USB: gadget: f_mtp: Add ioctl for sending events via the interrupt endpoint

Signed-off-by: Mike Lockwood <lockwood@android.com>

diff --git a/drivers/usb/gadget/f_mtp.c b/drivers/usb/gadget/f_mtp.c
index 910dd11271810fc4611236f648039ab9215714e3..2c61a2613475237ad92821a555984e00e4c404ab 100644 (file)
--- a/drivers/usb/gadget/f_mtp.c
+++ b/drivers/usb/gadget/f_mtp.c
@@ -40,6 +40,7 @@
 #include <linux/usb/f_mtp.h>
 
 #define BULK_BUFFER_SIZE           16384
+#define INTR_BUFFER_SIZE           28
 
 /* String IDs */
 #define INTERFACE_STRING_INDEX 0
@@ -80,6 +81,7 @@ struct mtp_dev {
        struct usb_composite_dev *cdev;
        spinlock_t lock;
 
+       /* appear as MTP or PTP when enumerating */
        int interface_mode;
 
        struct usb_ep *ep_in;
@@ -88,15 +90,23 @@ struct mtp_dev {
 
        int state;
 
+       /* synchronize access to our device file */
        atomic_t open_excl;
 
        struct list_head tx_idle;
 
        wait_queue_head_t read_wq;
        wait_queue_head_t write_wq;
+       wait_queue_head_t intr_wq;
        struct usb_request *rx_req[RX_REQ_MAX];
+       struct usb_request *intr_req;
        int rx_done;
 
+       /* synchronize access to interrupt endpoint */
+       struct mutex intr_mutex;
+       /* true if interrupt endpoint is busy */
+       int intr_busy;
+
        /* for our file IO thread */
        struct task_struct                      *thread;
        /* current command for IO thread (or zero for none) */
@@ -165,7 +175,7 @@ static struct usb_endpoint_descriptor mtp_intr_desc = {
        .bDescriptorType        = USB_DT_ENDPOINT,
        .bEndpointAddress       = USB_DIR_IN,
        .bmAttributes           = USB_ENDPOINT_XFER_INT,
-       .wMaxPacketSize         = __constant_cpu_to_le16(8),
+       .wMaxPacketSize         = __constant_cpu_to_le16(INTR_BUFFER_SIZE),
        .bInterval              = 6,
 };
 
@@ -368,6 +378,18 @@ static void mtp_complete_out(struct usb_ep *ep, struct usb_request *req)
        wake_up(&dev->read_wq);
 }
 
+static void mtp_complete_intr(struct usb_ep *ep, struct usb_request *req)
+{
+       struct mtp_dev *dev = _mtp_dev;
+
+       DBG(dev->cdev, "mtp_complete_intr status: %d actual: %d\n", req->status, req->actual);
+       dev->intr_busy = 0;
+       if (req->status != 0)
+               dev->state = STATE_ERROR;
+
+       wake_up(&dev->intr_wq);
+}
+
 static int __init create_bulk_endpoints(struct mtp_dev *dev,
                                struct usb_endpoint_descriptor *in_desc,
                                struct usb_endpoint_descriptor *out_desc,
@@ -431,6 +453,11 @@ static int __init create_bulk_endpoints(struct mtp_dev *dev,
                req->complete = mtp_complete_out;
                dev->rx_req[i] = req;
        }
+       req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
+       if (!req)
+               goto fail;
+       req->complete = mtp_complete_intr;
+       dev->intr_req = req;
 
        return 0;
 
@@ -476,7 +503,7 @@ requeue_req:
        req = dev->rx_req[0];
        req->length = count;
        dev->rx_done = 0;
-       ret = usb_ep_queue(dev->ep_out, req, GFP_ATOMIC);
+       ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
        if (ret < 0) {
                r = -EIO;
                goto done;
@@ -567,7 +594,7 @@ static ssize_t mtp_write(struct file *fp, const char __user *buf,
                }
 
                req->length = xfer;
-               ret = usb_ep_queue(dev->ep_in, req, GFP_ATOMIC);
+               ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
                if (ret < 0) {
                        DBG(cdev, "mtp_write: xfer error %d\n", ret);
                        r = -EIO;
@@ -627,7 +654,7 @@ static int mtp_send_file(struct mtp_dev *dev, struct file *filp,
                xfer = ret;
 
                req->length = xfer;
-               ret = usb_ep_queue(dev->ep_in, req, GFP_ATOMIC);
+               ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
                if (ret < 0) {
                        DBG(cdev, "mtp_write: xfer error %d\n", ret);
                        dev->state = STATE_ERROR;
@@ -668,7 +695,7 @@ static int mtp_receive_file(struct mtp_dev *dev, struct file *filp,
                        read_req->length = (count > BULK_BUFFER_SIZE
                                        ? BULK_BUFFER_SIZE : count);
                        dev->rx_done = 0;
-                       ret = usb_ep_queue(dev->ep_out, read_req, GFP_ATOMIC);
+                       ret = usb_ep_queue(dev->ep_out, read_req, GFP_KERNEL);
                        if (ret < 0) {
                                r = -EIO;
                                dev->state = STATE_ERROR;
@@ -764,6 +791,43 @@ done:
        complete_and_exit(&dev->thread_wait, 0);
 }
 
+static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
+{
+       struct usb_request *req;
+       int ret;
+       int length = event->length;
+
+       DBG(dev->cdev, "mtp_send_event(%d)\n", event->length);
+
+       if (length < 0 || length > INTR_BUFFER_SIZE)
+               return -EINVAL;
+
+       mutex_lock(&dev->intr_mutex);
+
+       /* wait for a request to complete */
+       ret = wait_event_interruptible(dev->intr_wq, !dev->intr_busy || dev->state == STATE_OFFLINE);
+       if (ret < 0)
+               goto done;
+       if (dev->state == STATE_OFFLINE) {
+               ret = -ENODEV;
+               goto done;
+       }
+       req = dev->intr_req;
+       if (copy_from_user(req->buf, (void __user *)event->data, length)) {
+               ret = -EFAULT;
+               goto done;
+       }
+       req->length = length;
+       dev->intr_busy = 1;
+       ret = usb_ep_queue(dev->ep_intr, req, GFP_KERNEL);
+       if (ret)
+               dev->intr_busy = 0;
+
+done:
+       mutex_unlock(&dev->intr_mutex);
+       return ret;
+}
+
 static long mtp_ioctl(struct file *fp, unsigned code, unsigned long value)
 {
        struct mtp_dev *dev = fp->private_data;
@@ -833,6 +897,17 @@ static long mtp_ioctl(struct file *fp, unsigned code, unsigned long value)
                        ret = 0;
                }
                break;
+       case MTP_SEND_EVENT:
+       {
+               struct mtp_event        event;
+               /* return here so we don't change dev->state below,
+                * which would interfere with bulk transfer state.
+                */
+               if (copy_from_user(&event, (void __user *)value, sizeof(event)))
+                       return -EFAULT;
+               else
+                       return mtp_send_event(dev, &event);
+       }
        }
 
 fail:
@@ -947,8 +1022,10 @@ mtp_function_unbind(struct usb_configuration *c, struct usb_function *f)
                mtp_request_free(req, dev->ep_in);
        for (i = 0; i < RX_REQ_MAX; i++)
                mtp_request_free(dev->rx_req[i], dev->ep_out);
+       mtp_request_free(dev->intr_req, dev->ep_intr);
        dev->state = STATE_OFFLINE;
        spin_unlock_irq(&dev->lock);
+       wake_up(&dev->intr_wq);
 
        misc_deregister(&mtp_device);
        kfree(_mtp_dev);
@@ -1113,6 +1190,7 @@ static void mtp_function_disable(struct usb_function *f)
 
        /* readers may be blocked waiting for us to go online */
        wake_up(&dev->read_wq);
+       wake_up(&dev->intr_wq);
 
        VDBG(cdev, "%s disabled\n", dev->function.name);
 }
@@ -1141,8 +1219,10 @@ static int mtp_bind_config(struct usb_configuration *c)
        init_completion(&dev->thread_wait);
        init_waitqueue_head(&dev->read_wq);
        init_waitqueue_head(&dev->write_wq);
+       init_waitqueue_head(&dev->intr_wq);
        atomic_set(&dev->open_excl, 0);
        INIT_LIST_HEAD(&dev->tx_idle);
+       mutex_init(&dev->intr_mutex);
 
        dev->cdev = c->cdev;
        dev->function.name = "mtp";

diff --git a/include/linux/usb/f_mtp.h b/include/linux/usb/f_mtp.h
index c1c9aeff25fd1dcb76c186a3ab91849b98803d25..426c6b5cc06a58905d722fda8d281f168e43d820 100644 (file)
--- a/include/linux/usb/f_mtp.h
+++ b/include/linux/usb/f_mtp.h
@@ -32,6 +32,13 @@ struct mtp_file_range {
        size_t          length;
 };
 
+struct mtp_event {
+       /* size of the event */
+       size_t          length;
+       /* event data to send */
+       void            *data;
+};
+
 /* Sends the specified file range to the host */
 #define MTP_SEND_FILE              _IOW('M', 0, struct mtp_file_range)
 /* Receives data from the host and writes it to a file.
@@ -40,5 +47,7 @@ struct mtp_file_range {
 #define MTP_RECEIVE_FILE           _IOW('M', 1, struct mtp_file_range)
 /* Sets the driver mode to either MTP or PTP */
 #define MTP_SET_INTERFACE_MODE     _IOW('M', 2, int)
+/* Sends an event to the host via the interrupt endpoint */
+#define MTP_SEND_EVENT             _IOW('M', 3, struct mtp_event)
 
 #endif /* __LINUX_USB_F_MTP_H */