From 32097060189bf215439e719c5df514399235c52e Mon Sep 17 00:00:00 2001 From: Ramalingam C Date: Fri, 15 Feb 2019 14:05:04 +0530 Subject: [PATCH] drm: helper functions for hdcp2 seq_num to from u32 Library functions for endianness are aligned for 16/32/64 bits. But hdcp sequence numbers are 24bits(big endian). So for their conversion to and from u32 helper functions are developed. v2: Comment is updated. [Daniel] Reviewed-by Uma. Signed-off-by: Ramalingam C Reviewed-by: Daniel Vetter Reviewed-by: Uma Shankar Acked-by: Dave Airlie Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/1550219730-17734-10-git-send-email-ramalingam.c@intel.com --- include/drm/drm_hdcp.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index a6de09c5e47f..c21682f76cd3 100644 --- a/include/drm/drm_hdcp.h +++ b/include/drm/drm_hdcp.h @@ -250,4 +250,22 @@ struct hdcp2_dp_errata_stream_type { #define HDCP_2_2_HDMI_RXSTATUS_READY(x) ((x) & BIT(2)) #define HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(x) ((x) & BIT(3)) +/* + * Helper functions to convert 24bit big endian hdcp sequence number to + * host format and back + */ +static inline +u32 drm_hdcp2_seq_num_to_u32(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN]) +{ + return (u32)(seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16); +} + +static inline +void drm_hdcp2_u32_to_seq_num(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN], u32 val) +{ + seq_num[0] = val >> 16; + seq_num[1] = val >> 8; + seq_num[2] = val; +} + #endif