[PATCH 1/2] drm/edid: add #defines and helpers for ELD

Jani Nikula
2014-10-28T14:20:47Z

In the interest of reducing magic numbers and having to cross check with
the specs all the time.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
include/drm/drm_edid.h | 102 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)

diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index b96031d947a0..c2f1bfa22010 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -207,6 +207,61 @@ struct detailed_timing {
#define DRM_EDID_HDMI_DC_30 (1 << 4)
#define DRM_EDID_HDMI_DC_Y444 (1 << 3)

+/* ELD Header Block */
+#define DRM_ELD_HEADER_BLOCK_SIZE 4
+
+#define DRM_ELD_VER 0
+# define DRM_ELD_VER_SHIFT 3
+# define DRM_ELD_VER_MASK (0x1f << 3)
+
+#define DRM_ELD_BASELINE_ELD_LEN 2 /* in dwords! */
+
+/* ELD Baseline Block for ELD_Ver == 2 */
+#define DRM_ELD_CEA_EDID_VER_MNL 4
+# define DRM_ELD_CEA_EDID_VER_SHIFT 5
+# define DRM_ELD_CEA_EDID_VER_MASK (7 << 5)
+# define DRM_ELD_CEA_EDID_VER_NONE (0 << 5)
+# define DRM_ELD_CEA_EDID_VER_CEA861 (1 << 5)
+# define DRM_ELD_CEA_EDID_VER_CEA861A (2 << 5)
+# define DRM_ELD_CEA_EDID_VER_CEA861BCD (3 << 5)
+# define DRM_ELD_MNL_SHIFT 0
+# define DRM_ELD_MNL_MASK (0x1f << 0)
+
+#define DRM_ELD_SAD_COUNT_CONN_TYPE 5
+# define DRM_ELD_SAD_COUNT_SHIFT 4
+# define DRM_ELD_SAD_COUNT_MASK (0xf << 4)
+# define DRM_ELD_CONN_TYPE_SHIFT 2
+# define DRM_ELD_CONN_TYPE_MASK (3 << 2)
+# define DRM_ELD_CONN_TYPE_HDMI (0 << 2)
+# define DRM_ELD_CONN_TYPE_DP (1 << 2)
+# define DRM_ELD_SUPPORTS_AI (1 << 1)
+# define DRM_ELD_SUPPORTS_HDCP (1 << 0)
+
+#define DRM_ELD_AUD_SYNCH_DELAY 6 /* in units of 2 ms */
+# define DRM_ELD_AUD_SYNCH_DELAY_MAX 0xfa /* 500 ms */
+
+#define DRM_ELD_SPEAKER 7
+# define DRM_ELD_SPEAKER_RLRC (1 << 6)
+# define DRM_ELD_SPEAKER_FLRC (1 << 5)
+# define DRM_ELD_SPEAKER_RC (1 << 4)
+# define DRM_ELD_SPEAKER_RLR (1 << 3)
+# define DRM_ELD_SPEAKER_FC (1 << 2)
+# define DRM_ELD_SPEAKER_LFE (1 << 1)
+# define DRM_ELD_SPEAKER_FLR (1 << 0)
+
+#define DRM_ELD_PORT_ID 8 /* offsets 8..15 inclusive */
+# define DRM_ELD_PORT_ID_LEN 8
+
+#define DRM_ELD_MANUFACTURER_NAME0 16
+#define DRM_ELD_MANUFACTURER_NAME1 17
+
+#define DRM_ELD_PRODUCT_CODE0 18
+#define DRM_ELD_PRODUCT_CODE1 19
+
+#define DRM_ELD_MONITOR_NAME_STRING 20 /* offsets 20..(20+mnl-1) inclusive */
+
+#define DRM_ELD_CEA_SAD(mnl, sad) (20 + (mnl) + 3 * (sad))
+
struct edid {
u8 header[8];
/* Vendor & product info */
@@ -279,4 +334,51 @@ int
drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
const struct drm_display_mode *mode);

+/**
+ * drm_eld_mnl - Get ELD monitor name length in bytes.
+ * @eld: pointer to an eld memory structure with mnl set
+ */
+static inline int drm_eld_mnl(const uint8_t *eld)
+{
+ return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
+}
+
+/**
+ * drm_eld_sad_count - Get ELD SAD count.
+ * @eld: pointer to an eld memory structure with sad_count set
+ */
+static inline int drm_eld_sad_count(const uint8_t *eld)
+{
+ return (eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_SAD_COUNT_MASK) >>
+ DRM_ELD_SAD_COUNT_SHIFT;
+}
+
+/**
+ * drm_eld_calc_baseline_block_size - Calculate baseline block size in bytes
+ * @eld: pointer to an eld memory structure with mnl and sad_count set
+ *
+ * This is a helper for determining the payload size of the baseline block, in
+ * bytes, for e.g. setting the Baseline_ELD_Len field in the ELD header block.
+ */
+static inline int drm_eld_calc_baseline_block_size(const uint8_t *eld)
+{
+ return DRM_ELD_MONITOR_NAME_STRING - DRM_ELD_HEADER_BLOCK_SIZE +
+ drm_eld_mnl(eld) + drm_eld_sad_count(eld) * 3;
+}
+
+/**
+ * drm_eld_size - Get ELD size in bytes
+ * @eld: pointer to a complete eld memory structure
+ *
+ * The returned value does not include the vendor block. It's vendor specific,
+ * and comprises of the remaining bytes in the ELD memory buffer after
+ * drm_eld_size() bytes of header and baseline block.
+ *
+ * The returned value is guaranteed to be a multiple of 4.
+ */
+static inline int drm_eld_size(const uint8_t *eld)
+{
+ return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
+}
+
#endif /* __DRM_EDID_H__ */
--
2.1.1

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