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__ */ 165