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Commit ed914f69 authored by Dave Airlie's avatar Dave Airlie
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Merge tag 'of_videomode_helper' of git://git.pengutronix.de/git/str/linux into drm-next 

videomode helpers for of + devicetree stuff, required for new kms drivers

(not the fbdev maintainer).

* tag 'of_videomode_helper' of git://git.pengutronix.de/git/str/linux:
  drm_modes: add of_videomode helpers
  drm_modes: add videomode helpers
  fbmon: add of_videomode helpers
  fbmon: add videomode helpers
  video: add of helper for display timings/videomode
  video: add display_timing and videomode
  viafb: rename display_timing to via_display_timing
parents bb0f78dd edb37a95

Documentation/devicetree/bindings/video/display-timing.txt

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+109 −0
Original line number Diff line number Diff line 
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>;

	};

drivers/gpu/drm/drm_modes.c

+70 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ 
#include <linux/export.h>

#include <drm/drmP.h>

#include <drm/drm_crtc.h>

#include <video/of_videomode.h>

#include <video/videomode.h>



/**

 * drm_mode_debug_printmodeline - debug print a mode
@@ -504,6 +506,74 @@ 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->dmt_flags & VESA_DMT_HSYNC_HIGH)

		dmode->flags |= DRM_MODE_FLAG_PHSYNC;

	else if (vm->dmt_flags & VESA_DMT_HSYNC_LOW)

		dmode->flags |= DRM_MODE_FLAG_NHSYNC;

	if (vm->dmt_flags & VESA_DMT_VSYNC_HIGH)

		dmode->flags |= DRM_MODE_FLAG_PVSYNC;

	else if (vm->dmt_flags & VESA_DMT_VSYNC_LOW)

		dmode->flags |= DRM_MODE_FLAG_NVSYNC;

	if (vm->data_flags & DISPLAY_FLAGS_INTERLACED)

		dmode->flags |= DRM_MODE_FLAG_INTERLACE;

	if (vm->data_flags & DISPLAY_FLAGS_DOUBLESCAN)

		dmode->flags |= DRM_MODE_FLAG_DBLSCAN;

	drm_mode_set_name(dmode);



	return 0;

}

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, 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_debug("%s: got %dx%d display mode from %s\n",

		of_node_full_name(np), 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

drivers/video/Kconfig

+21 −0
Original line number Diff line number Diff line
@@ -33,6 +33,27 @@ config VIDEO_OUTPUT_CONTROL 
	  This framework adds support for low-level control of the video 

	  output switch.



config DISPLAY_TIMING

       bool



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---

drivers/video/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -168,3 +168,7 @@ 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

drivers/video/display_timing.c

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/*

 * 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/slab.h>

#include <video/display_timing.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);