include/drm/drm_eld.h

   1 /* SPDX-License-Identifier: MIT */
   2 /*
   3  * Copyright © 2023 Intel Corporation
   4  */
   5
   6 #ifndef __DRM_ELD_H__
   7 #define __DRM_ELD_H__
   8
   9 #include <linux/types.h>
  10
  11 struct cea_sad;
  12
  13 /* ELD Header Block */
  14 #define DRM_ELD_HEADER_BLOCK_SIZE       4
  15
  16 #define DRM_ELD_VER                     0
  17 # define DRM_ELD_VER_SHIFT              3
  18 # define DRM_ELD_VER_MASK               (0x1f << 3)
  19 # define DRM_ELD_VER_CEA861D            (2 << 3) /* supports 861D or below */
  20 # define DRM_ELD_VER_CANNED             (0x1f << 3)
  21
  22 #define DRM_ELD_BASELINE_ELD_LEN        2       /* in dwords! */
  23
  24 /* ELD Baseline Block for ELD_Ver == 2 */
  25 #define DRM_ELD_CEA_EDID_VER_MNL        4
  26 # define DRM_ELD_CEA_EDID_VER_SHIFT     5
  27 # define DRM_ELD_CEA_EDID_VER_MASK      (7 << 5)
  28 # define DRM_ELD_CEA_EDID_VER_NONE      (0 << 5)
  29 # define DRM_ELD_CEA_EDID_VER_CEA861    (1 << 5)
  30 # define DRM_ELD_CEA_EDID_VER_CEA861A   (2 << 5)
  31 # define DRM_ELD_CEA_EDID_VER_CEA861BCD (3 << 5)
  32 # define DRM_ELD_MNL_SHIFT              0
  33 # define DRM_ELD_MNL_MASK               (0x1f << 0)
  34
  35 #define DRM_ELD_SAD_COUNT_CONN_TYPE     5
  36 # define DRM_ELD_SAD_COUNT_SHIFT        4
  37 # define DRM_ELD_SAD_COUNT_MASK         (0xf << 4)
  38 # define DRM_ELD_CONN_TYPE_SHIFT        2
  39 # define DRM_ELD_CONN_TYPE_MASK         (3 << 2)
  40 # define DRM_ELD_CONN_TYPE_HDMI         (0 << 2)
  41 # define DRM_ELD_CONN_TYPE_DP           (1 << 2)
  42 # define DRM_ELD_SUPPORTS_AI            (1 << 1)
  43 # define DRM_ELD_SUPPORTS_HDCP          (1 << 0)
  44
  45 #define DRM_ELD_AUD_SYNCH_DELAY         6       /* in units of 2 ms */
  46 # define DRM_ELD_AUD_SYNCH_DELAY_MAX    0xfa    /* 500 ms */
  47
  48 #define DRM_ELD_SPEAKER                 7
  49 # define DRM_ELD_SPEAKER_MASK           0x7f
  50 # define DRM_ELD_SPEAKER_RLRC           (1 << 6)
  51 # define DRM_ELD_SPEAKER_FLRC           (1 << 5)
  52 # define DRM_ELD_SPEAKER_RC             (1 << 4)
  53 # define DRM_ELD_SPEAKER_RLR            (1 << 3)
  54 # define DRM_ELD_SPEAKER_FC             (1 << 2)
  55 # define DRM_ELD_SPEAKER_LFE            (1 << 1)
  56 # define DRM_ELD_SPEAKER_FLR            (1 << 0)
  57
  58 #define DRM_ELD_PORT_ID                 8       /* offsets 8..15 inclusive */
  59 # define DRM_ELD_PORT_ID_LEN            8
  60
  61 #define DRM_ELD_MANUFACTURER_NAME0      16
  62 #define DRM_ELD_MANUFACTURER_NAME1      17
  63
  64 #define DRM_ELD_PRODUCT_CODE0           18
  65 #define DRM_ELD_PRODUCT_CODE1           19
  66
  67 #define DRM_ELD_MONITOR_NAME_STRING     20      /* offsets 20..(20+mnl-1) inclusive */
  68
  69 #define DRM_ELD_CEA_SAD(mnl, sad)       (20 + (mnl) + 3 * (sad))
  70
  71 /**
  72  * drm_eld_mnl - Get ELD monitor name length in bytes.
  73  * @eld: pointer to an eld memory structure with mnl set
  74  */
  75 static inline int drm_eld_mnl(const u8 *eld)
  76 {
  77         return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
  78 }
  79
  80 int drm_eld_sad_get(const u8 *eld, int sad_index, struct cea_sad *cta_sad);
  81 int drm_eld_sad_set(u8 *eld, int sad_index, const struct cea_sad *cta_sad);
  82
  83 /**
  84  * drm_eld_sad - Get ELD SAD structures.
  85  * @eld: pointer to an eld memory structure with sad_count set
  86  */
  87 static inline const u8 *drm_eld_sad(const u8 *eld)
  88 {
  89         unsigned int ver, mnl;
  90
  91         ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
  92         if (ver != 2 && ver != 31)
  93                 return NULL;
  94
  95         mnl = drm_eld_mnl(eld);
  96         if (mnl > 16)
  97                 return NULL;
  98
  99         return eld + DRM_ELD_CEA_SAD(mnl, 0);
 100 }
 101
 102 /**
 103  * drm_eld_sad_count - Get ELD SAD count.
 104  * @eld: pointer to an eld memory structure with sad_count set
 105  */
 106 static inline int drm_eld_sad_count(const u8 *eld)
 107 {
 108         return (eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_SAD_COUNT_MASK) >>
 109                 DRM_ELD_SAD_COUNT_SHIFT;
 110 }
 111
 112 /**
 113  * drm_eld_calc_baseline_block_size - Calculate baseline block size in bytes
 114  * @eld: pointer to an eld memory structure with mnl and sad_count set
 115  *
 116  * This is a helper for determining the payload size of the baseline block, in
 117  * bytes, for e.g. setting the Baseline_ELD_Len field in the ELD header block.
 118  */
 119 static inline int drm_eld_calc_baseline_block_size(const u8 *eld)
 120 {
 121         return DRM_ELD_MONITOR_NAME_STRING - DRM_ELD_HEADER_BLOCK_SIZE +
 122                 drm_eld_mnl(eld) + drm_eld_sad_count(eld) * 3;
 123 }
 124
 125 /**
 126  * drm_eld_size - Get ELD size in bytes
 127  * @eld: pointer to a complete eld memory structure
 128  *
 129  * The returned value does not include the vendor block. It's vendor specific,
 130  * and comprises of the remaining bytes in the ELD memory buffer after
 131  * drm_eld_size() bytes of header and baseline block.
 132  *
 133  * The returned value is guaranteed to be a multiple of 4.
 134  */
 135 static inline int drm_eld_size(const u8 *eld)
 136 {
 137         return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
 138 }
 139
 140 /**
 141  * drm_eld_get_spk_alloc - Get speaker allocation
 142  * @eld: pointer to an ELD memory structure
 143  *
 144  * The returned value is the speakers mask. User has to use %DRM_ELD_SPEAKER
 145  * field definitions to identify speakers.
 146  */
 147 static inline u8 drm_eld_get_spk_alloc(const u8 *eld)
 148 {
 149         return eld[DRM_ELD_SPEAKER] & DRM_ELD_SPEAKER_MASK;
 150 }
 151
 152 /**
 153  * drm_eld_get_conn_type - Get device type hdmi/dp connected
 154  * @eld: pointer to an ELD memory structure
 155  *
 156  * The caller need to use %DRM_ELD_CONN_TYPE_HDMI or %DRM_ELD_CONN_TYPE_DP to
 157  * identify the display type connected.
 158  */
 159 static inline u8 drm_eld_get_conn_type(const u8 *eld)
 160 {
 161         return eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_CONN_TYPE_MASK;
 162 }
 163
 164 #endif /* __DRM_ELD_H__ */