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 | 44 +++++++++++++++++ include/linux/display_timing.h | 104 ++++++++++++++++++++++++++++++++++++++++ include/linux/videomode.h | 54 +++++++++++++++++++++ 6 files changed, 234 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..784eaad --- /dev/null +++ b/drivers/video/videomode.c @@ -0,0 +1,44 @@ +/* + * 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/errno.h> +#include <linux/export.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..4986364 --- /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_TIMING_H +#define __LINUX_DISPLAY_TIMING_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..562f490 --- /dev/null +++ b/include/linux/videomode.h @@ -0,0 +1,54 @@ +/* + * 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> + +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