From e5b92773287c3eb3108a44785986a6c997866df8 Mon Sep 17 00:00:00 2001 From: Oleg Vasilev Date: Fri, 24 Apr 2020 18:20:51 +0530 Subject: drm: report dp downstream port type as a subconnector property MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, downstream port type is only reported in debugfs. This information should be considered important since it reflects the actual physical connector type. Some userspace (e.g. window compositors) may want to show this info to a user. The 'subconnector' property is already utilized for DVI-I and TV-out for reporting connector subtype. The initial motivation for this feature came from i2c test [1]. It is supposed to be skipped on VGA connectors, but it cannot detect VGA over DP and fails instead. v2: - Ville: utilized drm_dp_is_branch() - Ville: implement DP 1.0 downstream type info - Replaced create_dp_properties with add_dp_subconnector_property - Added dp_set_subconnector_property helper v4: - Ville: add DP1.0 best assumption about subconnector - Ville: assume DVI is DVI-D - Ville: reuse Writeback enum value for Virtual subconnector - Renamed #defines: HDMI -> HDMIA, DP -> DisplayPort v5: rebase v6: - Jani Nikula: renamed a function name - Jani Nikula: addressed the issues with documentation [1]: https://bugs.freedesktop.org/show_bug.cgi?id=104097 Cc: Ville Syrjälä Cc: intel-gfx@lists.freedesktop.org Signed-off-by: Jeevan B Signed-off-by: Oleg Vasilev Reviewed-by: Emil Velikov Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/1587732655-17544-1-git-send-email-jeevan.b@intel.com --- drivers/gpu/drm/drm_dp_helper.c | 71 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index a3c82e726057..4c21cf69dad5 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -597,6 +597,77 @@ void drm_dp_downstream_debug(struct seq_file *m, } EXPORT_SYMBOL(drm_dp_downstream_debug); +/** + * drm_dp_subconnector_type() - get DP branch device type + * + */ +enum drm_mode_subconnector +drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + int type; + if (!drm_dp_is_branch(dpcd)) + return DRM_MODE_SUBCONNECTOR_Native; + /* DP 1.0 approach */ + if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) { + type = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DWN_STRM_PORT_TYPE_MASK; + + switch (type) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + /* Can be HDMI or DVI-D, DVI-D is a safer option */ + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DWN_STRM_PORT_TYPE_ANALOG: + /* Can be VGA or DVI-A, VGA is more popular */ + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DWN_STRM_PORT_TYPE_DP: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DWN_STRM_PORT_TYPE_OTHER: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } + } + type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + + switch (type) { + case DP_DS_PORT_TYPE_DP: + case DP_DS_PORT_TYPE_DP_DUALMODE: + return DRM_MODE_SUBCONNECTOR_DisplayPort; + case DP_DS_PORT_TYPE_VGA: + return DRM_MODE_SUBCONNECTOR_VGA; + case DP_DS_PORT_TYPE_DVI: + return DRM_MODE_SUBCONNECTOR_DVID; + case DP_DS_PORT_TYPE_HDMI: + return DRM_MODE_SUBCONNECTOR_HDMIA; + case DP_DS_PORT_TYPE_WIRELESS: + return DRM_MODE_SUBCONNECTOR_Wireless; + case DP_DS_PORT_TYPE_NON_EDID: + default: + return DRM_MODE_SUBCONNECTOR_Unknown; + } +} +EXPORT_SYMBOL(drm_dp_subconnector_type); + +/** + * drm_mode_set_dp_subconnector_property - set subconnector for DP connector + * + * Called by a driver on every detect event. + */ +void drm_dp_set_subconnector_property(struct drm_connector *connector, + enum drm_connector_status status, + const u8 *dpcd, + const u8 port_cap[4]) +{ + enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown; + + if (status == connector_status_connected) + subconnector = drm_dp_subconnector_type(dpcd, port_cap); + drm_object_property_set_value(&connector->base, + connector->dev->mode_config.dp_subconnector_property, + subconnector); +} +EXPORT_SYMBOL(drm_dp_set_subconnector_property); + /* * I2C-over-AUX implementation */ -- cgit v1.2.1 From 3d3721ccb18a3dcec874c44120e2df7ec1c1db99 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Wed, 26 Aug 2020 14:24:49 -0400 Subject: drm/i915/dp: Extract drm_dp_read_downstream_info() We're going to be doing the same probing process in nouveau for determining downstream DP port capabilities, so let's deduplicate the work by moving i915's code for handling this into a shared helper: drm_dp_read_downstream_info(). Note that when we do this, we also do make some functional changes while we're at it: * We always clear the downstream port info before trying to read it, just to make things easier for the caller * We skip reading downstream port info if the DPCD indicates that we don't support downstream port info * We only read as many bytes as needed for the reported number of downstream ports, no sense in reading the whole thing every time v2: * Fixup logic for calculating the downstream port length to account for the fact that downstream port caps can be either 1 byte or 4 bytes long. We can actually skip fixing the max_clock/max_bpc helpers here since they all check for DP_DETAILED_CAP_INFO_AVAILABLE anyway. * Fix ret code check for drm_dp_dpcd_read v5: * Change name from drm_dp_downstream_read_info() to drm_dp_read_downstream_info() * Also, add "See Also" sections for the various downstream info functions (drm_dp_read_downstream_info(), drm_dp_downstream_max_clock(), drm_dp_downstream_max_bpc()) Reviewed-by: Sean Paul Signed-off-by: Lyude Paul Reviewed-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-14-lyude@redhat.com --- drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 60 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 4c21cf69dad5..f3643894ad95 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -423,6 +423,56 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); +static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK; + + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4) + port_count = 4; + + return port_count; +} + +/** + * drm_dp_read_downstream_info() - read DPCD downstream port info if available + * @aux: DisplayPort AUX channel + * @dpcd: A cached copy of the port's DPCD + * @downstream_ports: buffer to store the downstream port info in + * + * See also: + * drm_dp_downstream_max_clock() + * drm_dp_downstream_max_bpc() + * + * Returns: 0 if either the downstream port info was read successfully or + * there was no downstream info to read, or a negative error code otherwise. + */ +int drm_dp_read_downstream_info(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]) +{ + int ret; + u8 len; + + memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS); + + /* No downstream info to read */ + if (!drm_dp_is_branch(dpcd) || + dpcd[DP_DPCD_REV] < DP_DPCD_REV_10 || + !(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT)) + return 0; + + len = drm_dp_downstream_port_count(dpcd); + if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) + len *= 4; + + ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); + if (ret < 0) + return ret; + + return ret == len ? 0 : -EIO; +} +EXPORT_SYMBOL(drm_dp_read_downstream_info); + /** * drm_dp_downstream_max_clock() - extract branch device max * pixel rate for legacy VGA @@ -431,7 +481,11 @@ EXPORT_SYMBOL(drm_dp_send_real_edid_checksum); * @dpcd: DisplayPort configuration data * @port_cap: port capabilities * - * Returns max clock in kHz on success or 0 if max clock not defined + * See also: + * drm_dp_read_downstream_info() + * drm_dp_downstream_max_bpc() + * + * Returns: Max clock in kHz on success or 0 if max clock not defined */ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]) @@ -462,7 +516,11 @@ EXPORT_SYMBOL(drm_dp_downstream_max_clock); * @dpcd: DisplayPort configuration data * @port_cap: port capabilities * - * Returns max bpc on success or 0 if max bpc not defined + * See also: + * drm_dp_read_downstream_info() + * drm_dp_downstream_max_clock() + * + * Returns: Max bpc on success or 0 if max bpc not defined */ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]) -- cgit v1.2.1 From 693c3ec5976eb4b66cbd4f3f1c701a6f0ae1c9b9 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Wed, 26 Aug 2020 14:24:51 -0400 Subject: drm/i915/dp: Extract drm_dp_read_sink_count_cap() Since other drivers are also going to need to be aware of the sink count in order to do proper dongle detection, we might as well steal i915's DP_SINK_COUNT helpers and move them into DRM helpers so that other dirvers can use them as well. Note that this also starts using intel_dp_has_sink_count() in intel_dp_detect_dpcd(), which is a functional change. v5: * Change name from drm_dp_has_sink_count() to drm_dp_read_sink_count_cap() Signed-off-by: Lyude Paul Reviewed-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-16-lyude@redhat.com --- drivers/gpu/drm/drm_dp_helper.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index f3643894ad95..65ff21ae0c27 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -726,6 +726,28 @@ void drm_dp_set_subconnector_property(struct drm_connector *connector, } EXPORT_SYMBOL(drm_dp_set_subconnector_property); +/** + * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink + * count + * @connector: The DRM connector to check + * @dpcd: A cached copy of the connector's DPCD RX capabilities + * @desc: A cached copy of the connector's DP descriptor + * + * Returns: %True if the (e)DP connector has a valid sink count that should + * be probed, %false otherwise. + */ +bool drm_dp_read_sink_count_cap(struct drm_connector *connector, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const struct drm_dp_desc *desc) +{ + /* Some eDP panels don't set a valid value for the sink count */ + return connector->connector_type != DRM_MODE_CONNECTOR_eDP && + dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 && + dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && + !drm_dp_has_quirk(desc, 0, DP_DPCD_QUIRK_NO_SINK_COUNT); +} +EXPORT_SYMBOL(drm_dp_read_sink_count_cap); + /* * I2C-over-AUX implementation */ -- cgit v1.2.1 From 4778ff052812029bc076f5e78eff3ba1851cbea7 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Wed, 26 Aug 2020 14:24:52 -0400 Subject: drm/i915/dp: Extract drm_dp_read_sink_count() And of course, we'll also need to read the sink count from other drivers as well if we're checking whether or not it's supported. So, let's extract the code for this into another helper. v2: * Fix drm_dp_dpcd_readb() ret check * Add back comment and move back sink_count assignment in intel_dp_get_dpcd() v5: * Change name from drm_dp_get_sink_count() to drm_dp_read_sink_count() * Also, add "See also:" section to kdocs Signed-off-by: Lyude Paul Reviewed-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-17-lyude@redhat.com --- drivers/gpu/drm/drm_dp_helper.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 65ff21ae0c27..46d88ef4f59a 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -733,6 +733,8 @@ EXPORT_SYMBOL(drm_dp_set_subconnector_property); * @dpcd: A cached copy of the connector's DPCD RX capabilities * @desc: A cached copy of the connector's DP descriptor * + * See also: drm_dp_read_sink_count() + * * Returns: %True if the (e)DP connector has a valid sink count that should * be probed, %false otherwise. */ @@ -748,6 +750,30 @@ bool drm_dp_read_sink_count_cap(struct drm_connector *connector, } EXPORT_SYMBOL(drm_dp_read_sink_count_cap); +/** + * drm_dp_read_sink_count() - Retrieve the sink count for a given sink + * @aux: The DP AUX channel to use + * + * See also: drm_dp_read_sink_count_cap() + * + * Returns: The current sink count reported by @aux, or a negative error code + * otherwise. + */ +int drm_dp_read_sink_count(struct drm_dp_aux *aux) +{ + u8 count; + int ret; + + ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count); + if (ret < 0) + return ret; + if (ret != 1) + return -EIO; + + return DP_GET_SINK_COUNT(count); +} +EXPORT_SYMBOL(drm_dp_read_sink_count); + /* * I2C-over-AUX implementation */ -- cgit v1.2.1 From b9936121d95b0127d34fa6c25678994582d1b17c Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Wed, 26 Aug 2020 14:24:55 -0400 Subject: drm/i915/dp: Extract drm_dp_read_dpcd_caps() Since DP 1.3, it's been possible for DP receivers to specify an additional set of DPCD capabilities, which can take precedence over the capabilities reported at DP_DPCD_REV. Basically any device supporting DP is going to need to read these in an identical manner, in particular nouveau, so let's go ahead and just move this code out of i915 into a shared DRM DP helper that we can use in other drivers. v2: * Remove redundant dpcd[DP_DPCD_REV] == 0 check * Fix drm_dp_dpcd_read() ret checks Signed-off-by: Lyude Paul Reviewed-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-20-lyude@redhat.com --- drivers/gpu/drm/drm_dp_helper.c | 77 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 46d88ef4f59a..9ca88e6c7882 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -433,6 +433,83 @@ static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) return port_count; } +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 dpcd_ext[6]; + int ret; + + /* + * Prior to DP1.3 the bit represented by + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. + * If it is set DP_DPCD_REV at 0000h could be at a value less than + * the true capability of the panel. The only way to check is to + * then compare 0000h and 2200h. + */ + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) + return 0; + + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext, + sizeof(dpcd_ext)); + if (ret < 0) + return ret; + if (ret != sizeof(dpcd_ext)) + return -EIO; + + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", + aux->name, dpcd[DP_DPCD_REV], + dpcd_ext[DP_DPCD_REV]); + return 0; + } + + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) + return 0; + + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); + + return 0; +} + +/** + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if + * available + * @aux: DisplayPort AUX channel + * @dpcd: Buffer to store the resulting DPCD in + * + * Attempts to read the base DPCD caps for @aux. Additionally, this function + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if + * present. + * + * Returns: %0 if the DPCD was read successfully, negative error code + * otherwise. + */ +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); + if (ret < 0) + return ret; + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0) + return -EIO; + + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); + if (ret < 0) + return ret; + + DRM_DEBUG_KMS("%s: DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + return ret; +} +EXPORT_SYMBOL(drm_dp_read_dpcd_caps); + /** * drm_dp_read_downstream_info() - read DPCD downstream port info if available * @aux: DisplayPort AUX channel -- cgit v1.2.1 From 637f7240f602c078070cd2373845b7a80b59ae3f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:37 +0300 Subject: drm/dp: Dump downstream facing port caps MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It helps when the logs have a dump of the DFP capabilities. v2: Move the dumping to the new helper Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-2-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 1e7c638873c8..c21bbfc3d714 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -545,8 +545,13 @@ int drm_dp_read_downstream_info(struct drm_dp_aux *aux, ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len); if (ret < 0) return ret; + if (ret != len) + return -EIO; + + DRM_DEBUG_KMS("%s: DPCD DFP: %*ph\n", + aux->name, len, downstream_ports); - return ret == len ? 0 : -EIO; + return 0; } EXPORT_SYMBOL(drm_dp_read_downstream_info); -- cgit v1.2.1 From 38784f6f880580cbe168edbe7ba38c161dee3216 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:42 +0300 Subject: drm/dp: Add helpers to identify downstream facing port types MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a few helpers to let us better identify which kind of DFP we're dealing with. v2: Use Returns: for kdoc (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-7-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 60 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index c21bbfc3d714..56a3ba147713 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -363,6 +363,66 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); +static bool is_edid_digital_input_dp(const struct edid *edid) +{ + return edid && edid->revision >= 4 && + edid->input & DRM_EDID_INPUT_DIGITAL && + (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; +} + +/** + * drm_dp_downstream_is_type() - is the downstream facing port of certain type? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Caveat: Only works with DPCD 1.1+ port caps. + * + * Returns: whether the downstream facing port matches the type. + */ +bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], u8 type) +{ + return drm_dp_is_branch(dpcd) && + dpcd[DP_DPCD_REV] >= 0x11 && + (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; +} +EXPORT_SYMBOL(drm_dp_downstream_is_type); + +/** + * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: whether the downstream facing port is TMDS (HDMI/DVI). + */ +bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return true; + default: + return false; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return false; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + return true; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_is_tmds); + /** * drm_dp_send_real_edid_checksum() - send back real edid checksum value * @aux: DisplayPort AUX channel -- cgit v1.2.1 From 42f2562ca1b52810415107d919535c552196384e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:43 +0300 Subject: drm/dp: Pimp drm_dp_downstream_max_bpc() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Deal with more cases in drm_dp_downstream_max_bpc(): - DPCD 1.0 -> assume 8bpc for non-DP - DPCD 1.1+ DP (or DP++ with DP sink) -> allow anything - DPCD 1.1+ TMDS -> check the caps, assume 8bpc if the value is crap - anything else -> assume 8bpc v2: Use Returns: for kdoc (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-8-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 59 +++++++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 23 deletions(-) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 56a3ba147713..e1af400df65c 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -653,36 +653,44 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], EXPORT_SYMBOL(drm_dp_downstream_max_clock); /** - * drm_dp_downstream_max_bpc() - extract branch device max + * drm_dp_downstream_max_bpc() - extract downstream facing port max * bits per component * @dpcd: DisplayPort configuration data - * @port_cap: port capabilities - * - * See also: - * drm_dp_read_downstream_info() - * drm_dp_downstream_max_clock() + * @port_cap: downstream facing port capabilities + * @edid: EDID * * Returns: Max bpc on success or 0 if max bpc not defined */ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4]) + const u8 port_cap[4], + const struct edid *edid) { - int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; - bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DETAILED_CAP_INFO_AVAILABLE; - int bpc; - - if (!detailed_cap_info) + if (!drm_dp_is_branch(dpcd)) return 0; - switch (type) { - case DP_DS_PORT_TYPE_VGA: - case DP_DS_PORT_TYPE_DVI: - case DP_DS_PORT_TYPE_HDMI: + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_DP: + return 0; + default: + return 8; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return 0; case DP_DS_PORT_TYPE_DP_DUALMODE: - bpc = port_cap[2] & DP_DS_MAX_BPC_MASK; + if (is_edid_digital_input_dp(edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 8; - switch (bpc) { + switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { case DP_DS_8BPC: return 8; case DP_DS_10BPC: @@ -691,10 +699,12 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], return 12; case DP_DS_16BPC: return 16; + default: + return 8; } - fallthrough; + break; default: - return 0; + return 8; } } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); @@ -717,12 +727,15 @@ EXPORT_SYMBOL(drm_dp_downstream_id); * @m: pointer for debugfs file * @dpcd: DisplayPort configuration data * @port_cap: port capabilities + * @edid: EDID * @aux: DisplayPort AUX channel * */ void drm_dp_downstream_debug(struct seq_file *m, const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4], struct drm_dp_aux *aux) + const u8 port_cap[4], + const struct edid *edid, + struct drm_dp_aux *aux) { bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE; @@ -789,7 +802,7 @@ void drm_dp_downstream_debug(struct seq_file *m, seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); } - bpc = drm_dp_downstream_max_bpc(dpcd, port_cap); + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid); if (bpc > 0) seq_printf(m, "\t\tMax bpc: %d\n", bpc); -- cgit v1.2.1 From b770e84311451506d822574595631009267c7e78 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:44 +0300 Subject: drm/dp: Redo drm_dp_downstream_max_clock() as drm_dp_downstream_max_dotclock() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We want to differentiate between the DFP dotclock and TMDS clock limits. Let's convert the current thing to just give us the dotclock limit. v2: Use Returns: for kdoc (Lyude) Fix up nouveau code too Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-9-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 46 ++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 30 deletions(-) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index e1af400df65c..8767ad7f6690 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -616,41 +616,32 @@ int drm_dp_read_downstream_info(struct drm_dp_aux *aux, EXPORT_SYMBOL(drm_dp_read_downstream_info); /** - * drm_dp_downstream_max_clock() - extract branch device max - * pixel rate for legacy VGA - * converter or max TMDS clock - * rate for others + * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock * @dpcd: DisplayPort configuration data * @port_cap: port capabilities * - * See also: - * drm_dp_read_downstream_info() - * drm_dp_downstream_max_bpc() - * - * Returns: Max clock in kHz on success or 0 if max clock not defined + * Returns: Downstream facing port max dot clock in kHz on success, + * or 0 if max clock not defined */ -int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4]) +int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) { - int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; - bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DETAILED_CAP_INFO_AVAILABLE; + if (!drm_dp_is_branch(dpcd)) + return 0; - if (!detailed_cap_info) + if (dpcd[DP_DPCD_REV] < 0x11) return 0; - switch (type) { + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { case DP_DS_PORT_TYPE_VGA: - return port_cap[1] * 8 * 1000; - case DP_DS_PORT_TYPE_DVI: - case DP_DS_PORT_TYPE_HDMI: - case DP_DS_PORT_TYPE_DP_DUALMODE: - return port_cap[1] * 2500; + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 0; + return port_cap[1] * 8000; default: return 0; } } -EXPORT_SYMBOL(drm_dp_downstream_max_clock); +EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); /** * drm_dp_downstream_max_bpc() - extract downstream facing port max @@ -793,14 +784,9 @@ void drm_dp_downstream_debug(struct seq_file *m, seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]); if (detailed_cap_info) { - clk = drm_dp_downstream_max_clock(dpcd, port_cap); - - if (clk > 0) { - if (type == DP_DS_PORT_TYPE_VGA) - seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); - else - seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); - } + clk = drm_dp_downstream_max_dotclock(dpcd, port_cap); + if (clk > 0) + seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid); -- cgit v1.2.1 From 6509ca051abf4ff60d63732badcb2173a715f741 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:46 +0300 Subject: drm/dp: Add drm_dp_downstream_{min,max}_tmds_clock() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add helpers to get the TMDS clock limits for HDMI/DVI downstream facing ports. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-11-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 116 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 8767ad7f6690..5d8c9bd700c9 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -643,6 +643,114 @@ int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_dotclock); +/** + * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 165000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return 0; + /* + * It's left up to the driver to check the + * DP dual mode adapter's max TMDS clock. + * + * Unfortunatley it looks like branch devices + * may not fordward that the DP dual mode i2c + * access so we just usually get i2c nak :( + */ + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + /* + * We should perhaps assume 165 MHz when detailed cap + * info is not available. But looks like many typical + * branch devices fall into that category and so we'd + * probably end up with users complaining that they can't + * get high resolution modes with their favorite dongle. + * + * So let's limit to 300 MHz instead since DPCD 1.4 + * HDMI 2.0 DFPs are required to have the detailed cap + * info. So it's more likely we're dealing with a HDMI 1.4 + * compatible* device here. + */ + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 300000; + return port_cap[1] * 2500; + case DP_DS_PORT_TYPE_DVI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 165000; + /* FIXME what to do about DVI dual link? */ + return port_cap[1] * 2500; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock); + +/** + * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success, + * or 0 if max TMDS clock not defined + */ +int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (!drm_dp_is_branch(dpcd)) + return 0; + + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return 25000; + default: + return 0; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + /* + * Unclear whether the protocol converter could + * utilize pixel replication. Assume it won't. + */ + return 25000; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock); + /** * drm_dp_downstream_max_bpc() - extract downstream facing port max * bits per component @@ -788,6 +896,14 @@ void drm_dp_downstream_debug(struct seq_file *m, if (clk > 0) seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk); + clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, edid); + if (clk > 0) + seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); + + clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, edid); + if (clk > 0) + seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk); + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid); if (bpc > 0) -- cgit v1.2.1 From 7af655bce275f49b200b552921e55673624943c5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:49 +0300 Subject: drm/dp: Add drm_dp_downstream_mode() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The downstream facing port caps in the DPCD can give us a hint as to what kind of display mode the sink can use if it doesn't have an EDID. Use that information to pick a suitable mode. v2: Use Returns: for kdoc (Lyude) Add kdocs for drm_display_mode_from_cea_vic() (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-14-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 54 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 5d8c9bd700c9..63ac94c54e95 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -808,6 +808,60 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); +/** + * drm_dp_downstream_mode() - return a mode for downstream facing port + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Provides a suitable mode for downstream facing ports without EDID. + * + * Returns: A new drm_display_mode on success or NULL on failure + */ +struct drm_display_mode * +drm_dp_downstream_mode(struct drm_device *dev, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) + +{ + u8 vic; + + if (!drm_dp_is_branch(dpcd)) + return NULL; + + if (dpcd[DP_DPCD_REV] < 0x11) + return NULL; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_NON_EDID: + switch (port_cap[0] & DP_DS_NON_EDID_MASK) { + case DP_DS_NON_EDID_720x480i_60: + vic = 6; + break; + case DP_DS_NON_EDID_720x480i_50: + vic = 21; + break; + case DP_DS_NON_EDID_1920x1080i_60: + vic = 5; + break; + case DP_DS_NON_EDID_1920x1080i_50: + vic = 20; + break; + case DP_DS_NON_EDID_1280x720_60: + vic = 4; + break; + case DP_DS_NON_EDID_1280x720_50: + vic = 19; + break; + default: + return NULL; + } + return drm_display_mode_from_cea_vic(dev, vic); + default: + return NULL; + } +} +EXPORT_SYMBOL(drm_dp_downstream_mode); + /** * drm_dp_downstream_id() - identify branch device * @aux: DisplayPort AUX channel -- cgit v1.2.1 From 2ef8d0f7de0ec0bc30c48e5f544a6082eb03e9f7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:53 +0300 Subject: drm/dp: Add helpers for DFP YCbCr 4:2:0 handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add helpers to determine whether the DFP supports YCbCr 4:2:0 passthrough or YCbCr 4:4:4->4:2:0 conversion. v2: Add kdocs (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-18-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 60 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 63ac94c54e95..90807a6b415c 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -808,6 +808,66 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); +/** + * drm_dp_downstream_420_passthrough() - determine downstream facing port + * YCbCr 4:2:0 pass-through capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 + */ +bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return true; + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); + +/** + * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port + * YCbCr 4:4:4->4:2:0 conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 + */ +bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); + /** * drm_dp_downstream_mode() - return a mode for downstream facing port * @dpcd: DisplayPort configuration data -- cgit v1.2.1