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, 540 insertions, 0 deletions

diff --git a/sound/firewire/fireface/ff-protocol-latter.c b/sound/firewire/fireface/ff-protocol-latter.c
new file mode 100644
index 000000000..76c3eab36
--- /dev/null
+++ b/sound/firewire/fireface/ff-protocol-latter.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+// ff-protocol-latter.c - a part of driver for RME Fireface series
+//
+// Copyright (c) 2019 Takashi Sakamoto
+
+#include <linux/delay.h>
+
+#include "ff.h"
+
+#define LATTER_STF		0xffff00000004ULL
+#define LATTER_ISOC_CHANNELS	0xffff00000008ULL
+#define LATTER_ISOC_START	0xffff0000000cULL
+#define LATTER_FETCH_MODE	0xffff00000010ULL
+#define LATTER_SYNC_STATUS	0x0000801c0000ULL
+
+// The content of sync status register differs between models.
+//
+// Fireface UCX:
+//  0xf0000000: (unidentified)
+//  0x0f000000: effective rate of sampling clock
+//  0x00f00000: detected rate of word clock on BNC interface
+//  0x000f0000: detected rate of ADAT or S/PDIF on optical interface
+//  0x0000f000: detected rate of S/PDIF on coaxial interface
+//  0x00000e00: effective source of sampling clock
+//    0x00000e00: Internal
+//    0x00000800: (unidentified)
+//    0x00000600: Word clock on BNC interface
+//    0x00000400: ADAT on optical interface
+//    0x00000200: S/PDIF on coaxial or optical interface
+//  0x00000100: Optical interface is used for ADAT signal
+//  0x00000080: (unidentified)
+//  0x00000040: Synchronized to word clock on BNC interface
+//  0x00000020: Synchronized to ADAT or S/PDIF on optical interface
+//  0x00000010: Synchronized to S/PDIF on coaxial interface
+//  0x00000008: (unidentified)
+//  0x00000004: Lock word clock on BNC interface
+//  0x00000002: Lock ADAT or S/PDIF on optical interface
+//  0x00000001: Lock S/PDIF on coaxial interface
+//
+// Fireface 802 (and perhaps UFX):
+//   0xf0000000: effective rate of sampling clock
+//   0x0f000000: detected rate of ADAT-B on 2nd optical interface
+//   0x00f00000: detected rate of ADAT-A on 1st optical interface
+//   0x000f0000: detected rate of AES/EBU on XLR or coaxial interface
+//   0x0000f000: detected rate of word clock on BNC interface
+//   0x00000e00: effective source of sampling clock
+//     0x00000e00: internal
+//     0x00000800: ADAT-B
+//     0x00000600: ADAT-A
+//     0x00000400: AES/EBU
+//     0x00000200: Word clock
+//   0x00000080: Synchronized to ADAT-B on 2nd optical interface
+//   0x00000040: Synchronized to ADAT-A on 1st optical interface
+//   0x00000020: Synchronized to AES/EBU on XLR or 2nd optical interface
+//   0x00000010: Synchronized to word clock on BNC interface
+//   0x00000008: Lock ADAT-B on 2nd optical interface
+//   0x00000004: Lock ADAT-A on 1st optical interface
+//   0x00000002: Lock AES/EBU on XLR or 2nd optical interface
+//   0x00000001: Lock word clock on BNC interface
+//
+// The pattern for rate bits:
+//   0x00: 32.0 kHz
+//   0x01: 44.1 kHz
+//   0x02: 48.0 kHz
+//   0x04: 64.0 kHz
+//   0x05: 88.2 kHz
+//   0x06: 96.0 kHz
+//   0x08: 128.0 kHz
+//   0x09: 176.4 kHz
+//   0x0a: 192.0 kHz
+static int parse_clock_bits(u32 data, unsigned int *rate,
+			    enum snd_ff_clock_src *src,
+			    enum snd_ff_unit_version unit_version)
+{
+	static const struct {
+		unsigned int rate;
+		u32 flag;
+	} *rate_entry, rate_entries[] = {
+		{ 32000,	0x00, },
+		{ 44100,	0x01, },
+		{ 48000,	0x02, },
+		{ 64000,	0x04, },
+		{ 88200,	0x05, },
+		{ 96000,	0x06, },
+		{ 128000,	0x08, },
+		{ 176400,	0x09, },
+		{ 192000,	0x0a, },
+	};
+	static const struct {
+		enum snd_ff_clock_src src;
+		u32 flag;
+	} *clk_entry, *clk_entries, ucx_clk_entries[] = {
+		{ SND_FF_CLOCK_SRC_SPDIF,	0x00000200, },
+		{ SND_FF_CLOCK_SRC_ADAT1,	0x00000400, },
+		{ SND_FF_CLOCK_SRC_WORD,	0x00000600, },
+		{ SND_FF_CLOCK_SRC_INTERNAL,	0x00000e00, },
+	}, ufx_ff802_clk_entries[] = {
+		{ SND_FF_CLOCK_SRC_WORD,	0x00000200, },
+		{ SND_FF_CLOCK_SRC_SPDIF,	0x00000400, },
+		{ SND_FF_CLOCK_SRC_ADAT1,	0x00000600, },
+		{ SND_FF_CLOCK_SRC_ADAT2,	0x00000800, },
+		{ SND_FF_CLOCK_SRC_INTERNAL,	0x00000e00, },
+	};
+	u32 rate_bits;
+	unsigned int clk_entry_count;
+	int i;
+
+	if (unit_version == SND_FF_UNIT_VERSION_UCX) {
+		rate_bits = (data & 0x0f000000) >> 24;
+		clk_entries = ucx_clk_entries;
+		clk_entry_count = ARRAY_SIZE(ucx_clk_entries);
+	} else {
+		rate_bits = (data & 0xf0000000) >> 28;
+		clk_entries = ufx_ff802_clk_entries;
+		clk_entry_count = ARRAY_SIZE(ufx_ff802_clk_entries);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(rate_entries); ++i) {
+		rate_entry = rate_entries + i;
+		if (rate_bits == rate_entry->flag) {
+			*rate = rate_entry->rate;
+			break;
+		}
+	}
+	if (i == ARRAY_SIZE(rate_entries))
+		return -EIO;
+
+	for (i = 0; i < clk_entry_count; ++i) {
+		clk_entry = clk_entries + i;
+		if ((data & 0x000e00) == clk_entry->flag) {
+			*src = clk_entry->src;
+			break;
+		}
+	}
+	if (i == clk_entry_count)
+		return -EIO;
+
+	return 0;
+}
+
+static int latter_get_clock(struct snd_ff *ff, unsigned int *rate,
+			   enum snd_ff_clock_src *src)
+{
+	__le32 reg;
+	u32 data;
+	int err;
+
+	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
+				 LATTER_SYNC_STATUS, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+	data = le32_to_cpu(reg);
+
+	return parse_clock_bits(data, rate, src, ff->unit_version);
+}
+
+static int latter_switch_fetching_mode(struct snd_ff *ff, bool enable)
+{
+	u32 data;
+	__le32 reg;
+
+	if (enable)
+		data = 0x00000000;
+	else
+		data = 0xffffffff;
+	reg = cpu_to_le32(data);
+
+	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				  LATTER_FETCH_MODE, &reg, sizeof(reg), 0);
+}
+
+static int latter_allocate_resources(struct snd_ff *ff, unsigned int rate)
+{
+	enum snd_ff_stream_mode mode;
+	unsigned int code;
+	__le32 reg;
+	unsigned int count;
+	int i;
+	int err;
+
+	// Set the number of data blocks transferred in a second.
+	if (rate % 48000 == 0)
+		code = 0x04;
+	else if (rate % 44100 == 0)
+		code = 0x02;
+	else if (rate % 32000 == 0)
+		code = 0x00;
+	else
+		return -EINVAL;
+
+	if (rate >= 64000 && rate < 128000)
+		code |= 0x08;
+	else if (rate >= 128000)
+		code |= 0x10;
+
+	reg = cpu_to_le32(code);
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 LATTER_STF, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+
+	// Confirm to shift transmission clock.
+	count = 0;
+	while (count++ < 10) {
+		unsigned int curr_rate;
+		enum snd_ff_clock_src src;
+
+		err = latter_get_clock(ff, &curr_rate, &src);
+		if (err < 0)
+			return err;
+
+		if (curr_rate == rate)
+			break;
+	}
+	if (count > 10)
+		return -ETIMEDOUT;
+
+	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); ++i) {
+		if (rate == amdtp_rate_table[i])
+			break;
+	}
+	if (i == ARRAY_SIZE(amdtp_rate_table))
+		return -EINVAL;
+
+	err = snd_ff_stream_get_multiplier_mode(i, &mode);
+	if (err < 0)
+		return err;
+
+	// Keep resources for in-stream.
+	ff->tx_resources.channels_mask = 0x00000000000000ffuLL;
+	err = fw_iso_resources_allocate(&ff->tx_resources,
+			amdtp_stream_get_max_payload(&ff->tx_stream),
+			fw_parent_device(ff->unit)->max_speed);
+	if (err < 0)
+		return err;
+
+	// Keep resources for out-stream.
+	ff->rx_resources.channels_mask = 0x00000000000000ffuLL;
+	err = fw_iso_resources_allocate(&ff->rx_resources,
+			amdtp_stream_get_max_payload(&ff->rx_stream),
+			fw_parent_device(ff->unit)->max_speed);
+	if (err < 0)
+		fw_iso_resources_free(&ff->tx_resources);
+
+	return err;
+}
+
+static int latter_begin_session(struct snd_ff *ff, unsigned int rate)
+{
+	unsigned int generation = ff->rx_resources.generation;
+	unsigned int flag;
+	u32 data;
+	__le32 reg;
+	int err;
+
+	if (ff->unit_version == SND_FF_UNIT_VERSION_UCX) {
+		// For Fireface UCX. Always use the maximum number of data
+		// channels in data block of packet.
+		if (rate >= 32000 && rate <= 48000)
+			flag = 0x92;
+		else if (rate >= 64000 && rate <= 96000)
+			flag = 0x8e;
+		else if (rate >= 128000 && rate <= 192000)
+			flag = 0x8c;
+		else
+			return -EINVAL;
+	} else {
+		// For Fireface UFX and 802. Due to bandwidth limitation on
+		// IEEE 1394a (400 Mbps), Analog 1-12 and AES are available
+		// without any ADAT at quadruple speed.
+		if (rate >= 32000 && rate <= 48000)
+			flag = 0x9e;
+		else if (rate >= 64000 && rate <= 96000)
+			flag = 0x96;
+		else if (rate >= 128000 && rate <= 192000)
+			flag = 0x8e;
+		else
+			return -EINVAL;
+	}
+
+	if (generation != fw_parent_device(ff->unit)->card->generation) {
+		err = fw_iso_resources_update(&ff->tx_resources);
+		if (err < 0)
+			return err;
+
+		err = fw_iso_resources_update(&ff->rx_resources);
+		if (err < 0)
+			return err;
+	}
+
+	data = (ff->tx_resources.channel << 8) | ff->rx_resources.channel;
+	reg = cpu_to_le32(data);
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 LATTER_ISOC_CHANNELS, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+
+	reg = cpu_to_le32(flag);
+	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				  LATTER_ISOC_START, &reg, sizeof(reg), 0);
+}
+
+static void latter_finish_session(struct snd_ff *ff)
+{
+	__le32 reg;
+
+	reg = cpu_to_le32(0x00000000);
+	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+			   LATTER_ISOC_START, &reg, sizeof(reg), 0);
+}
+
+static void latter_dump_status(struct snd_ff *ff, struct snd_info_buffer *buffer)
+{
+	static const struct {
+		char *const label;
+		u32 locked_mask;
+		u32 synced_mask;
+	} *clk_entry, *clk_entries, ucx_clk_entries[] = {
+		{ "S/PDIF",	0x00000001, 0x00000010, },
+		{ "ADAT",	0x00000002, 0x00000020, },
+		{ "WDClk",	0x00000004, 0x00000040, },
+	}, ufx_ff802_clk_entries[] = {
+		{ "WDClk",	0x00000001, 0x00000010, },
+		{ "AES/EBU",	0x00000002, 0x00000020, },
+		{ "ADAT-A",	0x00000004, 0x00000040, },
+		{ "ADAT-B",	0x00000008, 0x00000080, },
+	};
+	__le32 reg;
+	u32 data;
+	unsigned int rate;
+	enum snd_ff_clock_src src;
+	const char *label;
+	unsigned int clk_entry_count;
+	int i;
+	int err;
+
+	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
+				 LATTER_SYNC_STATUS, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return;
+	data = le32_to_cpu(reg);
+
+	snd_iprintf(buffer, "External source detection:\n");
+
+	if (ff->unit_version == SND_FF_UNIT_VERSION_UCX) {
+		clk_entries = ucx_clk_entries;
+		clk_entry_count = ARRAY_SIZE(ucx_clk_entries);
+	} else {
+		clk_entries = ufx_ff802_clk_entries;
+		clk_entry_count = ARRAY_SIZE(ufx_ff802_clk_entries);
+	}
+
+	for (i = 0; i < clk_entry_count; ++i) {
+		clk_entry = clk_entries + i;
+		snd_iprintf(buffer, "%s: ", clk_entry->label);
+		if (data & clk_entry->locked_mask) {
+			if (data & clk_entry->synced_mask)
+				snd_iprintf(buffer, "sync\n");
+			else
+				snd_iprintf(buffer, "lock\n");
+		} else {
+			snd_iprintf(buffer, "none\n");
+		}
+	}
+
+	err = parse_clock_bits(data, &rate, &src, ff->unit_version);
+	if (err < 0)
+		return;
+	label = snd_ff_proc_get_clk_label(src);
+	if (!label)
+		return;
+
+	snd_iprintf(buffer, "Referred clock: %s %d\n", label, rate);
+}
+
+// NOTE: transactions are transferred within 0x00-0x7f in allocated range of
+// address. This seems to be for check of discontinuity in receiver side.
+//
+// Like Fireface 400, drivers can select one of 4 options for lower 4 bytes of
+// destination address by bit flags in quadlet register (little endian) at
+// 0x'ffff'0000'0014:
+//
+// bit flags: offset of destination address
+// - 0x00002000: 0x'....'....'0000'0000
+// - 0x00004000: 0x'....'....'0000'0080
+// - 0x00008000: 0x'....'....'0000'0100
+// - 0x00010000: 0x'....'....'0000'0180
+//
+// Drivers can suppress the device to transfer asynchronous transactions by
+// clear these bit flags.
+//
+// Actually, the register is write-only and includes the other settings such as
+// input attenuation. This driver allocates for the first option
+// (0x'....'....'0000'0000) and expects userspace application to configure the
+// register for it.
+static void latter_handle_midi_msg(struct snd_ff *ff, unsigned int offset,
+				   __le32 *buf, size_t length)
+{
+	u32 data = le32_to_cpu(*buf);
+	unsigned int index = (data & 0x000000f0) >> 4;
+	u8 byte[3];
+	struct snd_rawmidi_substream *substream;
+	unsigned int len;
+
+	if (index >= ff->spec->midi_in_ports)
+		return;
+
+	switch (data & 0x0000000f) {
+	case 0x00000008:
+	case 0x00000009:
+	case 0x0000000a:
+	case 0x0000000b:
+	case 0x0000000e:
+		len = 3;
+		break;
+	case 0x0000000c:
+	case 0x0000000d:
+		len = 2;
+		break;
+	default:
+		len = data & 0x00000003;
+		if (len == 0)
+			len = 3;
+		break;
+	}
+
+	byte[0] = (data & 0x0000ff00) >> 8;
+	byte[1] = (data & 0x00ff0000) >> 16;
+	byte[2] = (data & 0xff000000) >> 24;
+
+	substream = READ_ONCE(ff->tx_midi_substreams[index]);
+	if (substream)
+		snd_rawmidi_receive(substream, byte, len);
+}
+
+/*
+ * When return minus value, given argument is not MIDI status.
+ * When return 0, given argument is a beginning of system exclusive.
+ * When return the others, given argument is MIDI data.
+ */
+static inline int calculate_message_bytes(u8 status)
+{
+	switch (status) {
+	case 0xf6:	/* Tune request. */
+	case 0xf8:	/* Timing clock. */
+	case 0xfa:	/* Start. */
+	case 0xfb:	/* Continue. */
+	case 0xfc:	/* Stop. */
+	case 0xfe:	/* Active sensing. */
+	case 0xff:	/* System reset. */
+		return 1;
+	case 0xf1:	/* MIDI time code quarter frame. */
+	case 0xf3:	/* Song select. */
+		return 2;
+	case 0xf2:	/* Song position pointer. */
+		return 3;
+	case 0xf0:	/* Exclusive. */
+		return 0;
+	case 0xf7:	/* End of exclusive. */
+		break;
+	case 0xf4:	/* Undefined. */
+	case 0xf5:	/* Undefined. */
+	case 0xf9:	/* Undefined. */
+	case 0xfd:	/* Undefined. */
+		break;
+	default:
+		switch (status & 0xf0) {
+		case 0x80:	/* Note on. */
+		case 0x90:	/* Note off. */
+		case 0xa0:	/* Polyphonic key pressure. */
+		case 0xb0:	/* Control change and Mode change. */
+		case 0xe0:	/* Pitch bend change. */
+			return 3;
+		case 0xc0:	/* Program change. */
+		case 0xd0:	/* Channel pressure. */
+			return 2;
+		default:
+		break;
+		}
+	break;
+	}
+
+	return -EINVAL;
+}
+
+static int latter_fill_midi_msg(struct snd_ff *ff,
+				struct snd_rawmidi_substream *substream,
+				unsigned int port)
+{
+	u32 data = {0};
+	u8 *buf = (u8 *)&data;
+	int consumed;
+
+	buf[0] = port << 4;
+	consumed = snd_rawmidi_transmit_peek(substream, buf + 1, 3);
+	if (consumed <= 0)
+		return consumed;
+
+	if (!ff->on_sysex[port]) {
+		if (buf[1] != 0xf0) {
+			if (consumed < calculate_message_bytes(buf[1]))
+				return 0;
+		} else {
+			// The beginning of exclusives.
+			ff->on_sysex[port] = true;
+		}
+
+		buf[0] |= consumed;
+	} else {
+		if (buf[1] != 0xf7) {
+			if (buf[2] == 0xf7 || buf[3] == 0xf7) {
+				// Transfer end code at next time.
+				consumed -= 1;
+			}
+
+			buf[0] |= consumed;
+		} else {
+			// The end of exclusives.
+			ff->on_sysex[port] = false;
+			consumed = 1;
+			buf[0] |= 0x0f;
+		}
+	}
+
+	ff->msg_buf[port][0] = cpu_to_le32(data);
+	ff->rx_bytes[port] = consumed;
+
+	return 1;
+}
+
+const struct snd_ff_protocol snd_ff_protocol_latter = {
+	.handle_midi_msg	= latter_handle_midi_msg,
+	.fill_midi_msg		= latter_fill_midi_msg,
+	.get_clock		= latter_get_clock,
+	.switch_fetching_mode	= latter_switch_fetching_mode,
+	.allocate_resources	= latter_allocate_resources,
+	.begin_session		= latter_begin_session,
+	.finish_session		= latter_finish_session,
+	.dump_status		= latter_dump_status,
+};