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: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/07942d5011891b8e8f77245c78b34f4af97a9315.1617024940.git.jani.nikula@intel.com
This commit is contained in:
Jani Nikula 2021-03-29 16:37:16 +03:00
parent 43d16d847e
commit 4cc4f09eaa
5 changed files with 73 additions and 57 deletions

View File

@ -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 \

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@ -0,0 +1,59 @@
// 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;
}

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@ -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;
@ -3241,8 +3239,8 @@ 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,
int ext_id, int *ext_index)
const u8 *drm_find_edid_extension(const struct edid *edid,
int ext_id, int *ext_index)
{
const u8 *edid_ext = NULL;
int i;
@ -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)
{

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@ -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

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@ -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__ */