// SPDX-License-Identifier: GPL-2.0-only
/*
 *  PCM DRM helpers
 */
#include <linux/bitfield.h>
#include <linux/export.h>
#include <linux/hdmi.h>
#include <linux/unaligned.h>
#include <drm/drm_edid.h>
#include <drm/drm_eld.h>
#include <sound/info.h>
#include <sound/pcm.h>
#include <sound/pcm_drm_eld.h>

#define SAD0_CHANNELS_MASK      GENMASK(2, 0) /* max number of channels - 1 */
#define SAD0_FORMAT_MASK        GENMASK(6, 3) /* audio format */

#define SAD1_RATE_MASK          GENMASK(6, 0) /* bitfield of supported rates */
#define SAD1_RATE_32000_MASK    BIT(0)
#define SAD1_RATE_44100_MASK    BIT(1)
#define SAD1_RATE_48000_MASK    BIT(2)
#define SAD1_RATE_88200_MASK    BIT(3)
#define SAD1_RATE_96000_MASK    BIT(4)
#define SAD1_RATE_176400_MASK   BIT(5)
#define SAD1_RATE_192000_MASK   BIT(6)

static const unsigned int eld_rates[] = {
        32000,
        44100,
        48000,
        88200,
        96000,
        176400,
        192000,
};

static unsigned int map_rate_families(const u8 *sad,
                                      unsigned int mask_32000,
                                      unsigned int mask_44100,
                                      unsigned int mask_48000)
{
        unsigned int rate_mask = 0;

        if (sad[1] & SAD1_RATE_32000_MASK)
                rate_mask |= mask_32000;
        if (sad[1] & (SAD1_RATE_44100_MASK | SAD1_RATE_88200_MASK | SAD1_RATE_176400_MASK))
                rate_mask |= mask_44100;
        if (sad[1] & (SAD1_RATE_48000_MASK | SAD1_RATE_96000_MASK | SAD1_RATE_192000_MASK))
                rate_mask |= mask_48000;
        return rate_mask;
}

static unsigned int sad_rate_mask(const u8 *sad)
{
        switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
        case HDMI_AUDIO_CODING_TYPE_PCM:
                return sad[1] & SAD1_RATE_MASK;
        case HDMI_AUDIO_CODING_TYPE_AC3:
        case HDMI_AUDIO_CODING_TYPE_DTS:
                return map_rate_families(sad,
                                         SAD1_RATE_32000_MASK,
                                         SAD1_RATE_44100_MASK,
                                         SAD1_RATE_48000_MASK);
        case HDMI_AUDIO_CODING_TYPE_EAC3:
        case HDMI_AUDIO_CODING_TYPE_DTS_HD:
        case HDMI_AUDIO_CODING_TYPE_MLP:
                return map_rate_families(sad,
                                         0,
                                         SAD1_RATE_176400_MASK,
                                         SAD1_RATE_192000_MASK);
        default:
                /* TODO adjust for other compressed formats as well */
                return sad[1] & SAD1_RATE_MASK;
        }
}

static unsigned int sad_max_channels(const u8 *sad)
{
        switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
        case HDMI_AUDIO_CODING_TYPE_PCM:
                return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
        case HDMI_AUDIO_CODING_TYPE_AC3:
        case HDMI_AUDIO_CODING_TYPE_DTS:
        case HDMI_AUDIO_CODING_TYPE_EAC3:
                return 2;
        case HDMI_AUDIO_CODING_TYPE_DTS_HD:
        case HDMI_AUDIO_CODING_TYPE_MLP:
                return 8;
        default:
                /* TODO adjust for other compressed formats as well */
                return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
        }
}

static int eld_limit_rates(struct snd_pcm_hw_params *params,
                           struct snd_pcm_hw_rule *rule)
{
        struct snd_interval *r = hw_param_interval(params, rule->var);
        const struct snd_interval *c;
        unsigned int rate_mask = 7, i;
        const u8 *sad, *eld = rule->private;

        sad = drm_eld_sad(eld);
        if (sad) {
                c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);

                for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) {
                        unsigned max_channels = sad_max_channels(sad);

                        /*
                         * Exclude SADs which do not include the
                         * requested number of channels.
                         */
                        if (c->min <= max_channels)
                                rate_mask |= sad_rate_mask(sad);
                }
        }

        return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates,
                                 rate_mask);
}

static int eld_limit_channels(struct snd_pcm_hw_params *params,
                              struct snd_pcm_hw_rule *rule)
{
        struct snd_interval *c = hw_param_interval(params, rule->var);
        const struct snd_interval *r;
        struct snd_interval t = { .min = 1, .max = 2, .integer = 1, };
        unsigned int i;
        const u8 *sad, *eld = rule->private;

        sad = drm_eld_sad(eld);
        if (sad) {
                unsigned int rate_mask = 0;

                /* Convert the rate interval to a mask */
                r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
                for (i = 0; i < ARRAY_SIZE(eld_rates); i++)
                        if (r->min <= eld_rates[i] && r->max >= eld_rates[i])
                                rate_mask |= BIT(i);

                for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3)
                        if (rate_mask & sad_rate_mask(sad))
                                t.max = max(t.max, sad_max_channels(sad));
        }

        return snd_interval_refine(c, &t);
}

int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld)
{
        int ret;

        ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                  eld_limit_rates, eld,
                                  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
        if (ret < 0)
                return ret;

        ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
                                  eld_limit_channels, eld,
                                  SNDRV_PCM_HW_PARAM_RATE, -1);

        return ret;
}
EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);

#define SND_PRINT_RATES_ADVISED_BUFSIZE 80
#define SND_PRINT_BITS_ADVISED_BUFSIZE  16
#define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80

static const char * const eld_connection_type_names[4] = {
        "HDMI",
        "DisplayPort",
        "2-reserved",
        "3-reserved"
};

static const char * const cea_audio_coding_type_names[] = {
        /*  0 */ "undefined",
        /*  1 */ "LPCM",
        /*  2 */ "AC-3",
        /*  3 */ "MPEG1",
        /*  4 */ "MP3",
        /*  5 */ "MPEG2",
        /*  6 */ "AAC-LC",
        /*  7 */ "DTS",
        /*  8 */ "ATRAC",
        /*  9 */ "DSD (One Bit Audio)",
        /* 10 */ "E-AC-3/DD+ (Dolby Digital Plus)",
        /* 11 */ "DTS-HD",
        /* 12 */ "MLP (Dolby TrueHD)",
        /* 13 */ "DST",
        /* 14 */ "WMAPro",
        /* 15 */ "HE-AAC",
        /* 16 */ "HE-AACv2",
        /* 17 */ "MPEG Surround",
};

static const char * const cea_speaker_allocation_names[] = {
        /*  0 */ "FL/FR",
        /*  1 */ "LFE",
        /*  2 */ "FC",
        /*  3 */ "RL/RR",
        /*  4 */ "RC",
        /*  5 */ "FLC/FRC",
        /*  6 */ "RLC/RRC",
        /*  7 */ "FLW/FRW",
        /*  8 */ "FLH/FRH",
        /*  9 */ "TC",
        /* 10 */ "FCH",
};

/*
 * SS1:SS0 index => sample size
 */
static const int cea_sample_sizes[4] = {
        0,                      /* 0: Refer to Stream Header */
        ELD_PCM_BITS_16,        /* 1: 16 bits */
        ELD_PCM_BITS_20,        /* 2: 20 bits */
        ELD_PCM_BITS_24,        /* 3: 24 bits */
};

/*
 * SF2:SF1:SF0 index => sampling frequency
 */
static const int cea_sampling_frequencies[8] = {
        0,                      /* 0: Refer to Stream Header */
        SNDRV_PCM_RATE_32000,   /* 1:  32000Hz */
        SNDRV_PCM_RATE_44100,   /* 2:  44100Hz */
        SNDRV_PCM_RATE_48000,   /* 3:  48000Hz */
        SNDRV_PCM_RATE_88200,   /* 4:  88200Hz */
        SNDRV_PCM_RATE_96000,   /* 5:  96000Hz */
        SNDRV_PCM_RATE_176400,  /* 6: 176400Hz */
        SNDRV_PCM_RATE_192000,  /* 7: 192000Hz */
};

#define GRAB_BITS(buf, byte, lowbit, bits)              \
({                                                      \
        BUILD_BUG_ON(lowbit > 7);                       \
        BUILD_BUG_ON(bits > 8);                         \
        BUILD_BUG_ON(bits <= 0);                        \
                                                        \
        (buf[byte] >> (lowbit)) & ((1 << (bits)) - 1);  \
})

static void hdmi_update_short_audio_desc(struct device *dev,
                                         struct snd_cea_sad *a,
                                         const unsigned char *buf)
{
        int i;
        int val;

        val = GRAB_BITS(buf, 1, 0, 7);
        a->rates = 0;
        for (i = 0; i < 7; i++)
                if (val & (1 << i))
                        a->rates |= cea_sampling_frequencies[i + 1];

        a->channels = GRAB_BITS(buf, 0, 0, 3);
        a->channels++;

        a->sample_bits = 0;
        a->max_bitrate = 0;

        a->format = GRAB_BITS(buf, 0, 3, 4);
        switch (a->format) {
        case AUDIO_CODING_TYPE_REF_STREAM_HEADER:
                dev_info(dev, "HDMI: audio coding type 0 not expected\n");
                break;

        case AUDIO_CODING_TYPE_LPCM:
                val = GRAB_BITS(buf, 2, 0, 3);
                for (i = 0; i < 3; i++)
                        if (val & (1 << i))
                                a->sample_bits |= cea_sample_sizes[i + 1];
                break;

        case AUDIO_CODING_TYPE_AC3:
        case AUDIO_CODING_TYPE_MPEG1:
        case AUDIO_CODING_TYPE_MP3:
        case AUDIO_CODING_TYPE_MPEG2:
        case AUDIO_CODING_TYPE_AACLC:
        case AUDIO_CODING_TYPE_DTS:
        case AUDIO_CODING_TYPE_ATRAC:
                a->max_bitrate = GRAB_BITS(buf, 2, 0, 8);
                a->max_bitrate *= 8000;
                break;

        case AUDIO_CODING_TYPE_SACD:
                break;

        case AUDIO_CODING_TYPE_EAC3:
                break;

        case AUDIO_CODING_TYPE_DTS_HD:
                break;

        case AUDIO_CODING_TYPE_MLP:
                break;

        case AUDIO_CODING_TYPE_DST:
                break;

        case AUDIO_CODING_TYPE_WMAPRO:
                a->profile = GRAB_BITS(buf, 2, 0, 3);
                break;

        case AUDIO_CODING_TYPE_REF_CXT:
                a->format = GRAB_BITS(buf, 2, 3, 5);
                if (a->format == AUDIO_CODING_XTYPE_HE_REF_CT ||
                    a->format >= AUDIO_CODING_XTYPE_FIRST_RESERVED) {
                        dev_info(dev,
                                   "HDMI: audio coding xtype %d not expected\n",
                                   a->format);
                        a->format = 0;
                } else
                        a->format += AUDIO_CODING_TYPE_HE_AAC -
                                     AUDIO_CODING_XTYPE_HE_AAC;
                break;
        }
}

/*
 * Be careful, ELD buf could be totally rubbish!
 */
int snd_parse_eld(struct device *dev, struct snd_parsed_hdmi_eld *e,
                  const unsigned char *buf, int size)
{
        int mnl;
        int i;

        memset(e, 0, sizeof(*e));
        e->eld_ver = GRAB_BITS(buf, 0, 3, 5);
        if (e->eld_ver != ELD_VER_CEA_861D &&
            e->eld_ver != ELD_VER_PARTIAL) {
                dev_info(dev, "HDMI: Unknown ELD version %d\n", e->eld_ver);
                goto out_fail;
        }

        e->baseline_len = GRAB_BITS(buf, 2, 0, 8);
        mnl             = GRAB_BITS(buf, 4, 0, 5);
        e->cea_edid_ver = GRAB_BITS(buf, 4, 5, 3);

        e->support_hdcp = GRAB_BITS(buf, 5, 0, 1);
        e->support_ai   = GRAB_BITS(buf, 5, 1, 1);
        e->conn_type    = GRAB_BITS(buf, 5, 2, 2);
        e->sad_count    = GRAB_BITS(buf, 5, 4, 4);

        e->aud_synch_delay = GRAB_BITS(buf, 6, 0, 8) * 2;
        e->spk_alloc    = GRAB_BITS(buf, 7, 0, 7);

        e->port_id        = get_unaligned_le64(buf + 8);

        /* not specified, but the spec's tendency is little endian */
        e->manufacture_id = get_unaligned_le16(buf + 16);
        e->product_id     = get_unaligned_le16(buf + 18);

        if (mnl > ELD_MAX_MNL) {
                dev_info(dev, "HDMI: MNL is reserved value %d\n", mnl);
                goto out_fail;
        } else if (ELD_FIXED_BYTES + mnl > size) {
                dev_info(dev, "HDMI: out of range MNL %d\n", mnl);
                goto out_fail;
        } else
                strscpy(e->monitor_name, buf + ELD_FIXED_BYTES, mnl + 1);

        for (i = 0; i < e->sad_count; i++) {
                if (ELD_FIXED_BYTES + mnl + 3 * (i + 1) > size) {
                        dev_info(dev, "HDMI: out of range SAD %d\n", i);
                        goto out_fail;
                }
                hdmi_update_short_audio_desc(dev, e->sad + i,
                                             buf + ELD_FIXED_BYTES + mnl + 3 * i);
        }

        /*
         * HDMI sink's ELD info cannot always be retrieved for now, e.g.
         * in console or for audio devices. Assume the highest speakers
         * configuration, to _not_ prohibit multi-channel audio playback.
         */
        if (!e->spk_alloc && e->sad_count)
                e->spk_alloc = 0xffff;

        return 0;

out_fail:
        return -EINVAL;
}
EXPORT_SYMBOL_GPL(snd_parse_eld);

/*
 * SNDRV_PCM_RATE_* and AC_PAR_PCM values don't match, print correct rates with
 * hdmi-specific routine.
 */
static void hdmi_print_pcm_rates(int pcm, char *buf, int buflen)
{
        static const unsigned int alsa_rates[] = {
                5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
                88200, 96000, 176400, 192000, 384000
        };
        int i, j;

        for (i = 0, j = 0; i < ARRAY_SIZE(alsa_rates); i++)
                if (pcm & (1 << i))
                        j += scnprintf(buf + j, buflen - j,  " %d",
                                alsa_rates[i]);

        buf[j] = '\0'; /* necessary when j == 0 */
}

static void eld_print_pcm_bits(int pcm, char *buf, int buflen)
{
        static const unsigned int bits[] = { 8, 16, 20, 24, 32 };
        int i, j;

        for (i = 0, j = 0; i < ARRAY_SIZE(bits); i++)
                if (pcm & (ELD_PCM_BITS_8 << i))
                        j += scnprintf(buf + j, buflen - j,  " %d", bits[i]);

        buf[j] = '\0'; /* necessary when j == 0 */
}

static void hdmi_show_short_audio_desc(struct device *dev,
                                       struct snd_cea_sad *a)
{
        char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
        char buf2[8 + SND_PRINT_BITS_ADVISED_BUFSIZE] = ", bits =";

        if (!a->format)
                return;

        hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));

        if (a->format == AUDIO_CODING_TYPE_LPCM)
                eld_print_pcm_bits(a->sample_bits, buf2 + 8, sizeof(buf2) - 8);
        else if (a->max_bitrate)
                snprintf(buf2, sizeof(buf2),
                                ", max bitrate = %d", a->max_bitrate);
        else
                buf2[0] = '\0';

        dev_dbg(dev,
                "HDMI: supports coding type %s: channels = %d, rates =%s%s\n",
                cea_audio_coding_type_names[a->format],
                a->channels, buf, buf2);
}

static void snd_eld_print_channel_allocation(int spk_alloc, char *buf, int buflen)
{
        int i, j;

        for (i = 0, j = 0; i < ARRAY_SIZE(cea_speaker_allocation_names); i++) {
                if (spk_alloc & (1 << i))
                        j += scnprintf(buf + j, buflen - j,  " %s",
                                        cea_speaker_allocation_names[i]);
        }
        buf[j] = '\0';  /* necessary when j == 0 */
}

void snd_show_eld(struct device *dev, struct snd_parsed_hdmi_eld *e)
{
        int i;

        dev_dbg(dev, "HDMI: detected monitor %s at connection type %s\n",
                e->monitor_name,
                eld_connection_type_names[e->conn_type]);

        if (e->spk_alloc) {
                char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];

                snd_eld_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
                dev_dbg(dev, "HDMI: available speakers:%s\n", buf);
        }

        for (i = 0; i < e->sad_count; i++)
                hdmi_show_short_audio_desc(dev, e->sad + i);
}
EXPORT_SYMBOL_GPL(snd_show_eld);

#ifdef CONFIG_SND_PROC_FS
static void hdmi_print_sad_info(int i, struct snd_cea_sad *a,
                                struct snd_info_buffer *buffer)
{
        char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];

        snd_iprintf(buffer, "sad%d_coding_type\t[0x%x] %s\n",
                        i, a->format, cea_audio_coding_type_names[a->format]);
        snd_iprintf(buffer, "sad%d_channels\t\t%d\n", i, a->channels);

        hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
        snd_iprintf(buffer, "sad%d_rates\t\t[0x%x]%s\n", i, a->rates, buf);

        if (a->format == AUDIO_CODING_TYPE_LPCM) {
                eld_print_pcm_bits(a->sample_bits, buf, sizeof(buf));
                snd_iprintf(buffer, "sad%d_bits\t\t[0x%x]%s\n",
                                                        i, a->sample_bits, buf);
        }

        if (a->max_bitrate)
                snd_iprintf(buffer, "sad%d_max_bitrate\t%d\n",
                                                        i, a->max_bitrate);

        if (a->profile)
                snd_iprintf(buffer, "sad%d_profile\t\t%d\n", i, a->profile);
}

void snd_print_eld_info(struct snd_parsed_hdmi_eld *e,
                        struct snd_info_buffer *buffer)
{
        char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
        int i;
        static const char * const eld_version_names[32] = {
                "reserved",
                "reserved",
                "CEA-861D or below",
                [3 ... 30] = "reserved",
                [31] = "partial"
        };
        static const char * const cea_edid_version_names[8] = {
                "no CEA EDID Timing Extension block present",
                "CEA-861",
                "CEA-861-A",
                "CEA-861-B, C or D",
                [4 ... 7] = "reserved"
        };

        snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
        snd_iprintf(buffer, "connection_type\t\t%s\n",
                                eld_connection_type_names[e->conn_type]);
        snd_iprintf(buffer, "eld_version\t\t[0x%x] %s\n", e->eld_ver,
                                        eld_version_names[e->eld_ver]);
        snd_iprintf(buffer, "edid_version\t\t[0x%x] %s\n", e->cea_edid_ver,
                                cea_edid_version_names[e->cea_edid_ver]);
        snd_iprintf(buffer, "manufacture_id\t\t0x%x\n", e->manufacture_id);
        snd_iprintf(buffer, "product_id\t\t0x%x\n", e->product_id);
        snd_iprintf(buffer, "port_id\t\t\t0x%llx\n", (long long)e->port_id);
        snd_iprintf(buffer, "support_hdcp\t\t%d\n", e->support_hdcp);
        snd_iprintf(buffer, "support_ai\t\t%d\n", e->support_ai);
        snd_iprintf(buffer, "audio_sync_delay\t%d\n", e->aud_synch_delay);

        snd_eld_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
        snd_iprintf(buffer, "speakers\t\t[0x%x]%s\n", e->spk_alloc, buf);

        snd_iprintf(buffer, "sad_count\t\t%d\n", e->sad_count);

        for (i = 0; i < e->sad_count; i++)
                hdmi_print_sad_info(i, e->sad + i, buffer);
}
EXPORT_SYMBOL_GPL(snd_print_eld_info);
#endif /* CONFIG_SND_PROC_FS */