ANDROID: USB: gadget: f_accessory: Add support for HID input devices
Change-Id: I4f1452db32508382df52acdc47c0eb395ae328c7
Signed-off-by: Mike Lockwood <lockwood@google.com>
diff --git a/drivers/usb/gadget/f_accessory.c b/drivers/usb/gadget/f_accessory.c
index 07c29d9..921db5a 100644
--- a/drivers/usb/gadget/f_accessory.c
+++ b/drivers/usb/gadget/f_accessory.c
@@ -33,6 +33,8 @@
#include <linux/device.h>
#include <linux/miscdevice.h>
+#include <linux/hid.h>
+#include <linux/hiddev.h>
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/f_accessory.h>
@@ -49,6 +51,20 @@
#define TX_REQ_MAX 4
#define RX_REQ_MAX 2
+struct acc_hid_dev {
+ struct list_head list;
+ struct hid_device *hid;
+ struct acc_dev *dev;
+ /* accessory defined ID */
+ int id;
+ /* HID report descriptor */
+ u8 *report_desc;
+ /* length of HID report descriptor */
+ int report_desc_len;
+ /* number of bytes of report_desc we have received so far */
+ int report_desc_offset;
+};
+
struct acc_dev {
struct usb_function function;
struct usb_composite_dev *cdev;
@@ -89,7 +105,21 @@
wait_queue_head_t write_wq;
struct usb_request *rx_req[RX_REQ_MAX];
int rx_done;
- struct delayed_work work;
+
+ /* delayed work for handling ACCESSORY_START */
+ struct delayed_work start_work;
+
+ /* worker for registering and unregistering hid devices */
+ struct work_struct hid_work;
+
+ /* list of active HID devices */
+ struct list_head hid_list;
+
+ /* list of new HID devices to register */
+ struct list_head new_hid_list;
+
+ /* list of dead HID devices to unregister */
+ struct list_head dead_hid_list;
};
static struct usb_interface_descriptor acc_interface_desc = {
@@ -298,7 +328,161 @@
}
}
-static int create_bulk_endpoints(struct acc_dev *dev,
+static void acc_complete_set_hid_report_desc(struct usb_ep *ep,
+ struct usb_request *req)
+{
+ struct acc_hid_dev *hid = req->context;
+ struct acc_dev *dev = hid->dev;
+ int length = req->actual;
+
+ if (req->status != 0) {
+ pr_err("acc_complete_set_hid_report_desc, err %d\n",
+ req->status);
+ return;
+ }
+
+ memcpy(hid->report_desc + hid->report_desc_offset, req->buf, length);
+ hid->report_desc_offset += length;
+ if (hid->report_desc_offset == hid->report_desc_len) {
+ /* After we have received the entire report descriptor
+ * we schedule work to initialize the HID device
+ */
+ schedule_work(&dev->hid_work);
+ }
+}
+
+static void acc_complete_send_hid_event(struct usb_ep *ep,
+ struct usb_request *req)
+{
+ struct acc_hid_dev *hid = req->context;
+ int length = req->actual;
+
+ if (req->status != 0) {
+ pr_err("acc_complete_send_hid_event, err %d\n", req->status);
+ return;
+ }
+
+ hid_report_raw_event(hid->hid, HID_INPUT_REPORT, req->buf, length, 1);
+}
+
+static int acc_hid_parse(struct hid_device *hid)
+{
+ struct acc_hid_dev *hdev = hid->driver_data;
+
+ hid_parse_report(hid, hdev->report_desc, hdev->report_desc_len);
+ return 0;
+}
+
+static int acc_hid_start(struct hid_device *hid)
+{
+ return 0;
+}
+
+static void acc_hid_stop(struct hid_device *hid)
+{
+}
+
+static int acc_hid_open(struct hid_device *hid)
+{
+ return 0;
+}
+
+static void acc_hid_close(struct hid_device *hid)
+{
+}
+
+static struct hid_ll_driver acc_hid_ll_driver = {
+ .parse = acc_hid_parse,
+ .start = acc_hid_start,
+ .stop = acc_hid_stop,
+ .open = acc_hid_open,
+ .close = acc_hid_close,
+};
+
+static struct acc_hid_dev *acc_hid_new(struct acc_dev *dev,
+ int id, int desc_len)
+{
+ struct acc_hid_dev *hdev;
+
+ hdev = kzalloc(sizeof(*hdev), GFP_ATOMIC);
+ if (!hdev)
+ return NULL;
+ hdev->report_desc = kzalloc(desc_len, GFP_ATOMIC);
+ if (!hdev->report_desc) {
+ kfree(hdev);
+ return NULL;
+ }
+ hdev->dev = dev;
+ hdev->id = id;
+ hdev->report_desc_len = desc_len;
+
+ return hdev;
+}
+
+static struct acc_hid_dev *acc_hid_get(struct list_head *list, int id)
+{
+ struct acc_hid_dev *hid;
+
+ list_for_each_entry(hid, list, list) {
+ if (hid->id == id)
+ return hid;
+ }
+ return NULL;
+}
+
+static int acc_register_hid(struct acc_dev *dev, int id, int desc_length)
+{
+ struct acc_hid_dev *hid;
+ unsigned long flags;
+
+ /* report descriptor length must be > 0 */
+ if (desc_length <= 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ /* replace HID if one already exists with this ID */
+ hid = acc_hid_get(&dev->hid_list, id);
+ if (!hid)
+ hid = acc_hid_get(&dev->new_hid_list, id);
+ if (hid)
+ list_move(&hid->list, &dev->dead_hid_list);
+
+ hid = acc_hid_new(dev, id, desc_length);
+ if (!hid) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -ENOMEM;
+ }
+
+ list_add(&hid->list, &dev->new_hid_list);
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ /* schedule work to register the HID device */
+ schedule_work(&dev->hid_work);
+ return 0;
+}
+
+static int acc_unregister_hid(struct acc_dev *dev, int id)
+{
+ struct acc_hid_dev *hid;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ hid = acc_hid_get(&dev->hid_list, id);
+ if (!hid)
+ hid = acc_hid_get(&dev->new_hid_list, id);
+ if (!hid) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -EINVAL;
+ }
+
+ list_move(&hid->list, &dev->dead_hid_list);
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ schedule_work(&dev->hid_work);
+ return 0;
+}
+
+static int __init create_bulk_endpoints(struct acc_dev *dev,
struct usb_endpoint_descriptor *in_desc,
struct usb_endpoint_descriptor *out_desc)
{
@@ -355,7 +539,7 @@
return 0;
fail:
- printk(KERN_ERR "acc_bind() could not allocate requests\n");
+ pr_err("acc_bind() could not allocate requests\n");
while ((req = req_get(dev, &dev->tx_idle)))
acc_request_free(req, dev->ep_in);
for (i = 0; i < RX_REQ_MAX; i++)
@@ -544,7 +728,7 @@
return 0;
}
-/* file operations for /dev/acc_usb */
+/* file operations for /dev/usb_accessory */
static const struct file_operations acc_fops = {
.owner = THIS_MODULE,
.read = acc_read,
@@ -554,23 +738,47 @@
.release = acc_release,
};
+static int acc_hid_probe(struct hid_device *hdev,
+ const struct hid_device_id *id)
+{
+ int ret;
+
+ ret = hid_parse(hdev);
+ if (ret)
+ return ret;
+ return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+}
+
static struct miscdevice acc_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "usb_accessory",
.fops = &acc_fops,
};
+static const struct hid_device_id acc_hid_table[] = {
+ { HID_USB_DEVICE(HID_ANY_ID, HID_ANY_ID) },
+ { }
+};
+
+static struct hid_driver acc_hid_driver = {
+ .name = "USB accessory",
+ .id_table = acc_hid_table,
+ .probe = acc_hid_probe,
+};
static int acc_ctrlrequest(struct usb_composite_dev *cdev,
const struct usb_ctrlrequest *ctrl)
{
struct acc_dev *dev = _acc_dev;
int value = -EOPNOTSUPP;
+ struct acc_hid_dev *hid;
+ int offset;
u8 b_requestType = ctrl->bRequestType;
u8 b_request = ctrl->bRequest;
u16 w_index = le16_to_cpu(ctrl->wIndex);
u16 w_value = le16_to_cpu(ctrl->wValue);
u16 w_length = le16_to_cpu(ctrl->wLength);
+ unsigned long flags;
/*
printk(KERN_INFO "acc_ctrlrequest "
@@ -583,7 +791,7 @@
if (b_request == ACCESSORY_START) {
dev->start_requested = 1;
schedule_delayed_work(
- &dev->work, msecs_to_jiffies(10));
+ &dev->start_work, msecs_to_jiffies(10));
value = 0;
} else if (b_request == ACCESSORY_SEND_STRING) {
dev->string_index = w_index;
@@ -594,6 +802,38 @@
w_index == 0 && w_length == 0) {
dev->audio_mode = w_value;
value = 0;
+ } else if (b_request == ACCESSORY_REGISTER_HID) {
+ value = acc_register_hid(dev, w_value, w_index);
+ } else if (b_request == ACCESSORY_UNREGISTER_HID) {
+ value = acc_unregister_hid(dev, w_value);
+ } else if (b_request == ACCESSORY_SET_HID_REPORT_DESC) {
+ spin_lock_irqsave(&dev->lock, flags);
+ hid = acc_hid_get(&dev->new_hid_list, w_value);
+ spin_unlock_irqrestore(&dev->lock, flags);
+ if (!hid) {
+ value = -EINVAL;
+ goto err;
+ }
+ offset = w_index;
+ if (offset != hid->report_desc_offset
+ || offset + w_length > hid->report_desc_len) {
+ value = -EINVAL;
+ goto err;
+ }
+ cdev->req->context = hid;
+ cdev->req->complete = acc_complete_set_hid_report_desc;
+ value = w_length;
+ } else if (b_request == ACCESSORY_SEND_HID_EVENT) {
+ spin_lock_irqsave(&dev->lock, flags);
+ hid = acc_hid_get(&dev->hid_list, w_value);
+ spin_unlock_irqrestore(&dev->lock, flags);
+ if (!hid) {
+ value = -EINVAL;
+ goto err;
+ }
+ cdev->req->context = hid;
+ cdev->req->complete = acc_complete_send_hid_event;
+ value = w_length;
}
} else if (b_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) {
if (b_request == ACCESSORY_GET_PROTOCOL) {
@@ -621,6 +861,7 @@
__func__);
}
+err:
if (value == -EOPNOTSUPP)
VDBG(cdev,
"unknown class-specific control req "
@@ -640,6 +881,10 @@
DBG(cdev, "acc_function_bind dev: %p\n", dev);
+ ret = hid_register_driver(&acc_hid_driver);
+ if (ret)
+ return ret;
+
dev->start_requested = 0;
/* allocate interface ID(s) */
@@ -669,6 +914,36 @@
}
static void
+kill_all_hid_devices(struct acc_dev *dev)
+{
+ struct acc_hid_dev *hid;
+ struct list_head *entry, *temp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ list_for_each_safe(entry, temp, &dev->hid_list) {
+ hid = list_entry(entry, struct acc_hid_dev, list);
+ list_del(&hid->list);
+ list_add(&hid->list, &dev->dead_hid_list);
+ }
+ list_for_each_safe(entry, temp, &dev->new_hid_list) {
+ hid = list_entry(entry, struct acc_hid_dev, list);
+ list_del(&hid->list);
+ list_add(&hid->list, &dev->dead_hid_list);
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ schedule_work(&dev->hid_work);
+}
+
+static void
+acc_hid_unbind(struct acc_dev *dev)
+{
+ hid_unregister_driver(&acc_hid_driver);
+ kill_all_hid_devices(dev);
+}
+
+static void
acc_function_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct acc_dev *dev = func_to_dev(f);
@@ -679,14 +954,104 @@
acc_request_free(req, dev->ep_in);
for (i = 0; i < RX_REQ_MAX; i++)
acc_request_free(dev->rx_req[i], dev->ep_out);
+
+ acc_hid_unbind(dev);
}
-static void acc_work(struct work_struct *data)
+static void acc_start_work(struct work_struct *data)
{
char *envp[2] = { "ACCESSORY=START", NULL };
kobject_uevent_env(&acc_device.this_device->kobj, KOBJ_CHANGE, envp);
}
+static int acc_hid_init(struct acc_hid_dev *hdev)
+{
+ struct hid_device *hid;
+ int ret;
+
+ hid = hid_allocate_device();
+ if (IS_ERR(hid))
+ return PTR_ERR(hid);
+
+ hid->ll_driver = &acc_hid_ll_driver;
+ hid->dev.parent = acc_device.this_device;
+
+ hid->bus = BUS_USB;
+ hid->vendor = HID_ANY_ID;
+ hid->product = HID_ANY_ID;
+ hid->driver_data = hdev;
+ ret = hid_add_device(hid);
+ if (ret) {
+ pr_err("can't add hid device: %d\n", ret);
+ hid_destroy_device(hid);
+ return ret;
+ }
+
+ hdev->hid = hid;
+ return 0;
+}
+
+static void acc_hid_delete(struct acc_hid_dev *hid)
+{
+ kfree(hid->report_desc);
+ kfree(hid);
+}
+
+static void acc_hid_work(struct work_struct *data)
+{
+ struct acc_dev *dev = _acc_dev;
+ struct list_head *entry, *temp;
+ struct acc_hid_dev *hid;
+ struct list_head new_list, dead_list;
+ unsigned long flags;
+
+ INIT_LIST_HEAD(&new_list);
+
+ spin_lock_irqsave(&dev->lock, flags);
+
+ /* copy hids that are ready for initialization to new_list */
+ list_for_each_safe(entry, temp, &dev->new_hid_list) {
+ hid = list_entry(entry, struct acc_hid_dev, list);
+ if (hid->report_desc_offset == hid->report_desc_len)
+ list_move(&hid->list, &new_list);
+ }
+
+ if (list_empty(&dev->dead_hid_list)) {
+ INIT_LIST_HEAD(&dead_list);
+ } else {
+ /* move all of dev->dead_hid_list to dead_list */
+ dead_list.prev = dev->dead_hid_list.prev;
+ dead_list.next = dev->dead_hid_list.next;
+ dead_list.next->prev = &dead_list;
+ dead_list.prev->next = &dead_list;
+ INIT_LIST_HEAD(&dev->dead_hid_list);
+ }
+
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ /* register new HID devices */
+ list_for_each_safe(entry, temp, &new_list) {
+ hid = list_entry(entry, struct acc_hid_dev, list);
+ if (acc_hid_init(hid)) {
+ pr_err("can't add HID device %p\n", hid);
+ acc_hid_delete(hid);
+ } else {
+ spin_lock_irqsave(&dev->lock, flags);
+ list_move(&hid->list, &dev->hid_list);
+ spin_unlock_irqrestore(&dev->lock, flags);
+ }
+ }
+
+ /* remove dead HID devices */
+ list_for_each_safe(entry, temp, &dead_list) {
+ hid = list_entry(entry, struct acc_hid_dev, list);
+ list_del(&hid->list);
+ if (hid->hid)
+ hid_destroy_device(hid->hid);
+ acc_hid_delete(hid);
+ }
+}
+
static int acc_function_set_alt(struct usb_function *f,
unsigned intf, unsigned alt)
{
@@ -780,7 +1145,11 @@
init_waitqueue_head(&dev->write_wq);
atomic_set(&dev->open_excl, 0);
INIT_LIST_HEAD(&dev->tx_idle);
- INIT_DELAYED_WORK(&dev->work, acc_work);
+ INIT_LIST_HEAD(&dev->hid_list);
+ INIT_LIST_HEAD(&dev->new_hid_list);
+ INIT_LIST_HEAD(&dev->dead_hid_list);
+ INIT_DELAYED_WORK(&dev->start_work, acc_start_work);
+ INIT_WORK(&dev->hid_work, acc_hid_work);
/* _acc_dev must be set before calling usb_gadget_register_driver */
_acc_dev = dev;
@@ -793,10 +1162,16 @@
err:
kfree(dev);
- printk(KERN_ERR "USB accessory gadget driver failed to initialize\n");
+ pr_err("USB accessory gadget driver failed to initialize\n");
return ret;
}
+static void acc_disconnect(void)
+{
+ /* unregister all HID devices if USB is disconnected */
+ kill_all_hid_devices(_acc_dev);
+}
+
static void acc_cleanup(void)
{
misc_deregister(&acc_device);