- Add support for software pre-scaling of ISOCHRONOUS transfers.

MFC after:	14 days
Approved by:	thompsa (mentor)

6 files changed, 30 insertions, 22 deletions

diff --git a/lib/libusb/libusb10.c b/lib/libusb/libusb10.c
index 3b8d567dae9b..fa50ea784dfb 100644
--- a/lib/libusb/libusb10.c
+++ b/lib/libusb/libusb10.c
@@ -51,7 +51,6 @@ struct libusb_context *usbi_default_context = NULL;
 /* Prototypes */
 
 static struct libusb20_transfer *libusb10_get_transfer(struct libusb20_device *, uint8_t, uint8_t);
-static int libusb10_get_maxframe(struct libusb20_device *, libusb_transfer *);
 static int libusb10_get_buffsize(struct libusb20_device *, libusb_transfer *);
 static int libusb10_convert_error(uint8_t status);
 static void libusb10_complete_transfer(struct libusb20_transfer *, struct libusb_super_transfer *, int);
@@ -810,25 +809,14 @@ libusb_free_transfer(struct libusb_transfer *uxfer)
 	free(sxfer);
 }
 
-static int
+static uint32_t
 libusb10_get_maxframe(struct libusb20_device *pdev, libusb_transfer *xfer)
 {
-	int ret;
-	int usb_speed;
-
-	usb_speed = libusb20_dev_get_speed(pdev);
+	uint32_t ret;
 
 	switch (xfer->type) {
 	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
-		switch (usb_speed) {
-		case LIBUSB20_SPEED_LOW:
-		case LIBUSB20_SPEED_FULL:
-			ret = 60 * 1;
-			break;
-		default:
-			ret = 60 * 8;
-			break;
-		}
+		ret = 60 | LIBUSB20_MAX_FRAME_PRE_SCALE;	/* 60ms */
 		break;
 	case LIBUSB_TRANSFER_TYPE_CONTROL:
 		ret = 2;
diff --git a/lib/libusb/libusb20.3 b/lib/libusb/libusb20.3
index a6dc890a70b4..93dfe18cf5be 100644
--- a/lib/libusb/libusb20.3
+++ b/lib/libusb/libusb20.3
@@ -261,6 +261,16 @@ The actual buffer size can be greater than
 and is returned by
 .Fn libusb20_tr_get_max_total_length .
 .
+If
+.Fa max_frame_count
+is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the
+argument is converted from milliseconds into the actual number of
+frames rounded up, when this function returns.
+This flag is only valid for ISOCHRONOUS transfers and has no effect
+for other transfer types.
+The actual number of frames setup is found by calling
+.Fn libusb20_tr_get_max_frames .
+.
 This function returns zero upon success.
 .
 Non-zero return values indicate a LIBUSB20_ERROR value.
diff --git a/lib/libusb/libusb20.c b/lib/libusb/libusb20.c
index f8edfc38d343..bcaa1e47ff13 100644
--- a/lib/libusb/libusb20.c
+++ b/lib/libusb/libusb20.c
@@ -156,14 +156,20 @@ libusb20_tr_open(struct libusb20_transfer *xfer, uint32_t MaxBufSize,
     uint32_t MaxFrameCount, uint8_t ep_no)
 {
 	uint32_t size;
+	uint8_t pre_scale;
 	int error;
 
-	if (xfer->is_opened) {
+	if (xfer->is_opened)
 		return (LIBUSB20_ERROR_BUSY);
+	if (MaxFrameCount & LIBUSB20_MAX_FRAME_PRE_SCALE) {
+		MaxFrameCount &= ~LIBUSB20_MAX_FRAME_PRE_SCALE;
+		pre_scale = 1;
+	} else {
+		pre_scale = 0;
 	}
-	if (MaxFrameCount == 0) {
+	if (MaxFrameCount == 0)
 		return (LIBUSB20_ERROR_INVALID_PARAM);
-	}
+
 	xfer->maxFrames = MaxFrameCount;
 
 	size = MaxFrameCount * sizeof(xfer->pLength[0]);
@@ -182,7 +188,7 @@ libusb20_tr_open(struct libusb20_transfer *xfer, uint32_t MaxBufSize,
 	memset(xfer->ppBuffer, 0, size);
 
 	error = xfer->pdev->methods->tr_open(xfer, MaxBufSize,
-	    MaxFrameCount, ep_no);
+	    MaxFrameCount, ep_no, pre_scale);
 
 	if (error) {
 		free(xfer->ppBuffer);
diff --git a/lib/libusb/libusb20.h b/lib/libusb/libusb20.h
index d16c6a628ea6..958a379ed254 100644
--- a/lib/libusb/libusb20.h
+++ b/lib/libusb/libusb20.h
@@ -197,8 +197,9 @@ struct libusb20_quirk {
 	char	quirkname[64 - 12];
 };
 
-/* USB transfer operations */
+#define	LIBUSB20_MAX_FRAME_PRE_SCALE	(1U << 31)
 
+/* USB transfer operations */
 int	libusb20_tr_close(struct libusb20_transfer *xfer);
 int	libusb20_tr_open(struct libusb20_transfer *xfer, uint32_t max_buf_size, uint32_t max_frame_count, uint8_t ep_no);
 struct libusb20_transfer *libusb20_tr_get_pointer(struct libusb20_device *pdev, uint16_t tr_index);
diff --git a/lib/libusb/libusb20_int.h b/lib/libusb/libusb20_int.h
index 64885f28877e..2ecfb4770a39 100644
--- a/lib/libusb/libusb20_int.h
+++ b/lib/libusb/libusb20_int.h
@@ -110,7 +110,7 @@ typedef int (libusb20_set_config_index_t)(struct libusb20_device *pdev, uint8_t
 typedef int (libusb20_check_connected_t)(struct libusb20_device *pdev);
 
 /* USB transfer specific */
-typedef int (libusb20_tr_open_t)(struct libusb20_transfer *xfer, uint32_t MaxBufSize, uint32_t MaxFrameCount, uint8_t ep_no);
+typedef int (libusb20_tr_open_t)(struct libusb20_transfer *xfer, uint32_t MaxBufSize, uint32_t MaxFrameCount, uint8_t ep_no, uint8_t pre_scale);
 typedef int (libusb20_tr_close_t)(struct libusb20_transfer *xfer);
 typedef int (libusb20_tr_clear_stall_sync_t)(struct libusb20_transfer *xfer);
 typedef void (libusb20_tr_submit_t)(struct libusb20_transfer *xfer);
diff --git a/lib/libusb/libusb20_ugen20.c b/lib/libusb/libusb20_ugen20.c
index 5b7d5e85a063..933d7286b679 100644
--- a/lib/libusb/libusb20_ugen20.c
+++ b/lib/libusb/libusb20_ugen20.c
@@ -736,11 +736,14 @@ ugen20_process(struct libusb20_device *pdev)
 
 static int
 ugen20_tr_open(struct libusb20_transfer *xfer, uint32_t MaxBufSize,
-    uint32_t MaxFrameCount, uint8_t ep_no)
+    uint32_t MaxFrameCount, uint8_t ep_no, uint8_t pre_scale)
 {
 	struct usb_fs_open temp;
 	struct usb_fs_endpoint *fsep;
 
+	if (pre_scale)
+		MaxFrameCount |= USB_FS_MAX_FRAMES_PRE_SCALE;
+
 	memset(&temp, 0, sizeof(temp));
 
 	fsep = xfer->pdev->privBeData;