The VFIO reset hook is called every time a platform device is passed to a guest or removed from a guest.
When the XHCI device is unbound from the host, the host driver disables the XHCI clocks/phys/regulators so when the device is passed to the guest it becomes dis-functional. This initial implementation uses the VFIO reset hook to enable the XHCI clocks/phys on behalf of the guest. Ported from Marvell LSP code originally written by Yehuda Yitschak Signed-off-by: Gregory CLEMENT <[email protected]> --- drivers/vfio/platform/reset/Kconfig | 8 +++ drivers/vfio/platform/reset/Makefile | 2 + .../vfio/platform/reset/vfio_platform_xhci.c | 60 +++++++++++++++++++ 3 files changed, 70 insertions(+) create mode 100644 drivers/vfio/platform/reset/vfio_platform_xhci.c diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig index 392e3c09def0..14f620fd250d 100644 --- a/drivers/vfio/platform/reset/Kconfig +++ b/drivers/vfio/platform/reset/Kconfig @@ -22,3 +22,11 @@ config VFIO_PLATFORM_BCMFLEXRM_RESET Enables the VFIO platform driver to handle reset for Broadcom FlexRM If you don't know what to do here, say N. + +config VFIO_PLATFORM_XHCI_RESET + tristate "VFIO support for USB XHCI reset" + depends on VFIO_PLATFORM + help + Enables the VFIO platform driver to handle reset for USB XHCI + + If you don't know what to do here, say N. diff --git a/drivers/vfio/platform/reset/Makefile b/drivers/vfio/platform/reset/Makefile index 7294c5ea122e..d84c4d3dc041 100644 --- a/drivers/vfio/platform/reset/Makefile +++ b/drivers/vfio/platform/reset/Makefile @@ -1,7 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o +vfio-platform-xhci-y := vfio_platform_xhci.o obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o +obj-$(CONFIG_VFIO_PLATFORM_XHCI_RESET) += vfio-platform-xhci.o diff --git a/drivers/vfio/platform/reset/vfio_platform_xhci.c b/drivers/vfio/platform/reset/vfio_platform_xhci.c new file mode 100644 index 000000000000..7b75a04402ee --- /dev/null +++ b/drivers/vfio/platform/reset/vfio_platform_xhci.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * VFIO platform driver specialized for XHCI reset + * + * Copyright 2016 Marvell Semiconductors, Inc. + * + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/usb/phy.h> + +#include "../vfio_platform_private.h" + +#define MAX_XHCI_CLOCKS 4 +#define MAX_XHCI_PHYS 2 + +int vfio_platform_xhci_reset(struct vfio_platform_device *vdev) +{ + struct device *dev = vdev->device; + struct device_node *np = dev->of_node; + struct usb_phy *usb_phy; + struct clk *clk; + int ret, i; + + /* + * Compared to the native driver, no need to handle the + * deferred case, because the resources are already + * there + */ + for (i = 0; i < MAX_XHCI_CLOCKS; i++) { + clk = of_clk_get(np, i); + if (!IS_ERR(clk)) { + ret = clk_prepare_enable(clk); + if (ret) + return -ENODEV; + } + } + + usb_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0); + if (!IS_ERR(usb_phy)) { + ret = usb_phy_init(usb_phy); + if (ret) + return -ENODEV; + } + + return 0; +} + +module_vfio_reset_handler("generic-xhci", vfio_platform_xhci_reset); + +MODULE_AUTHOR("Yehuda Yitschak"); +MODULE_DESCRIPTION("Reset support for XHCI vfio platform device"); +MODULE_LICENSE("GPL"); -- 2.20.1
