Commit 0daf44ea authored by Imre Deak's avatar Imre Deak
Browse files

drm/dp: Add helper to dump an LTTPR PHY descriptor 

Add a helper to dump the DPCD descriptor for an LTTPR PHY. This is based
on [1] and [2] moving the helper to DRM core as suggested by Ville.

[1] https://lore.kernel.org/all/20240703155937.1674856-5-imre.deak@intel.com
[2] https://lore.kernel.org/all/20240703155937.1674856-6-imre.deak@intel.com



Cc: dri-devel@lists.freedesktop.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240708190029.271247-6-imre.deak@intel.com
parent 993d36ac

drivers/gpu/drm/display/drm_dp_helper.c

+56 −10
Original line number Diff line number Diff line
@@ -2328,6 +2328,31 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch) 
#undef DEVICE_ID_ANY

#undef DEVICE_ID



static int drm_dp_read_ident(struct drm_dp_aux *aux, unsigned int offset,

			     struct drm_dp_dpcd_ident *ident)

{

	int ret;



	ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident));



	return ret < 0 ? ret : 0;

}



static void drm_dp_dump_desc(struct drm_dp_aux *aux,

			     const char *device_name, const struct drm_dp_desc *desc)

{

	const struct drm_dp_dpcd_ident *ident = &desc->ident;



	drm_dbg_kms(aux->drm_dev,

		    "%s: %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n",

		    aux->name, device_name,

		    (int)sizeof(ident->oui), ident->oui,

		    (int)strnlen(ident->device_id, sizeof(ident->device_id)), ident->device_id,

		    ident->hw_rev >> 4, ident->hw_rev & 0xf,

		    ident->sw_major_rev, ident->sw_minor_rev,

		    desc->quirks);

}



/**

 * drm_dp_read_desc - read sink/branch descriptor from DPCD

 * @aux: DisplayPort AUX channel
@@ -2344,27 +2369,48 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, 
{

	struct drm_dp_dpcd_ident *ident = &desc->ident;

	unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI;

	int ret, dev_id_len;

	int ret;



	ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident));

	ret = drm_dp_read_ident(aux, offset, ident);

	if (ret < 0)

		return ret;



	desc->quirks = drm_dp_get_quirks(ident, is_branch);



	dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id));



	drm_dbg_kms(aux->drm_dev,

		    "%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n",

		    aux->name, is_branch ? "branch" : "sink",

		    (int)sizeof(ident->oui), ident->oui, dev_id_len,

		    ident->device_id, ident->hw_rev >> 4, ident->hw_rev & 0xf,

		    ident->sw_major_rev, ident->sw_minor_rev, desc->quirks);

	drm_dp_dump_desc(aux, is_branch ? "DP branch" : "DP sink", desc);



	return 0;

}

EXPORT_SYMBOL(drm_dp_read_desc);



/**

 * drm_dp_dump_lttpr_desc - read and dump the DPCD descriptor for an LTTPR PHY

 * @aux: DisplayPort AUX channel

 * @dp_phy: LTTPR PHY instance

 *

 * Read the DPCD LTTPR PHY descriptor for @dp_phy and print a debug message

 * with its details to dmesg.

 *

 * Returns 0 on success or a negative error code on failure.

 */

int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy)

{

	struct drm_dp_desc desc = {};

	int ret;



	if (drm_WARN_ON(aux->drm_dev, dp_phy < DP_PHY_LTTPR1 || dp_phy > DP_MAX_LTTPR_COUNT))

		return -EINVAL;



	ret = drm_dp_read_ident(aux, DP_OUI_PHY_REPEATER(dp_phy), &desc.ident);

	if (ret < 0)

		return ret;



	drm_dp_dump_desc(aux, drm_dp_phy_name(dp_phy), &desc);



	return 0;

}

EXPORT_SYMBOL(drm_dp_dump_lttpr_desc);



/**

 * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment

 * @dsc_dpcd: DSC capabilities from DPCD

include/drm/display/drm_dp.h

+4 −0
Original line number Diff line number Diff line
@@ -1523,6 +1523,10 @@ enum drm_dp_phy { 
#define DP_SYMBOL_ERROR_COUNT_LANE2_PHY_REPEATER1	    0xf0039 /* 1.3 */

#define DP_SYMBOL_ERROR_COUNT_LANE3_PHY_REPEATER1	    0xf003b /* 1.3 */



#define DP_OUI_PHY_REPEATER1				    0xf003d /* 1.3 */

#define DP_OUI_PHY_REPEATER(dp_phy) \

	DP_LTTPR_REG(dp_phy, DP_OUI_PHY_REPEATER1)



#define __DP_FEC1_BASE					    0xf0290 /* 1.4 */

#define __DP_FEC2_BASE					    0xf0298 /* 1.4 */

#define DP_FEC_BASE(dp_phy) \

include/drm/display/drm_dp_helper.h

+2 −0
Original line number Diff line number Diff line
@@ -656,6 +656,8 @@ struct drm_dp_desc { 
int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,

		     bool is_branch);



int drm_dp_dump_lttpr_desc(struct drm_dp_aux *aux, enum drm_dp_phy dp_phy);



/**

 * enum drm_dp_quirk - Display Port sink/branch device specific quirks

 *