From mboxrd@z Thu Jan  1 00:00:00 1970
From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Subject: =?UTF-8?q?=5BPATCH=20v17=202/7=5D=20video=3A=20add=20display=5Ftiming=20and=20videomode?=
Date: Fri, 25 Jan 2013 10:01:50 +0100
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To: devicetree-discuss@lists.ozlabs.org, Dave Airlie <airlied@linux.ie>
Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de>, Rob Herring <robherring2@gmail.com>, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Laurent Pinchart <laurent.pinchart@ideasonboard.com>, Thierry Reding <thierry.reding@avionic-design.de>, Guennady Liakhovetski <g.liakhovetski@gmx.de>, linux-media@vger.kernel.org, Tomi Valkeinen <tomi.valkeinen@ti.com>, Stephen Warren <swarren@wwwdotorg.org>, Florian Tobias Schandinat <FlorianSchandinat@gmx.de>, Rob Clark <robdclark@gmail.com>, Leela Krishna Amudala <leelakrishna.a@gmail.com>, "Mohammed, Afzal" <afzal@ti.com>, kernel@pengutronix.de
List-Id: devicetree@vger.kernel.org

Add display_timing structure and the according helper functions. This a=
llows
the description of a display via its supported timing parameters.

Also, add helper functions to convert from display timings to a generic=
 videomode
structure.

The struct display_timing specifies all needed parameters to describe t=
he signal
properties of a display in one mode. This includes
    - ranges for signals that may have min-, max- and typical values
    - single integers for signals that can be on, off or are ignored
    - booleans for signals that are either on or off

As a display may support multiple modes like this, a struct display_tim=
ings is
added, that holds all given struct display_timing pointers and declares=
 the
native mode of the display.

Although a display may state that a signal can be in a range, it is dri=
ven with
fixed values that indicate a videomode. Therefore graphic drivers don't=
 need all
the information of struct display_timing, but would generate a videomod=
e from
the given set of supported signal timings and work with that.

The video subsystems all define their own structs that describe a mode =
and work
with that (e.g. fb_videomode or drm_display_mode). To slowly replace al=
l those
various structures and allow code reuse across those subsystems, add st=
ruct
videomode as a generic description.

This patch only includes the most basic fields in struct videomode. All=
 missing
fields that are needed to have a really generic video mode description =
can be
added at a later stage.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Afzal Mohammed <Afzal@ti.com>
Tested-by: Rob Clark <robclark@gmail.com>
Tested-by: Leela Krishna Amudala <leelakrishna.a@gmail.com>
---
 drivers/video/Kconfig          |    6 ++
 drivers/video/Makefile         |    2 +
 drivers/video/display_timing.c |   24 ++++++++
 drivers/video/videomode.c      |   39 +++++++++++++
 include/video/display_timing.h |  124 ++++++++++++++++++++++++++++++++=
++++++++
 include/video/videomode.h      |   48 ++++++++++++++++
 6 files changed, 243 insertions(+)
 create mode 100644 drivers/video/display_timing.c
 create mode 100644 drivers/video/videomode.c
 create mode 100644 include/video/display_timing.h
 create mode 100644 include/video/videomode.h

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index e7068c5..09a8f0d 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -33,6 +33,12 @@ config VIDEO_OUTPUT_CONTROL
 	  This framework adds support for low-level control of the video=20
 	  output switch.
=20
+config DISPLAY_TIMING
+       bool
+
+config VIDEOMODE
+       bool
+
 menuconfig FB
 	tristate "Support for frame buffer devices"
 	---help---
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 768a137..e0dd820 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -168,3 +168,5 @@ obj-$(CONFIG_FB_VIRTUAL)          +=3D vfb.o
=20
 #video output switch sysfs driver
 obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) +=3D output.o
+obj-$(CONFIG_DISPLAY_TIMING) +=3D display_timing.o
+obj-$(CONFIG_VIDEOMODE) +=3D videomode.o
diff --git a/drivers/video/display_timing.c b/drivers/video/display_tim=
ing.c
new file mode 100644
index 0000000..5e1822c
--- /dev/null
+++ b/drivers/video/display_timing.c
@@ -0,0 +1,24 @@
+/*
+ * generic display timing functions
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pe=
ngutronix
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <video/display_timing.h>
+
+void display_timings_release(struct display_timings *disp)
+{
+	if (disp->timings) {
+		unsigned int i;
+
+		for (i =3D 0; i < disp->num_timings; i++)
+			kfree(disp->timings[i]);
+		kfree(disp->timings);
+	}
+	kfree(disp);
+}
+EXPORT_SYMBOL_GPL(display_timings_release);
diff --git a/drivers/video/videomode.c b/drivers/video/videomode.c
new file mode 100644
index 0000000..21c47a2
--- /dev/null
+++ b/drivers/video/videomode.c
@@ -0,0 +1,39 @@
+/*
+ * generic display timing functions
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pe=
ngutronix
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <video/display_timing.h>
+#include <video/videomode.h>
+
+int videomode_from_timing(const struct display_timings *disp,
+			  struct videomode *vm, unsigned int index)
+{
+	struct display_timing *dt;
+
+	dt =3D display_timings_get(disp, index);
+	if (!dt)
+		return -EINVAL;
+
+	vm->pixelclock =3D display_timing_get_value(&dt->pixelclock, TE_TYP);
+	vm->hactive =3D display_timing_get_value(&dt->hactive, TE_TYP);
+	vm->hfront_porch =3D display_timing_get_value(&dt->hfront_porch, TE_T=
YP);
+	vm->hback_porch =3D display_timing_get_value(&dt->hback_porch, TE_TYP=
);
+	vm->hsync_len =3D display_timing_get_value(&dt->hsync_len, TE_TYP);
+
+	vm->vactive =3D display_timing_get_value(&dt->vactive, TE_TYP);
+	vm->vfront_porch =3D display_timing_get_value(&dt->vfront_porch, TE_T=
YP);
+	vm->vback_porch =3D display_timing_get_value(&dt->vback_porch, TE_TYP=
);
+	vm->vsync_len =3D display_timing_get_value(&dt->vsync_len, TE_TYP);
+
+	vm->dmt_flags =3D dt->dmt_flags;
+	vm->data_flags =3D dt->data_flags;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(videomode_from_timing);
diff --git a/include/video/display_timing.h b/include/video/display_tim=
ing.h
new file mode 100644
index 0000000..71e9a38
--- /dev/null
+++ b/include/video/display_timing.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * description of display timings
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_DISPLAY_TIMING_H
+#define __LINUX_DISPLAY_TIMING_H
+
+#include <linux/bitops.h>
+#include <linux/types.h>
+
+/* VESA display monitor timing parameters */
+#define VESA_DMT_HSYNC_LOW		BIT(0)
+#define VESA_DMT_HSYNC_HIGH		BIT(1)
+#define VESA_DMT_VSYNC_LOW		BIT(2)
+#define VESA_DMT_VSYNC_HIGH		BIT(3)
+
+/* display specific flags */
+#define DISPLAY_FLAGS_DE_LOW		BIT(0)	/* data enable flag */
+#define DISPLAY_FLAGS_DE_HIGH		BIT(1)
+#define DISPLAY_FLAGS_PIXDATA_POSEDGE	BIT(2)	/* drive data on pos. edg=
e */
+#define DISPLAY_FLAGS_PIXDATA_NEGEDGE	BIT(3)	/* drive data on neg. edg=
e */
+#define DISPLAY_FLAGS_INTERLACED	BIT(4)
+#define DISPLAY_FLAGS_DOUBLESCAN	BIT(5)
+
+/*
+ * A single signal can be specified via a range of minimal and maximal=
 values
+ * with a typical value, that lies somewhere inbetween.
+ */
+struct timing_entry {
+	u32 min;
+	u32 typ;
+	u32 max;
+};
+
+enum timing_entry_index {
+	TE_MIN =3D 0,
+	TE_TYP =3D 1,
+	TE_MAX =3D 2,
+};
+
+/*
+ * Single "mode" entry. This describes one set of signal timings a dis=
play can
+ * have in one setting. This struct can later be converted to struct v=
ideomode
+ * (see include/video/videomode.h). As each timing_entry can be define=
d as a
+ * range, one struct display_timing may become multiple struct videomo=
des.
+ *
+ * Example: hsync active high, vsync active low
+ *
+ *				    Active Video
+ * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX________________=
_____
+ *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
+ *	  |	     |	 porch  |		     |	 porch	 |
+ *
+ * HSync _|=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=
|___________________________________________|=C2=AF=C2=AF=C2=AF=C2=AF=C2=
=AF=C2=AF=C2=AF=C2=AF=C2=AF
+ *
+ * VSync =C2=AF|__________|=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=
=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=
=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=
=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF=C2=AF|_=
________
+ */
+struct display_timing {
+	struct timing_entry pixelclock;
+
+	struct timing_entry hactive;		/* hor. active video */
+	struct timing_entry hfront_porch;	/* hor. front porch */
+	struct timing_entry hback_porch;	/* hor. back porch */
+	struct timing_entry hsync_len;		/* hor. sync len */
+
+	struct timing_entry vactive;		/* ver. active video */
+	struct timing_entry vfront_porch;	/* ver. front porch */
+	struct timing_entry vback_porch;	/* ver. back porch */
+	struct timing_entry vsync_len;		/* ver. sync len */
+
+	unsigned int dmt_flags;			/* VESA DMT flags */
+	unsigned int data_flags;		/* video data flags */
+};
+
+/*
+ * This describes all timing settings a display provides.
+ * The native_mode is the default setting for this display.
+ * Drivers that can handle multiple videomodes should work with this s=
truct and
+ * convert each entry to the desired end result.
+ */
+struct display_timings {
+	unsigned int num_timings;
+	unsigned int native_mode;
+
+	struct display_timing **timings;
+};
+
+/* get value specified by index from struct timing_entry */
+static inline u32 display_timing_get_value(const struct timing_entry *=
te,
+					   enum timing_entry_index index)
+{
+	switch (index) {
+	case TE_MIN:
+		return te->min;
+		break;
+	case TE_TYP:
+		return te->typ;
+		break;
+	case TE_MAX:
+		return te->max;
+		break;
+	default:
+		return te->typ;
+	}
+}
+
+/* get one entry from struct display_timings */
+static inline struct display_timing *display_timings_get(const struct
+							 display_timings *disp,
+							 unsigned int index)
+{
+	if (disp->num_timings > index)
+		return disp->timings[index];
+	else
+		return NULL;
+}
+
+void display_timings_release(struct display_timings *disp);
+
+#endif
diff --git a/include/video/videomode.h b/include/video/videomode.h
new file mode 100644
index 0000000..a421562
--- /dev/null
+++ b/include/video/videomode.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * generic videomode description
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_VIDEOMODE_H
+#define __LINUX_VIDEOMODE_H
+
+#include <linux/types.h>
+#include <video/display_timing.h>
+
+/*
+ * Subsystem independent description of a videomode.
+ * Can be generated from struct display_timing.
+ */
+struct videomode {
+	unsigned long pixelclock;	/* pixelclock in Hz */
+
+	u32 hactive;
+	u32 hfront_porch;
+	u32 hback_porch;
+	u32 hsync_len;
+
+	u32 vactive;
+	u32 vfront_porch;
+	u32 vback_porch;
+	u32 vsync_len;
+
+	unsigned int dmt_flags;	/* VESA DMT flags */
+	unsigned int data_flags; /* video data flags */
+};
+
+/**
+ * videomode_from_timing - convert display timing to videomode
+ * @disp: structure with all possible timing entries
+ * @vm: return value
+ * @index: index into the list of display timings in devicetree
+ *
+ * DESCRIPTION:
+ * This function converts a struct display_timing to a struct videomod=
e.
+ */
+int videomode_from_timing(const struct display_timings *disp,
+			  struct videomode *vm, unsigned int index);
+
+#endif
--=20
1.7.10.4