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@xxxxxxxxx [2] https://lore.kernel.org/all/20240703155937.1674856-6-imre.deak@xxxxxxxxx Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> --- drivers/gpu/drm/display/drm_dp_helper.c | 66 +++++++++++++++++++++---- include/drm/display/drm_dp.h | 4 ++ include/drm/display/drm_dp_helper.h | 2 + 3 files changed, 62 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index d4c34f3641400..6ee51003de3ce 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -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 diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h index 173548c6473a9..a6f8b098c56f1 100644 --- a/include/drm/display/drm_dp.h +++ b/include/drm/display/drm_dp.h @@ -1543,6 +1543,10 @@ 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) \ diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index ea03e1dd26ba7..bbb1cdc4fc68d 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -657,6 +657,8 @@ 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 * -- 2.43.3
