/* SPDX-License-Identifier: MIT */
/*
 * Copyright © 2023 Intel Corporation
 */

#ifndef __DRM_ELD_H__
#define __DRM_ELD_H__

#include <linux/types.h>

struct cea_sad;

/* 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_VER_CEA861D            (2 << 3) /* supports 861D or below */
# define DRM_ELD_VER_CANNED             (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_MASK           0x7f
# 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))

/**
 * 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 u8 *eld)
{
        return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
}

int drm_eld_sad_get(const u8 *eld, int sad_index, struct cea_sad *cta_sad);
int drm_eld_sad_set(u8 *eld, int sad_index, const struct cea_sad *cta_sad);

/**
 * drm_eld_sad - Get ELD SAD structures.
 * @eld: pointer to an eld memory structure with sad_count set
 */
static inline const u8 *drm_eld_sad(const u8 *eld)
{
        unsigned int ver, mnl;

        ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
        if (ver != 2 && ver != 31)
                return NULL;

        mnl = drm_eld_mnl(eld);
        if (mnl > 16)
                return NULL;

        return eld + DRM_ELD_CEA_SAD(mnl, 0);
}

/**
 * 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 u8 *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 u8 *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 u8 *eld)
{
        return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
}

/**
 * drm_eld_get_spk_alloc - Get speaker allocation
 * @eld: pointer to an ELD memory structure
 *
 * The returned value is the speakers mask. User has to use %DRM_ELD_SPEAKER
 * field definitions to identify speakers.
 */
static inline u8 drm_eld_get_spk_alloc(const u8 *eld)
{
        return eld[DRM_ELD_SPEAKER] & DRM_ELD_SPEAKER_MASK;
}

/**
 * drm_eld_get_conn_type - Get device type hdmi/dp connected
 * @eld: pointer to an ELD memory structure
 *
 * The caller need to use %DRM_ELD_CONN_TYPE_HDMI or %DRM_ELD_CONN_TYPE_DP to
 * identify the display type connected.
 */
static inline u8 drm_eld_get_conn_type(const u8 *eld)
{
        return eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_CONN_TYPE_MASK;
}

#endif /* __DRM_ELD_H__ */