drivers/video/hdmi.c

   1 /*
   2  * Copyright (C) 2012 Avionic Design GmbH
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include <linux/bitops.h>
  25 #include <linux/errno.h>
  26 #include <linux/export.h>
  27 #include <linux/hdmi.h>
  28 #include <linux/string.h>
  29
  30 static void hdmi_infoframe_checksum(void *buffer, size_t size)
  31 {
  32         u8 *ptr = buffer;
  33         u8 csum = 0;
  34         size_t i;
  35
  36         /* compute checksum */
  37         for (i = 0; i < size; i++)
  38                 csum += ptr[i];
  39
  40         ptr[3] = 256 - csum;
  41 }
  42
  43 /**
  44  * hdmi_avi_infoframe_init() - initialize an HDMI AVI infoframe
  45  * @frame: HDMI AVI infoframe
  46  *
  47  * Returns 0 on success or a negative error code on failure.
  48  */
  49 int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
  50 {
  51         memset(frame, 0, sizeof(*frame));
  52
  53         frame->type = HDMI_INFOFRAME_TYPE_AVI;
  54         frame->version = 2;
  55         frame->length = 13;
  56
  57         return 0;
  58 }
  59 EXPORT_SYMBOL(hdmi_avi_infoframe_init);
  60
  61 /**
  62  * hdmi_avi_infoframe_pack() - write HDMI AVI infoframe to binary buffer
  63  * @frame: HDMI AVI infoframe
  64  * @buffer: destination buffer
  65  * @size: size of buffer
  66  *
  67  * Packs the information contained in the @frame structure into a binary
  68  * representation that can be written into the corresponding controller
  69  * registers. Also computes the checksum as required by section 5.3.5 of
  70  * the HDMI 1.4 specification.
  71  *
  72  * Returns the number of bytes packed into the binary buffer or a negative
  73  * error code on failure.
  74  */
  75 ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
  76                                 size_t size)
  77 {
  78         u8 *ptr = buffer;
  79         size_t length;
  80
  81         length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
  82
  83         if (size < length)
  84                 return -ENOSPC;
  85
  86         memset(buffer, 0, length);
  87
  88         ptr[0] = frame->type;
  89         ptr[1] = frame->version;
  90         ptr[2] = frame->length;
  91         ptr[3] = 0; /* checksum */
  92
  93         /* start infoframe payload */
  94         ptr += HDMI_INFOFRAME_HEADER_SIZE;
  95
  96         ptr[0] = ((frame->colorspace & 0x3) << 5) | (frame->scan_mode & 0x3);
  97
  98         if (frame->active_info_valid)
  99                 ptr[0] |= BIT(4);
 100
 101         if (frame->horizontal_bar_valid)
 102                 ptr[0] |= BIT(3);
 103
 104         if (frame->vertical_bar_valid)
 105                 ptr[0] |= BIT(2);
 106
 107         ptr[1] = ((frame->colorimetry & 0x3) << 6) |
 108                  ((frame->picture_aspect & 0x3) << 4) |
 109                  (frame->active_aspect & 0xf);
 110
 111         ptr[2] = ((frame->extended_colorimetry & 0x7) << 4) |
 112                  ((frame->quantization_range & 0x3) << 2) |
 113                  (frame->nups & 0x3);
 114
 115         if (frame->itc)
 116                 ptr[2] |= BIT(7);
 117
 118         ptr[3] = frame->video_code & 0x7f;
 119
 120         ptr[4] = ((frame->ycc_quantization_range & 0x3) << 6) |
 121                  ((frame->content_type & 0x3) << 4) |
 122                  (frame->pixel_repeat & 0xf);
 123
 124         ptr[5] = frame->top_bar & 0xff;
 125         ptr[6] = (frame->top_bar >> 8) & 0xff;
 126         ptr[7] = frame->bottom_bar & 0xff;
 127         ptr[8] = (frame->bottom_bar >> 8) & 0xff;
 128         ptr[9] = frame->left_bar & 0xff;
 129         ptr[10] = (frame->left_bar >> 8) & 0xff;
 130         ptr[11] = frame->right_bar & 0xff;
 131         ptr[12] = (frame->right_bar >> 8) & 0xff;
 132
 133         hdmi_infoframe_checksum(buffer, length);
 134
 135         return length;
 136 }
 137 EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
 138
 139 /**
 140  * hdmi_spd_infoframe_init() - initialize an HDMI SPD infoframe
 141  * @frame: HDMI SPD infoframe
 142  * @vendor: vendor string
 143  * @product: product string
 144  *
 145  * Returns 0 on success or a negative error code on failure.
 146  */
 147 int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
 148                             const char *vendor, const char *product)
 149 {
 150         memset(frame, 0, sizeof(*frame));
 151
 152         frame->type = HDMI_INFOFRAME_TYPE_SPD;
 153         frame->version = 1;
 154         frame->length = 25;
 155
 156         strncpy(frame->vendor, vendor, sizeof(frame->vendor));
 157         strncpy(frame->product, product, sizeof(frame->product));
 158
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(hdmi_spd_infoframe_init);
 162
 163 /**
 164  * hdmi_spd_infoframe_pack() - write HDMI SPD infoframe to binary buffer
 165  * @frame: HDMI SPD infoframe
 166  * @buffer: destination buffer
 167  * @size: size of buffer
 168  *
 169  * Packs the information contained in the @frame structure into a binary
 170  * representation that can be written into the corresponding controller
 171  * registers. Also computes the checksum as required by section 5.3.5 of
 172  * the HDMI 1.4 specification.
 173  *
 174  * Returns the number of bytes packed into the binary buffer or a negative
 175  * error code on failure.
 176  */
 177 ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
 178                                 size_t size)
 179 {
 180         u8 *ptr = buffer;
 181         size_t length;
 182
 183         length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 184
 185         if (size < length)
 186                 return -ENOSPC;
 187
 188         memset(buffer, 0, length);
 189
 190         ptr[0] = frame->type;
 191         ptr[1] = frame->version;
 192         ptr[2] = frame->length;
 193         ptr[3] = 0; /* checksum */
 194
 195         /* start infoframe payload */
 196         ptr += HDMI_INFOFRAME_HEADER_SIZE;
 197
 198         memcpy(ptr, frame->vendor, sizeof(frame->vendor));
 199         memcpy(ptr + 8, frame->product, sizeof(frame->product));
 200
 201         ptr[24] = frame->sdi;
 202
 203         hdmi_infoframe_checksum(buffer, length);
 204
 205         return length;
 206 }
 207 EXPORT_SYMBOL(hdmi_spd_infoframe_pack);
 208
 209 /**
 210  * hdmi_audio_infoframe_init() - initialize an HDMI audio infoframe
 211  * @frame: HDMI audio infoframe
 212  *
 213  * Returns 0 on success or a negative error code on failure.
 214  */
 215 int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
 216 {
 217         memset(frame, 0, sizeof(*frame));
 218
 219         frame->type = HDMI_INFOFRAME_TYPE_AUDIO;
 220         frame->version = 1;
 221         frame->length = 10;
 222
 223         return 0;
 224 }
 225 EXPORT_SYMBOL(hdmi_audio_infoframe_init);
 226
 227 /**
 228  * hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
 229  * @frame: HDMI audio infoframe
 230  * @buffer: destination buffer
 231  * @size: size of buffer
 232  *
 233  * Packs the information contained in the @frame structure into a binary
 234  * representation that can be written into the corresponding controller
 235  * registers. Also computes the checksum as required by section 5.3.5 of
 236  * the HDMI 1.4 specification.
 237  *
 238  * Returns the number of bytes packed into the binary buffer or a negative
 239  * error code on failure.
 240  */
 241 ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
 242                                   void *buffer, size_t size)
 243 {
 244         unsigned char channels;
 245         u8 *ptr = buffer;
 246         size_t length;
 247
 248         length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 249
 250         if (size < length)
 251                 return -ENOSPC;
 252
 253         memset(buffer, 0, length);
 254
 255         if (frame->channels >= 2)
 256                 channels = frame->channels - 1;
 257         else
 258                 channels = 0;
 259
 260         ptr[0] = frame->type;
 261         ptr[1] = frame->version;
 262         ptr[2] = frame->length;
 263         ptr[3] = 0; /* checksum */
 264
 265         /* start infoframe payload */
 266         ptr += HDMI_INFOFRAME_HEADER_SIZE;
 267
 268         ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
 269         ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
 270                  (frame->sample_size & 0x3);
 271         ptr[2] = frame->coding_type_ext & 0x1f;
 272         ptr[3] = frame->channel_allocation;
 273         ptr[4] = (frame->level_shift_value & 0xf) << 3;
 274
 275         if (frame->downmix_inhibit)
 276                 ptr[4] |= BIT(7);
 277
 278         hdmi_infoframe_checksum(buffer, length);
 279
 280         return length;
 281 }
 282 EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
 283
 284 /**
 285  * hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary
 286  *                                buffer
 287  * @frame: HDMI vendor infoframe
 288  * @buffer: destination buffer
 289  * @size: size of buffer
 290  *
 291  * Packs the information contained in the @frame structure into a binary
 292  * representation that can be written into the corresponding controller
 293  * registers. Also computes the checksum as required by section 5.3.5 of
 294  * the HDMI 1.4 specification.
 295  *
 296  * Returns the number of bytes packed into the binary buffer or a negative
 297  * error code on failure.
 298  */
 299 ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
 300                                    void *buffer, size_t size)
 301 {
 302         u8 *ptr = buffer;
 303         size_t length;
 304
 305         length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 306
 307         if (size < length)
 308                 return -ENOSPC;
 309
 310         memset(buffer, 0, length);
 311
 312         ptr[0] = frame->type;
 313         ptr[1] = frame->version;
 314         ptr[2] = frame->length;
 315         ptr[3] = 0; /* checksum */
 316
 317         memcpy(&ptr[HDMI_INFOFRAME_HEADER_SIZE], frame->data, frame->length);
 318
 319         hdmi_infoframe_checksum(buffer, length);
 320
 321         return length;
 322 }
 323 EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);