linux/drivers/video/hdmi.c
Thierry Reding 96d672e0e5 video: hdmi: Relicense under MIT
In order to make it easier to port the code to other operating systems
(like the BSDs), relicense the HDMI helpers under the more permissive
MIT license.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-04-12 14:01:40 +10:00

324 lines
8.6 KiB
C

/*
* 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);