new file mode 100644
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright 2022 Google LLC. All Rights Reserved.
+ *
+ * Interface to the AoC USB control service
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+
+#include "aoc-usb.h"
+
+#define AOC_USB_NAME "aoc_usb"
+
+extern struct blocking_notifier_head aoc_usb_notifier_list;
+
+int xhci_set_offload_state(bool enabled)
+{
+ return blocking_notifier_call_chain(&aoc_usb_notifier_list, SET_OFFLOAD_STATE, &enabled);
+}
+
+int xhci_set_dcbaa_ptr(u64 aoc_dcbaa_ptr)
+{
+ return blocking_notifier_call_chain(&aoc_usb_notifier_list, SET_DCBAA_PTR, &aoc_dcbaa_ptr);
+}
+
+int xhci_setup_done(void)
+{
+ return blocking_notifier_call_chain(&aoc_usb_notifier_list, SETUP_DONE, NULL);
+}
+
+int xhci_sync_conn_stat(unsigned int bus_id, unsigned int dev_num, unsigned int slot_id,
+ unsigned int conn_stat)
+{
+ struct conn_stat_args args;
+
+ args.bus_id = bus_id;
+ args.dev_num = dev_num;
+ args.slot_id = slot_id;
+ args.conn_stat = conn_stat;
+
+ return blocking_notifier_call_chain(&aoc_usb_notifier_list, SYNC_CONN_STAT, &args);
+}
+
+int usb_host_mode_state_notify(enum usb_conn_state usb_state)
+{
+ return xhci_sync_conn_stat(0, 0, 0, usb_state);
+}
+
+int xhci_set_isoc_tr_info(u16 ep_id, u16 dir, struct xhci_ring *ep_ring)
+{
+ struct get_isoc_tr_info_args tr_info;
+
+ tr_info.ep_id = ep_id;
+ tr_info.dir = dir;
+ tr_info.num_segs = ep_ring->num_segs;
+ tr_info.max_packet = ep_ring->bounce_buf_len;
+ tr_info.type = ep_ring->type;
+ tr_info.seg_ptr = ep_ring->first_seg->dma;
+ tr_info.cycle_state = ep_ring->cycle_state;
+ tr_info.num_trbs_free = ep_ring->num_trbs_free;
+
+ return blocking_notifier_call_chain(&aoc_usb_notifier_list, SET_ISOC_TR_INFO, &tr_info);
+}
+
+static int aoc_usb_match(struct device *dev, void *data)
+{
+ if (sysfs_streq(dev_driver_string(dev), "xhci-hcd-exynos"))
+ return 1;
+
+ return 0;
+}
+
+static bool aoc_usb_is_hcd_working(void)
+{
+ struct device_node *np;
+ struct platform_device *pdev;
+ struct device *udev;
+ int ret;
+
+ np = of_find_node_by_name(NULL, "dwc3");
+ if (!np || !of_device_is_available(np)) {
+ pr_err("Cannot find dwc3 device node\n");
+ return false;
+ }
+
+ pdev = of_find_device_by_node(np);
+ if (!pdev)
+ return false;
+
+ udev = device_find_child(&pdev->dev, NULL, aoc_usb_match);
+ if (!udev)
+ return false;
+
+ ret = usb_host_mode_state_notify(USB_CONNECTED);
+ if (ret)
+ dev_err(udev, "Notifying AoC for xhci driver status is failed.\n");
+
+ return true;
+}
+
+static struct work_struct usb_host_mode_checking_ws;
+static void usb_host_mode_checking_work(struct work_struct *ws)
+{
+ if (aoc_usb_is_hcd_working())
+ pr_info("USB HCD is working, send notification to AoC\n");
+}
+
+/*
+ * This variable used to present if aoc_usb module was probed done. If offload
+ * is enabled, the controller needs to wait for the aoc_usb probe done and then
+ * continue the controller's probe.
+ */
+static bool aoc_usb_probe_done;
+static int aoc_usb_probe(struct aoc_service_dev *adev)
+{
+ struct device *dev = &adev->dev;
+ struct aoc_usb_drvdata *drvdata;
+
+ drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->adev = adev;
+
+ mutex_init(&drvdata->lock);
+
+ drvdata->ws = wakeup_source_register(dev, dev_name(dev));
+ if (!drvdata->ws) {
+ dev_err(&drvdata->adev->dev, "wakeup_source_register failed!\n");
+ return -ENOMEM;
+ }
+
+ drvdata->usb_conn_state = 0;
+ dev_set_drvdata(dev, drvdata);
+
+ aoc_usb_probe_done = true;
+
+ schedule_work(&usb_host_mode_checking_ws);
+
+ return 0;
+}
+
+static int aoc_usb_remove(struct aoc_service_dev *adev)
+{
+ struct aoc_usb_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+ wakeup_source_unregister(drvdata->ws);
+ mutex_destroy(&drvdata->lock);
+
+ kfree(drvdata);
+
+ aoc_usb_probe_done = false;
+
+ return 0;
+}
+
+bool is_aoc_usb_probe_done(void)
+{
+ return aoc_usb_probe_done;
+}
+
+static const char *const aoc_usb_service_names[] = {
+ "usb_control",
+ NULL,
+};
+
+static struct aoc_driver aoc_usb_driver = {
+ .drv = {
+ .name = AOC_USB_NAME,
+ },
+ .service_names = aoc_usb_service_names,
+ .probe = aoc_usb_probe,
+ .remove = aoc_usb_remove,
+};
+
+static int __init aoc_usb_init(void)
+{
+ xhci_offload_helper_init();
+
+ INIT_WORK(&usb_host_mode_checking_ws, usb_host_mode_checking_work);
+
+ return driver_register(&aoc_usb_driver.drv);
+}
+
+static void __exit aoc_usb_exit(void)
+{
+ driver_unregister(&aoc_usb_driver.drv);
+}
+
+module_init(aoc_usb_init);
+module_exit(aoc_usb_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Howard Yen (Google)");
+MODULE_DESCRIPTION("USB driver for AoC");
new file mode 100644
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022 Google Corp.
+ *
+ * Author:
+ * Howard.Yen <howardyen@google.com>
+ */
+
+#ifndef __LINUX_AOC_USB_H
+#define __LINUX_AOC_USB_H
+
+#include "xhci.h"
+
+struct aoc_service_dev {
+ struct device dev;
+ wait_queue_head_t read_queue;
+ wait_queue_head_t write_queue;
+
+ void *ipc_base;
+ void *prvdata;
+ uint64_t suspend_rx_count;
+
+ uint8_t mbox_index;
+ uint8_t service_index;
+
+ bool dead;
+ bool wake_capable;
+};
+
+struct aoc_driver {
+ struct device_driver drv;
+
+ /* Array of service names to match against. Last entry must be NULL */
+ const char * const *service_names;
+ int (*probe)(struct aoc_service_dev *dev);
+ int (*remove)(struct aoc_service_dev *dev);
+};
+
+enum usb_offload_msg {
+ SET_DCBAA_PTR,
+ GET_TR_DEQUEUE_PTR,
+ SETUP_DONE,
+ SET_ISOC_TR_INFO,
+ SYNC_CONN_STAT,
+ SET_OFFLOAD_STATE
+};
+
+enum usb_offload_op_mode {
+ USB_OFFLOAD_STOP,
+ USB_OFFLOAD_DRAM
+};
+
+enum usb_conn_state {
+ USB_DISCONNECTED,
+ USB_CONNECTED
+};
+
+enum usb_recover_state {
+ NONE,
+ RECOVER_HOST_OFF,
+ RECOVER_HOST_ON,
+ RECOVERED
+};
+
+struct aoc_usb_drvdata {
+ struct aoc_service_dev *adev;
+
+ struct mutex lock;
+ struct wakeup_source *ws;
+
+ struct notifier_block nb;
+
+ unsigned int usb_conn_state;
+};
+
+struct conn_stat_args {
+ u16 bus_id;
+ u16 dev_num;
+ u16 slot_id;
+ u32 conn_stat;
+};
+
+struct get_isoc_tr_info_args {
+ u16 ep_id;
+ u16 dir;
+ u32 type;
+ u32 num_segs;
+ u32 seg_ptr;
+ u32 max_packet;
+ u32 deq_ptr;
+ u32 enq_ptr;
+ u32 cycle_state;
+ u32 num_trbs_free;
+};
+
+int xhci_set_offload_state(bool enabled);
+int xhci_set_dcbaa_ptr(u64 aoc_dcbaa_ptr);
+int xhci_setup_done(void);
+int xhci_sync_conn_stat(unsigned int bus_id, unsigned int dev_num, unsigned int slot_id,
+ unsigned int conn_stat);
+int usb_host_mode_state_notify(enum usb_conn_state usb_state);
+int xhci_set_isoc_tr_info(u16 ep_id, u16 dir, struct xhci_ring *ep_ring);
+
+bool is_aoc_usb_probe_done(void);
+
+int xhci_offload_helper_init(void);
+
+#endif /* __LINUX_AOC_USB_H */
new file mode 100644
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Google Corp.
+ *
+ * Author:
+ * Howard.Yen <howardyen@google.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <linux/usb/hcd.h>
+
+#include "aoc-usb.h"
+#include "xhci-plat.h"
+
+struct xhci_offload_data {
+ struct xhci_hcd *xhci;
+
+ bool usb_accessory_enabled;
+ bool usb_audio_offload;
+ bool dt_direct_usb_access;
+ bool offload_state;
+
+ enum usb_offload_op_mode op_mode;
+};
+
+static struct xhci_offload_data *offload_data;
+struct xhci_offload_data *xhci_get_offload_data(void)
+{
+ return offload_data;
+}
+
+/*
+ * Determine if an USB device is a compatible devices:
+ * True: Devices are audio class and they contain ISOC endpoint
+ * False: Devices are not audio class or they're audio class but no ISOC endpoint or
+ * they have at least one interface is video class
+ */
+static bool is_compatible_with_usb_audio_offload(struct usb_device *udev)
+{
+ struct usb_endpoint_descriptor *epd;
+ struct usb_host_config *config;
+ struct usb_host_interface *alt;
+ struct usb_interface_cache *intfc;
+ int i, j, k;
+ bool is_audio = false;
+
+ config = udev->config;
+ for (i = 0; i < config->desc.bNumInterfaces; i++) {
+ intfc = config->intf_cache[i];
+ for (j = 0; j < intfc->num_altsetting; j++) {
+ alt = &intfc->altsetting[j];
+
+ if (alt->desc.bInterfaceClass == USB_CLASS_VIDEO) {
+ is_audio = false;
+ goto out;
+ }
+
+ if (alt->desc.bInterfaceClass == USB_CLASS_AUDIO) {
+ for (k = 0; k < alt->desc.bNumEndpoints; k++) {
+ epd = &alt->endpoint[k].desc;
+ if (usb_endpoint_xfer_isoc(epd)) {
+ is_audio = true;
+ break;
+ }
+ }
+ }
+ }
+ }
+
+out:
+ return is_audio;
+}
+
+/*
+ * check the usb device including the video class:
+ * True: Devices contain video class
+ * False: Device doesn't contain video class
+ */
+static bool is_usb_video_device(struct usb_device *udev)
+{
+ struct usb_host_config *config;
+ struct usb_host_interface *alt;
+ struct usb_interface_cache *intfc;
+ int i, j;
+ bool is_video = false;
+
+ if (!udev || !udev->config)
+ return is_video;
+
+ config = udev->config;
+
+ for (i = 0; i < config->desc.bNumInterfaces; i++) {
+ intfc = config->intf_cache[i];
+ for (j = 0; j < intfc->num_altsetting; j++) {
+ alt = &intfc->altsetting[j];
+
+ if (alt->desc.bInterfaceClass == USB_CLASS_VIDEO) {
+ is_video = true;
+ goto out;
+ }
+ }
+ }
+
+out:
+ return is_video;
+}
+
+static int xhci_udev_notify(struct notifier_block *self, unsigned long action,
+ void *dev)
+{
+ struct usb_device *udev = dev;
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+
+ switch (action) {
+ case USB_DEVICE_ADD:
+ if (is_compatible_with_usb_audio_offload(udev)) {
+ dev_dbg(&udev->dev, "Compatible with usb audio offload\n");
+ if (offload_data->op_mode == USB_OFFLOAD_DRAM) {
+ xhci_sync_conn_stat(udev->bus->busnum, udev->devnum, udev->slot_id,
+ USB_CONNECTED);
+ }
+ }
+ offload_data->usb_accessory_enabled = false;
+ break;
+ case USB_DEVICE_REMOVE:
+ if (is_compatible_with_usb_audio_offload(udev) &&
+ (offload_data->op_mode == USB_OFFLOAD_DRAM)) {
+ xhci_sync_conn_stat(udev->bus->busnum, udev->devnum, udev->slot_id,
+ USB_DISCONNECTED);
+ }
+ offload_data->usb_accessory_enabled = false;
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block xhci_udev_nb = {
+ .notifier_call = xhci_udev_notify,
+};
+
+static int usb_audio_offload_init(struct xhci_hcd *xhci)
+{
+ struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+ int ret;
+ u32 out_val;
+
+ if (!is_aoc_usb_probe_done()) {
+ dev_info(dev, "%s: deferring the probe\n", __func__);
+ return -EPROBE_DEFER;
+ }
+
+ offload_data = kzalloc(sizeof(struct xhci_offload_data), GFP_KERNEL);
+ if (!offload_data)
+ return -ENOMEM;
+
+ if (!of_property_read_u32(dev->of_node, "offload", &out_val))
+ offload_data->usb_audio_offload = (out_val == 1) ? true : false;
+
+ ret = of_reserved_mem_device_init(dev);
+ if (ret) {
+ dev_err(dev, "Could not get reserved memory\n");
+ kfree(offload_data);
+ return ret;
+ }
+
+ offload_data->dt_direct_usb_access =
+ of_property_read_bool(dev->of_node, "direct-usb-access") ? true : false;
+ if (!offload_data->dt_direct_usb_access)
+ dev_warn(dev, "Direct USB access is not supported\n");
+
+ offload_data->offload_state = true;
+
+ usb_register_notify(&xhci_udev_nb);
+ offload_data->op_mode = USB_OFFLOAD_DRAM;
+ offload_data->xhci = xhci;
+
+ return 0;
+}
+
+static void usb_audio_offload_cleanup(struct xhci_hcd *xhci)
+{
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+
+ offload_data->usb_audio_offload = false;
+ offload_data->op_mode = USB_OFFLOAD_STOP;
+ offload_data->xhci = NULL;
+
+ usb_unregister_notify(&xhci_udev_nb);
+
+ /* Notification for xhci driver removing */
+ usb_host_mode_state_notify(USB_DISCONNECTED);
+
+ kfree(offload_data);
+}
+
+static bool is_offload_enabled(struct xhci_hcd *xhci,
+ struct xhci_virt_device *vdev, unsigned int ep_index)
+{
+ struct usb_device *udev;
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+ bool global_enabled = offload_data->op_mode != USB_OFFLOAD_STOP;
+ struct xhci_ring *ep_ring;
+
+ if (vdev == NULL || vdev->eps[ep_index].ring == NULL)
+ return global_enabled;
+
+ udev = vdev->udev;
+
+ if (global_enabled) {
+ ep_ring = vdev->eps[ep_index].ring;
+ if (offload_data->op_mode == USB_OFFLOAD_DRAM) {
+ if (is_usb_video_device(udev))
+ return false;
+ else if (ep_ring->type == TYPE_ISOC)
+ return offload_data->offload_state;
+ }
+ }
+
+ return false;
+}
+
+static bool is_usb_bulk_transfer_enabled(struct xhci_hcd *xhci, struct urb *urb)
+{
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+ struct usb_endpoint_descriptor *desc = &urb->ep->desc;
+ int ep_type = usb_endpoint_type(desc);
+ struct usb_ctrlrequest *cmd;
+ bool skip_bulk = false;
+
+ cmd = (struct usb_ctrlrequest *) urb->setup_packet;
+
+ if (ep_type == USB_ENDPOINT_XFER_CONTROL) {
+ if (!usb_endpoint_dir_in(desc) && cmd->bRequest == 0x35)
+ offload_data->usb_accessory_enabled = true;
+ else
+ offload_data->usb_accessory_enabled = false;
+ }
+
+ if (ep_type == USB_ENDPOINT_XFER_BULK && !usb_endpoint_dir_in(desc))
+ skip_bulk = offload_data->usb_accessory_enabled;
+
+ return skip_bulk;
+}
+
+static void alloc_dcbaa(struct xhci_hcd *xhci, gfp_t flags)
+{
+ dma_addr_t dma;
+ struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+ struct xhci_offload_data *offload_data = xhci_get_offload_data();
+
+ if (offload_data->op_mode == USB_OFFLOAD_DRAM) {
+ xhci->dcbaa = dma_alloc_coherent(dev, sizeof(*xhci->dcbaa),
+ &dma, flags);
+ if (!xhci->dcbaa)
+ return;
+
+ xhci->dcbaa->dma = dma;
+ if (xhci_set_dcbaa_ptr(xhci->dcbaa->dma) != 0) {
+ xhci_err(xhci, "Set DCBAA pointer failed\n");
+ xhci->dcbaa = NULL;
+ return;
+ }
+ xhci_setup_done();
+
+ xhci_dbg(xhci, "Set dcbaa_ptr=%llx to AoC\n", xhci->dcbaa->dma);
+ } else {
+ xhci->dcbaa = dma_alloc_coherent(dev, sizeof(*xhci->dcbaa),
+ &dma, flags);
+ if (!xhci->dcbaa)
+ return;
+
+ xhci->dcbaa->dma = dma;
+ }
+}
+
+static void free_dcbaa(struct xhci_hcd *xhci)
+{
+ struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+
+ if (!xhci->dcbaa)
+ return;
+
+ dma_free_coherent(dev, sizeof(*xhci->dcbaa),
+ xhci->dcbaa, xhci->dcbaa->dma);
+
+ xhci->dcbaa = NULL;
+}
+
+static struct xhci_ring *alloc_transfer_ring(struct xhci_hcd *xhci,
+ u32 endpoint_type, enum xhci_ring_type ring_type,
+ unsigned int max_packet, gfp_t mem_flags)
+{
+ struct xhci_ring *ep_ring;
+ u16 dir;
+
+ ep_ring = xhci_ring_alloc(xhci, 1, 1, ring_type, max_packet, mem_flags);
+ dir = endpoint_type == ISOC_IN_EP ? 0 : 1;
+
+ xhci_set_isoc_tr_info(0, dir, ep_ring);
+
+ return ep_ring;
+}
+
+static void free_transfer_ring(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev,
+ unsigned int ep_index)
+{
+ struct xhci_ring *ring, *new_ring;
+ struct xhci_ep_ctx *ep_ctx;
+ struct xhci_input_control_ctx *ctrl_ctx;
+ u32 ep_type;
+ u32 ep_is_added, ep_is_dropped;
+
+ ring = virt_dev->eps[ep_index].ring;
+ new_ring = virt_dev->eps[ep_index].new_ring;
+ ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->out_ctx, ep_index);
+ ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
+
+ ctrl_ctx = xhci_get_input_control_ctx(virt_dev->in_ctx);
+ if (!ctrl_ctx) {
+ xhci_warn(xhci, "%s: Could not get input context, bad type.\n", __func__);
+ return;
+ }
+ ep_is_added = EP_IS_ADDED(ctrl_ctx, ep_index);
+ ep_is_dropped = EP_IS_DROPPED(ctrl_ctx, ep_index);
+
+ xhci_dbg(xhci, "%s: ep %u is added(0x%x), is dropped(0x%x)\n", __func__, ep_index,
+ ep_is_added, ep_is_dropped);
+
+ if (ring) {
+ xhci_dbg(xhci, "%s: ep_index=%u, ep_type=%u, ring type=%u, new_ring=%pK\n",
+ __func__, ep_index, ep_type, ring->type, new_ring);
+
+ xhci_ring_free(xhci, virt_dev->eps[ep_index].ring);
+
+ virt_dev->eps[ep_index].ring = NULL;
+
+ if (ep_is_added == 0 && ep_is_dropped == 0)
+ return;
+ }
+
+ if (new_ring) {
+ xhci_dbg(xhci, "%s: ep_index=%u, ep_type=%u, new_ring type=%u\n", __func__,
+ ep_index, ep_type, new_ring->type);
+
+ xhci_ring_free(xhci, virt_dev->eps[ep_index].new_ring);
+
+ virt_dev->eps[ep_index].new_ring = NULL;
+
+ return;
+ }
+}
+
+static bool offload_skip_urb(struct xhci_hcd *xhci, struct urb *urb)
+{
+ struct xhci_virt_device *vdev = xhci->devs[urb->dev->slot_id];
+ struct usb_endpoint_descriptor *desc = &urb->ep->desc;
+ int ep_type = usb_endpoint_type(desc);
+ unsigned int ep_index;
+
+ if (ep_type == USB_ENDPOINT_XFER_CONTROL)
+ ep_index = (unsigned int)(usb_endpoint_num(desc)*2);
+ else
+ ep_index = (unsigned int)(usb_endpoint_num(desc)*2) +
+ (usb_endpoint_dir_in(desc) ? 1 : 0) - 1;
+
+ xhci_dbg(xhci, "%s: ep_index=%u, ep_type=%d\n", __func__, ep_index, ep_type);
+
+ if (is_offload_enabled(xhci, vdev, ep_index))
+ return true;
+
+ if (is_usb_bulk_transfer_enabled(xhci, urb))
+ return true;
+
+ return false;
+}
+
+static struct xhci_offload_ops offload_ops = {
+ .offload_init = usb_audio_offload_init,
+ .offload_cleanup = usb_audio_offload_cleanup,
+ .is_offload_enabled = is_offload_enabled,
+ .alloc_dcbaa = alloc_dcbaa,
+ .free_dcbaa = free_dcbaa,
+ .alloc_transfer_ring = alloc_transfer_ring,
+ .free_transfer_ring = free_transfer_ring,
+ .usb_offload_skip_urb = offload_skip_urb,
+};
+
+int xhci_offload_helper_init(void)
+{
+ return xhci_plat_register_offload_ops(&offload_ops);
+}