[RFC 1/2] video: Add generic HDMI helpers
Thierry Reding
thierry.reding at avionic-design.de
Wed Nov 21 07:01:52 PST 2012
Add generic helpers to pack HDMI infoframes into a binary buffers.
Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
---
drivers/video/Kconfig | 3 ++
drivers/video/Makefile | 1 +
drivers/video/hdmi.c | 84 ++++++++++++++++++++++++++++++++++
include/linux/hdmi.h | 119 +++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 207 insertions(+)
create mode 100644 drivers/video/hdmi.c
create mode 100644 include/linux/hdmi.h
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index fb9a14e..17ac897 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -52,6 +52,9 @@ config OF_VIDEOMODE
help
helper to get videomodes from the devicetree
+config HDMI
+ bool
+
menuconfig FB
tristate "Support for frame buffer devices"
---help---
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index b936b00..d1d38ea 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -5,6 +5,7 @@
# Each configuration option enables a list of files.
obj-$(CONFIG_VGASTATE) += vgastate.o
+obj-$(CONFIG_HDMI) += hdmi.o
obj-y += fb_notify.o
obj-$(CONFIG_FB) += fb.o
fb-y := fbmem.o fbmon.o fbcmap.o fbsysfs.o \
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
new file mode 100644
index 0000000..3d6ee5e
--- /dev/null
+++ b/drivers/video/hdmi.c
@@ -0,0 +1,84 @@
+/*
+ * 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>
+
+/**
+ * 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.
+ */
+ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
+ size_t size)
+{
+ u8 *ptr = buffer;
+ unsigned int i;
+ u8 csum = 0;
+
+ if (frame->length > 0x1f)
+ return -EINVAL;
+
+ ptr[0] = frame->type;
+ ptr[1] = frame->version;
+ ptr[2] = frame->length;
+ ptr[3] = 0; /* checksum */
+ ptr[4] = ((frame->colorspace & 0x3) << 5) | (frame->scan_mode & 0x3);
+
+ if (frame->active_info_valid)
+ ptr[4] |= BIT(4);
+
+ if (frame->horizontal_bar_valid)
+ ptr[4] |= BIT(3);
+
+ if (frame->vertical_bar_valid)
+ ptr[4] |= BIT(2);
+
+ ptr[5] = ((frame->colorimetry & 0x3) << 6) |
+ ((frame->picture_aspect & 0x3) << 4) |
+ (frame->active_aspect & 0xf);
+
+ ptr[6] = ((frame->extended_colorimetry & 0x7) << 4) |
+ ((frame->quantization_range & 0x3) << 2) |
+ (frame->nups & 0x3);
+
+ if (frame->itc)
+ ptr[6] |= BIT(7);
+
+ ptr[7] = frame->video_code & 0x7f;
+
+ ptr[8] = ((frame->ycc_quantization_range & 0x3) << 6) |
+ ((frame->content_type & 0x3) << 4) |
+ (frame->pixel_repeat & 0xf);
+
+ ptr[9] = frame->top_bar & 0xff;
+ ptr[10] = (frame->top_bar >> 8) & 0xff;
+ ptr[11] = frame->bottom_bar & 0xff;
+ ptr[12] = (frame->bottom_bar >> 8) & 0xff;
+ ptr[13] = frame->left_bar & 0xff;
+ ptr[14] = (frame->left_bar >> 8) & 0xff;
+ ptr[15] = frame->right_bar & 0xff;
+ ptr[16] = (frame->right_bar >> 8) & 0xff;
+
+ /* compute checksum */
+ for (i = 0; i < 4 + frame->length; i++)
+ csum += ptr[i];
+
+ ptr[3] = 256 - csum;
+
+ return 4 + frame->length;
+}
+EXPORT_SYMBOL_GPL(hdmi_avi_infoframe_pack);
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
new file mode 100644
index 0000000..132556f
--- /dev/null
+++ b/include/linux/hdmi.h
@@ -0,0 +1,119 @@
+/*
+ * 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.
+ */
+
+#ifndef __LINUX_HDMI_H_
+#define __LINUX_HDMI_H_
+
+#include <linux/types.h>
+
+enum hdmi_infoframe_type {
+ HDMI_INFOFRAME_TYPE_AVI,
+};
+
+enum hdmi_colorspace {
+ HDMI_COLORSPACE_RGB,
+ HDMI_COLORSPACE_YUV422,
+ HDMI_COLORSPACE_YUV444,
+};
+
+enum hdmi_scan_mode {
+ HDMI_SCAN_MODE_NONE,
+ HDMI_SCAN_MODE_OVERSCAN,
+ HDMI_SCAN_MODE_UNDERSCAN,
+};
+
+enum hdmi_colorimetry {
+ HDMI_COLORIMETRY_NONE,
+ HDMI_COLORIMETRY_ITU_601,
+ HDMI_COLORIMETRY_ITU_709,
+ HDMI_COLORIMETRY_EXTENDED,
+};
+
+enum hdmi_picture_aspect {
+ HDMI_PICTURE_ASPECT_NONE,
+ HDMI_PICTURE_ASPECT_4_3,
+ HDMI_PICTURE_ASPECT_16_9,
+};
+
+enum hdmi_active_aspect {
+ HDMI_ACTIVE_ASPECT_16_9_TOP = 2,
+ HDMI_ACTIVE_ASPECT_14_9_TOP = 3,
+ HDMI_ACTIVE_ASPECT_16_9_CENTER = 4,
+ HDMI_ACTIVE_ASPECT_PICTURE = 8,
+ HDMI_ACTIVE_ASPECT_4_3 = 9,
+ HDMI_ACTIVE_ASPECT_16_9 = 10,
+ HDMI_ACTIVE_ASPECT_14_9 = 11,
+ HDMI_ACTIVE_ASPECT_4_3_SP_14_9 = 13,
+ HDMI_ACTIVE_ASPECT_16_9_SP_14_9 = 14,
+ HDMI_ACTIVE_ASPECT_16_9_SP_4_3 = 15,
+};
+
+enum hdmi_extended_colorimetry {
+ HDMI_EXTENDED_COLORIMETRY_XV_YCC_601,
+ HDMI_EXTENDED_COLORIMETRY_XV_YCC_709,
+ HDMI_EXTENDED_COLORIMETRY_S_YCC_601,
+ HDMI_EXTENDED_COLORIMETRY_ADOBE_YCC_601,
+ HDMI_EXTENDED_COLORIMETRY_ADOBE_RGB,
+};
+
+enum hdmi_quantization_range {
+ HDMI_QUANTIZATION_RANGE_DEFAULT,
+ HDMI_QUANTIZATION_RANGE_LIMITED,
+ HDMI_QUANTIZATION_RANGE_FULL,
+};
+
+/* non-uniform picture scaling */
+enum hdmi_nups {
+ HDMI_NUPS_UNKNOWN,
+ HDMI_NUPS_HORIZONTAL,
+ HDMI_NUPS_VERTICAL,
+ HDMI_NUPS_BOTH,
+};
+
+enum hdmi_ycc_quantization_range {
+ HDMI_YCC_QUANTIZATION_RANGE_LIMITED,
+ HDMI_YCC_QUANTIZATION_RANGE_FULL,
+};
+
+enum hdmi_content_type {
+ HDMI_CONTENT_TYPE_NONE,
+ HDMI_CONTENT_TYPE_PHOTO,
+ HDMI_CONTENT_TYPE_CINEMA,
+ HDMI_CONTENT_TYPE_GAME,
+};
+
+struct hdmi_avi_infoframe {
+ enum hdmi_infoframe_type type;
+ unsigned char version;
+ unsigned char length;
+ enum hdmi_colorspace colorspace;
+ bool active_info_valid;
+ bool horizontal_bar_valid;
+ bool vertical_bar_valid;
+ enum hdmi_scan_mode scan_mode;
+ enum hdmi_colorimetry colorimetry;
+ enum hdmi_picture_aspect picture_aspect;
+ enum hdmi_active_aspect active_aspect;
+ bool itc;
+ enum hdmi_extended_colorimetry extended_colorimetry;
+ enum hdmi_quantization_range quantization_range;
+ enum hdmi_nups nups;
+ unsigned char video_code;
+ enum hdmi_ycc_quantization_range ycc_quantization_range;
+ enum hdmi_content_type content_type;
+ unsigned char pixel_repeat;
+ unsigned short top_bar;
+ unsigned short bottom_bar;
+ unsigned short left_bar;
+ unsigned short right_bar;
+};
+
+ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
+ size_t size);
+
+#endif /* _DRM_HDMI_H */
--
1.8.0
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