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 --- drivers/video/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/video/Makefile') diff --git a/drivers/video/Makefile b/drivers/video/Makefile index 768a137a1bac..e0dd8202365f 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -168,3 +168,5 @@ 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 -- cgit v1.2.3 From cc3f414cf2e404130584b63d373161ba6fd24bc2 Mon Sep 17 00:00:00 2001 From: Steffen Trumtrar Date: Thu, 4 Oct 2012 15:32:52 +0200 Subject: video: add of helper for display timings/videomode 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 driver 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. Signed-off-by: Steffen Trumtrar Signed-off-by: Philipp Zabel Acked-by: Stephen Warren 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 --- .../devicetree/bindings/video/display-timing.txt | 109 ++++++++++ drivers/video/Kconfig | 15 ++ drivers/video/Makefile | 2 + drivers/video/of_display_timing.c | 239 +++++++++++++++++++++ drivers/video/of_videomode.c | 54 +++++ include/video/of_display_timing.h | 20 ++ include/video/of_videomode.h | 18 ++ 7 files changed, 457 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/display-timing.txt create mode 100644 drivers/video/of_display_timing.c create mode 100644 drivers/video/of_videomode.c create mode 100644 include/video/of_display_timing.h create mode 100644 include/video/of_videomode.h (limited to 'drivers/video/Makefile') diff --git a/Documentation/devicetree/bindings/video/display-timing.txt b/Documentation/devicetree/bindings/video/display-timing.txt new file mode 100644 index 000000000000..150038552bc3 --- /dev/null +++ b/Documentation/devicetree/bindings/video/display-timing.txt @@ -0,0 +1,109 @@ +display-timing 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. + +timing 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-active: with + - active high = drive pixel data on rising edge/ + sample data on falling edge + - active low = drive pixel data on falling edge/ + sample data on rising edge + - ignored = ignored + - interlaced (bool): boolean to enable interlaced mode + - doublescan (bool): boolean to enable doublescan mode + +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 minimum, typical and maximum values 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 09a8f0d8a3d4..807c7fa689fa 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 device tree display timing support" + depends on OF + select DISPLAY_TIMING + help + helper to parse display timings from the devicetree + +config OF_VIDEOMODE + bool "Enable device tree 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 e0dd8202365f..f592f3b32ec7 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -169,4 +169,6 @@ 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 000000000000..13ecd9897010 --- /dev/null +++ b/drivers/video/of_display_timing.c @@ -0,0 +1,239 @@ +/* + * OF helpers for parsing display timings + * + * Copyright (c) 2012 Steffen Trumtrar , Pengutronix + * + * based on of_videomode.c by Sascha Hauer + * + * This file is released under the GPLv2 + */ +#include +#include +#include +#include