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path: root/drivers/media/video/em28xx/em28xx-core.c
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Diffstat (limited to 'drivers/media/video/em28xx/em28xx-core.c')
-rw-r--r--drivers/media/video/em28xx/em28xx-core.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 841c7c2c91b..cb9f721ca28 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -53,6 +53,12 @@ static int alt = EM28XX_PINOUT;
module_param(alt, int, 0644);
MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
+/* FIXME */
+#define em28xx_isocdbg(fmt, arg...) do {\
+ if (core_debug) \
+ printk(KERN_INFO "%s %s :"fmt, \
+ dev->name, __func__ , ##arg); } while (0)
+
/*
* em28xx_read_reg_req()
* reads data from the usb device specifying bRequest
@@ -455,3 +461,178 @@ int em28xx_set_alternate(struct em28xx *dev)
}
return 0;
}
+
+/* ------------------------------------------------------------------
+ URB control
+ ------------------------------------------------------------------*/
+
+/*
+ * IRQ callback, called by URB callback
+ */
+static void em28xx_irq_callback(struct urb *urb)
+{
+ struct em28xx_dmaqueue *dma_q = urb->context;
+ struct em28xx *dev = container_of(dma_q, struct em28xx, vidq);
+ int rc, i;
+
+ /* Copy data from URB */
+ spin_lock(&dev->slock);
+ rc = dev->isoc_ctl.isoc_copy(dev, urb);
+ spin_unlock(&dev->slock);
+
+ /* Reset urb buffers */
+ for (i = 0; i < urb->number_of_packets; i++) {
+ urb->iso_frame_desc[i].status = 0;
+ urb->iso_frame_desc[i].actual_length = 0;
+ }
+ urb->status = 0;
+
+ urb->status = usb_submit_urb(urb, GFP_ATOMIC);
+ if (urb->status) {
+ em28xx_err("urb resubmit failed (error=%i)\n",
+ urb->status);
+ }
+}
+
+/*
+ * Stop and Deallocate URBs
+ */
+void em28xx_uninit_isoc(struct em28xx *dev)
+{
+ struct urb *urb;
+ int i;
+
+ em28xx_isocdbg("em28xx: called em28xx_uninit_isoc\n");
+
+ dev->isoc_ctl.nfields = -1;
+ for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
+ urb = dev->isoc_ctl.urb[i];
+ if (urb) {
+ usb_kill_urb(urb);
+ usb_unlink_urb(urb);
+ if (dev->isoc_ctl.transfer_buffer[i]) {
+ usb_buffer_free(dev->udev,
+ urb->transfer_buffer_length,
+ dev->isoc_ctl.transfer_buffer[i],
+ urb->transfer_dma);
+ }
+ usb_free_urb(urb);
+ dev->isoc_ctl.urb[i] = NULL;
+ }
+ dev->isoc_ctl.transfer_buffer[i] = NULL;
+ }
+
+ kfree(dev->isoc_ctl.urb);
+ kfree(dev->isoc_ctl.transfer_buffer);
+
+ dev->isoc_ctl.urb = NULL;
+ dev->isoc_ctl.transfer_buffer = NULL;
+ dev->isoc_ctl.num_bufs = 0;
+
+ em28xx_capture_start(dev, 0);
+}
+EXPORT_SYMBOL_GPL(em28xx_uninit_isoc);
+
+/*
+ * Allocate URBs and start IRQ
+ */
+int em28xx_init_isoc(struct em28xx *dev, int max_packets,
+ int num_bufs, int max_pkt_size,
+ int (*isoc_copy) (struct em28xx *dev, struct urb *urb),
+ int cap_type)
+{
+ struct em28xx_dmaqueue *dma_q = &dev->vidq;
+ int i;
+ int sb_size, pipe;
+ struct urb *urb;
+ int j, k;
+ int rc;
+
+ em28xx_isocdbg("em28xx: called em28xx_prepare_isoc\n");
+
+ /* De-allocates all pending stuff */
+ em28xx_uninit_isoc(dev);
+
+ dev->isoc_ctl.isoc_copy = isoc_copy;
+ dev->isoc_ctl.num_bufs = num_bufs;
+
+ dev->isoc_ctl.urb = kzalloc(sizeof(void *)*num_bufs, GFP_KERNEL);
+ if (!dev->isoc_ctl.urb) {
+ em28xx_errdev("cannot alloc memory for usb buffers\n");
+ return -ENOMEM;
+ }
+
+ dev->isoc_ctl.transfer_buffer = kzalloc(sizeof(void *)*num_bufs,
+ GFP_KERNEL);
+ if (!dev->isoc_ctl.urb) {
+ em28xx_errdev("cannot allocate memory for usbtransfer\n");
+ kfree(dev->isoc_ctl.urb);
+ return -ENOMEM;
+ }
+
+ dev->isoc_ctl.max_pkt_size = max_pkt_size;
+ dev->isoc_ctl.buf = NULL;
+
+ sb_size = max_packets * dev->isoc_ctl.max_pkt_size;
+
+ /* allocate urbs and transfer buffers */
+ for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
+ urb = usb_alloc_urb(max_packets, GFP_KERNEL);
+ if (!urb) {
+ em28xx_err("cannot alloc isoc_ctl.urb %i\n", i);
+ em28xx_uninit_isoc(dev);
+ return -ENOMEM;
+ }
+ dev->isoc_ctl.urb[i] = urb;
+
+ dev->isoc_ctl.transfer_buffer[i] = usb_buffer_alloc(dev->udev,
+ sb_size, GFP_KERNEL, &urb->transfer_dma);
+ if (!dev->isoc_ctl.transfer_buffer[i]) {
+ em28xx_err("unable to allocate %i bytes for transfer"
+ " buffer %i%s\n",
+ sb_size, i,
+ in_interrupt()?" while in int":"");
+ em28xx_uninit_isoc(dev);
+ return -ENOMEM;
+ }
+ memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
+
+ /* FIXME: this is a hack - should be
+ 'desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK'
+ should also be using 'desc.bInterval'
+ */
+ pipe = usb_rcvisocpipe(dev->udev, cap_type == EM28XX_ANALOG_CAPTURE ? 0x82 : 0x84);
+ usb_fill_int_urb(urb, dev->udev, pipe,
+ dev->isoc_ctl.transfer_buffer[i], sb_size,
+ em28xx_irq_callback, dma_q, 1);
+
+ urb->number_of_packets = max_packets;
+ urb->transfer_flags = URB_ISO_ASAP;
+
+ k = 0;
+ for (j = 0; j < max_packets; j++) {
+ urb->iso_frame_desc[j].offset = k;
+ urb->iso_frame_desc[j].length =
+ dev->isoc_ctl.max_pkt_size;
+ k += dev->isoc_ctl.max_pkt_size;
+ }
+ }
+
+ init_waitqueue_head(&dma_q->wq);
+
+ em28xx_capture_start(dev, cap_type);
+
+ /* submit urbs and enables IRQ */
+ for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
+ rc = usb_submit_urb(dev->isoc_ctl.urb[i], GFP_ATOMIC);
+ if (rc) {
+ em28xx_err("submit of urb %i failed (error=%i)\n", i,
+ rc);
+ em28xx_uninit_isoc(dev);
+ return rc;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(em28xx_init_isoc);