| Message ID | 1544673701-6353-12-git-send-email-ramalingam.c@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Implement HDCP2.2 | expand |
On Thu, Dec 13, 2018 at 09:31:13AM +0530, Ramalingam C wrote: > 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. > > Signed-off-by: Ramalingam C <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..d8093ecf3ddc 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)) > > +/* > + * Library functions for endianness are aligned for 16/32/64 bits. > + * But hdcp sequence numbers are 24bits(big endian). So for their conversion > + * from and to u32 below functions are developed. Comment is a bit confusing, I'd do a simple: /* * Helper functions to convert 24bit big endian hdcp sequence number to * host format and back */ Explaining why we need them exactly isn't terribly interesting. > + */ > +static inline void > +drm_hdcp2_seq_num_to_u32(u32 *val, u8 seq_num[HDCP_2_2_SEQ_NUM_LEN]) make u32 val the return value of this function, should be cleaner. > +{ > + *val = seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16; > +} > + > +static inline void drm_hdcp2_u32_to_seq_num(u8 *seq_num, u32 val) u8 seq_num[HDCP_2_2_SEQ_NUM_LEN]. Not any different in the actual function type, just a bit more informative. > +{ > + seq_num[0] = (val & (0xff << 16)) >> 16; > + seq_num[1] = (val & (0xff << 8)) >> 8; Shift alone should be enough, since seq_num[x] is of type u8 the & 0xff is implied. With the above comments addressed: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > + seq_num[2] = val & 0xff; > +} > + > #endif > -- > 2.7.4 >
diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index a6de09c5e47f..d8093ecf3ddc 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)) +/* + * Library functions for endianness are aligned for 16/32/64 bits. + * But hdcp sequence numbers are 24bits(big endian). So for their conversion + * from and to u32 below functions are developed. + */ +static inline void +drm_hdcp2_seq_num_to_u32(u32 *val, u8 seq_num[HDCP_2_2_SEQ_NUM_LEN]) +{ + *val = seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16; +} + +static inline void drm_hdcp2_u32_to_seq_num(u8 *seq_num, u32 val) +{ + seq_num[0] = (val & (0xff << 16)) >> 16; + seq_num[1] = (val & (0xff << 8)) >> 8; + seq_num[2] = val & 0xff; +} + #endif
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. Signed-off-by: Ramalingam C <ramalingam.c@intel.com> --- include/drm/drm_hdcp.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)