> - struct platform_device *usb_phy;
> + struct faux_device *usb_phy;
> struct phy *phy;
> struct usb_phy *xceiv;
> enum phy_mode phy_mode;
> @@ -507,7 +507,7 @@ static int mtk_musb_probe(struct platform_device *pdev)
> static void mtk_musb_remove(struct platform_device *pdev)
> {
> struct mtk_glue *glue = platform_get_drvdata(pdev);
> - struct platform_device *usb_phy = glue->usb_phy;
> + struct faux_device *usb_phy = glue->usb_phy;
>
> platform_device_unregister(glue->musb_pdev);
> usb_phy_generic_unregister(usb_phy);
> diff --git a/drivers/usb/musb/mpfs.c b/drivers/usb/musb/mpfs.c
> index 7edc8429b274..ef20794aee12 100644
> --- a/drivers/usb/musb/mpfs.c
> +++ b/drivers/usb/musb/mpfs.c
> @@ -25,7 +25,7 @@
> struct mpfs_glue {
> struct device *dev;
> struct platform_device *musb;
> - struct platform_device *phy;
> + struct faux_device *phy;
> struct clk *clk;
> };
>
> @@ -356,7 +356,7 @@ static void mpfs_remove(struct platform_device *pdev)
>
> clk_disable_unprepare(glue->clk);
> platform_device_unregister(glue->musb);
> - usb_phy_generic_unregister(pdev);
> + usb_phy_generic_unregister(glue->phy);
> }
>
> #ifdef CONFIG_OF
> diff --git a/drivers/usb/musb/tusb6010.c b/drivers/usb/musb/tusb6010.c
> index 90b760a95e4e..92609f9d20ff 100644
> --- a/drivers/usb/musb/tusb6010.c
> +++ b/drivers/usb/musb/tusb6010.c
> @@ -32,7 +32,7 @@
> struct tusb6010_glue {
> struct device *dev;
> struct platform_device *musb;
> - struct platform_device *phy;
> + struct faux_device *phy;
> struct gpio_desc *enable;
> struct gpio_desc *intpin;
> };
> diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c
> index 6c3ececf9137..a6cece75d0f8 100644
> --- a/drivers/usb/phy/phy-generic.c
> +++ b/drivers/usb/phy/phy-generic.c
> @@ -30,16 +30,15 @@
> (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
> IRQF_ONESHOT)
>
> -struct platform_device *usb_phy_generic_register(void)
> +struct faux_device *usb_phy_generic_register(void)
> {
> - return platform_device_register_simple("usb_phy_generic",
> - PLATFORM_DEVID_AUTO, NULL, 0);
> + return faux_device_create("usb_phy_generic", NULL);
> }
> EXPORT_SYMBOL_GPL(usb_phy_generic_register);
>
> -void usb_phy_generic_unregister(struct platform_device *pdev)
> +void usb_phy_generic_unregister(struct faux_device *fdev)
> {
> - platform_device_unregister(pdev);
> + faux_device_destroy(fdev);
> }
> EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
>
> diff --git a/include/linux/usb/usb_phy_generic.h b/include/linux/usb/usb_phy_generic.h
> index cd9e70a552a0..856db2bacc07 100644
> --- a/include/linux/usb/usb_phy_generic.h
> +++ b/include/linux/usb/usb_phy_generic.h
> @@ -3,18 +3,19 @@
> #define __LINUX_USB_NOP_XCEIV_H
>
> #include <linux/usb/otg.h>
> +#include <linux/device/faux.h>
>
> #if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
> /* sometimes transceivers are accessed only through e.g. ULPI */
> -extern struct platform_device *usb_phy_generic_register(void);
> -extern void usb_phy_generic_unregister(struct platform_device *);
> +struct faux_device *usb_phy_generic_register(void);
> +void usb_phy_generic_unregister(struct faux_device *);
> #else
> -static inline struct platform_device *usb_phy_generic_register(void)
> +static inline struct faux_device *usb_phy_generic_register(void)
> {
> return NULL;
> }
>
> -static inline void usb_phy_generic_unregister(struct platform_device *pdev)
> +static inline void usb_phy_generic_unregister(struct faux_device *fdev)
> {
> }
> #endif
> --
> 2.48.1
>
>