[PATCHv14 0/7] of: add display helper

[PATCHv14 0/7] of: add display helper

[Steffen Trumtrar]

Hi!

Changes since v13:
        - fix "const struct *" warning
                (reported by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>)
        - prevent division by zero in fb_videomode_from_videomode

Changes since v12:
        - rename struct display_timing to via_display_timing in via subsystem
        - fix refreshrate calculation
        - fix "const struct *" warnings
                (reported by: Manjunathappa, Prakash <prakash.pm@ti.com>)
        - some CodingStyle fixes
        - rewrite parts of commit messages and display-timings.txt
        - let display_timing_get_value get all values instead of just typical

Changes since v11:
        - make pointers const where applicable
        - add reviewed-by Laurent Pinchart

Changes since v10:
        - fix function name (drm_)display_mode_from_videomode
        - add acked-by, reviewed-by, tested-by

Changes since v9:
        - don't leak memory when previous timings were correct
        - CodingStyle fixes
        - move blank lines around

Changes since v8:
        - fix memory leaks
        - change API to be more consistent (foo_from_bar(struct bar, struct foo))
        - include headers were necessary
        - misc minor bufixe

Changes since v7:
        - move of_xxx to drivers/video
        - remove non-binding documentation from display-timings.txt
        - squash display_timings and videomode in one patch
        - misc minor fixes

Changes since v6:
        - get rid of some empty lines etc.
        - move functions to their subsystems
        - split of_ from non-of_ functions
        - add at least some kerneldoc to some functions

Changes since v5:
        - removed all display stuff and just describe timings

Changes since v4:
        - refactored functions

Changes since v3:
        - print error messages
        - free alloced memory
        - general cleanup

Changes since v2:
        - use hardware-near property-names
        - provide a videomode structure
        - allow ranges for all properties (<min,typ,max>)
        - functions to get display_mode or fb_videomode


Steffen Trumtrar (7):
  viafb: rename display_timing to via_display_timing
  video: add display_timing and videomode
  video: add of helper for display timings/videomode
  fbmon: add videomode helpers
  fbmon: add of_videomode helpers
  drm_modes: add videomode helpers
  drm_modes: add of_videomode helpers

 .../devicetree/bindings/video/display-timings.txt  |  107 ++++++++++
 drivers/gpu/drm/drm_modes.c                        |   69 ++++++
 drivers/video/Kconfig                              |   21 ++
 drivers/video/Makefile                             |    4 +
 drivers/video/display_timing.c                     |   24 +++
 drivers/video/fbmon.c                              |   89 ++++++++
 drivers/video/of_display_timing.c                  |  223 ++++++++++++++++++++
 drivers/video/of_videomode.c                       |   48 +++++
 drivers/video/via/hw.c                             |    6 +-
 drivers/video/via/hw.h                             |    2 +-
 drivers/video/via/lcd.c                            |    2 +-
 drivers/video/via/share.h                          |    2 +-
 drivers/video/via/via_modesetting.c                |    8 +-
 drivers/video/via/via_modesetting.h                |    6 +-
 drivers/video/videomode.c                          |   45 ++++
 include/drm/drmP.h                                 |   12 ++
 include/linux/display_timing.h                     |  104 +++++++++
 include/linux/fb.h                                 |   12 ++
 include/linux/of_display_timings.h                 |   20 ++
 include/linux/of_videomode.h                       |   18 ++
 include/linux/videomode.h                          |   52 +++++
 21 files changed, 861 insertions(+), 13 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt
 create mode 100644 drivers/video/display_timing.c
 create mode 100644 drivers/video/of_display_timing.c
 create mode 100644 drivers/video/of_videomode.c
 create mode 100644 drivers/video/videomode.c
 create mode 100644 include/linux/display_timing.h
 create mode 100644 include/linux/of_display_timings.h
 create mode 100644 include/linux/of_videomode.h
 create mode 100644 include/linux/videomode.h

-- 
1.7.10.4

[PATCHv14 1/7] viafb: rename display_timing to via_display_timing

[Steffen Trumtrar]

The struct display_timing is specific to the via subsystem. The naming leads to
collisions with the new struct display_timing, that is supposed to be a shared
struct between different subsystems.
To clean this up, prepend the existing struct with the subsystem it is specific
to.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
 drivers/video/via/hw.c              |    6 +++---
 drivers/video/via/hw.h              |    2 +-
 drivers/video/via/lcd.c             |    2 +-
 drivers/video/via/share.h           |    2 +-
 drivers/video/via/via_modesetting.c |    8 ++++----
 drivers/video/via/via_modesetting.h |    6 +++---
 6 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/video/via/hw.c b/drivers/video/via/hw.c
index 898590d..5563c67 100644
--- a/drivers/video/via/hw.c
+++ b/drivers/video/via/hw.c
@@ -1467,10 +1467,10 @@ void viafb_set_vclock(u32 clk, int set_iga)
 	via_write_misc_reg_mask(0x0C, 0x0C); /* select external clock */
 }
 
-struct display_timing var_to_timing(const struct fb_var_screeninfo *var,
+struct via_display_timing var_to_timing(const struct fb_var_screeninfo *var,
 	u16 cxres, u16 cyres)
 {
-	struct display_timing timing;
+	struct via_display_timing timing;
 	u16 dx = (var->xres - cxres) / 2, dy = (var->yres - cyres) / 2;
 
 	timing.hor_addr = cxres;
@@ -1491,7 +1491,7 @@ struct display_timing var_to_timing(const struct fb_var_screeninfo *var,
 void viafb_fill_crtc_timing(const struct fb_var_screeninfo *var,
 	u16 cxres, u16 cyres, int iga)
 {
-	struct display_timing crt_reg = var_to_timing(var,
+	struct via_display_timing crt_reg = var_to_timing(var,
 		cxres ? cxres : var->xres, cyres ? cyres : var->yres);
 
 	if (iga == IGA1)
diff --git a/drivers/video/via/hw.h b/drivers/video/via/hw.h
index 6be243c..c3f2572 100644
--- a/drivers/video/via/hw.h
+++ b/drivers/video/via/hw.h
@@ -637,7 +637,7 @@ extern int viafb_LCD_ON;
 extern int viafb_DVI_ON;
 extern int viafb_hotplug;
 
-struct display_timing var_to_timing(const struct fb_var_screeninfo *var,
+struct via_display_timing var_to_timing(const struct fb_var_screeninfo *var,
 	u16 cxres, u16 cyres);
 void viafb_fill_crtc_timing(const struct fb_var_screeninfo *var,
 	u16 cxres, u16 cyres, int iga);
diff --git a/drivers/video/via/lcd.c b/drivers/video/via/lcd.c
index 1650379..022b0df 100644
--- a/drivers/video/via/lcd.c
+++ b/drivers/video/via/lcd.c
@@ -549,7 +549,7 @@ void viafb_lcd_set_mode(const struct fb_var_screeninfo *var, u16 cxres,
 	int panel_hres = plvds_setting_info->lcd_panel_hres;
 	int panel_vres = plvds_setting_info->lcd_panel_vres;
 	u32 clock;
-	struct display_timing timing;
+	struct via_display_timing timing;
 	struct fb_var_screeninfo panel_var;
 	const struct fb_videomode *mode_crt_table, *panel_crt_table;
 
diff --git a/drivers/video/via/share.h b/drivers/video/via/share.h
index 3158dfc..65c65c6 100644
--- a/drivers/video/via/share.h
+++ b/drivers/video/via/share.h
@@ -319,7 +319,7 @@ struct crt_mode_table {
 	int refresh_rate;
 	int h_sync_polarity;
 	int v_sync_polarity;
-	struct display_timing crtc;
+	struct via_display_timing crtc;
 };
 
 struct io_reg {
diff --git a/drivers/video/via/via_modesetting.c b/drivers/video/via/via_modesetting.c
index 0e431ae..0b414b0 100644
--- a/drivers/video/via/via_modesetting.c
+++ b/drivers/video/via/via_modesetting.c
@@ -30,9 +30,9 @@
 #include "debug.h"
 
 
-void via_set_primary_timing(const struct display_timing *timing)
+void via_set_primary_timing(const struct via_display_timing *timing)
 {
-	struct display_timing raw;
+	struct via_display_timing raw;
 
 	raw.hor_total = timing->hor_total / 8 - 5;
 	raw.hor_addr = timing->hor_addr / 8 - 1;
@@ -88,9 +88,9 @@ void via_set_primary_timing(const struct display_timing *timing)
 	via_write_reg_mask(VIACR, 0x17, 0x80, 0x80);
 }
 
-void via_set_secondary_timing(const struct display_timing *timing)
+void via_set_secondary_timing(const struct via_display_timing *timing)
 {
-	struct display_timing raw;
+	struct via_display_timing raw;
 
 	raw.hor_total = timing->hor_total - 1;
 	raw.hor_addr = timing->hor_addr - 1;
diff --git a/drivers/video/via/via_modesetting.h b/drivers/video/via/via_modesetting.h
index 06e09fe..f6a6503 100644
--- a/drivers/video/via/via_modesetting.h
+++ b/drivers/video/via/via_modesetting.h
@@ -33,7 +33,7 @@
 #define VIA_PITCH_MAX	0x3FF8
 
 
-struct display_timing {
+struct via_display_timing {
 	u16 hor_total;
 	u16 hor_addr;
 	u16 hor_blank_start;
@@ -49,8 +49,8 @@ struct display_timing {
 };
 
 
-void via_set_primary_timing(const struct display_timing *timing);
-void via_set_secondary_timing(const struct display_timing *timing);
+void via_set_primary_timing(const struct via_display_timing *timing);
+void via_set_secondary_timing(const struct via_display_timing *timing);
 void via_set_primary_address(u32 addr);
 void via_set_secondary_address(u32 addr);
 void via_set_primary_pitch(u32 pitch);
-- 
1.7.10.4

[PATCHv14 2/7] video: add display_timing and videomode

[Steffen Trumtrar]

Add display_timing structure and the according helper functions. This allows
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 the 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_timings 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 driven with
fixed values that indicate a videomode. Therefore graphic drivers don't need all
the information of struct display_timing, but would generate a videomode 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 all those
various structures and allow code reuse across those subsystems, add struct
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>
---
 drivers/video/Kconfig          |    6 +++
 drivers/video/Makefile         |    2 +
 drivers/video/display_timing.c |   24 ++++++++++
 drivers/video/videomode.c      |   45 +++++++++++++++++
 include/linux/display_timing.h |  104 ++++++++++++++++++++++++++++++++++++++++
 include/linux/videomode.h      |   52 ++++++++++++++++++++
 6 files changed, 233 insertions(+)
 create mode 100644 drivers/video/display_timing.c
 create mode 100644 drivers/video/videomode.c
 create mode 100644 include/linux/display_timing.h
 create mode 100644 include/linux/videomode.h

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index d08d799..2a23b18 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 
 	  output switch.
 
+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 23e948e..fc30439 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -167,3 +167,5 @@ obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
 
 #video output switch sysfs driver
 obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) += output.o
+obj-$(CONFIG_DISPLAY_TIMING) += display_timing.o
+obj-$(CONFIG_VIDEOMODE) += videomode.o
diff --git a/drivers/video/display_timing.c b/drivers/video/display_timing.c
new file mode 100644
index 0000000..ac9bbbc
--- /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>, Pengutronix
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/display_timing.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+
+void display_timings_release(struct display_timings *disp)
+{
+	if (disp->timings) {
+		unsigned int i;
+
+		for (i = 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..86a8558
--- /dev/null
+++ b/drivers/video/videomode.c
@@ -0,0 +1,45 @@
+/*
+ * generic display timing functions
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/display_timing.h>
+#include <linux/kernel.h>
+#include <linux/videomode.h>
+
+int videomode_from_timing(const struct display_timings *disp,
+			  struct videomode *vm, unsigned int index)
+{
+	struct display_timing *dt;
+
+	dt = display_timings_get(disp, index);
+	if (!dt)
+		return -EINVAL;
+
+	vm->pixelclock = display_timing_get_value(&dt->pixelclock, TE_TYP);
+	vm->hactive = display_timing_get_value(&dt->hactive, TE_TYP);
+	vm->hfront_porch = display_timing_get_value(&dt->hfront_porch, TE_TYP);
+	vm->hback_porch = display_timing_get_value(&dt->hback_porch, TE_TYP);
+	vm->hsync_len = display_timing_get_value(&dt->hsync_len, TE_TYP);
+
+	vm->vactive = display_timing_get_value(&dt->vactive, TE_TYP);
+	vm->vfront_porch = display_timing_get_value(&dt->vfront_porch, TE_TYP);
+	vm->vback_porch = display_timing_get_value(&dt->vback_porch, TE_TYP);
+	vm->vsync_len = display_timing_get_value(&dt->vsync_len, TE_TYP);
+
+	vm->vah = dt->vsync_pol_active;
+	vm->hah = dt->hsync_pol_active;
+	vm->de = dt->de_pol_active;
+	vm->pixelclk_pol = dt->pixelclk_pol;
+
+	vm->interlaced = dt->interlaced;
+	vm->doublescan = dt->doublescan;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(videomode_from_timing);
diff --git a/include/linux/display_timing.h b/include/linux/display_timing.h
new file mode 100644
index 0000000..b8922ea
--- /dev/null
+++ b/include/linux/display_timing.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * description of display timings
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_DISPLAY_TIMINGS_H
+#define __LINUX_DISPLAY_TIMINGS_H
+
+#include <linux/types.h>
+
+/*
+ * A single signal can be specified via a range with a typical value, that lies
+ * somewhere inbetween. Do not use an array, to prevent any confusion about the
+ * meaning of every entry.
+ */
+struct timing_entry {
+	u32 min;
+	u32 typ;
+	u32 max;
+};
+
+enum timing_entry_index {
+	TE_MIN = 0,
+	TE_TYP = 1,
+	TE_MAX = 2,
+};
+
+/*
+ * Single "mode" entry. This describes one set of signal timings a display can
+ * have in one setting. This struct can later be converted to struct videomode
+ * (see include/linux/videomode.h). As each timing_entry can be defined as a
+ * range, one struct display_timing may become multiple struct videomodes.
+ */
+struct display_timing {
+	struct timing_entry pixelclock;
+
+	struct timing_entry hactive;
+	struct timing_entry hfront_porch;
+	struct timing_entry hback_porch;
+	struct timing_entry hsync_len;
+
+	struct timing_entry vactive;
+	struct timing_entry vfront_porch;
+	struct timing_entry vback_porch;
+	struct timing_entry vsync_len;
+
+	unsigned int vsync_pol_active;
+	unsigned int hsync_pol_active;
+	unsigned int de_pol_active;
+	unsigned int pixelclk_pol;
+	bool interlaced;
+	bool doublescan;
+};
+
+/*
+ * This describes all timing settings a display provides.
+ * The native_mode is the default setting for this display. It can be specified
+ * in the devicetree or will be the first that is provided. Drivers that can
+ * handle multiple videomode should work with this struct 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/linux/videomode.h b/include/linux/videomode.h
new file mode 100644
index 0000000..41749f2
--- /dev/null
+++ b/include/linux/videomode.h
@@ -0,0 +1,52 @@
+/*
+ * 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
+
+struct display_timings;
+
+/*
+ * Subsystem independent description of a videomode.
+ * Can be generated from struct display_timing.
+ */
+struct videomode {
+	u32 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;
+
+	u32 hah;		/* hsync active high */
+	u32 vah;		/* vsync active high */
+	u32 de;			/* data enable */
+	u32 pixelclk_pol;
+
+	bool interlaced;
+	bool doublescan;
+};
+
+/**
+ * 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 videomode.
+ */
+int videomode_from_timing(const struct display_timings *disp,
+			  struct videomode *vm, unsigned int index);
+
+#endif
-- 
1.7.10.4

[PATCHv14 3/7] video: add of helper for display timings/videomode

[Steffen Trumtrar]

This adds support for reading display timings from DT into a struct
display_timings. The of_display_timing implementation supports multiple
subnodes. All children are read into an array, that can be queried.

If no native mode is specified, the first subnode will be used.

For cases, where the graphics drivers knows, there can be only one
mode description or where the driver only supports one mode, a helper
function of_get_videomode is added, that gets a struct videomode from DT.
(As this function is implemented in an expensive fashion, it should only
be used in the aforementioned case).

This also demonstrates how of_display_timings may be utilized.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
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>
---
 .../devicetree/bindings/video/display-timings.txt  |  107 ++++++++++
 drivers/video/Kconfig                              |   15 ++
 drivers/video/Makefile                             |    2 +
 drivers/video/of_display_timing.c                  |  223 ++++++++++++++++++++
 drivers/video/of_videomode.c                       |   48 +++++
 include/linux/of_display_timings.h                 |   20 ++
 include/linux/of_videomode.h                       |   18 ++
 7 files changed, 433 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt
 create mode 100644 drivers/video/of_display_timing.c
 create mode 100644 drivers/video/of_videomode.c
 create mode 100644 include/linux/of_display_timings.h
 create mode 100644 include/linux/of_videomode.h

diff --git a/Documentation/devicetree/bindings/video/display-timings.txt b/Documentation/devicetree/bindings/video/display-timings.txt
new file mode 100644
index 0000000..2b25d58
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/display-timings.txt
@@ -0,0 +1,107 @@
+display-timings bindings
+========================
+
+display-timings node
+--------------------
+
+required properties:
+ - none
+
+optional properties:
+ - native-mode: The native mode for the display, in case multiple modes are
+		provided. When omitted, assume the first node is the native.
+
+timings subnode
+---------------
+
+required properties:
+ - hactive, vactive: Display resolution
+ - hfront-porch, hback-porch, hsync-len: Horizontal Display timing parameters
+   in pixels
+   vfront-porch, vback-porch, vsync-len: Vertical display timing parameters in
+   lines
+ - clock-frequency: display clock in Hz
+
+optional properties:
+ - hsync-active: Hsync pulse is active low/high/ignored
+ - vsync-active: Vsync pulse is active low/high/ignored
+ - de-active: Data-Enable pulse is active low/high/ignored
+ - pixelclk-inverted: pixelclock is inverted (active on falling edge)/
+				non-inverted (active on rising edge)/
+				     ignored (ignore property)
+ - interlaced (bool): boolean to enable interlaced mode
+ - doublescan (bool): boolean to enable doublescan mode
+ - doubleclk (bool)
+
+All the optional properties that are not bool follow the following logic:
+    <1>: high active
+    <0>: low active
+    omitted: not used on hardware
+
+There are different ways of describing the capabilities of a display. The devicetree
+representation corresponds to the one commonly found in datasheets for displays.
+If a display supports multiple signal timings, the native-mode can be specified.
+
+The parameters are defined as
+
+  +----------+---------------------------------------------+----------+-------+
+  |          |                ↑                            |          |       |
+  |          |                |vback_porch                 |          |       |
+  |          |                ↓                            |          |       |
+  +----------###############################################----------+-------+
+  |          #                ↑                            #          |       |
+  |          #                |                            #          |       |
+  |  hback   #                |                            #  hfront  | hsync |
+  |   porch  #                |       hactive              #  porch   |  len  |
+  |<-------->#<---------------+--------------------------->#<-------->|<----->|
+  |          #                |                            #          |       |
+  |          #                |vactive                     #          |       |
+  |          #                |                            #          |       |
+  |          #                ↓                            #          |       |
+  +----------###############################################----------+-------+
+  |          |                ↑                            |          |       |
+  |          |                |vfront_porch                |          |       |
+  |          |                ↓                            |          |       |
+  +----------+---------------------------------------------+----------+-------+
+  |          |                ↑                            |          |       |
+  |          |                |vsync_len                   |          |       |
+  |          |                ↓                            |          |       |
+  +----------+---------------------------------------------+----------+-------+
+
+
+Example:
+
+	display-timings {
+		native-mode = <&timing0>;
+		timing0: 1080p24 {
+			/* 1920x1080p24 */
+			clock-frequency = <52000000>;
+			hactive = <1920>;
+			vactive = <1080>;
+			hfront-porch = <25>;
+			hback-porch = <25>;
+			hsync-len = <25>;
+			vback-porch = <2>;
+			vfront-porch = <2>;
+			vsync-len = <2>;
+			hsync-active = <1>;
+		};
+	};
+
+Every required property also supports the use of ranges, so the commonly used
+datasheet description with <min typ max>-tuples can be used.
+
+Example:
+
+	timing1: timing {
+		/* 1920x1080p24 */
+		clock-frequency = <148500000>;
+		hactive = <1920>;
+		vactive = <1080>;
+		hsync-len = <0 44 60>;
+		hfront-porch = <80 88 95>;
+		hback-porch = <100 148 160>;
+		vfront-porch = <0 4 6>;
+		vback-porch = <0 36 50>;
+		vsync-len = <0 5 6>;
+	};
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 2a23b18..c5b7bcf 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -39,6 +39,21 @@ config DISPLAY_TIMING
 config VIDEOMODE
        bool
 
+config OF_DISPLAY_TIMING
+	bool "Enable OF display timing support"
+	depends on OF
+	select DISPLAY_TIMING
+	help
+	  helper to parse display timings from the devicetree
+
+config OF_VIDEOMODE
+	bool "Enable OF videomode support"
+	depends on OF
+	select VIDEOMODE
+	select OF_DISPLAY_TIMING
+	help
+	  helper to get videomodes from the devicetree
+
 menuconfig FB
 	tristate "Support for frame buffer devices"
 	---help---
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index fc30439..b936b00 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -168,4 +168,6 @@ obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
 #video output switch sysfs driver
 obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) += output.o
 obj-$(CONFIG_DISPLAY_TIMING) += display_timing.o
+obj-$(CONFIG_OF_DISPLAY_TIMING) += of_display_timing.o
 obj-$(CONFIG_VIDEOMODE) += videomode.o
+obj-$(CONFIG_OF_VIDEOMODE) += of_videomode.o
diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c
new file mode 100644
index 0000000..645f43d
--- /dev/null
+++ b/drivers/video/of_display_timing.c
@@ -0,0 +1,223 @@
+/*
+ * OF helpers for parsing display timings
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
+ *
+ * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * This file is released under the GPLv2
+ */
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/of_display_timings.h>
+
+/**
+ * parse_property - parse timing_entry from device_node
+ * @np: device_node with the property
+ * @name: name of the property
+ * @result: will be set to the return value
+ *
+ * DESCRIPTION:
+ * Every display_timing can be specified with either just the typical value or
+ * a range consisting of min/typ/max. This function helps handling this
+ **/
+static int parse_property(const struct device_node *np, const char *name,
+			  struct timing_entry *result)
+{
+	struct property *prop;
+	int length, cells, ret;
+
+	prop = of_find_property(np, name, &length);
+	if (!prop) {
+		pr_err("%s: could not find property %s\n", __func__, name);
+		return -EINVAL;
+	}
+
+	cells = length / sizeof(u32);
+	if (cells == 1) {
+		ret = of_property_read_u32(np, name, &result->typ);
+		result->min = result->typ;
+		result->max = result->typ;
+	} else if (cells == 3) {
+		ret = of_property_read_u32_array(np, name, &result->min, cells);
+	} else {
+		pr_err("%s: illegal timing specification in %s\n", __func__,
+			name);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * of_get_display_timing - parse display_timing entry from device_node
+ * @np: device_node with the properties
+ **/
+static struct display_timing *of_get_display_timing(const struct device_node
+						    *np)
+{
+	struct display_timing *dt;
+	int ret = 0;
+
+	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
+	if (!dt) {
+		pr_err("%s: could not allocate display_timing struct\n",
+			__func__);
+		return NULL;
+	}
+
+	ret |= parse_property(np, "hback-porch", &dt->hback_porch);
+	ret |= parse_property(np, "hfront-porch", &dt->hfront_porch);
+	ret |= parse_property(np, "hactive", &dt->hactive);
+	ret |= parse_property(np, "hsync-len", &dt->hsync_len);
+	ret |= parse_property(np, "vback-porch", &dt->vback_porch);
+	ret |= parse_property(np, "vfront-porch", &dt->vfront_porch);
+	ret |= parse_property(np, "vactive", &dt->vactive);
+	ret |= parse_property(np, "vsync-len", &dt->vsync_len);
+	ret |= parse_property(np, "clock-frequency", &dt->pixelclock);
+
+	of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active);
+	of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active);
+	of_property_read_u32(np, "de-active", &dt->de_pol_active);
+	of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol);
+	dt->interlaced = of_property_read_bool(np, "interlaced");
+	dt->doublescan = of_property_read_bool(np, "doublescan");
+
+	if (ret) {
+		pr_err("%s: error reading timing properties\n", __func__);
+		kfree(dt);
+		return NULL;
+	}
+
+	return dt;
+}
+
+/**
+ * of_get_display_timings - parse all display_timing entries from a device_node
+ * @np: device_node with the subnodes
+ **/
+struct display_timings *of_get_display_timings(struct device_node *np)
+{
+	struct device_node *timings_np;
+	struct device_node *entry;
+	struct device_node *native_mode;
+	struct display_timings *disp;
+
+	if (!np) {
+		pr_err("%s: no devicenode given\n", __func__);
+		return NULL;
+	}
+
+	timings_np = of_find_node_by_name(np, "display-timings");
+	if (!timings_np) {
+		pr_err("%s: could not find display-timings node\n", __func__);
+		return NULL;
+	}
+
+	disp = kzalloc(sizeof(*disp), GFP_KERNEL);
+	if (!disp) {
+		pr_err("%s: could not allocate struct disp'\n", __func__);
+		goto dispfail;
+	}
+
+	entry = of_parse_phandle(timings_np, "native-mode", 0);
+	/* assume first child as native mode if none provided */
+	if (!entry)
+		entry = of_get_next_child(np, NULL);
+	/* if there is no child, it is useless to go on */
+	if (!entry) {
+		pr_err("%s: no timing specifications given\n", __func__);
+		goto entryfail;
+	}
+
+	pr_info("%s: using %s as default timing\n", __func__, entry->name);
+
+	native_mode = entry;
+
+	disp->num_timings = of_get_child_count(timings_np);
+	if (disp->num_timings == 0) {
+		/* should never happen, as entry was already found above */
+		pr_err("%s: no timings specified\n", __func__);
+		goto entryfail;
+	}
+
+	disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings,
+				GFP_KERNEL);
+	if (!disp->timings) {
+		pr_err("%s: could not allocate timings array\n", __func__);
+		goto entryfail;
+	}
+
+	disp->num_timings = 0;
+	disp->native_mode = 0;
+
+	for_each_child_of_node(timings_np, entry) {
+		struct display_timing *dt;
+
+		dt = of_get_display_timing(entry);
+		if (!dt) {
+			/*
+			 * to not encourage wrong devicetrees, fail in case of
+			 * an error
+			 */
+			pr_err("%s: error in timing %d\n", __func__,
+			       disp->num_timings + 1);
+			goto timingfail;
+		}
+
+		if (native_mode == entry)
+			disp->native_mode = disp->num_timings;
+
+		disp->timings[disp->num_timings] = dt;
+		disp->num_timings++;
+	}
+	of_node_put(timings_np);
+	/*
+	 * native_mode points to the device_node returned by of_parse_phandle
+	 * therefore call of_node_put on it
+	 */
+	of_node_put(native_mode);
+
+	if (disp->num_timings > 0)
+		pr_info("%s: got %d timings. Using timing #%d as default\n",
+			__func__, disp->num_timings, disp->native_mode + 1);
+	else {
+		pr_err("%s: no valid timings specified\n", __func__);
+		display_timings_release(disp);
+		return NULL;
+	}
+	return disp;
+
+timingfail:
+	if (native_mode)
+		of_node_put(native_mode);
+	display_timings_release(disp);
+entryfail:
+	if (disp)
+		kfree(disp);
+dispfail:
+	of_node_put(timings_np);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_get_display_timings);
+
+/**
+ * of_display_timings_exists - check if a display-timings node is provided
+ * @np: device_node with the timing
+ **/
+int of_display_timings_exists(const struct device_node *np)
+{
+	struct device_node *timings_np;
+
+	if (!np)
+		return -EINVAL;
+
+	timings_np = of_parse_phandle(np, "display-timings", 0);
+	if (!timings_np)
+		return -EINVAL;
+
+	of_node_put(timings_np);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(of_display_timings_exists);
diff --git a/drivers/video/of_videomode.c b/drivers/video/of_videomode.c
new file mode 100644
index 0000000..358aa56
--- /dev/null
+++ b/drivers/video/of_videomode.c
@@ -0,0 +1,48 @@
+/*
+ * generic videomode helper
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
+ *
+ * This file is released under the GPLv2
+ */
+#include <linux/of.h>
+#include <linux/of_display_timings.h>
+#include <linux/of_videomode.h>
+#include <linux/export.h>
+
+/**
+ * of_get_videomode - get the videomode #<index> from devicetree
+ * @np - devicenode with the display_timings
+ * @vm - set to return value
+ * @index - index into list of display_timings
+ * DESCRIPTION:
+ * Get a list of all display timings and put the one
+ * specified by index into *vm. This function should only be used, if
+ * only one videomode is to be retrieved. A driver that needs to work
+ * with multiple/all videomodes should work with
+ * of_get_display_timings instead.
+ **/
+int of_get_videomode(struct device_node *np, struct videomode *vm,
+		     int index)
+{
+	struct display_timings *disp;
+	int ret;
+
+	disp = of_get_display_timings(np);
+	if (!disp) {
+		pr_err("%s: no timings specified\n", __func__);
+		return -EINVAL;
+	}
+
+	if (index == OF_USE_NATIVE_MODE)
+		index = disp->native_mode;
+
+	ret = videomode_from_timing(disp, vm, index);
+	if (ret)
+		return ret;
+
+	display_timings_release(disp);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_get_videomode);
diff --git a/include/linux/of_display_timings.h b/include/linux/of_display_timings.h
new file mode 100644
index 0000000..b3e3455
--- /dev/null
+++ b/include/linux/of_display_timings.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * display timings of helpers
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_OF_DISPLAY_TIMINGS_H
+#define __LINUX_OF_DISPLAY_TIMINGS_H
+
+#include <linux/display_timing.h>
+#include <linux/of.h>
+
+#define OF_USE_NATIVE_MODE -1
+
+struct display_timings *of_get_display_timings(struct device_node *np);
+int of_display_timings_exists(const struct device_node *np);
+
+#endif
diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h
new file mode 100644
index 0000000..a72ad78
--- /dev/null
+++ b/include/linux/of_videomode.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * videomode of-helpers
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_OF_VIDEOMODE_H
+#define __LINUX_OF_VIDEOMODE_H
+
+#include <linux/videomode.h>
+#include <linux/of.h>
+
+int of_get_videomode(struct device_node *np, struct videomode *vm,
+		     int index);
+
+#endif /* __LINUX_OF_VIDEOMODE_H */
-- 
1.7.10.4

[PATCHv14 4/7] fbmon: add videomode helpers

[Steffen Trumtrar]

Add a function to convert from the generic videomode to a fb_videomode.

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>
---
 drivers/video/fbmon.c |   49 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fb.h    |    6 ++++++
 2 files changed, 55 insertions(+)

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index cef6557..bcbfe8f 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -31,6 +31,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <video/edid.h>
+#include <linux/videomode.h>
 #ifdef CONFIG_PPC_OF
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
@@ -1373,6 +1374,54 @@ int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_inf
 	kfree(timings);
 	return err;
 }
+
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+int fb_videomode_from_videomode(const struct videomode *vm,
+				struct fb_videomode *fbmode)
+{
+	unsigned int htotal, vtotal;
+
+	fbmode->xres = vm->hactive;
+	fbmode->left_margin = vm->hback_porch;
+	fbmode->right_margin = vm->hfront_porch;
+	fbmode->hsync_len = vm->hsync_len;
+
+	fbmode->yres = vm->vactive;
+	fbmode->upper_margin = vm->vback_porch;
+	fbmode->lower_margin = vm->vfront_porch;
+	fbmode->vsync_len = vm->vsync_len;
+
+	/* prevent division by zero in KHZ2PICOS macro */
+	fbmode->pixclock = vm->pixelclock ? KHZ2PICOS(vm->pixelclock / 1000) : 0;
+
+	fbmode->sync = 0;
+	fbmode->vmode = 0;
+	if (vm->hah)
+		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (vm->vah)
+		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
+	if (vm->interlaced)
+		fbmode->vmode |= FB_VMODE_INTERLACED;
+	if (vm->doublescan)
+		fbmode->vmode |= FB_VMODE_DOUBLE;
+	fbmode->flag = 0;
+
+	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
+		 vm->hsync_len;
+	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
+		 vm->vsync_len;
+	/* prevent division by zero */
+	if (htotal && vtotal)
+		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
+	else
+		fbmode->refresh = vm->pixelclock;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
+#endif
+
+
 #else
 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
 {
diff --git a/include/linux/fb.h b/include/linux/fb.h
index c7a9571..4404ec2 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -19,6 +19,7 @@ struct vm_area_struct;
 struct fb_info;
 struct device;
 struct file;
+struct videomode;
 
 /* Definitions below are used in the parsed monitor specs */
 #define FB_DPMS_ACTIVE_OFF	1
@@ -714,6 +715,11 @@ extern void fb_destroy_modedb(struct fb_videomode *modedb);
 extern int fb_find_mode_cvt(struct fb_videomode *mode, int margins, int rb);
 extern unsigned char *fb_ddc_read(struct i2c_adapter *adapter);
 
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+extern int fb_videomode_from_videomode(const struct videomode *vm,
+				       struct fb_videomode *fbmode);
+#endif
+
 /* drivers/video/modedb.c */
 #define VESA_MODEDB_SIZE 34
 extern void fb_var_to_videomode(struct fb_videomode *mode,
-- 
1.7.10.4

[PATCHv14 5/7] fbmon: add of_videomode helpers

[Steffen Trumtrar]

Add helper to get fb_videomode from devicetree.

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>
---
 drivers/video/fbmon.c |   42 +++++++++++++++++++++++++++++++++++++++++-
 include/linux/fb.h    |    6 ++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index bcbfe8f..287e66b 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -31,7 +31,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <video/edid.h>
-#include <linux/videomode.h>
+#include <linux/of_videomode.h>
 #ifdef CONFIG_PPC_OF
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
@@ -1421,6 +1421,46 @@ int fb_videomode_from_videomode(const struct videomode *vm,
 EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
 #endif
 
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
+static inline void dump_fb_videomode(const struct fb_videomode *m)
+{
+	pr_debug("fb_videomode = %ux%u@%uHz (%ukHz) %u %u %u %u %u %u %u %u %u\n",
+		 m->xres, m->yres, m->refresh, m->pixclock, m->left_margin,
+		 m->right_margin, m->upper_margin, m->lower_margin,
+		 m->hsync_len, m->vsync_len, m->sync, m->vmode, m->flag);
+}
+
+/**
+ * of_get_fb_videomode - get a fb_videomode from devicetree
+ * @np: device_node with the timing specification
+ * @fb: will be set to the return value
+ * @index: index into the list of display timings in devicetree
+ *
+ * DESCRIPTION:
+ * This function is expensive and should only be used, if only one mode is to be
+ * read from DT. To get multiple modes start with of_get_display_timings ond
+ * work with that instead.
+ */
+int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fb,
+			unsigned int index)
+{
+	struct videomode vm;
+	int ret;
+
+	ret = of_get_videomode(np, &vm, index);
+	if (ret)
+		return ret;
+
+	fb_videomode_from_videomode(&vm, fb);
+
+	pr_info("%s: got %dx%d display mode from %s\n", __func__, vm.hactive,
+		vm.vactive, np->name);
+	dump_fb_videomode(fb);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_get_fb_videomode);
+#endif
 
 #else
 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 4404ec2..7e1c8cf 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -20,6 +20,7 @@ struct fb_info;
 struct device;
 struct file;
 struct videomode;
+struct device_node;
 
 /* Definitions below are used in the parsed monitor specs */
 #define FB_DPMS_ACTIVE_OFF	1
@@ -715,6 +716,11 @@ extern void fb_destroy_modedb(struct fb_videomode *modedb);
 extern int fb_find_mode_cvt(struct fb_videomode *mode, int margins, int rb);
 extern unsigned char *fb_ddc_read(struct i2c_adapter *adapter);
 
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
+extern int of_get_fb_videomode(struct device_node *np,
+			       struct fb_videomode *fb,
+			       unsigned int index);
+#endif
 #if IS_ENABLED(CONFIG_VIDEOMODE)
 extern int fb_videomode_from_videomode(const struct videomode *vm,
 				       struct fb_videomode *fbmode);
-- 
1.7.10.4

[PATCHv14 6/7] drm_modes: add videomode helpers

[Steffen Trumtrar]

Add conversion from videomode to drm_display_mode

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>
---
 drivers/gpu/drm/drm_modes.c |   37 +++++++++++++++++++++++++++++++++++++
 include/drm/drmP.h          |    6 ++++++
 2 files changed, 43 insertions(+)

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 59450f3..0073b27 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -35,6 +35,7 @@
 #include <linux/export.h>
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
+#include <linux/videomode.h>
 
 /**
  * drm_mode_debug_printmodeline - debug print a mode
@@ -504,6 +505,42 @@ drm_gtf_mode(struct drm_device *dev, int hdisplay, int vdisplay, int vrefresh,
 }
 EXPORT_SYMBOL(drm_gtf_mode);
 
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+int drm_display_mode_from_videomode(const struct videomode *vm,
+				    struct drm_display_mode *dmode)
+{
+	dmode->hdisplay = vm->hactive;
+	dmode->hsync_start = dmode->hdisplay + vm->hfront_porch;
+	dmode->hsync_end = dmode->hsync_start + vm->hsync_len;
+	dmode->htotal = dmode->hsync_end + vm->hback_porch;
+
+	dmode->vdisplay = vm->vactive;
+	dmode->vsync_start = dmode->vdisplay + vm->vfront_porch;
+	dmode->vsync_end = dmode->vsync_start + vm->vsync_len;
+	dmode->vtotal = dmode->vsync_end + vm->vback_porch;
+
+	dmode->clock = vm->pixelclock / 1000;
+
+	dmode->flags = 0;
+	if (vm->hah)
+		dmode->flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		dmode->flags |= DRM_MODE_FLAG_NHSYNC;
+	if (vm->vah)
+		dmode->flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		dmode->flags |= DRM_MODE_FLAG_NVSYNC;
+	if (vm->interlaced)
+		dmode->flags |= DRM_MODE_FLAG_INTERLACE;
+	if (vm->doublescan)
+		dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
+	drm_mode_set_name(dmode);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
+#endif
+
 /**
  * drm_mode_set_name - set the name on a mode
  * @mode: name will be set in this mode
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 3fd8280..3d0ccaa 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -85,6 +85,7 @@ struct module;
 struct drm_file;
 struct drm_device;
 
+struct videomode;
 #include <drm/drm_os_linux.h>
 #include <drm/drm_hashtab.h>
 #include <drm/drm_mm.h>
@@ -1454,6 +1455,11 @@ extern struct drm_display_mode *
 drm_mode_create_from_cmdline_mode(struct drm_device *dev,
 				  struct drm_cmdline_mode *cmd);
 
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+extern int drm_display_mode_from_videomode(const struct videomode *vm,
+					   struct drm_display_mode *dmode);
+#endif
+
 /* Modesetting support */
 extern void drm_vblank_pre_modeset(struct drm_device *dev, int crtc);
 extern void drm_vblank_post_modeset(struct drm_device *dev, int crtc);
-- 
1.7.10.4

[PATCHv14 7/7] drm_modes: add of_videomode helpers

[Steffen Trumtrar]

Add helper to get drm_display_mode from devicetree.

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>
---
 drivers/gpu/drm/drm_modes.c |   34 +++++++++++++++++++++++++++++++++-
 include/drm/drmP.h          |    6 ++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 0073b27..2d6edfa 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -35,7 +35,7 @@
 #include <linux/export.h>
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
-#include <linux/videomode.h>
+#include <linux/of_videomode.h>
 
 /**
  * drm_mode_debug_printmodeline - debug print a mode
@@ -541,6 +541,38 @@ int drm_display_mode_from_videomode(const struct videomode *vm,
 EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
 #endif
 
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
+/**
+ * of_get_drm_display_mode - get a drm_display_mode from devicetree
+ * @np: device_node with the timing specification
+ * @dmode: will be set to the return value
+ * @index: index into the list of display timings in devicetree
+ *
+ * This function is expensive and should only be used, if only one mode is to be
+ * read from DT. To get multiple modes start with of_get_display_timings and
+ * work with that instead.
+ */
+int of_get_drm_display_mode(struct device_node *np,
+			    struct drm_display_mode *dmode, unsigned int index)
+{
+	struct videomode vm;
+	int ret;
+
+	ret = of_get_videomode(np, &vm, index);
+	if (ret)
+		return ret;
+
+	drm_display_mode_from_videomode(&vm, dmode);
+
+	pr_info("%s: got %dx%d display mode from %s\n", __func__, vm.hactive,
+		vm.vactive, np->name);
+	drm_mode_debug_printmodeline(dmode);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_get_drm_display_mode);
+#endif
+
 /**
  * drm_mode_set_name - set the name on a mode
  * @mode: name will be set in this mode
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 3d0ccaa..84ecabd 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -86,6 +86,7 @@ struct drm_file;
 struct drm_device;
 
 struct videomode;
+struct device_node;
 #include <drm/drm_os_linux.h>
 #include <drm/drm_hashtab.h>
 #include <drm/drm_mm.h>
@@ -1459,6 +1460,11 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev,
 extern int drm_display_mode_from_videomode(const struct videomode *vm,
 					   struct drm_display_mode *dmode);
 #endif
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
+extern int of_get_drm_display_mode(struct device_node *np,
+				   struct drm_display_mode *dmode,
+				   unsigned int index);
+#endif
 
 /* Modesetting support */
 extern void drm_vblank_pre_modeset(struct drm_device *dev, int crtc);
-- 
1.7.10.4

Re: [PATCHv14 3/7] video: add of helper for display timings/videomode

[Leela Krishna Amudala]

Hello Steffen,

On Fri, Nov 23, 2012 at 2:34 PM, Steffen Trumtrar
<s.trumtrar@pengutronix.de> wrote:
> This adds support for reading display timings from DT into a struct
> display_timings. The of_display_timing implementation supports multiple
> subnodes. All children are read into an array, that can be queried.
>
> If no native mode is specified, the first subnode will be used.
>
> For cases, where the graphics drivers knows, there can be only one
> mode description or where the driver only supports one mode, a helper
> function of_get_videomode is added, that gets a struct videomode from DT.
> (As this function is implemented in an expensive fashion, it should only
> be used in the aforementioned case).
>
> This also demonstrates how of_display_timings may be utilized.
>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> Acked-by: Stephen Warren <swarren@nvidia.com>
> 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>
> ---
>  .../devicetree/bindings/video/display-timings.txt  |  107 ++++++++++
>  drivers/video/Kconfig                              |   15 ++
>  drivers/video/Makefile                             |    2 +
>  drivers/video/of_display_timing.c                  |  223 ++++++++++++++++++++
>  drivers/video/of_videomode.c                       |   48 +++++
>  include/linux/of_display_timings.h                 |   20 ++
>  include/linux/of_videomode.h                       |   18 ++
>  7 files changed, 433 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt
>  create mode 100644 drivers/video/of_display_timing.c
>  create mode 100644 drivers/video/of_videomode.c
>  create mode 100644 include/linux/of_display_timings.h
>  create mode 100644 include/linux/of_videomode.h
>

<<<snip>>>

> diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c
> new file mode 100644
> index 0000000..645f43d
> --- /dev/null
> +++ b/drivers/video/of_display_timing.c
> @@ -0,0 +1,223 @@
> +/*
> + * OF helpers for parsing display timings
> + *
> + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
> + *
> + * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
> + *
> + * This file is released under the GPLv2
> + */
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <linux/export.h>
> +#include <linux/of_display_timings.h>
> +
> +/**
> + * parse_property - parse timing_entry from device_node
> + * @np: device_node with the property
> + * @name: name of the property
> + * @result: will be set to the return value
> + *
> + * DESCRIPTION:
> + * Every display_timing can be specified with either just the typical value or
> + * a range consisting of min/typ/max. This function helps handling this
> + **/
> +static int parse_property(const struct device_node *np, const char *name,
> +                         struct timing_entry *result)
> +{
> +       struct property *prop;
> +       int length, cells, ret;
> +
> +       prop = of_find_property(np, name, &length);
> +       if (!prop) {
> +               pr_err("%s: could not find property %s\n", __func__, name);
> +               return -EINVAL;
> +       }
> +
> +       cells = length / sizeof(u32);
> +       if (cells == 1) {
> +               ret = of_property_read_u32(np, name, &result->typ);
> +               result->min = result->typ;
> +               result->max = result->typ;
> +       } else if (cells == 3) {
> +               ret = of_property_read_u32_array(np, name, &result->min, cells);
> +       } else {
> +               pr_err("%s: illegal timing specification in %s\n", __func__,
> +                       name);
> +               return -EINVAL;
> +       }
> +
> +       return ret;
> +}
> +
> +/**
> + * of_get_display_timing - parse display_timing entry from device_node
> + * @np: device_node with the properties
> + **/
> +static struct display_timing *of_get_display_timing(const struct device_node
> +                                                   *np)
> +{
> +       struct display_timing *dt;
> +       int ret = 0;
> +
> +       dt = kzalloc(sizeof(*dt), GFP_KERNEL);
> +       if (!dt) {
> +               pr_err("%s: could not allocate display_timing struct\n",
> +                       __func__);
> +               return NULL;
> +       }
> +
> +       ret |= parse_property(np, "hback-porch", &dt->hback_porch);
> +       ret |= parse_property(np, "hfront-porch", &dt->hfront_porch);
> +       ret |= parse_property(np, "hactive", &dt->hactive);
> +       ret |= parse_property(np, "hsync-len", &dt->hsync_len);
> +       ret |= parse_property(np, "vback-porch", &dt->vback_porch);
> +       ret |= parse_property(np, "vfront-porch", &dt->vfront_porch);
> +       ret |= parse_property(np, "vactive", &dt->vactive);
> +       ret |= parse_property(np, "vsync-len", &dt->vsync_len);
> +       ret |= parse_property(np, "clock-frequency", &dt->pixelclock);
> +
> +       of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active);
> +       of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active);
> +       of_property_read_u32(np, "de-active", &dt->de_pol_active);
> +       of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol);
> +       dt->interlaced = of_property_read_bool(np, "interlaced");
> +       dt->doublescan = of_property_read_bool(np, "doublescan");
> +
> +       if (ret) {
> +               pr_err("%s: error reading timing properties\n", __func__);
> +               kfree(dt);
> +               return NULL;
> +       }
> +
> +       return dt;
> +}
> +
> +/**
> + * of_get_display_timings - parse all display_timing entries from a device_node
> + * @np: device_node with the subnodes
> + **/
> +struct display_timings *of_get_display_timings(struct device_node *np)
> +{
> +       struct device_node *timings_np;
> +       struct device_node *entry;
> +       struct device_node *native_mode;
> +       struct display_timings *disp;
> +
> +       if (!np) {
> +               pr_err("%s: no devicenode given\n", __func__);
> +               return NULL;
> +       }
> +
> +       timings_np = of_find_node_by_name(np, "display-timings");
> +       if (!timings_np) {
> +               pr_err("%s: could not find display-timings node\n", __func__);
> +               return NULL;
> +       }
> +
> +       disp = kzalloc(sizeof(*disp), GFP_KERNEL);
> +       if (!disp) {
> +               pr_err("%s: could not allocate struct disp'\n", __func__);
> +               goto dispfail;
> +       }
> +
> +       entry = of_parse_phandle(timings_np, "native-mode", 0);
> +       /* assume first child as native mode if none provided */
> +       if (!entry)
> +               entry = of_get_next_child(np, NULL);
> +       /* if there is no child, it is useless to go on */
> +       if (!entry) {
> +               pr_err("%s: no timing specifications given\n", __func__);
> +               goto entryfail;
> +       }
> +
> +       pr_info("%s: using %s as default timing\n", __func__, entry->name);
> +
> +       native_mode = entry;
> +
> +       disp->num_timings = of_get_child_count(timings_np);
> +       if (disp->num_timings == 0) {
> +               /* should never happen, as entry was already found above */
> +               pr_err("%s: no timings specified\n", __func__);
> +               goto entryfail;
> +       }
> +
> +       disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings,
> +                               GFP_KERNEL);
> +       if (!disp->timings) {
> +               pr_err("%s: could not allocate timings array\n", __func__);
> +               goto entryfail;
> +       }
> +
> +       disp->num_timings = 0;
> +       disp->native_mode = 0;
> +
> +       for_each_child_of_node(timings_np, entry) {
> +               struct display_timing *dt;
> +
> +               dt = of_get_display_timing(entry);
> +               if (!dt) {
> +                       /*
> +                        * to not encourage wrong devicetrees, fail in case of
> +                        * an error
> +                        */
> +                       pr_err("%s: error in timing %d\n", __func__,
> +                              disp->num_timings + 1);
> +                       goto timingfail;
> +               }
> +
> +               if (native_mode == entry)
> +                       disp->native_mode = disp->num_timings;
> +
> +               disp->timings[disp->num_timings] = dt;
> +               disp->num_timings++;
> +       }
> +       of_node_put(timings_np);
> +       /*
> +        * native_mode points to the device_node returned by of_parse_phandle
> +        * therefore call of_node_put on it
> +        */
> +       of_node_put(native_mode);
> +
> +       if (disp->num_timings > 0)
> +               pr_info("%s: got %d timings. Using timing #%d as default\n",
> +                       __func__, disp->num_timings, disp->native_mode + 1);
> +       else {
> +               pr_err("%s: no valid timings specified\n", __func__);
> +               display_timings_release(disp);
> +               return NULL;
> +       }
> +       return disp;
> +
> +timingfail:
> +       if (native_mode)
> +               of_node_put(native_mode);
> +       display_timings_release(disp);
> +entryfail:
> +       if (disp)
> +               kfree(disp);
> +dispfail:
> +       of_node_put(timings_np);
> +       return NULL;
> +}
> +EXPORT_SYMBOL_GPL(of_get_display_timings);
> +
> +/**
> + * of_display_timings_exists - check if a display-timings node is provided
> + * @np: device_node with the timing
> + **/
> +int of_display_timings_exists(const struct device_node *np)
> +{
> +       struct device_node *timings_np;
> +
> +       if (!np)
> +               return -EINVAL;
> +
> +       timings_np = of_parse_phandle(np, "display-timings", 0);

I'm seeing warning for the above call
"passing argument 1 of 'of_parse_phandle' discards qualifiers from
pointer target type
expected 'struct device_node *' but argument is of type 'const struct
device_node *' "
Please take care of it.

Best Wishes,
Leela Krishna Amudala

> +       if (!timings_np)
> +               return -EINVAL;
> +
> +       of_node_put(timings_np);
> +       return 1;
> +}
> +EXPORT_SYMBOL_GPL(of_display_timings_exists);
> diff --git a/drivers/video/of_videomode.c b/drivers/video/of_videomode.c
> new file mode 100644
> index 0000000..358aa56
> --- /dev/null
> +++ b/drivers/video/of_videomode.c
> @@ -0,0 +1,48 @@
> +/*
> + * generic videomode helper
> + *
> + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
> + *
> + * This file is released under the GPLv2
> + */
> +#include <linux/of.h>
> +#include <linux/of_display_timings.h>
> +#include <linux/of_videomode.h>
> +#include <linux/export.h>
> +
> +/**
> + * of_get_videomode - get the videomode #<index> from devicetree
> + * @np - devicenode with the display_timings
> + * @vm - set to return value
> + * @index - index into list of display_timings
> + * DESCRIPTION:
> + * Get a list of all display timings and put the one
> + * specified by index into *vm. This function should only be used, if
> + * only one videomode is to be retrieved. A driver that needs to work
> + * with multiple/all videomodes should work with
> + * of_get_display_timings instead.
> + **/
> +int of_get_videomode(struct device_node *np, struct videomode *vm,
> +                    int index)
> +{
> +       struct display_timings *disp;
> +       int ret;
> +
> +       disp = of_get_display_timings(np);
> +       if (!disp) {
> +               pr_err("%s: no timings specified\n", __func__);
> +               return -EINVAL;
> +       }
> +
> +       if (index == OF_USE_NATIVE_MODE)
> +               index = disp->native_mode;
> +
> +       ret = videomode_from_timing(disp, vm, index);
> +       if (ret)
> +               return ret;
> +
> +       display_timings_release(disp);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_get_videomode);
> diff --git a/include/linux/of_display_timings.h b/include/linux/of_display_timings.h
> new file mode 100644
> index 0000000..b3e3455
> --- /dev/null
> +++ b/include/linux/of_display_timings.h
> @@ -0,0 +1,20 @@
> +/*
> + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
> + *
> + * display timings of helpers
> + *
> + * This file is released under the GPLv2
> + */
> +
> +#ifndef __LINUX_OF_DISPLAY_TIMINGS_H
> +#define __LINUX_OF_DISPLAY_TIMINGS_H
> +
> +#include <linux/display_timing.h>
> +#include <linux/of.h>
> +
> +#define OF_USE_NATIVE_MODE -1
> +
> +struct display_timings *of_get_display_timings(struct device_node *np);
> +int of_display_timings_exists(const struct device_node *np);
> +
> +#endif
> diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h
> new file mode 100644
> index 0000000..a72ad78
> --- /dev/null
> +++ b/include/linux/of_videomode.h
> @@ -0,0 +1,18 @@
> +/*
> + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
> + *
> + * videomode of-helpers
> + *
> + * This file is released under the GPLv2
> + */
> +
> +#ifndef __LINUX_OF_VIDEOMODE_H
> +#define __LINUX_OF_VIDEOMODE_H
> +
> +#include <linux/videomode.h>
> +#include <linux/of.h>
> +
> +int of_get_videomode(struct device_node *np, struct videomode *vm,
> +                    int index);
> +
> +#endif /* __LINUX_OF_VIDEOMODE_H */
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCHv14 3/7] video: add of helper for display timings/videomode

[Steffen Trumtrar]

On Fri, Nov 23, 2012 at 03:49:37PM +0530, Leela Krishna Amudala wrote:
> Hello Steffen,
> 
> On Fri, Nov 23, 2012 at 2:34 PM, Steffen Trumtrar
> <s.trumtrar@pengutronix.de> wrote:
> > This adds support for reading display timings from DT into a struct
> > display_timings. The of_display_timing implementation supports multiple
> > subnodes. All children are read into an array, that can be queried.
> >
> > If no native mode is specified, the first subnode will be used.
> >
> > For cases, where the graphics drivers knows, there can be only one
> > mode description or where the driver only supports one mode, a helper
> > function of_get_videomode is added, that gets a struct videomode from DT.
> > (As this function is implemented in an expensive fashion, it should only
> > be used in the aforementioned case).
> >
> > This also demonstrates how of_display_timings may be utilized.
> >
> > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > Acked-by: Stephen Warren <swarren@nvidia.com>
> > 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>
> > ---
> >  .../devicetree/bindings/video/display-timings.txt  |  107 ++++++++++
> >  drivers/video/Kconfig                              |   15 ++
> >  drivers/video/Makefile                             |    2 +
> >  drivers/video/of_display_timing.c                  |  223 ++++++++++++++++++++
> >  drivers/video/of_videomode.c                       |   48 +++++
> >  include/linux/of_display_timings.h                 |   20 ++
> >  include/linux/of_videomode.h                       |   18 ++
> >  7 files changed, 433 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt
> >  create mode 100644 drivers/video/of_display_timing.c
> >  create mode 100644 drivers/video/of_videomode.c
> >  create mode 100644 include/linux/of_display_timings.h
> >  create mode 100644 include/linux/of_videomode.h
> >
> 
> <<<snip>>>
> 
> > diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c
> > new file mode 100644
> > index 0000000..645f43d
> > --- /dev/null
> > +++ b/drivers/video/of_display_timing.c
> > @@ -0,0 +1,223 @@
> > +/*
> > + * OF helpers for parsing display timings
> > + *
> > + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
> > + *
> > + * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
> > + *
> > + * This file is released under the GPLv2
> > + */
> > +#include <linux/of.h>
> > +#include <linux/slab.h>
> > +#include <linux/export.h>
> > +#include <linux/of_display_timings.h>
> > +
> > +/**
> > + * parse_property - parse timing_entry from device_node
> > + * @np: device_node with the property
> > + * @name: name of the property
> > + * @result: will be set to the return value
> > + *
> > + * DESCRIPTION:
> > + * Every display_timing can be specified with either just the typical value or
> > + * a range consisting of min/typ/max. This function helps handling this
> > + **/
> > +static int parse_property(const struct device_node *np, const char *name,
> > +                         struct timing_entry *result)
> > +{
> > +       struct property *prop;
> > +       int length, cells, ret;
> > +
> > +       prop = of_find_property(np, name, &length);
> > +       if (!prop) {
> > +               pr_err("%s: could not find property %s\n", __func__, name);
> > +               return -EINVAL;
> > +       }
> > +
> > +       cells = length / sizeof(u32);
> > +       if (cells == 1) {
> > +               ret = of_property_read_u32(np, name, &result->typ);
> > +               result->min = result->typ;
> > +               result->max = result->typ;
> > +       } else if (cells == 3) {
> > +               ret = of_property_read_u32_array(np, name, &result->min, cells);
> > +       } else {
> > +               pr_err("%s: illegal timing specification in %s\n", __func__,
> > +                       name);
> > +               return -EINVAL;
> > +       }
> > +
> > +       return ret;
> > +}
> > +
> > +/**
> > + * of_get_display_timing - parse display_timing entry from device_node
> > + * @np: device_node with the properties
> > + **/
> > +static struct display_timing *of_get_display_timing(const struct device_node
> > +                                                   *np)
> > +{
> > +       struct display_timing *dt;
> > +       int ret = 0;
> > +
> > +       dt = kzalloc(sizeof(*dt), GFP_KERNEL);
> > +       if (!dt) {
> > +               pr_err("%s: could not allocate display_timing struct\n",
> > +                       __func__);
> > +               return NULL;
> > +       }
> > +
> > +       ret |= parse_property(np, "hback-porch", &dt->hback_porch);
> > +       ret |= parse_property(np, "hfront-porch", &dt->hfront_porch);
> > +       ret |= parse_property(np, "hactive", &dt->hactive);
> > +       ret |= parse_property(np, "hsync-len", &dt->hsync_len);
> > +       ret |= parse_property(np, "vback-porch", &dt->vback_porch);
> > +       ret |= parse_property(np, "vfront-porch", &dt->vfront_porch);
> > +       ret |= parse_property(np, "vactive", &dt->vactive);
> > +       ret |= parse_property(np, "vsync-len", &dt->vsync_len);
> > +       ret |= parse_property(np, "clock-frequency", &dt->pixelclock);
> > +
> > +       of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active);
> > +       of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active);
> > +       of_property_read_u32(np, "de-active", &dt->de_pol_active);
> > +       of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol);
> > +       dt->interlaced = of_property_read_bool(np, "interlaced");
> > +       dt->doublescan = of_property_read_bool(np, "doublescan");
> > +
> > +       if (ret) {
> > +               pr_err("%s: error reading timing properties\n", __func__);
> > +               kfree(dt);
> > +               return NULL;
> > +       }
> > +
> > +       return dt;
> > +}
> > +
> > +/**
> > + * of_get_display_timings - parse all display_timing entries from a device_node
> > + * @np: device_node with the subnodes
> > + **/
> > +struct display_timings *of_get_display_timings(struct device_node *np)
> > +{
> > +       struct device_node *timings_np;
> > +       struct device_node *entry;
> > +       struct device_node *native_mode;
> > +       struct display_timings *disp;
> > +
> > +       if (!np) {
> > +               pr_err("%s: no devicenode given\n", __func__);
> > +               return NULL;
> > +       }
> > +
> > +       timings_np = of_find_node_by_name(np, "display-timings");
> > +       if (!timings_np) {
> > +               pr_err("%s: could not find display-timings node\n", __func__);
> > +               return NULL;
> > +       }
> > +
> > +       disp = kzalloc(sizeof(*disp), GFP_KERNEL);
> > +       if (!disp) {
> > +               pr_err("%s: could not allocate struct disp'\n", __func__);
> > +               goto dispfail;
> > +       }
> > +
> > +       entry = of_parse_phandle(timings_np, "native-mode", 0);
> > +       /* assume first child as native mode if none provided */
> > +       if (!entry)
> > +               entry = of_get_next_child(np, NULL);
> > +       /* if there is no child, it is useless to go on */
> > +       if (!entry) {
> > +               pr_err("%s: no timing specifications given\n", __func__);
> > +               goto entryfail;
> > +       }
> > +
> > +       pr_info("%s: using %s as default timing\n", __func__, entry->name);
> > +
> > +       native_mode = entry;
> > +
> > +       disp->num_timings = of_get_child_count(timings_np);
> > +       if (disp->num_timings == 0) {
> > +               /* should never happen, as entry was already found above */
> > +               pr_err("%s: no timings specified\n", __func__);
> > +               goto entryfail;
> > +       }
> > +
> > +       disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings,
> > +                               GFP_KERNEL);
> > +       if (!disp->timings) {
> > +               pr_err("%s: could not allocate timings array\n", __func__);
> > +               goto entryfail;
> > +       }
> > +
> > +       disp->num_timings = 0;
> > +       disp->native_mode = 0;
> > +
> > +       for_each_child_of_node(timings_np, entry) {
> > +               struct display_timing *dt;
> > +
> > +               dt = of_get_display_timing(entry);
> > +               if (!dt) {
> > +                       /*
> > +                        * to not encourage wrong devicetrees, fail in case of
> > +                        * an error
> > +                        */
> > +                       pr_err("%s: error in timing %d\n", __func__,
> > +                              disp->num_timings + 1);
> > +                       goto timingfail;
> > +               }
> > +
> > +               if (native_mode == entry)
> > +                       disp->native_mode = disp->num_timings;
> > +
> > +               disp->timings[disp->num_timings] = dt;
> > +               disp->num_timings++;
> > +       }
> > +       of_node_put(timings_np);
> > +       /*
> > +        * native_mode points to the device_node returned by of_parse_phandle
> > +        * therefore call of_node_put on it
> > +        */
> > +       of_node_put(native_mode);
> > +
> > +       if (disp->num_timings > 0)
> > +               pr_info("%s: got %d timings. Using timing #%d as default\n",
> > +                       __func__, disp->num_timings, disp->native_mode + 1);
> > +       else {
> > +               pr_err("%s: no valid timings specified\n", __func__);
> > +               display_timings_release(disp);
> > +               return NULL;
> > +       }
> > +       return disp;
> > +
> > +timingfail:
> > +       if (native_mode)
> > +               of_node_put(native_mode);
> > +       display_timings_release(disp);
> > +entryfail:
> > +       if (disp)
> > +               kfree(disp);
> > +dispfail:
> > +       of_node_put(timings_np);
> > +       return NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(of_get_display_timings);
> > +
> > +/**
> > + * of_display_timings_exists - check if a display-timings node is provided
> > + * @np: device_node with the timing
> > + **/
> > +int of_display_timings_exists(const struct device_node *np)
> > +{
> > +       struct device_node *timings_np;
> > +
> > +       if (!np)
> > +               return -EINVAL;
> > +
> > +       timings_np = of_parse_phandle(np, "display-timings", 0);
> 
> I'm seeing warning for the above call
> "passing argument 1 of 'of_parse_phandle' discards qualifiers from
> pointer target type
> expected 'struct device_node *' but argument is of type 'const struct
> device_node *' "
> Please take care of it.
> 

I already sent a patch for of_parse_phandle that makes its device_node pointer
const. That fixes this warning. As I got that patch also on my tree, I did
miss removing the const for the time being.

Regards,
Steffen

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCHv14 4/7] fbmon: add videomode helpers

[Laurent Pinchart]

Hi Steffen,

On Friday 23 November 2012 10:04:24 Steffen Trumtrar wrote:
> Add a function to convert from the generic videomode to a fb_videomode.
> 
> 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>
> ---
>  drivers/video/fbmon.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/fb.h    |    6 ++++++
>  2 files changed, 55 insertions(+)
> 
> diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
> index cef6557..bcbfe8f 100644
> --- a/drivers/video/fbmon.c
> +++ b/drivers/video/fbmon.c
> @@ -31,6 +31,7 @@
>  #include <linux/pci.h>
>  #include <linux/slab.h>
>  #include <video/edid.h>
> +#include <linux/videomode.h>

You could move this one line up to keep headers sorted alphabetically 
(assuming they are in the first place).

>  #ifdef CONFIG_PPC_OF
>  #include <asm/prom.h>
>  #include <asm/pci-bridge.h>
> @@ -1373,6 +1374,54 @@ int fb_get_mode(int flags, u32 val, struct
> fb_var_screeninfo *var, struct fb_inf kfree(timings);
>  	return err;
>  }
> +
> +#if IS_ENABLED(CONFIG_VIDEOMODE)
> +int fb_videomode_from_videomode(const struct videomode *vm,
> +				struct fb_videomode *fbmode)

This is inside the #if CONFIG_FB_MODE_HELPERS block, is that intentional ?

> +{
> +	unsigned int htotal, vtotal;
> +
> +	fbmode->xres = vm->hactive;
> +	fbmode->left_margin = vm->hback_porch;
> +	fbmode->right_margin = vm->hfront_porch;
> +	fbmode->hsync_len = vm->hsync_len;
> +
> +	fbmode->yres = vm->vactive;
> +	fbmode->upper_margin = vm->vback_porch;
> +	fbmode->lower_margin = vm->vfront_porch;
> +	fbmode->vsync_len = vm->vsync_len;
> +
> +	/* prevent division by zero in KHZ2PICOS macro */
> +	fbmode->pixclock = vm->pixelclock ? KHZ2PICOS(vm->pixelclock / 1000) : 0;
> +
> +	fbmode->sync = 0;
> +	fbmode->vmode = 0;
> +	if (vm->hah)
> +		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
> +	if (vm->vah)
> +		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
> +	if (vm->interlaced)
> +		fbmode->vmode |= FB_VMODE_INTERLACED;
> +	if (vm->doublescan)
> +		fbmode->vmode |= FB_VMODE_DOUBLE;
> +	fbmode->flag = 0;
> +
> +	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
> +		 vm->hsync_len;
> +	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
> +		 vm->vsync_len;
> +	/* prevent division by zero */
> +	if (htotal && vtotal)
> +		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
> +	else
> +		fbmode->refresh = vm->pixelclock;

What about returning an error if htotal * vtotal == 0 ? The input is clearly 
invalid in that case. I would then set fbmode->refresh to 0, setting it to vm-
>pixelclock doesn't really make sense.

> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
> +#endif
> +
> +

A single blank line should be enough.

>  #else
>  int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
>  {
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index c7a9571..4404ec2 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -19,6 +19,7 @@ struct vm_area_struct;
>  struct fb_info;
>  struct device;
>  struct file;
> +struct videomode;
> 
>  /* Definitions below are used in the parsed monitor specs */
>  #define FB_DPMS_ACTIVE_OFF	1
> @@ -714,6 +715,11 @@ extern void fb_destroy_modedb(struct fb_videomode
> *modedb); extern int fb_find_mode_cvt(struct fb_videomode *mode, int
> margins, int rb); extern unsigned char *fb_ddc_read(struct i2c_adapter
> *adapter);
> 
> +#if IS_ENABLED(CONFIG_VIDEOMODE)
> +extern int fb_videomode_from_videomode(const struct videomode *vm,
> +				       struct fb_videomode *fbmode);
> +#endif
> +
>  /* drivers/video/modedb.c */
>  #define VESA_MODEDB_SIZE 34
>  extern void fb_var_to_videomode(struct fb_videomode *mode,
-- 
Regards,

Laurent Pinchart

Re: [PATCHv14 4/7] fbmon: add videomode helpers

[Steffen Trumtrar]

Hi Laurent,

On Fri, Nov 23, 2012 at 11:53:10AM +0100, Laurent Pinchart wrote:
> Hi Steffen,
> 
> On Friday 23 November 2012 10:04:24 Steffen Trumtrar wrote:
> > Add a function to convert from the generic videomode to a fb_videomode.
> > 
> > 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>
> > ---
> >  drivers/video/fbmon.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/fb.h    |    6 ++++++
> >  2 files changed, 55 insertions(+)
> > 
> > diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
> > index cef6557..bcbfe8f 100644
> > --- a/drivers/video/fbmon.c
> > +++ b/drivers/video/fbmon.c
> > @@ -31,6 +31,7 @@
> >  #include <linux/pci.h>
> >  #include <linux/slab.h>
> >  #include <video/edid.h>
> > +#include <linux/videomode.h>
> 
> You could move this one line up to keep headers sorted alphabetically 
> (assuming they are in the first place).
> 

Because of the careless mistake below, I will do that.

> >  #ifdef CONFIG_PPC_OF
> >  #include <asm/prom.h>
> >  #include <asm/pci-bridge.h>
> > @@ -1373,6 +1374,54 @@ int fb_get_mode(int flags, u32 val, struct
> > fb_var_screeninfo *var, struct fb_inf kfree(timings);
> >  	return err;
> >  }
> > +
> > +#if IS_ENABLED(CONFIG_VIDEOMODE)
> > +int fb_videomode_from_videomode(const struct videomode *vm,
> > +				struct fb_videomode *fbmode)
> 
> This is inside the #if CONFIG_FB_MODE_HELPERS block, is that intentional ?
> 

Yes. Intentional. It is a fb_mode helper, that is why ... oh, wait. I should
add a "depends on" to the Kconfig then.

> > +{
> > +	unsigned int htotal, vtotal;
> > +
> > +	fbmode->xres = vm->hactive;
> > +	fbmode->left_margin = vm->hback_porch;
> > +	fbmode->right_margin = vm->hfront_porch;
> > +	fbmode->hsync_len = vm->hsync_len;
> > +
> > +	fbmode->yres = vm->vactive;
> > +	fbmode->upper_margin = vm->vback_porch;
> > +	fbmode->lower_margin = vm->vfront_porch;
> > +	fbmode->vsync_len = vm->vsync_len;
> > +
> > +	/* prevent division by zero in KHZ2PICOS macro */
> > +	fbmode->pixclock = vm->pixelclock ? KHZ2PICOS(vm->pixelclock / 1000) : 0;
> > +
> > +	fbmode->sync = 0;
> > +	fbmode->vmode = 0;
> > +	if (vm->hah)
> > +		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
> > +	if (vm->vah)
> > +		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
> > +	if (vm->interlaced)
> > +		fbmode->vmode |= FB_VMODE_INTERLACED;
> > +	if (vm->doublescan)
> > +		fbmode->vmode |= FB_VMODE_DOUBLE;
> > +	fbmode->flag = 0;
> > +
> > +	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
> > +		 vm->hsync_len;
> > +	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
> > +		 vm->vsync_len;
> > +	/* prevent division by zero */
> > +	if (htotal && vtotal)
> > +		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
> > +	else
> > +		fbmode->refresh = vm->pixelclock;
> 
> What about returning an error if htotal * vtotal == 0 ? The input is clearly 
> invalid in that case. I would then set fbmode->refresh to 0, setting it to vm-
> >pixelclock doesn't really make sense.
> 

Yes, pixelclock makes no sense. It was supposed to be 0. I was careless here.

> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
> > +#endif
> > +
> > +
> 
> A single blank line should be enough.
> 

Regards,
Steffen

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