From b9392d9920fdce50abbe4af758cd1a24b922c81c Mon Sep 17 00:00:00 2001 From: Gregory Herrero Date: Thu, 5 Nov 2015 09:41:42 +0100 Subject: [PATCH] usb: dwc2: host: add function to compare frame index This function allow comparing frame index used for descriptor list which has 64 entries. Acked-by: John Youn Signed-off-by: Gregory Herrero Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/hcd.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/usb/dwc2/hcd.h b/drivers/usb/dwc2/hcd.h index f105bada2fd1..a19837f655c9 100644 --- a/drivers/usb/dwc2/hcd.h +++ b/drivers/usb/dwc2/hcd.h @@ -534,6 +534,19 @@ static inline bool dbg_perio(void) { return false; } /* Packet size for any kind of endpoint descriptor */ #define dwc2_max_packet(wmaxpacketsize) ((wmaxpacketsize) & 0x07ff) +/* + * Returns true if frame1 index is greater than frame2 index. The comparison + * is done modulo FRLISTEN_64_SIZE. This accounts for the rollover of the + * frame number when the max index frame number is reached. + */ +static inline bool dwc2_frame_idx_num_gt(u16 fr_idx1, u16 fr_idx2) +{ + u16 diff = fr_idx1 - fr_idx2; + u16 sign = diff & (FRLISTEN_64_SIZE >> 1); + + return diff && !sign; +} + /* * Returns true if frame1 is less than or equal to frame2. The comparison is * done modulo HFNUM_MAX_FRNUM. This accounts for the rollover of the -- 2.20.1