target/linux/bcm27xx/patches-5.4/950-0920-vc4-Report-channel-mapping-back-to-userspace.patch

   1 From 058328afcdd3d5c9531cfac8b980d0c0db75856f Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Mon, 20 Apr 2020 18:00:38 +0100
   4 Subject: [PATCH] vc4: Report channel mapping back to userspace
   5
   6 This follows logic in hdmi-codec.c to use speaker layout
   7 from ELD to choose a suitable speaker mapping based on
   8 number of channels requested and signal that in audio
   9 infoframe  and report this back to userspace.
  10
  11 This allows apps like speaker-test and kodi to get the
  12 output to the right speakers.
  13
  14 Signed-off-by: Dom Cobley <popcornmix@gmail.com>
  15 ---
  16  drivers/gpu/drm/vc4/vc4_hdmi.c | 415 +++++++++++++++++++++++++++++++++
  17  drivers/gpu/drm/vc4/vc4_hdmi.h |   3 +
  18  2 files changed, 418 insertions(+)
  19
  20 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  21 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  22 @@ -48,6 +48,7 @@
  23  #include <sound/pcm_drm_eld.h>
  24  #include <sound/pcm_params.h>
  25  #include <sound/soc.h>
  26 +#include <sound/tlv.h>
  27  #include "media/cec.h"
  28  #include "vc4_drv.h"
  29  #include "vc4_hdmi.h"
  30 @@ -82,6 +83,311 @@
  31  #define CEC_CLOCK_FREQ 40000
  32  #define VC4_HSM_CLOCK 163682864
  33
  34 +#define HDMI_CODEC_CHMAP_IDX_UNKNOWN  -1
  35 +
  36 +/*
  37 + * CEA speaker placement for HDMI 1.4:
  38 + *
  39 + *  FL  FLC   FC   FRC   FR   FRW
  40 + *
  41 + *                                  LFE
  42 + *
  43 + *  RL  RLC   RC   RRC   RR
  44 + *
  45 + *  Speaker placement has to be extended to support HDMI 2.0
  46 + */
  47 +enum hdmi_codec_cea_spk_placement {
  48 +       FL  = BIT(0),   /* Front Left           */
  49 +       FC  = BIT(1),   /* Front Center         */
  50 +       FR  = BIT(2),   /* Front Right          */
  51 +       FLC = BIT(3),   /* Front Left Center    */
  52 +       FRC = BIT(4),   /* Front Right Center   */
  53 +       RL  = BIT(5),   /* Rear Left            */
  54 +       RC  = BIT(6),   /* Rear Center          */
  55 +       RR  = BIT(7),   /* Rear Right           */
  56 +       RLC = BIT(8),   /* Rear Left Center     */
  57 +       RRC = BIT(9),   /* Rear Right Center    */
  58 +       LFE = BIT(10),  /* Low Frequency Effect */
  59 +};
  60 +
  61 +/*
  62 + * cea Speaker allocation structure
  63 + */
  64 +struct hdmi_codec_cea_spk_alloc {
  65 +       const int ca_id;
  66 +       unsigned int n_ch;
  67 +       unsigned long mask;
  68 +};
  69 +
  70 +/* Channel maps  stereo HDMI */
  71 +static const struct snd_pcm_chmap_elem hdmi_codec_stereo_chmaps[] = {
  72 +       { .channels = 2,
  73 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
  74 +       { }
  75 +};
  76 +
  77 +/* Channel maps for multi-channel playbacks, up to 8 n_ch */
  78 +static const struct snd_pcm_chmap_elem hdmi_codec_8ch_chmaps[] = {
  79 +       { .channels = 2, /* CA_ID 0x00 */
  80 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
  81 +       { .channels = 4, /* CA_ID 0x01 */
  82 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
  83 +                  SNDRV_CHMAP_NA } },
  84 +       { .channels = 4, /* CA_ID 0x02 */
  85 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
  86 +                  SNDRV_CHMAP_FC } },
  87 +       { .channels = 4, /* CA_ID 0x03 */
  88 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
  89 +                  SNDRV_CHMAP_FC } },
  90 +       { .channels = 6, /* CA_ID 0x04 */
  91 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
  92 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
  93 +       { .channels = 6, /* CA_ID 0x05 */
  94 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
  95 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
  96 +       { .channels = 6, /* CA_ID 0x06 */
  97 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
  98 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
  99 +       { .channels = 6, /* CA_ID 0x07 */
 100 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 101 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
 102 +       { .channels = 6, /* CA_ID 0x08 */
 103 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 104 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
 105 +       { .channels = 6, /* CA_ID 0x09 */
 106 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 107 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
 108 +       { .channels = 6, /* CA_ID 0x0A */
 109 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 110 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
 111 +       { .channels = 6, /* CA_ID 0x0B */
 112 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 113 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
 114 +       { .channels = 8, /* CA_ID 0x0C */
 115 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 116 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 117 +                  SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
 118 +       { .channels = 8, /* CA_ID 0x0D */
 119 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 120 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 121 +                  SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
 122 +       { .channels = 8, /* CA_ID 0x0E */
 123 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 124 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 125 +                  SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
 126 +       { .channels = 8, /* CA_ID 0x0F */
 127 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 128 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 129 +                  SNDRV_CHMAP_RC, SNDRV_CHMAP_NA } },
 130 +       { .channels = 8, /* CA_ID 0x10 */
 131 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 132 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 133 +                  SNDRV_CHMAP_RLC, SNDRV_CHMAP_RRC } },
 134 +       { .channels = 8, /* CA_ID 0x11 */
 135 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 136 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 137 +                  SNDRV_CHMAP_RLC, SNDRV_CHMAP_RRC } },
 138 +       { .channels = 8, /* CA_ID 0x12 */
 139 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 140 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 141 +                  SNDRV_CHMAP_RLC, SNDRV_CHMAP_RRC } },
 142 +       { .channels = 8, /* CA_ID 0x13 */
 143 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 144 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
 145 +                  SNDRV_CHMAP_RLC, SNDRV_CHMAP_RRC } },
 146 +       { .channels = 8, /* CA_ID 0x14 */
 147 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 148 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 149 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 150 +       { .channels = 8, /* CA_ID 0x15 */
 151 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 152 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 153 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 154 +       { .channels = 8, /* CA_ID 0x16 */
 155 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 156 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 157 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 158 +       { .channels = 8, /* CA_ID 0x17 */
 159 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 160 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 161 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 162 +       { .channels = 8, /* CA_ID 0x18 */
 163 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 164 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 165 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 166 +       { .channels = 8, /* CA_ID 0x19 */
 167 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 168 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 169 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 170 +       { .channels = 8, /* CA_ID 0x1A */
 171 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 172 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 173 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 174 +       { .channels = 8, /* CA_ID 0x1B */
 175 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 176 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 177 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 178 +       { .channels = 8, /* CA_ID 0x1C */
 179 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 180 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 181 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 182 +       { .channels = 8, /* CA_ID 0x1D */
 183 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 184 +                  SNDRV_CHMAP_NA, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 185 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 186 +       { .channels = 8, /* CA_ID 0x1E */
 187 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_NA,
 188 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 189 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 190 +       { .channels = 8, /* CA_ID 0x1F */
 191 +         .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_LFE,
 192 +                  SNDRV_CHMAP_FC, SNDRV_CHMAP_NA, SNDRV_CHMAP_NA,
 193 +                  SNDRV_CHMAP_FLC, SNDRV_CHMAP_FRC } },
 194 +       { }
 195 +};
 196 +
 197 +/*
 198 + * hdmi_codec_channel_alloc: speaker configuration available for CEA
 199 + *
 200 + * This is an ordered list that must match with hdmi_codec_8ch_chmaps struct
 201 + * The preceding ones have better chances to be selected by
 202 + * hdmi_codec_get_ch_alloc_table_idx().
 203 + */
 204 +static const struct hdmi_codec_cea_spk_alloc hdmi_codec_channel_alloc[] = {
 205 +       { .ca_id = 0x00, .n_ch = 2,
 206 +         .mask = FL | FR},
 207 +       /* 2.1 */
 208 +       { .ca_id = 0x01, .n_ch = 4,
 209 +         .mask = FL | FR | LFE},
 210 +       /* Dolby Surround */
 211 +       { .ca_id = 0x02, .n_ch = 4,
 212 +         .mask = FL | FR | FC },
 213 +       /* surround51 */
 214 +       { .ca_id = 0x0b, .n_ch = 6,
 215 +         .mask = FL | FR | LFE | FC | RL | RR},
 216 +       /* surround40 */
 217 +       { .ca_id = 0x08, .n_ch = 6,
 218 +         .mask = FL | FR | RL | RR },
 219 +       /* surround41 */
 220 +       { .ca_id = 0x09, .n_ch = 6,
 221 +         .mask = FL | FR | LFE | RL | RR },
 222 +       /* surround50 */
 223 +       { .ca_id = 0x0a, .n_ch = 6,
 224 +         .mask = FL | FR | FC | RL | RR },
 225 +       /* 6.1 */
 226 +       { .ca_id = 0x0f, .n_ch = 8,
 227 +         .mask = FL | FR | LFE | FC | RL | RR | RC },
 228 +       /* surround71 */
 229 +       { .ca_id = 0x13, .n_ch = 8,
 230 +         .mask = FL | FR | LFE | FC | RL | RR | RLC | RRC },
 231 +       /* others */
 232 +       { .ca_id = 0x03, .n_ch = 8,
 233 +         .mask = FL | FR | LFE | FC },
 234 +       { .ca_id = 0x04, .n_ch = 8,
 235 +         .mask = FL | FR | RC},
 236 +       { .ca_id = 0x05, .n_ch = 8,
 237 +         .mask = FL | FR | LFE | RC },
 238 +       { .ca_id = 0x06, .n_ch = 8,
 239 +         .mask = FL | FR | FC | RC },
 240 +       { .ca_id = 0x07, .n_ch = 8,
 241 +         .mask = FL | FR | LFE | FC | RC },
 242 +       { .ca_id = 0x0c, .n_ch = 8,
 243 +         .mask = FL | FR | RC | RL | RR },
 244 +       { .ca_id = 0x0d, .n_ch = 8,
 245 +         .mask = FL | FR | LFE | RL | RR | RC },
 246 +       { .ca_id = 0x0e, .n_ch = 8,
 247 +         .mask = FL | FR | FC | RL | RR | RC },
 248 +       { .ca_id = 0x10, .n_ch = 8,
 249 +         .mask = FL | FR | RL | RR | RLC | RRC },
 250 +       { .ca_id = 0x11, .n_ch = 8,
 251 +         .mask = FL | FR | LFE | RL | RR | RLC | RRC },
 252 +       { .ca_id = 0x12, .n_ch = 8,
 253 +         .mask = FL | FR | FC | RL | RR | RLC | RRC },
 254 +       { .ca_id = 0x14, .n_ch = 8,
 255 +         .mask = FL | FR | FLC | FRC },
 256 +       { .ca_id = 0x15, .n_ch = 8,
 257 +         .mask = FL | FR | LFE | FLC | FRC },
 258 +       { .ca_id = 0x16, .n_ch = 8,
 259 +         .mask = FL | FR | FC | FLC | FRC },
 260 +       { .ca_id = 0x17, .n_ch = 8,
 261 +         .mask = FL | FR | LFE | FC | FLC | FRC },
 262 +       { .ca_id = 0x18, .n_ch = 8,
 263 +         .mask = FL | FR | RC | FLC | FRC },
 264 +       { .ca_id = 0x19, .n_ch = 8,
 265 +         .mask = FL | FR | LFE | RC | FLC | FRC },
 266 +       { .ca_id = 0x1a, .n_ch = 8,
 267 +         .mask = FL | FR | RC | FC | FLC | FRC },
 268 +       { .ca_id = 0x1b, .n_ch = 8,
 269 +         .mask = FL | FR | LFE | RC | FC | FLC | FRC },
 270 +       { .ca_id = 0x1c, .n_ch = 8,
 271 +         .mask = FL | FR | RL | RR | FLC | FRC },
 272 +       { .ca_id = 0x1d, .n_ch = 8,
 273 +         .mask = FL | FR | LFE | RL | RR | FLC | FRC },
 274 +       { .ca_id = 0x1e, .n_ch = 8,
 275 +         .mask = FL | FR | FC | RL | RR | FLC | FRC },
 276 +       { .ca_id = 0x1f, .n_ch = 8,
 277 +         .mask = FL | FR | LFE | FC | RL | RR | FLC | FRC },
 278 +};
 279 +
 280 +static unsigned long hdmi_codec_spk_mask_from_alloc(int spk_alloc)
 281 +{
 282 +       int i;
 283 +       static const unsigned long hdmi_codec_eld_spk_alloc_bits[] = {
 284 +               [0] = FL | FR, [1] = LFE, [2] = FC, [3] = RL | RR,
 285 +               [4] = RC, [5] = FLC | FRC, [6] = RLC | RRC,
 286 +       };
 287 +       unsigned long spk_mask = 0;
 288 +
 289 +       for (i = 0; i < ARRAY_SIZE(hdmi_codec_eld_spk_alloc_bits); i++) {
 290 +               if (spk_alloc & (1 << i))
 291 +                       spk_mask |= hdmi_codec_eld_spk_alloc_bits[i];
 292 +       }
 293 +
 294 +       return spk_mask;
 295 +}
 296 +
 297 +static int hdmi_codec_get_ch_alloc_table_idx(struct vc4_hdmi *vc4_hdmi,
 298 +                                            unsigned char channels)
 299 +{
 300 +       struct drm_connector *connector = &vc4_hdmi->connector;
 301 +       int i;
 302 +       u8 spk_alloc;
 303 +       unsigned long spk_mask;
 304 +       const struct hdmi_codec_cea_spk_alloc *cap = hdmi_codec_channel_alloc;
 305 +
 306 +       spk_alloc = drm_eld_get_spk_alloc(connector->eld);
 307 +       spk_mask = hdmi_codec_spk_mask_from_alloc(spk_alloc);
 308 +
 309 +       for (i = 0; i < ARRAY_SIZE(hdmi_codec_channel_alloc); i++, cap++) {
 310 +               /* If spk_alloc == 0, HDMI is unplugged return stereo config*/
 311 +               if (!spk_alloc && cap->ca_id == 0)
 312 +                       return i;
 313 +               if (cap->n_ch != channels)
 314 +                       continue;
 315 +               if (!(cap->mask == (spk_mask & cap->mask)))
 316 +                       continue;
 317 +               return i;
 318 +       }
 319 +
 320 +       return -EINVAL;
 321 +}
 322 +
 323 +static void hdmi_codec_eld_chmap(struct vc4_hdmi *vc4_hdmi)
 324 +{
 325 +       struct drm_connector *connector = &vc4_hdmi->connector;
 326 +       u8 spk_alloc;
 327 +       unsigned long spk_mask;
 328 +
 329 +       spk_alloc = drm_eld_get_spk_alloc(connector->eld);
 330 +       spk_mask = hdmi_codec_spk_mask_from_alloc(spk_alloc);
 331 +
 332 +       /* Detect if only stereo supported, else return 8 channels mappings */
 333 +       if ((spk_mask & ~(FL | FR)))
 334 +               vc4_hdmi->audio.chmap = hdmi_codec_8ch_chmaps;
 335 +       else
 336 +               vc4_hdmi->audio.chmap = hdmi_codec_stereo_chmaps;
 337 +}
 338 +
 339  static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused)
 340  {
 341         struct drm_info_node *node = (struct drm_info_node *)m->private;
 342 @@ -350,6 +656,9 @@ static void vc4_hdmi_set_audio_infoframe
 343         frame.audio.sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
 344         frame.audio.channels = vc4_hdmi->audio.channels;
 345
 346 +       /* Select a channel allocation that matches with ELD and pcm channels */
 347 +       frame.audio.channel_allocation = vc4_hdmi->audio.chmap_idx;
 348 +
 349         vc4_hdmi_write_infoframe(encoder, &frame);
 350  }
 351
 352 @@ -881,6 +1190,10 @@ static int vc4_hdmi_audio_startup(struct
 353         if (ret)
 354                 return ret;
 355
 356 +       /* Select chmap supported */
 357 +       vc4_hdmi->audio.max_channels = 8;
 358 +       hdmi_codec_eld_chmap(vc4_hdmi);
 359 +
 360         return 0;
 361  }
 362
 363 @@ -967,6 +1280,7 @@ static int vc4_hdmi_audio_prepare(struct
 364         u32 channel_map;
 365         u32 mai_audio_format;
 366         u32 mai_sample_rate;
 367 +       int idx;
 368
 369         if (substream != vc4_hdmi->audio.substream)
 370                 return -EINVAL;
 371 @@ -1027,6 +1341,14 @@ static int vc4_hdmi_audio_prepare(struct
 372         HDMI_WRITE(HDMI_AUDIO_PACKET_CONFIG, audio_packet_config);
 373         vc4_hdmi_set_n_cts(vc4_hdmi);
 374
 375 +       idx = hdmi_codec_get_ch_alloc_table_idx(vc4_hdmi, vc4_hdmi->audio.channels);
 376 +       if (idx < 0) {
 377 +               DRM_ERROR("Not able to map channels to speakers (%d)\n", idx);
 378 +               vc4_hdmi->audio.chmap_idx = HDMI_CODEC_CHMAP_IDX_UNKNOWN;
 379 +       } else {
 380 +               vc4_hdmi->audio.chmap_idx = hdmi_codec_channel_alloc[idx].ca_id;
 381 +       }
 382 +
 383         return 0;
 384  }
 385
 386 @@ -1145,6 +1467,89 @@ static int vc4_spdif_mask_get(struct snd
 387         return 0;
 388  }
 389
 390 +/*
 391 + * ALSA API channel-map control callbacks
 392 + */
 393 +static int vc4_chmap_ctl_info(struct snd_kcontrol *kcontrol,
 394 +                               struct snd_ctl_elem_info *uinfo)
 395 +{
 396 +       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
 397 +       struct vc4_hdmi *vc4_hdmi = snd_component_to_hdmi(component);
 398 +
 399 +       uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 400 +       uinfo->count = vc4_hdmi->audio.max_channels;
 401 +       uinfo->value.integer.min = 0;
 402 +       uinfo->value.integer.max = SNDRV_CHMAP_LAST;
 403 +
 404 +       return 0;
 405 +}
 406 +
 407 +static int vc4_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 408 +                            struct snd_ctl_elem_value *ucontrol)
 409 +{
 410 +       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
 411 +       struct vc4_hdmi *vc4_hdmi = snd_component_to_hdmi(component);
 412 +       unsigned const char *map;
 413 +       unsigned int i;
 414 +
 415 +       if (!vc4_hdmi->audio.chmap)
 416 +               return -EINVAL;
 417 +
 418 +       map = vc4_hdmi->audio.chmap[vc4_hdmi->audio.chmap_idx].map;
 419 +
 420 +       for (i = 0; i < vc4_hdmi->audio.max_channels; i++) {
 421 +               if (vc4_hdmi->audio.chmap_idx == HDMI_CODEC_CHMAP_IDX_UNKNOWN)
 422 +                       ucontrol->value.integer.value[i] = 0;
 423 +               else
 424 +                       ucontrol->value.integer.value[i] = map[i];
 425 +       }
 426 +       return 0;
 427 +}
 428 +
 429 +static int vc4_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 430 +                            unsigned int size, unsigned int __user *tlv)
 431 +{
 432 +       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
 433 +       struct vc4_hdmi *vc4_hdmi = snd_component_to_hdmi(component);
 434 +       const struct snd_pcm_chmap_elem *map;
 435 +       unsigned int __user *dst;
 436 +       int c, count = 0;
 437 +
 438 +       if (!vc4_hdmi->audio.chmap)
 439 +               return -EINVAL;
 440 +       if (size < 8)
 441 +               return -ENOMEM;
 442 +       if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
 443 +               return -EFAULT;
 444 +       size -= 8;
 445 +       dst = tlv + 2;
 446 +       for (map = vc4_hdmi->audio.chmap; map->channels; map++) {
 447 +               int chs_bytes = map->channels * 4;
 448 +               //if (!valid_chmap_channels(info, map->channels))
 449 +               //      continue;
 450 +               if (size < 8)
 451 +                       return -ENOMEM;
 452 +               if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
 453 +                   put_user(chs_bytes, dst + 1))
 454 +                       return -EFAULT;
 455 +               dst += 2;
 456 +               size -= 8;
 457 +               count += 8;
 458 +               if (size < chs_bytes)
 459 +                       return -ENOMEM;
 460 +               size -= chs_bytes;
 461 +               count += chs_bytes;
 462 +               for (c = 0; c < map->channels; c++) {
 463 +                       if (put_user(map->map[c], dst))
 464 +                               return -EFAULT;
 465 +                       dst++;
 466 +               }
 467 +       }
 468 +       if (put_user(count, tlv + 1))
 469 +               return -EFAULT;
 470 +       return 0;
 471 +}
 472 +
 473  static const struct snd_kcontrol_new vc4_hdmi_audio_controls[] = {
 474         {
 475                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
 476 @@ -1167,6 +1572,16 @@ static const struct snd_kcontrol_new vc4
 477                 .info =    vc4_spdif_info,
 478                 .get =     vc4_spdif_mask_get,
 479         },
 480 +       {
 481 +               .access = SNDRV_CTL_ELEM_ACCESS_READ |
 482 +                       SNDRV_CTL_ELEM_ACCESS_TLV_READ |
 483 +                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
 484 +               .iface = SNDRV_CTL_ELEM_IFACE_PCM,
 485 +               .name = "Playback Channel Map",
 486 +               .info = vc4_chmap_ctl_info,
 487 +               .get = vc4_chmap_ctl_get,
 488 +               .tlv.c = vc4_chmap_ctl_tlv,
 489 +       },
 490  };
 491
 492  static const struct snd_soc_dapm_widget vc4_hdmi_audio_widgets[] = {
 493 --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
 494 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
 495 @@ -117,6 +117,9 @@ struct vc4_hdmi_audio {
 496         bool streaming;
 497
 498         unsigned char iec_status[4];
 499 +       const struct snd_pcm_chmap_elem *chmap;
 500 +       unsigned int chmap_idx;
 501 +       unsigned int max_channels;
 502  };
 503
 504  /* General HDMI hardware state. */