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authorThierry Reding <thierry.reding@avionic-design.de>2012-11-21 15:29:29 +0100
committerThierry Reding <thierry.reding@avionic-design.de>2013-02-22 08:20:05 +0100
commitf142d3bd556c5e82e9bb3d33d07d6708702ea4ce (patch)
tree16dc228f0bcb8766753bc737353ac01c7929768c /drivers/video/hdmi.c
parent595887eb90b7e74a3e276b8f17d35236d85b0d37 (diff)
downloadlinux-f142d3bd556c5e82e9bb3d33d07d6708702ea4ce.tar.gz
video: Add generic HDMI infoframe helpers
Add generic helpers to pack HDMI infoframes into binary buffers. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/video/hdmi.c')
-rw-r--r--drivers/video/hdmi.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
new file mode 100644
index 00000000000..ab23c9b7914
--- /dev/null
+++ b/drivers/video/hdmi.c
@@ -0,0 +1,308 @@
+/*
+ * Copyright (C) 2012 Avionic Design GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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);