Commit 4cc4f09e authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/displayid: add separate drm_displayid.c 



We'll be adding more DisplayID specific functions going forward, so
start off by splitting out a few functions to a separate file.

We don't bother with exporting the functions; at least for now they
should be needed solely within drm.ko.

No functional changes.

Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/07942d5011891b8e8f77245c78b34f4af97a9315.1617024940.git.jani.nikula@intel.com
parent 43d16d84

drivers/gpu/drm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ drm-y := drm_auth.o drm_cache.o \ 
		drm_file.o drm_gem.o drm_ioctl.o drm_irq.o \

		drm_drv.o \

		drm_sysfs.o drm_hashtab.o drm_mm.o \

		drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o \

		drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o drm_displayid.o \

		drm_encoder_slave.o \

		drm_trace_points.o drm_prime.o \

		drm_rect.o drm_vma_manager.o drm_flip_work.o \

drivers/gpu/drm/drm_displayid.c

0 → 100644
+59 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: MIT

/*

 * Copyright © 2021 Intel Corporation

 */



#include <drm/drm_displayid.h>

#include <drm/drm_edid.h>

#include <drm/drm_print.h>



static int validate_displayid(const u8 *displayid, int length, int idx)

{

	int i, dispid_length;

	u8 csum = 0;

	const struct displayid_hdr *base;



	base = (const struct displayid_hdr *)&displayid[idx];



	DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",

		      base->rev, base->bytes, base->prod_id, base->ext_count);



	/* +1 for DispID checksum */

	dispid_length = sizeof(*base) + base->bytes + 1;

	if (dispid_length > length - idx)

		return -EINVAL;



	for (i = 0; i < dispid_length; i++)

		csum += displayid[idx + i];

	if (csum) {

		DRM_NOTE("DisplayID checksum invalid, remainder is %d\n", csum);

		return -EINVAL;

	}



	return 0;

}



const u8 *drm_find_displayid_extension(const struct edid *edid,

				       int *length, int *idx,

				       int *ext_index)

{

	const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);

	const struct displayid_hdr *base;

	int ret;



	if (!displayid)

		return NULL;



	/* EDID extensions block checksum isn't for us */

	*length = EDID_LENGTH - 1;

	*idx = 1;



	ret = validate_displayid(displayid, *length, *idx);

	if (ret)

		return NULL;



	base = (const struct displayid_hdr *)&displayid[*idx];

	*length = *idx + sizeof(*base) + base->bytes;



	return displayid;

}

drivers/gpu/drm/drm_edid.c

+2 −56
Original line number Diff line number Diff line
@@ -1585,8 +1585,6 @@ module_param_named(edid_fixup, edid_fixup, int, 0400); 
MODULE_PARM_DESC(edid_fixup,

		 "Minimum number of valid EDID header bytes (0-8, default 6)");



static int validate_displayid(const u8 *displayid, int length, int idx);



static int drm_edid_block_checksum(const u8 *raw_edid)

{

	int i;
@@ -3241,7 +3239,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid, 
/*

 * Search EDID for CEA extension block.

 */

static const u8 *drm_find_edid_extension(const struct edid *edid,

const u8 *drm_find_edid_extension(const struct edid *edid,

				  int ext_id, int *ext_index)

{

	const u8 *edid_ext = NULL;
@@ -3266,32 +3264,6 @@ static const u8 *drm_find_edid_extension(const struct edid *edid, 
	return edid_ext;

}





static const u8 *drm_find_displayid_extension(const struct edid *edid,

					      int *length, int *idx,

					      int *ext_index)

{

	const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);

	const struct displayid_hdr *base;

	int ret;



	if (!displayid)

		return NULL;



	/* EDID extensions block checksum isn't for us */

	*length = EDID_LENGTH - 1;

	*idx = 1;



	ret = validate_displayid(displayid, *length, *idx);

	if (ret)

		return NULL;



	base = (const struct displayid_hdr *)&displayid[*idx];

	*length = *idx + sizeof(*base) + base->bytes;



	return displayid;

}



static const u8 *drm_find_cea_extension(const struct edid *edid)

{

	int length, idx;
@@ -5287,32 +5259,6 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi 
	return quirks;

}



static int validate_displayid(const u8 *displayid, int length, int idx)

{

	int i, dispid_length;

	u8 csum = 0;

	const struct displayid_hdr *base;



	base = (const struct displayid_hdr *)&displayid[idx];



	DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",

		      base->rev, base->bytes, base->prod_id, base->ext_count);



	/* +1 for DispID checksum */

	dispid_length = sizeof(*base) + base->bytes + 1;

	if (dispid_length > length - idx)

		return -EINVAL;



	for (i = 0; i < dispid_length; i++)

		csum += displayid[idx + i];

	if (csum) {

		DRM_NOTE("DisplayID checksum invalid, remainder is %d\n", csum);

		return -EINVAL;

	}



	return 0;

}



static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev,

							    struct displayid_detailed_timings_1 *timings)

{

include/drm/drm_displayid.h

+8 −0
Original line number Diff line number Diff line
@@ -22,6 +22,10 @@ 
#ifndef DRM_DISPLAYID_H

#define DRM_DISPLAYID_H



#include <linux/types.h>



struct edid;



#define DATA_BLOCK_PRODUCT_ID 0x00

#define DATA_BLOCK_DISPLAY_PARAMETERS 0x01

#define DATA_BLOCK_COLOR_CHARACTERISTICS 0x02
@@ -100,4 +104,8 @@ struct displayid_detailed_timing_block { 
	     (idx) += sizeof(struct displayid_block) + (block)->num_bytes, \

	     (block) = (const struct displayid_block *)&(displayid)[idx])



const u8 *drm_find_displayid_extension(const struct edid *edid,

				       int *length, int *idx,

				       int *ext_index);



#endif

include/drm/drm_edid.h

+3 −0
Original line number Diff line number Diff line
@@ -543,5 +543,8 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev, 
struct drm_display_mode *

drm_display_mode_from_cea_vic(struct drm_device *dev,

			      u8 video_code);

const u8 *drm_find_edid_extension(const struct edid *edid,

				  int ext_id, int *ext_index);





#endif /* __DRM_EDID_H__ */