From 8714c0cecfc28f7ce73a520be4831f09743c4fd7 Mon Sep 17 00:00:00 2001 From: Steffen Trumtrar Date: Mon, 17 Dec 2012 14:20:17 +0100 Subject: video: add display_timing and videomode 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 Reviewed-by: Thierry Reding Acked-by: Thierry Reding Tested-by: Thierry Reding Tested-by: Philipp Zabel Reviewed-by: Laurent Pinchart Acked-by: Laurent Pinchart Tested-by: Afzal Mohammed Tested-by: Rob Clark Tested-by: Leela Krishna Amudala --- include/video/display_timing.h | 124 +++++++++++++++++++++++++++++++++++++++++ include/video/videomode.h | 48 ++++++++++++++++ 2 files changed, 172 insertions(+) create mode 100644 include/video/display_timing.h create mode 100644 include/video/videomode.h (limited to 'include') diff --git a/include/video/display_timing.h b/include/video/display_timing.h new file mode 100644 index 000000000000..71e9a383a981 --- /dev/null +++ b/include/video/display_timing.h @@ -0,0 +1,124 @@ +/* + * Copyright 2012 Steffen Trumtrar + * + * description of display timings + * + * This file is released under the GPLv2 + */ + +#ifndef __LINUX_DISPLAY_TIMING_H +#define __LINUX_DISPLAY_TIMING_H + +#include +#include + +/* VESA display monitor timing parameters */ +#define VESA_DMT_HSYNC_LOW BIT(0) +#define VESA_DMT_HSYNC_HIGH BIT(1) +#define VESA_DMT_VSYNC_LOW BIT(2) +#define VESA_DMT_VSYNC_HIGH BIT(3) + +/* display specific flags */ +#define DISPLAY_FLAGS_DE_LOW BIT(0) /* data enable flag */ +#define DISPLAY_FLAGS_DE_HIGH BIT(1) +#define DISPLAY_FLAGS_PIXDATA_POSEDGE BIT(2) /* drive data on pos. edge */ +#define DISPLAY_FLAGS_PIXDATA_NEGEDGE BIT(3) /* drive data on neg. edge */ +#define DISPLAY_FLAGS_INTERLACED BIT(4) +#define DISPLAY_FLAGS_DOUBLESCAN BIT(5) + +/* + * A single signal can be specified via a range of minimal and maximal values + * with a typical value, that lies somewhere inbetween. + */ +struct timing_entry { + u32 min; + u32 typ; + u32 max; +}; + +enum timing_entry_index { + TE_MIN = 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/video/videomode.h). As each timing_entry can be defined as a + * range, one struct display_timing may become multiple struct videomodes. + * + * Example: hsync active high, vsync active low + * + * Active Video + * Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________ + * |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync.. + * | | porch | | porch | + * + * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯ + * + * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________ + */ +struct display_timing { + struct timing_entry pixelclock; + + struct timing_entry hactive; /* hor. active video */ + struct timing_entry hfront_porch; /* hor. front porch */ + struct timing_entry hback_porch; /* hor. back porch */ + struct timing_entry hsync_len; /* hor. sync len */ + + struct timing_entry vactive; /* ver. active video */ + struct timing_entry vfront_porch; /* ver. front porch */ + struct timing_entry vback_porch; /* ver. back porch */ + struct timing_entry vsync_len; /* ver. sync len */ + + unsigned int dmt_flags; /* VESA DMT flags */ + unsigned int data_flags; /* video data flags */ +}; + +/* + * This describes all timing settings a display provides. + * The native_mode is the default setting for this display. + * Drivers that can handle multiple videomodes should work with this 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/video/videomode.h b/include/video/videomode.h new file mode 100644 index 000000000000..a42156234dd4 --- /dev/null +++ b/include/video/videomode.h @@ -0,0 +1,48 @@ +/* + * Copyright 2012 Steffen Trumtrar + * + * generic videomode description + * + * This file is released under the GPLv2 + */ + +#ifndef __LINUX_VIDEOMODE_H +#define __LINUX_VIDEOMODE_H + +#include +#include