linux/drivers/video/hdmi.c

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/*
* Copyright (C) 2012 Avionic Design GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sub license,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/hdmi.h>
#include <linux/string.h>
static void hdmi_infoframe_checksum(void *buffer, size_t size)
{
u8 *ptr = buffer;
u8 csum = 0;
size_t i;
/* compute checksum */
for (i = 0; i < size; i++)
csum += ptr[i];
ptr[3] = 256 - csum;
}
/**
* hdmi_avi_infoframe_init() - initialize an HDMI AVI infoframe
* @frame: HDMI AVI infoframe
*
* Returns 0 on success or a negative error code on failure.
*/
int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
{
memset(frame, 0, sizeof(*frame));
frame->type = HDMI_INFOFRAME_TYPE_AVI;
frame->version = 2;
frame->length = 13;
return 0;
}
EXPORT_SYMBOL(hdmi_avi_infoframe_init);
/**
* hdmi_avi_infoframe_pack() - write HDMI AVI infoframe to binary buffer
* @frame: HDMI AVI infoframe
* @buffer: destination buffer
* @size: size of buffer
*
* Packs the information contained in the @frame structure into a binary
* representation that can be written into the corresponding controller
* registers. Also computes the checksum as required by section 5.3.5 of
* the HDMI 1.4 specification.
*
* Returns the number of bytes packed into the binary buffer or a negative
* error code on failure.
*/
ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
size_t size)
{
u8 *ptr = buffer;
size_t length;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
memset(buffer, 0, length);
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
ptr[3] = 0; /* checksum */
/* start infoframe payload */
ptr += HDMI_INFOFRAME_HEADER_SIZE;
ptr[0] = ((frame->colorspace & 0x3) << 5) | (frame->scan_mode & 0x3);
if (frame->active_info_valid)
ptr[0] |= BIT(4);
if (frame->horizontal_bar_valid)
ptr[0] |= BIT(3);
if (frame->vertical_bar_valid)
ptr[0] |= BIT(2);
ptr[1] = ((frame->colorimetry & 0x3) << 6) |
((frame->picture_aspect & 0x3) << 4) |
(frame->active_aspect & 0xf);
ptr[2] = ((frame->extended_colorimetry & 0x7) << 4) |
((frame->quantization_range & 0x3) << 2) |
(frame->nups & 0x3);
if (frame->itc)
ptr[2] |= BIT(7);
ptr[3] = frame->video_code & 0x7f;
ptr[4] = ((frame->ycc_quantization_range & 0x3) << 6) |
((frame->content_type & 0x3) << 4) |
(frame->pixel_repeat & 0xf);
ptr[5] = frame->top_bar & 0xff;
ptr[6] = (frame->top_bar >> 8) & 0xff;
ptr[7] = frame->bottom_bar & 0xff;
ptr[8] = (frame->bottom_bar >> 8) & 0xff;
ptr[9] = frame->left_bar & 0xff;
ptr[10] = (frame->left_bar >> 8) & 0xff;
ptr[11] = frame->right_bar & 0xff;
ptr[12] = (frame->right_bar >> 8) & 0xff;
hdmi_infoframe_checksum(buffer, length);
return length;
}
EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
/**
* hdmi_spd_infoframe_init() - initialize an HDMI SPD infoframe
* @frame: HDMI SPD infoframe
* @vendor: vendor string
* @product: product string
*
* Returns 0 on success or a negative error code on failure.
*/
int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
const char *vendor, const char *product)
{
memset(frame, 0, sizeof(*frame));
frame->type = HDMI_INFOFRAME_TYPE_SPD;
frame->version = 1;
frame->length = 25;
strncpy(frame->vendor, vendor, sizeof(frame->vendor));
strncpy(frame->product, product, sizeof(frame->product));
return 0;
}
EXPORT_SYMBOL(hdmi_spd_infoframe_init);
/**
* hdmi_spd_infoframe_pack() - write HDMI SPD infoframe to binary buffer
* @frame: HDMI SPD infoframe
* @buffer: destination buffer
* @size: size of buffer
*
* Packs the information contained in the @frame structure into a binary
* representation that can be written into the corresponding controller
* registers. Also computes the checksum as required by section 5.3.5 of
* the HDMI 1.4 specification.
*
* Returns the number of bytes packed into the binary buffer or a negative
* error code on failure.
*/
ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
size_t size)
{
u8 *ptr = buffer;
size_t length;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
memset(buffer, 0, length);
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
ptr[3] = 0; /* checksum */
/* start infoframe payload */
ptr += HDMI_INFOFRAME_HEADER_SIZE;
memcpy(ptr, frame->vendor, sizeof(frame->vendor));
memcpy(ptr + 8, frame->product, sizeof(frame->product));
ptr[24] = frame->sdi;
hdmi_infoframe_checksum(buffer, length);
return length;
}
EXPORT_SYMBOL(hdmi_spd_infoframe_pack);
/**
* hdmi_audio_infoframe_init() - initialize an HDMI audio infoframe
* @frame: HDMI audio infoframe
*
* Returns 0 on success or a negative error code on failure.
*/
int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
{
memset(frame, 0, sizeof(*frame));
frame->type = HDMI_INFOFRAME_TYPE_AUDIO;
frame->version = 1;
frame->length = 10;
return 0;
}
EXPORT_SYMBOL(hdmi_audio_infoframe_init);
/**
* hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
* @frame: HDMI audio infoframe
* @buffer: destination buffer
* @size: size of buffer
*
* Packs the information contained in the @frame structure into a binary
* representation that can be written into the corresponding controller
* registers. Also computes the checksum as required by section 5.3.5 of
* the HDMI 1.4 specification.
*
* Returns the number of bytes packed into the binary buffer or a negative
* error code on failure.
*/
ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size)
{
unsigned char channels;
u8 *ptr = buffer;
size_t length;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
memset(buffer, 0, length);
if (frame->channels >= 2)
channels = frame->channels - 1;
else
channels = 0;
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
ptr[3] = 0; /* checksum */
/* start infoframe payload */
ptr += HDMI_INFOFRAME_HEADER_SIZE;
ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
(frame->sample_size & 0x3);
ptr[2] = frame->coding_type_ext & 0x1f;
ptr[3] = frame->channel_allocation;
ptr[4] = (frame->level_shift_value & 0xf) << 3;
if (frame->downmix_inhibit)
ptr[4] |= BIT(7);
hdmi_infoframe_checksum(buffer, length);
return length;
}
EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
/**
* hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary
* buffer
* @frame: HDMI vendor infoframe
* @buffer: destination buffer
* @size: size of buffer
*
* Packs the information contained in the @frame structure into a binary
* representation that can be written into the corresponding controller
* registers. Also computes the checksum as required by section 5.3.5 of
* the HDMI 1.4 specification.
*
* Returns the number of bytes packed into the binary buffer or a negative
* error code on failure.
*/
ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
void *buffer, size_t size)
{
u8 *ptr = buffer;
size_t length;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
memset(buffer, 0, length);
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
ptr[3] = 0; /* checksum */
memcpy(&ptr[HDMI_INFOFRAME_HEADER_SIZE], frame->data, frame->length);
hdmi_infoframe_checksum(buffer, length);
return length;
}
EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);