This driver is for Samsung Exynos xhci host conroller. It uses xhci-plat driver mainly and extends some functions by xhci hooks and overrides. It supports USB Audio offload with Co-processor. It only cares DCBAA, Device Context, Transfer Ring, Event Ring, and ERST. They are allocated on specific address with xhci hooks. Co-processor could use them directly without xhci driver after then. Signed-off-by: Daehwan Jung <dh10.jung@xxxxxxxxxxx> --- drivers/usb/host/Kconfig | 8 + drivers/usb/host/Makefile | 1 + drivers/usb/host/xhci-exynos.c | 567 +++++++++++++++++++++++++++++++++ drivers/usb/host/xhci-exynos.h | 50 +++ 4 files changed, 626 insertions(+) create mode 100644 drivers/usb/host/xhci-exynos.c create mode 100644 drivers/usb/host/xhci-exynos.h diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig index 682b3d2da623..ccafcd9b4212 100644 --- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -104,6 +104,14 @@ config USB_XHCI_TEGRA Say 'Y' to enable the support for the xHCI host controller found in NVIDIA Tegra124 and later SoCs. +config USB_XHCI_EXYNOS + tristate "xHCI support for Samsung Exynos SoC Series" + depends on USB_XHCI_PLATFORM + depends on ARCH_EXYNOS || COMPILE_TEST + help + Say 'Y' to enable the support for the xHCI host controller + found in Samsung Exynos SoCs. + endif # USB_XHCI_HCD config USB_EHCI_BRCMSTB diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile index 2948983618fb..300f22b6eb1b 100644 --- a/drivers/usb/host/Makefile +++ b/drivers/usb/host/Makefile @@ -86,3 +86,4 @@ obj-$(CONFIG_USB_HCD_SSB) += ssb-hcd.o obj-$(CONFIG_USB_FOTG210_HCD) += fotg210-hcd.o obj-$(CONFIG_USB_MAX3421_HCD) += max3421-hcd.o obj-$(CONFIG_USB_XEN_HCD) += xen-hcd.o +obj-$(CONFIG_USB_XHCI_EXYNOS) += xhci-exynos.o diff --git a/drivers/usb/host/xhci-exynos.c b/drivers/usb/host/xhci-exynos.c new file mode 100644 index 000000000000..4f22f620d7e0 --- /dev/null +++ b/drivers/usb/host/xhci-exynos.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * xhci-exynos.c - xHCI host controller driver platform Bus Glue for Exynos. + * + * Copyright (C) 2022 Samsung Electronics Incorporated - http://www.samsung.com + * Author: Daehwan Jung <dh10.jung@xxxxxxxxxxx> + * + * A lot of code borrowed from the Linux xHCI driver. + */ +#include <linux/pci.h> +#include <linux/platform_device.h> + +#include "xhci.h" +#include "xhci-plat.h" +#include "xhci-exynos.h" + +static const struct dev_pm_ops xhci_exynos_pm_ops; + +static struct xhci_vendor_ops ops; +static void xhci_exynos_parse_endpoint(struct xhci_hcd *xhci, struct usb_device *udev, + struct usb_endpoint_descriptor *desc, struct xhci_container_ctx *ctx); +static void xhci_exynos_free_event_ring(struct xhci_hcd *xhci); +static struct xhci_ring *xhci_ring_alloc_uram(struct xhci_hcd *xhci, + unsigned int num_segs, unsigned int cycle_state, + enum xhci_ring_type type, unsigned int max_packet, gfp_t flags, + u32 endpoint_type); +static void xhci_exynos_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring); +static int xhci_exynos_alloc_event_ring(struct xhci_hcd *xhci, gfp_t flags); + +static int xhci_exynos_register_vendor_ops(struct xhci_vendor_ops *vendor_ops) +{ + return xhci_plat_register_vendor_ops(&ops); +} + +static void xhci_exynos_quirks(struct device *dev, struct xhci_hcd *xhci) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + + xhci->quirks |= XHCI_PLAT | xhci_exynos->quirks; +} + +/* called during probe() after chip reset completes */ +static int xhci_exynos_setup(struct usb_hcd *hcd) +{ + int ret; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + + ret = xhci_gen_setup(hcd, xhci_exynos_quirks); + xhci_exynos_alloc_event_ring(xhci, GFP_KERNEL); + + return ret; +} + +static void xhci_exynos_usb_offload_enable_event_ring(struct xhci_hcd *xhci) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + + u32 temp; + u64 temp_64; + + temp_64 = xhci_read_64(xhci, &xhci_exynos->ir_set_audio->erst_dequeue); + temp_64 &= ~ERST_PTR_MASK; + xhci_info(xhci, "ERST2 deq = 64'h%0lx", (unsigned long) temp_64); + + xhci_info(xhci, "// [USB Audio] Set the interrupt modulation register"); + temp = readl(&xhci_exynos->ir_set_audio->irq_control); + temp &= ~ER_IRQ_INTERVAL_MASK; + temp |= (u32)160; + writel(temp, &xhci_exynos->ir_set_audio->irq_control); + + temp = readl(&xhci_exynos->ir_set_audio->irq_pending); + xhci_info(xhci, "// [USB Audio] Enabling event ring interrupter %p by writing 0x%x to irq_pending", + xhci_exynos->ir_set_audio, (unsigned int) ER_IRQ_ENABLE(temp)); + writel(ER_IRQ_ENABLE(temp), &xhci_exynos->ir_set_audio->irq_pending); +} + +static int xhci_exynos_start(struct usb_hcd *hcd) +{ + struct xhci_hcd *xhci; + int ret; + + ret = xhci_run(hcd); + + xhci = hcd_to_xhci(hcd); + xhci_exynos_usb_offload_enable_event_ring(xhci); + + return ret; +} + +static int xhci_exynos_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev, + struct usb_host_endpoint *ep) +{ + int ret; + struct xhci_hcd *xhci; + struct xhci_virt_device *virt_dev; + + ret = xhci_add_endpoint(hcd, udev, ep); + + if (!ret && udev->slot_id) { + xhci = hcd_to_xhci(hcd); + virt_dev = xhci->devs[udev->slot_id]; + xhci_exynos_parse_endpoint(xhci, udev, &ep->desc, virt_dev->out_ctx); + } + + return ret; +} + +static int xhci_exynos_address_device(struct usb_hcd *hcd, struct usb_device *udev) +{ + struct xhci_hcd *xhci; + int ret; + + ret = xhci_address_device(hcd, udev); + xhci = hcd_to_xhci(hcd); + + /* TODO: store and pass hw info to Co-Processor here*/ + + return ret; +} + +static int xhci_exynos_wake_lock(struct xhci_hcd_exynos *xhci_exynos, + int is_main_hcd, int is_lock) +{ + struct usb_hcd *hcd = xhci_exynos->hcd; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + struct wakeup_source *main_wakelock, *shared_wakelock; + + main_wakelock = xhci_exynos->main_wakelock; + shared_wakelock = xhci_exynos->shared_wakelock; + + if (xhci->xhc_state & XHCI_STATE_REMOVING) + return -ESHUTDOWN; + + if (is_lock) { + if (is_main_hcd) + __pm_stay_awake(main_wakelock); + else + __pm_stay_awake(shared_wakelock); + } else { + if (is_main_hcd) + __pm_relax(main_wakelock); + else + __pm_relax(shared_wakelock); + } + + return 0; +} + +static int xhci_exynos_bus_suspend(struct usb_hcd *hcd) +{ + struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + + + int ret, main_hcd; + + if (hcd == xhci->main_hcd) + main_hcd = 1; + else + main_hcd = 0; + + ret = xhci_bus_suspend(hcd); + xhci_exynos_wake_lock(xhci_exynos, main_hcd, 0); + + return ret; +} + +static int xhci_exynos_bus_resume(struct usb_hcd *hcd) +{ + struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + + int ret, main_hcd; + + if (hcd == xhci->main_hcd) + main_hcd = 1; + else + main_hcd = 0; + + ret = xhci_bus_resume(hcd); + xhci_exynos_wake_lock(xhci_exynos, main_hcd, 1); + + return ret; +} + +const struct xhci_driver_overrides xhci_exynos_overrides = { + .reset = xhci_exynos_setup, + .start = xhci_exynos_start, + .add_endpoint = xhci_exynos_add_endpoint, + .address_device = xhci_exynos_address_device, + .bus_suspend = xhci_exynos_bus_suspend, + .bus_resume = xhci_exynos_bus_resume, +}; + +static int xhci_exynos_vendor_init(struct xhci_hcd *xhci, struct device *dev) +{ + struct usb_hcd *hcd; + struct xhci_hcd_exynos *xhci_exynos; + struct xhci_plat_priv *priv; + struct wakeup_source *main_wakelock, *shared_wakelock; + struct platform_device *pdev; + + pdev = to_platform_device(dev); + + xhci_plat_override_driver(&xhci_exynos_overrides); + dev->driver->pm = &xhci_exynos_pm_ops; + + main_wakelock = wakeup_source_register(dev, dev_name(dev)); + __pm_stay_awake(main_wakelock); + + /* Initialization shared wakelock for SS HCD */ + shared_wakelock = wakeup_source_register(dev, dev_name(dev)); + __pm_stay_awake(shared_wakelock); + + hcd = xhci->main_hcd; + + priv = hcd_to_xhci_priv(hcd); + xhci_exynos = priv->vendor_priv; + xhci_exynos->dev = dev; + xhci_exynos->main_wakelock = main_wakelock; + xhci_exynos->shared_wakelock = shared_wakelock; + + return 0; +} + +static void xhci_exynos_vendor_cleanup(struct xhci_hcd *xhci) +{ + xhci_exynos_free_event_ring(xhci); +} + +static bool xhci_exynos_is_usb_offload_enabled(struct xhci_hcd *xhci, + struct xhci_virt_device *virt_dev, unsigned int ep_index) +{ + /* TODO */ + return true; +} + +static struct xhci_device_context_array *xhci_exynos_alloc_dcbaa( + struct xhci_hcd *xhci, gfp_t flags) +{ + int i; + + xhci->dcbaa = ioremap(EXYNOS_URAM_DCBAA_ADDR, + sizeof(*xhci->dcbaa)); + if (!xhci->dcbaa) + return NULL; + /* Clear DCBAA */ + for (i = 0; i < MAX_HC_SLOTS; i++) + xhci->dcbaa->dev_context_ptrs[i] = 0x0; + + xhci->dcbaa->dma = EXYNOS_URAM_DCBAA_ADDR; + + return xhci->dcbaa; +} + +static void xhci_exynos_free_dcbaa(struct xhci_hcd *xhci) +{ + iounmap(xhci->dcbaa); + xhci->dcbaa = NULL; +} + +static struct xhci_ring *xhci_exynos_alloc_transfer_ring(struct xhci_hcd *xhci, u32 endpoint_type, + enum xhci_ring_type ring_type, unsigned int max_packet, gfp_t mem_flags) +{ + return xhci_ring_alloc_uram(xhci, 1, 1, ring_type, max_packet, mem_flags, endpoint_type); +} + +static void xhci_exynos_free_transfer_ring(struct xhci_hcd *xhci, struct xhci_ring *ring, + unsigned int ep_index) +{ + xhci_exynos_ring_free(xhci, ring); +} + +static void xhci_exynos_alloc_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx, + int type, gfp_t flags) +{ + /* Only first Device Context uses URAM */ + int i; + + ctx->bytes = ioremap(EXYNOS_URAM_DEVICE_CTX_ADDR, EXYNOS_URAM_CTX_SIZE); + if (!ctx->bytes) + return; + + for (i = 0; i < EXYNOS_URAM_CTX_SIZE; i++) + ctx->bytes[i] = 0; + + ctx->dma = EXYNOS_URAM_DEVICE_CTX_ADDR; +} + +static void xhci_exynos_free_container_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx) +{ + /* Ignore dma_pool_free if it is allocated from URAM */ + if (ctx->dma != EXYNOS_URAM_DEVICE_CTX_ADDR) + dma_pool_free(xhci->device_pool, ctx->bytes, ctx->dma); +} + +static int xhci_exynos_sync_dev_ctx(struct xhci_hcd *xhci, unsigned int slot_id) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + struct xhci_virt_device *virt_dev; + struct xhci_slot_ctx *slot_ctx; + + int i; + int last_ep; + int last_ep_ctx = 31; + + virt_dev = xhci->devs[slot_id]; + slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx); + + last_ep = LAST_CTX_TO_EP_NUM(le32_to_cpu(slot_ctx->dev_info)); + + if (last_ep < 31) + last_ep_ctx = last_ep + 1; + + for (i = 0; i < last_ep_ctx; ++i) { + unsigned int epaddr = xhci_get_endpoint_address(i); + struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->out_ctx, i); + + if (epaddr == xhci_exynos->in_ep) + xhci_exynos->in_deq = ep_ctx->deq; + else if (epaddr == xhci_exynos->out_ep) + xhci_exynos->out_deq = ep_ctx->deq; + } + + return 0; +} +static struct xhci_vendor_ops ops = { + .vendor_init = xhci_exynos_vendor_init, + .vendor_cleanup = xhci_exynos_vendor_cleanup, + .is_usb_offload_enabled = xhci_exynos_is_usb_offload_enabled, + .alloc_dcbaa = xhci_exynos_alloc_dcbaa, + .free_dcbaa = xhci_exynos_free_dcbaa, + .alloc_transfer_ring = xhci_exynos_alloc_transfer_ring, + .free_transfer_ring = xhci_exynos_free_transfer_ring, + .alloc_container_ctx = xhci_exynos_alloc_container_ctx, + .free_container_ctx = xhci_exynos_free_container_ctx, + .sync_dev_ctx = xhci_exynos_sync_dev_ctx, +}; + + +static void xhci_exynos_parse_endpoint(struct xhci_hcd *xhci, struct usb_device *udev, + struct usb_endpoint_descriptor *desc, struct xhci_container_ctx *ctx) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + struct usb_endpoint_descriptor *d = desc; + unsigned int ep_index; + struct xhci_ep_ctx *ep_ctx; + + ep_index = xhci_get_endpoint_index(d); + ep_ctx = xhci_get_ep_ctx(xhci, ctx, ep_index); + + if ((d->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == + USB_ENDPOINT_XFER_ISOC) { + if (d->bEndpointAddress & USB_ENDPOINT_DIR_MASK) + xhci_exynos->in_ep = d->bEndpointAddress; + else + xhci_exynos->out_ep = d->bEndpointAddress; + } +} + +static void xhci_exynos_segment_free_skip(struct xhci_hcd *xhci, struct xhci_segment *seg) +{ + kfree(seg->bounce_buf); + kfree(seg); +} + +static void xhci_exynos_free_segments_for_ring(struct xhci_hcd *xhci, + struct xhci_segment *first) +{ + struct xhci_segment *seg; + + seg = first->next; + + while (seg != first) { + struct xhci_segment *next = seg->next; + + xhci_exynos_segment_free_skip(xhci, seg); + seg = next; + } + xhci_exynos_segment_free_skip(xhci, first); +} + +static void xhci_exynos_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring) +{ + if (!ring) + return; + + if (ring->first_seg) { + if (ring->type == TYPE_STREAM) + xhci_remove_stream_mapping(ring); + + xhci_exynos_free_segments_for_ring(xhci, ring->first_seg); + } + + kfree(ring); +} + +static void xhci_exynos_free_event_ring(struct xhci_hcd *xhci) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + + xhci_exynos_ring_free(xhci, xhci_exynos->event_ring_audio); +} + +static void xhci_exynos_set_hc_event_deq_audio(struct xhci_hcd *xhci) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + + u64 temp; + dma_addr_t deq; + + deq = xhci_trb_virt_to_dma(xhci_exynos->event_ring_audio->deq_seg, + xhci_exynos->event_ring_audio->dequeue); + if (deq == 0 && !in_interrupt()) + xhci_warn(xhci, "WARN something wrong with SW event ring " + "dequeue ptr.\n"); + /* Update HC event ring dequeue pointer */ + temp = xhci_read_64(xhci, &xhci_exynos->ir_set_audio->erst_dequeue); + temp &= ERST_PTR_MASK; + /* Don't clear the EHB bit (which is RW1C) because + * there might be more events to service. + */ + temp &= ~ERST_EHB; + xhci_info(xhci, "//[%s] Write event ring dequeue pointer = 0x%llx, " + "preserving EHB bit", __func__, + ((u64) deq & (u64) ~ERST_PTR_MASK) | temp); + xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp, + &xhci_exynos->ir_set_audio->erst_dequeue); + +} + + + +static int xhci_exynos_alloc_event_ring(struct xhci_hcd *xhci, gfp_t flags) +{ + struct xhci_plat_priv *priv = xhci_to_priv(xhci); + struct xhci_hcd_exynos *xhci_exynos = priv->vendor_priv; + + if (xhci_check_trb_in_td_math(xhci) < 0) + goto fail; + + xhci_exynos->event_ring_audio = xhci_ring_alloc(xhci, ERST_NUM_SEGS, 1, + TYPE_EVENT, 0, flags); + /* Set the event ring dequeue address */ + xhci_exynos_set_hc_event_deq_audio(xhci); + + return 0; +fail: + return -1; +} + +static int xhci_alloc_segments_for_ring_uram(struct xhci_hcd *xhci, + struct xhci_segment **first, struct xhci_segment **last, + unsigned int num_segs, unsigned int cycle_state, + enum xhci_ring_type type, unsigned int max_packet, gfp_t flags, + u32 endpoint_type) +{ + struct xhci_segment *prev; + bool chain_links = false; + + while (num_segs > 0) { + struct xhci_segment *next = NULL; + + if (!next) { + prev = *first; + while (prev) { + next = prev->next; + xhci_segment_free(xhci, prev); + prev = next; + } + return -ENOMEM; + } + xhci_link_segments(prev, next, type, chain_links); + + prev = next; + num_segs--; + } + xhci_link_segments(prev, *first, type, chain_links); + *last = prev; + + return 0; +} + +static struct xhci_ring *xhci_ring_alloc_uram(struct xhci_hcd *xhci, + unsigned int num_segs, unsigned int cycle_state, + enum xhci_ring_type type, unsigned int max_packet, gfp_t flags, + u32 endpoint_type) +{ + struct xhci_ring *ring; + int ret; + struct device *dev = xhci_to_hcd(xhci)->self.sysdev; + + ring = kzalloc_node(sizeof(*ring), flags, dev_to_node(dev)); + if (!ring) + return NULL; + + ring->num_segs = num_segs; + ring->bounce_buf_len = max_packet; + INIT_LIST_HEAD(&ring->td_list); + ring->type = type; + if (num_segs == 0) + return ring; + + ret = xhci_alloc_segments_for_ring_uram(xhci, &ring->first_seg, + &ring->last_seg, num_segs, cycle_state, type, + max_packet, flags, endpoint_type); + if (ret) + goto fail; + + /* Only event ring does not use link TRB */ + if (type != TYPE_EVENT) { + /* See section 4.9.2.1 and 6.4.4.1 */ + ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |= + cpu_to_le32(LINK_TOGGLE); + } + xhci_initialize_ring_info(ring, cycle_state); + + return ring; + +fail: + kfree(ring); + return NULL; +} + +static int xhci_exynos_suspend(struct device *dev) +{ + struct usb_hcd *hcd = dev_get_drvdata(dev); + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + + /* TODO: AP sleep scenario*/ + + return xhci_suspend(xhci, device_may_wakeup(dev)); +} + +static int xhci_exynos_resume(struct device *dev) +{ + struct usb_hcd *hcd = dev_get_drvdata(dev); + struct xhci_hcd *xhci = hcd_to_xhci(hcd); + int ret; + + /* TODO: AP resume scenario*/ + + ret = xhci_resume(xhci, 0); + if (ret) + return ret; + + pm_runtime_disable(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + return 0; +} + +static const struct dev_pm_ops xhci_exynos_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(xhci_exynos_suspend, xhci_exynos_resume) +}; + +MODULE_DESCRIPTION("xHCI Exynos Host Controller Driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/usb/host/xhci-exynos.h b/drivers/usb/host/xhci-exynos.h new file mode 100644 index 000000000000..4428f8f3a5ff --- /dev/null +++ b/drivers/usb/host/xhci-exynos.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xhci-exynos.h - xHCI host controller driver platform Bus Glue for Exynos. + * + * Copyright (C) 2022 Samsung Electronics Incorporated - http://www.samsung.com + * Author: Daehwan Jung <dh10.jung@xxxxxxxxxxx> + * + * A lot of code borrowed from the Linux xHCI driver. + */ + +#include "xhci.h" + +/* EXYNOS uram memory map */ +#define EXYNOS_URAM_ABOX_EVT_RING_ADDR 0x02a00000 +#define EXYNOS_URAM_ISOC_OUT_RING_ADDR 0x02a01000 +#define EXYNOS_URAM_ISOC_IN_RING_ADDR 0x02a02000 +#define EXYNOS_URAM_DEVICE_CTX_ADDR 0x02a03000 +#define EXYNOS_URAM_DCBAA_ADDR 0x02a03880 +#define EXYNOS_URAM_ABOX_ERST_SEG_ADDR 0x02a03C80 +#define EXYNOS_URAM_CTX_SIZE 2112 + +struct xhci_hcd_exynos { + struct xhci_intr_reg __iomem *ir_set_audio; + + struct xhci_ring *event_ring_audio; + struct xhci_erst erst_audio; + + struct device *dev; + struct usb_hcd *hcd; + struct usb_hcd *shared_hcd; + + struct wakeup_source *main_wakelock; /* Wakelock for HS HCD */ + struct wakeup_source *shared_wakelock; /* Wakelock for SS HCD */ + + u32 in_ep; + u32 out_ep; + u32 in_deq; + u32 out_deq; + + unsigned long long quirks; +}; + +int xhci_check_trb_in_td_math(struct xhci_hcd *xhci); +void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg); +void xhci_link_segments(struct xhci_segment *prev, + struct xhci_segment *next, + enum xhci_ring_type type, bool chain_links); +void xhci_initialize_ring_info(struct xhci_ring *ring, + unsigned int cycle_state); +void xhci_remove_stream_mapping(struct xhci_ring *ring); -- 2.31.1
