V4L/DVB (7602): em28xx: generalise URB setup code

Move the URB setup and management code to em28xx-core.c and generalise
it slighlty so that the DVB code can use it.

Signed-off-by: Aidan Thornton <makosoft@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

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 841c7c2c91b3..cb9f721ca280 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);