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
 11struct 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 */
 75static 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
 80int drm_eld_sad_get(const u8 *eld, int sad_index, struct cea_sad *cta_sad);
 81int 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 */
 87static 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 */
106static 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 */
119static 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 */
135static 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 */
147static 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 */
159static 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__ */