Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 766 insertions, 0 deletions

diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
new file mode 100644
index 000000000..ab55453f2
--- /dev/null
+++ b/include/drm/display/drm_dp_helper.h
@@ -0,0 +1,766 @@
+/*
+ * Copyright © 2008 Keith Packard
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef _DRM_DP_HELPER_H_
+#define _DRM_DP_HELPER_H_
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+
+#include <drm/display/drm_dp.h>
+#include <drm/drm_connector.h>
+
+struct drm_device;
+struct drm_dp_aux;
+struct drm_panel;
+
+bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
+			  int lane_count);
+bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
+			      int lane_count);
+u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
+				     int lane);
+u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
+					  int lane);
+u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
+				   int lane);
+
+int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				     enum drm_dp_phy dp_phy, bool uhbr);
+int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				 enum drm_dp_phy dp_phy, bool uhbr);
+
+void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
+					    const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+void drm_dp_lttpr_link_train_clock_recovery_delay(void);
+void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
+					const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
+					      const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
+
+int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux);
+bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
+					  int lane_count);
+bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
+					int lane_count);
+bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
+bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE]);
+bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE]);
+
+u8 drm_dp_link_rate_to_bw_code(int link_rate);
+int drm_dp_bw_code_to_link_rate(u8 link_bw);
+
+const char *drm_dp_phy_name(enum drm_dp_phy dp_phy);
+
+/**
+ * struct drm_dp_vsc_sdp - drm DP VSC SDP
+ *
+ * This structure represents a DP VSC SDP of drm
+ * It is based on DP 1.4 spec [Table 2-116: VSC SDP Header Bytes] and
+ * [Table 2-117: VSC SDP Payload for DB16 through DB18]
+ *
+ * @sdp_type: secondary-data packet type
+ * @revision: revision number
+ * @length: number of valid data bytes
+ * @pixelformat: pixel encoding format
+ * @colorimetry: colorimetry format
+ * @bpc: bit per color
+ * @dynamic_range: dynamic range information
+ * @content_type: CTA-861-G defines content types and expected processing by a sink device
+ */
+struct drm_dp_vsc_sdp {
+	unsigned char sdp_type;
+	unsigned char revision;
+	unsigned char length;
+	enum dp_pixelformat pixelformat;
+	enum dp_colorimetry colorimetry;
+	int bpc;
+	enum dp_dynamic_range dynamic_range;
+	enum dp_content_type content_type;
+};
+
+void drm_dp_vsc_sdp_log(const char *level, struct device *dev,
+			const struct drm_dp_vsc_sdp *vsc);
+
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
+
+static inline int
+drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
+}
+
+static inline u8
+drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
+}
+
+static inline bool
+drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x11 &&
+		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
+}
+
+static inline bool
+drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x11 &&
+		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
+}
+
+static inline bool
+drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x12 &&
+		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
+}
+
+static inline bool
+drm_dp_max_downspread(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x11 ||
+		dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
+}
+
+static inline bool
+drm_dp_tps4_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x14 &&
+		dpcd[DP_MAX_DOWNSPREAD] & DP_TPS4_SUPPORTED;
+}
+
+static inline u8
+drm_dp_training_pattern_mask(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return (dpcd[DP_DPCD_REV] >= 0x14) ? DP_TRAINING_PATTERN_MASK_1_4 :
+		DP_TRAINING_PATTERN_MASK;
+}
+
+static inline bool
+drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
+}
+
+/* DP/eDP DSC support */
+u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
+				   bool is_edp);
+u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
+int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
+					 u8 dsc_bpc[3]);
+
+static inline bool
+drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
+{
+	return dsc_dpcd[DP_DSC_SUPPORT - DP_DSC_SUPPORT] &
+		DP_DSC_DECOMPRESSION_IS_SUPPORTED;
+}
+
+static inline u16
+drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
+{
+	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
+		(dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
+		 DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK <<
+		 DP_DSC_MAX_BITS_PER_PIXEL_HI_SHIFT);
+}
+
+static inline u32
+drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
+{
+	/* Max Slicewidth = Number of Pixels * 320 */
+	return dsc_dpcd[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] *
+		DP_DSC_SLICE_WIDTH_MULTIPLIER;
+}
+
+/* Forward Error Correction Support on DP 1.4 */
+static inline bool
+drm_dp_sink_supports_fec(const u8 fec_capable)
+{
+	return fec_capable & DP_FEC_CAPABLE;
+}
+
+static inline bool
+drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
+}
+
+static inline bool
+drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_EDP_CONFIGURATION_CAP] &
+			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
+}
+
+/* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
+static inline bool
+drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
+		DP_MSA_TIMING_PAR_IGNORED;
+}
+
+/**
+ * drm_edp_backlight_supported() - Check an eDP DPCD for VESA backlight support
+ * @edp_dpcd: The DPCD to check
+ *
+ * Note that currently this function will return %false for panels which support various DPCD
+ * backlight features but which require the brightness be set through PWM, and don't support setting
+ * the brightness level via the DPCD.
+ *
+ * Returns: %True if @edp_dpcd indicates that VESA backlight controls are supported, %false
+ * otherwise
+ */
+static inline bool
+drm_edp_backlight_supported(const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
+{
+	return !!(edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP);
+}
+
+/*
+ * DisplayPort AUX channel
+ */
+
+/**
+ * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
+ * @address: address of the (first) register to access
+ * @request: contains the type of transaction (see DP_AUX_* macros)
+ * @reply: upon completion, contains the reply type of the transaction
+ * @buffer: pointer to a transmission or reception buffer
+ * @size: size of @buffer
+ */
+struct drm_dp_aux_msg {
+	unsigned int address;
+	u8 request;
+	u8 reply;
+	void *buffer;
+	size_t size;
+};
+
+struct cec_adapter;
+struct edid;
+struct drm_connector;
+
+/**
+ * struct drm_dp_aux_cec - DisplayPort CEC-Tunneling-over-AUX
+ * @lock: mutex protecting this struct
+ * @adap: the CEC adapter for CEC-Tunneling-over-AUX support.
+ * @connector: the connector this CEC adapter is associated with
+ * @unregister_work: unregister the CEC adapter
+ */
+struct drm_dp_aux_cec {
+	struct mutex lock;
+	struct cec_adapter *adap;
+	struct drm_connector *connector;
+	struct delayed_work unregister_work;
+};
+
+/**
+ * struct drm_dp_aux - DisplayPort AUX channel
+ *
+ * An AUX channel can also be used to transport I2C messages to a sink. A
+ * typical application of that is to access an EDID that's present in the sink
+ * device. The @transfer() function can also be used to execute such
+ * transactions. The drm_dp_aux_register() function registers an I2C adapter
+ * that can be passed to drm_probe_ddc(). Upon removal, drivers should call
+ * drm_dp_aux_unregister() to remove the I2C adapter. The I2C adapter uses long
+ * transfers by default; if a partial response is received, the adapter will
+ * drop down to the size given by the partial response for this transaction
+ * only.
+ */
+struct drm_dp_aux {
+	/**
+	 * @name: user-visible name of this AUX channel and the
+	 * I2C-over-AUX adapter.
+	 *
+	 * It's also used to specify the name of the I2C adapter. If set
+	 * to %NULL, dev_name() of @dev will be used.
+	 */
+	const char *name;
+
+	/**
+	 * @ddc: I2C adapter that can be used for I2C-over-AUX
+	 * communication
+	 */
+	struct i2c_adapter ddc;
+
+	/**
+	 * @dev: pointer to struct device that is the parent for this
+	 * AUX channel.
+	 */
+	struct device *dev;
+
+	/**
+	 * @drm_dev: pointer to the &drm_device that owns this AUX channel.
+	 * Beware, this may be %NULL before drm_dp_aux_register() has been
+	 * called.
+	 *
+	 * It should be set to the &drm_device that will be using this AUX
+	 * channel as early as possible. For many graphics drivers this should
+	 * happen before drm_dp_aux_init(), however it's perfectly fine to set
+	 * this field later so long as it's assigned before calling
+	 * drm_dp_aux_register().
+	 */
+	struct drm_device *drm_dev;
+
+	/**
+	 * @crtc: backpointer to the crtc that is currently using this
+	 * AUX channel
+	 */
+	struct drm_crtc *crtc;
+
+	/**
+	 * @hw_mutex: internal mutex used for locking transfers.
+	 *
+	 * Note that if the underlying hardware is shared among multiple
+	 * channels, the driver needs to do additional locking to
+	 * prevent concurrent access.
+	 */
+	struct mutex hw_mutex;
+
+	/**
+	 * @crc_work: worker that captures CRCs for each frame
+	 */
+	struct work_struct crc_work;
+
+	/**
+	 * @crc_count: counter of captured frame CRCs
+	 */
+	u8 crc_count;
+
+	/**
+	 * @transfer: transfers a message representing a single AUX
+	 * transaction.
+	 *
+	 * This is a hardware-specific implementation of how
+	 * transactions are executed that the drivers must provide.
+	 *
+	 * A pointer to a &drm_dp_aux_msg structure describing the
+	 * transaction is passed into this function. Upon success, the
+	 * implementation should return the number of payload bytes that
+	 * were transferred, or a negative error-code on failure.
+	 *
+	 * Helpers will propagate these errors, with the exception of
+	 * the %-EBUSY error, which causes a transaction to be retried.
+	 * On a short, helpers will return %-EPROTO to make it simpler
+	 * to check for failure.
+	 *
+	 * The @transfer() function must only modify the reply field of
+	 * the &drm_dp_aux_msg structure. The retry logic and i2c
+	 * helpers assume this is the case.
+	 *
+	 * Also note that this callback can be called no matter the
+	 * state @dev is in and also no matter what state the panel is
+	 * in. It's expected:
+	 *
+	 * - If the @dev providing the AUX bus is currently unpowered then
+	 *   it will power itself up for the transfer.
+	 *
+	 * - If we're on eDP (using a drm_panel) and the panel is not in a
+	 *   state where it can respond (it's not powered or it's in a
+	 *   low power state) then this function may return an error, but
+	 *   not crash. It's up to the caller of this code to make sure that
+	 *   the panel is powered on if getting an error back is not OK. If a
+	 *   drm_panel driver is initiating a DP AUX transfer it may power
+	 *   itself up however it wants. All other code should ensure that
+	 *   the pre_enable() bridge chain (which eventually calls the
+	 *   drm_panel prepare function) has powered the panel.
+	 */
+	ssize_t (*transfer)(struct drm_dp_aux *aux,
+			    struct drm_dp_aux_msg *msg);
+
+	/**
+	 * @wait_hpd_asserted: wait for HPD to be asserted
+	 *
+	 * This is mainly useful for eDP panels drivers to wait for an eDP
+	 * panel to finish powering on. This is an optional function.
+	 *
+	 * This function will efficiently wait for the HPD signal to be
+	 * asserted. The `wait_us` parameter that is passed in says that we
+	 * know that the HPD signal is expected to be asserted within `wait_us`
+	 * microseconds. This function could wait for longer than `wait_us` if
+	 * the logic in the DP controller has a long debouncing time. The
+	 * important thing is that if this function returns success that the
+	 * DP controller is ready to send AUX transactions.
+	 *
+	 * This function returns 0 if HPD was asserted or -ETIMEDOUT if time
+	 * expired and HPD wasn't asserted. This function should not print
+	 * timeout errors to the log.
+	 *
+	 * The semantics of this function are designed to match the
+	 * readx_poll_timeout() function. That means a `wait_us` of 0 means
+	 * to wait forever. Like readx_poll_timeout(), this function may sleep.
+	 *
+	 * NOTE: this function specifically reports the state of the HPD pin
+	 * that's associated with the DP AUX channel. This is different from
+	 * the HPD concept in much of the rest of DRM which is more about
+	 * physical presence of a display. For eDP, for instance, a display is
+	 * assumed always present even if the HPD pin is deasserted.
+	 */
+	int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us);
+
+	/**
+	 * @i2c_nack_count: Counts I2C NACKs, used for DP validation.
+	 */
+	unsigned i2c_nack_count;
+	/**
+	 * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
+	 */
+	unsigned i2c_defer_count;
+	/**
+	 * @cec: struct containing fields used for CEC-Tunneling-over-AUX.
+	 */
+	struct drm_dp_aux_cec cec;
+	/**
+	 * @is_remote: Is this AUX CH actually using sideband messaging.
+	 */
+	bool is_remote;
+};
+
+int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset);
+ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
+			 void *buffer, size_t size);
+ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
+			  void *buffer, size_t size);
+
+/**
+ * drm_dp_dpcd_readb() - read a single byte from the DPCD
+ * @aux: DisplayPort AUX channel
+ * @offset: address of the register to read
+ * @valuep: location where the value of the register will be stored
+ *
+ * Returns the number of bytes transferred (1) on success, or a negative
+ * error code on failure.
+ */
+static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
+					unsigned int offset, u8 *valuep)
+{
+	return drm_dp_dpcd_read(aux, offset, valuep, 1);
+}
+
+/**
+ * drm_dp_dpcd_writeb() - write a single byte to the DPCD
+ * @aux: DisplayPort AUX channel
+ * @offset: address of the register to write
+ * @value: value to write to the register
+ *
+ * Returns the number of bytes transferred (1) on success, or a negative
+ * error code on failure.
+ */
+static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
+					 unsigned int offset, u8 value)
+{
+	return drm_dp_dpcd_write(aux, offset, &value, 1);
+}
+
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+
+int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
+				 u8 status[DP_LINK_STATUS_SIZE]);
+
+int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
+				     enum drm_dp_phy dp_phy,
+				     u8 link_status[DP_LINK_STATUS_SIZE]);
+
+bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
+				    u8 real_edid_checksum);
+
+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]);
+bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       const u8 port_cap[4], u8 type);
+bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       const u8 port_cap[4],
+			       const struct edid *edid);
+int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				   const u8 port_cap[4]);
+int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				     const u8 port_cap[4],
+				     const struct edid *edid);
+int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				     const u8 port_cap[4],
+				     const struct edid *edid);
+int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			      const u8 port_cap[4],
+			      const struct edid *edid);
+bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				       const u8 port_cap[4]);
+bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+					     const u8 port_cap[4]);
+struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
+						const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+						const u8 port_cap[4]);
+int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
+void drm_dp_downstream_debug(struct seq_file *m,
+			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			     const u8 port_cap[4],
+			     const struct edid *edid,
+			     struct drm_dp_aux *aux);
+enum drm_mode_subconnector
+drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			 const u8 port_cap[4]);
+void drm_dp_set_subconnector_property(struct drm_connector *connector,
+				      enum drm_connector_status status,
+				      const u8 *dpcd,
+				      const u8 port_cap[4]);
+
+struct drm_dp_desc;
+bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
+				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				const struct drm_dp_desc *desc);
+int drm_dp_read_sink_count(struct drm_dp_aux *aux);
+
+int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
+				  const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				  u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
+int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
+			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       enum drm_dp_phy dp_phy,
+			       u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
+int drm_dp_lttpr_count(const u8 cap[DP_LTTPR_COMMON_CAP_SIZE]);
+int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
+int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE]);
+bool drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
+bool drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE]);
+
+void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
+void drm_dp_aux_init(struct drm_dp_aux *aux);
+int drm_dp_aux_register(struct drm_dp_aux *aux);
+void drm_dp_aux_unregister(struct drm_dp_aux *aux);
+
+int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
+int drm_dp_stop_crc(struct drm_dp_aux *aux);
+
+struct drm_dp_dpcd_ident {
+	u8 oui[3];
+	u8 device_id[6];
+	u8 hw_rev;
+	u8 sw_major_rev;
+	u8 sw_minor_rev;
+} __packed;
+
+/**
+ * struct drm_dp_desc - DP branch/sink device descriptor
+ * @ident: DP device identification from DPCD 0x400 (sink) or 0x500 (branch).
+ * @quirks: Quirks; use drm_dp_has_quirk() to query for the quirks.
+ */
+struct drm_dp_desc {
+	struct drm_dp_dpcd_ident ident;
+	u32 quirks;
+};
+
+int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
+		     bool is_branch);
+
+/**
+ * enum drm_dp_quirk - Display Port sink/branch device specific quirks
+ *
+ * Display Port sink and branch devices in the wild have a variety of bugs, try
+ * to collect them here. The quirks are shared, but it's up to the drivers to
+ * implement workarounds for them.
+ */
+enum drm_dp_quirk {
+	/**
+	 * @DP_DPCD_QUIRK_CONSTANT_N:
+	 *
+	 * The device requires main link attributes Mvid and Nvid to be limited
+	 * to 16 bits. So will give a constant value (0x8000) for compatability.
+	 */
+	DP_DPCD_QUIRK_CONSTANT_N,
+	/**
+	 * @DP_DPCD_QUIRK_NO_PSR:
+	 *
+	 * The device does not support PSR even if reports that it supports or
+	 * driver still need to implement proper handling for such device.
+	 */
+	DP_DPCD_QUIRK_NO_PSR,
+	/**
+	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
+	 *
+	 * The device does not set SINK_COUNT to a non-zero value.
+	 * The driver should ignore SINK_COUNT during detection. Note that
+	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
+	 */
+	DP_DPCD_QUIRK_NO_SINK_COUNT,
+	/**
+	 * @DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD:
+	 *
+	 * The device supports MST DSC despite not supporting Virtual DPCD.
+	 * The DSC caps can be read from the physical aux instead.
+	 */
+	DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD,
+	/**
+	 * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS:
+	 *
+	 * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite
+	 * the DP_MAX_LINK_RATE register reporting a lower max multiplier.
+	 */
+	DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
+};
+
+/**
+ * drm_dp_has_quirk() - does the DP device have a specific quirk
+ * @desc: Device descriptor filled by drm_dp_read_desc()
+ * @quirk: Quirk to query for
+ *
+ * Return true if DP device identified by @desc has @quirk.
+ */
+static inline bool
+drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
+{
+	return desc->quirks & BIT(quirk);
+}
+
+/**
+ * struct drm_edp_backlight_info - Probed eDP backlight info struct
+ * @pwmgen_bit_count: The pwmgen bit count
+ * @pwm_freq_pre_divider: The PWM frequency pre-divider value being used for this backlight, if any
+ * @max: The maximum backlight level that may be set
+ * @lsb_reg_used: Do we also write values to the DP_EDP_BACKLIGHT_BRIGHTNESS_LSB register?
+ * @aux_enable: Does the panel support the AUX enable cap?
+ * @aux_set: Does the panel support setting the brightness through AUX?
+ *
+ * This structure contains various data about an eDP backlight, which can be populated by using
+ * drm_edp_backlight_init().
+ */
+struct drm_edp_backlight_info {
+	u8 pwmgen_bit_count;
+	u8 pwm_freq_pre_divider;
+	u16 max;
+
+	bool lsb_reg_used : 1;
+	bool aux_enable : 1;
+	bool aux_set : 1;
+};
+
+int
+drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
+		       u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
+		       u16 *current_level, u8 *current_mode);
+int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
+				u16 level);
+int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
+			     u16 level);
+int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl);
+
+#if IS_ENABLED(CONFIG_DRM_KMS_HELPER) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
+	(IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
+
+int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux);
+
+#else
+
+static inline int drm_panel_dp_aux_backlight(struct drm_panel *panel,
+					     struct drm_dp_aux *aux)
+{
+	return 0;
+}
+
+#endif
+
+#ifdef CONFIG_DRM_DP_CEC
+void drm_dp_cec_irq(struct drm_dp_aux *aux);
+void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
+				   struct drm_connector *connector);
+void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
+void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid);
+void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
+#else
+static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
+{
+}
+
+static inline void
+drm_dp_cec_register_connector(struct drm_dp_aux *aux,
+			      struct drm_connector *connector)
+{
+}
+
+static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
+{
+}
+
+static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
+				       const struct edid *edid)
+{
+}
+
+static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
+{
+}
+
+#endif
+
+/**
+ * struct drm_dp_phy_test_params - DP Phy Compliance parameters
+ * @link_rate: Requested Link rate from DPCD 0x219
+ * @num_lanes: Number of lanes requested by sing through DPCD 0x220
+ * @phy_pattern: DP Phy test pattern from DPCD 0x248
+ * @hbr2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
+ * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
+ * @enhanced_frame_cap: flag for enhanced frame capability.
+ */
+struct drm_dp_phy_test_params {
+	int link_rate;
+	u8 num_lanes;
+	u8 phy_pattern;
+	u8 hbr2_reset[2];
+	u8 custom80[10];
+	bool enhanced_frame_cap;
+};
+
+int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data);
+int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data, u8 dp_rev);
+int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       const u8 port_cap[4]);
+int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
+bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
+int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
+				u8 frl_mode);
+int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
+				u8 frl_type);
+int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
+int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
+
+bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux);
+int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask);
+void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
+					   struct drm_connector *connector);
+bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
+int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
+int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
+int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]);
+int drm_dp_pcon_pps_default(struct drm_dp_aux *aux);
+int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128]);
+int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6]);
+bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+					       const u8 port_cap[4], u8 color_spc);
+int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc);
+
+#endif /* _DRM_DP_HELPER_H_ */