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, 755 insertions, 0 deletions

diff --git a/drivers/w1/slaves/w1_ds28e17.c b/drivers/w1/slaves/w1_ds28e17.c
new file mode 100644
index 000000000..aed10b72f
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds28e17.c
@@ -0,0 +1,755 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	w1_ds28e17.c - w1 family 19 (DS28E17) driver
+ *
+ * Copyright (c) 2016 Jan Kandziora <jjj@gmx.de>
+ */
+
+#include <linux/crc16.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#define CRC16_INIT 0
+
+#include <linux/w1.h>
+
+#define W1_FAMILY_DS28E17 0x19
+
+/* Module setup. */
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Jan Kandziora <jjj@gmx.de>");
+MODULE_DESCRIPTION("w1 family 19 driver for DS28E17, 1-wire to I2C master bridge");
+MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS28E17));
+
+
+/* Default I2C speed to be set when a DS28E17 is detected. */
+static int i2c_speed = 100;
+module_param_named(speed, i2c_speed, int, (S_IRUSR | S_IWUSR));
+MODULE_PARM_DESC(speed, "Default I2C speed to be set when a DS28E17 is detected");
+
+/* Default I2C stretch value to be set when a DS28E17 is detected. */
+static char i2c_stretch = 1;
+module_param_named(stretch, i2c_stretch, byte, (S_IRUSR | S_IWUSR));
+MODULE_PARM_DESC(stretch, "Default I2C stretch value to be set when a DS28E17 is detected");
+
+/* DS28E17 device command codes. */
+#define W1_F19_WRITE_DATA_WITH_STOP      0x4B
+#define W1_F19_WRITE_DATA_NO_STOP        0x5A
+#define W1_F19_WRITE_DATA_ONLY           0x69
+#define W1_F19_WRITE_DATA_ONLY_WITH_STOP 0x78
+#define W1_F19_READ_DATA_WITH_STOP       0x87
+#define W1_F19_WRITE_READ_DATA_WITH_STOP 0x2D
+#define W1_F19_WRITE_CONFIGURATION       0xD2
+#define W1_F19_READ_CONFIGURATION        0xE1
+#define W1_F19_ENABLE_SLEEP_MODE         0x1E
+#define W1_F19_READ_DEVICE_REVISION      0xC4
+
+/* DS28E17 status bits */
+#define W1_F19_STATUS_CRC     0x01
+#define W1_F19_STATUS_ADDRESS 0x02
+#define W1_F19_STATUS_START   0x08
+
+/*
+ * Maximum number of I2C bytes to transfer within one CRC16 protected onewire
+ * command.
+ * */
+#define W1_F19_WRITE_DATA_LIMIT 255
+
+/* Maximum number of I2C bytes to read with one onewire command. */
+#define W1_F19_READ_DATA_LIMIT 255
+
+/* Constants for calculating the busy sleep. */
+#define W1_F19_BUSY_TIMEBASES { 90, 23, 10 }
+#define W1_F19_BUSY_GRATUITY  1000
+
+/* Number of checks for the busy flag before timeout. */
+#define W1_F19_BUSY_CHECKS 1000
+
+
+/* Slave specific data. */
+struct w1_f19_data {
+	u8 speed;
+	u8 stretch;
+	struct i2c_adapter adapter;
+};
+
+
+/* Wait a while until the busy flag clears. */
+static int w1_f19_i2c_busy_wait(struct w1_slave *sl, size_t count)
+{
+	const unsigned long timebases[3] = W1_F19_BUSY_TIMEBASES;
+	struct w1_f19_data *data = sl->family_data;
+	unsigned int checks;
+
+	/* Check the busy flag first in any case.*/
+	if (w1_touch_bit(sl->master, 1) == 0)
+		return 0;
+
+	/*
+	 * Do a generously long sleep in the beginning,
+	 * as we have to wait at least this time for all
+	 * the I2C bytes at the given speed to be transferred.
+	 */
+	usleep_range(timebases[data->speed] * (data->stretch) * count,
+		timebases[data->speed] * (data->stretch) * count
+		+ W1_F19_BUSY_GRATUITY);
+
+	/* Now continusly check the busy flag sent by the DS28E17. */
+	checks = W1_F19_BUSY_CHECKS;
+	while ((checks--) > 0) {
+		/* Return success if the busy flag is cleared. */
+		if (w1_touch_bit(sl->master, 1) == 0)
+			return 0;
+
+		/* Wait one non-streched byte timeslot. */
+		udelay(timebases[data->speed]);
+	}
+
+	/* Timeout. */
+	dev_warn(&sl->dev, "busy timeout\n");
+	return -ETIMEDOUT;
+}
+
+
+/* Utility function: result. */
+static size_t w1_f19_error(struct w1_slave *sl, u8 w1_buf[])
+{
+	/* Warnings. */
+	if (w1_buf[0] & W1_F19_STATUS_CRC)
+		dev_warn(&sl->dev, "crc16 mismatch\n");
+	if (w1_buf[0] & W1_F19_STATUS_ADDRESS)
+		dev_warn(&sl->dev, "i2c device not responding\n");
+	if ((w1_buf[0] & (W1_F19_STATUS_CRC | W1_F19_STATUS_ADDRESS)) == 0
+			&& w1_buf[1] != 0) {
+		dev_warn(&sl->dev, "i2c short write, %d bytes not acknowledged\n",
+			w1_buf[1]);
+	}
+
+	/* Check error conditions. */
+	if (w1_buf[0] & W1_F19_STATUS_ADDRESS)
+		return -ENXIO;
+	if (w1_buf[0] & W1_F19_STATUS_START)
+		return -EAGAIN;
+	if (w1_buf[0] != 0 || w1_buf[1] != 0)
+		return -EIO;
+
+	/* All ok. */
+	return 0;
+}
+
+
+/* Utility function: write data to I2C slave, single chunk. */
+static int __w1_f19_i2c_write(struct w1_slave *sl,
+	const u8 *command, size_t command_count,
+	const u8 *buffer, size_t count)
+{
+	u16 crc;
+	int error;
+	u8 w1_buf[2];
+
+	/* Send command and I2C data to DS28E17. */
+	crc = crc16(CRC16_INIT, command, command_count);
+	w1_write_block(sl->master, command, command_count);
+
+	w1_buf[0] = count;
+	crc = crc16(crc, w1_buf, 1);
+	w1_write_8(sl->master, w1_buf[0]);
+
+	crc = crc16(crc, buffer, count);
+	w1_write_block(sl->master, buffer, count);
+
+	w1_buf[0] = ~(crc & 0xFF);
+	w1_buf[1] = ~((crc >> 8) & 0xFF);
+	w1_write_block(sl->master, w1_buf, 2);
+
+	/* Wait until busy flag clears (or timeout). */
+	if (w1_f19_i2c_busy_wait(sl, count + 1) < 0)
+		return -ETIMEDOUT;
+
+	/* Read status from DS28E17. */
+	w1_read_block(sl->master, w1_buf, 2);
+
+	/* Check error conditions. */
+	error = w1_f19_error(sl, w1_buf);
+	if (error < 0)
+		return error;
+
+	/* Return number of bytes written. */
+	return count;
+}
+
+
+/* Write data to I2C slave. */
+static int w1_f19_i2c_write(struct w1_slave *sl, u16 i2c_address,
+	const u8 *buffer, size_t count, bool stop)
+{
+	int result;
+	int remaining = count;
+	const u8 *p;
+	u8 command[2];
+
+	/* Check input. */
+	if (count == 0)
+		return -EOPNOTSUPP;
+
+	/* Check whether we need multiple commands. */
+	if (count <= W1_F19_WRITE_DATA_LIMIT) {
+		/*
+		 * Small data amount. Data can be sent with
+		 * a single onewire command.
+		 */
+
+		/* Send all data to DS28E17. */
+		command[0] = (stop ? W1_F19_WRITE_DATA_WITH_STOP
+			: W1_F19_WRITE_DATA_NO_STOP);
+		command[1] = i2c_address << 1;
+		result = __w1_f19_i2c_write(sl, command, 2, buffer, count);
+	} else {
+		/* Large data amount. Data has to be sent in multiple chunks. */
+
+		/* Send first chunk to DS28E17. */
+		p = buffer;
+		command[0] = W1_F19_WRITE_DATA_NO_STOP;
+		command[1] = i2c_address << 1;
+		result = __w1_f19_i2c_write(sl, command, 2, p,
+			W1_F19_WRITE_DATA_LIMIT);
+		if (result < 0)
+			return result;
+
+		/* Resume to same DS28E17. */
+		if (w1_reset_resume_command(sl->master))
+			return -EIO;
+
+		/* Next data chunk. */
+		p += W1_F19_WRITE_DATA_LIMIT;
+		remaining -= W1_F19_WRITE_DATA_LIMIT;
+
+		while (remaining > W1_F19_WRITE_DATA_LIMIT) {
+			/* Send intermediate chunk to DS28E17. */
+			command[0] = W1_F19_WRITE_DATA_ONLY;
+			result = __w1_f19_i2c_write(sl, command, 1, p,
+					W1_F19_WRITE_DATA_LIMIT);
+			if (result < 0)
+				return result;
+
+			/* Resume to same DS28E17. */
+			if (w1_reset_resume_command(sl->master))
+				return -EIO;
+
+			/* Next data chunk. */
+			p += W1_F19_WRITE_DATA_LIMIT;
+			remaining -= W1_F19_WRITE_DATA_LIMIT;
+		}
+
+		/* Send final chunk to DS28E17. */
+		command[0] = (stop ? W1_F19_WRITE_DATA_ONLY_WITH_STOP
+			: W1_F19_WRITE_DATA_ONLY);
+		result = __w1_f19_i2c_write(sl, command, 1, p, remaining);
+	}
+
+	return result;
+}
+
+
+/* Read data from I2C slave. */
+static int w1_f19_i2c_read(struct w1_slave *sl, u16 i2c_address,
+	u8 *buffer, size_t count)
+{
+	u16 crc;
+	int error;
+	u8 w1_buf[5];
+
+	/* Check input. */
+	if (count == 0)
+		return -EOPNOTSUPP;
+
+	/* Send command to DS28E17. */
+	w1_buf[0] = W1_F19_READ_DATA_WITH_STOP;
+	w1_buf[1] = i2c_address << 1 | 0x01;
+	w1_buf[2] = count;
+	crc = crc16(CRC16_INIT, w1_buf, 3);
+	w1_buf[3] = ~(crc & 0xFF);
+	w1_buf[4] = ~((crc >> 8) & 0xFF);
+	w1_write_block(sl->master, w1_buf, 5);
+
+	/* Wait until busy flag clears (or timeout). */
+	if (w1_f19_i2c_busy_wait(sl, count + 1) < 0)
+		return -ETIMEDOUT;
+
+	/* Read status from DS28E17. */
+	w1_buf[0] = w1_read_8(sl->master);
+	w1_buf[1] = 0;
+
+	/* Check error conditions. */
+	error = w1_f19_error(sl, w1_buf);
+	if (error < 0)
+		return error;
+
+	/* Read received I2C data from DS28E17. */
+	return w1_read_block(sl->master, buffer, count);
+}
+
+
+/* Write to, then read data from I2C slave. */
+static int w1_f19_i2c_write_read(struct w1_slave *sl, u16 i2c_address,
+	const u8 *wbuffer, size_t wcount, u8 *rbuffer, size_t rcount)
+{
+	u16 crc;
+	int error;
+	u8 w1_buf[3];
+
+	/* Check input. */
+	if (wcount == 0 || rcount == 0)
+		return -EOPNOTSUPP;
+
+	/* Send command and I2C data to DS28E17. */
+	w1_buf[0] = W1_F19_WRITE_READ_DATA_WITH_STOP;
+	w1_buf[1] = i2c_address << 1;
+	w1_buf[2] = wcount;
+	crc = crc16(CRC16_INIT, w1_buf, 3);
+	w1_write_block(sl->master, w1_buf, 3);
+
+	crc = crc16(crc, wbuffer, wcount);
+	w1_write_block(sl->master, wbuffer, wcount);
+
+	w1_buf[0] = rcount;
+	crc = crc16(crc, w1_buf, 1);
+	w1_buf[1] = ~(crc & 0xFF);
+	w1_buf[2] = ~((crc >> 8) & 0xFF);
+	w1_write_block(sl->master, w1_buf, 3);
+
+	/* Wait until busy flag clears (or timeout). */
+	if (w1_f19_i2c_busy_wait(sl, wcount + rcount + 2) < 0)
+		return -ETIMEDOUT;
+
+	/* Read status from DS28E17. */
+	w1_read_block(sl->master, w1_buf, 2);
+
+	/* Check error conditions. */
+	error = w1_f19_error(sl, w1_buf);
+	if (error < 0)
+		return error;
+
+	/* Read received I2C data from DS28E17. */
+	return w1_read_block(sl->master, rbuffer, rcount);
+}
+
+
+/* Do an I2C master transfer. */
+static int w1_f19_i2c_master_transfer(struct i2c_adapter *adapter,
+	struct i2c_msg *msgs, int num)
+{
+	struct w1_slave *sl = (struct w1_slave *) adapter->algo_data;
+	int i = 0;
+	int result = 0;
+
+	/* Start onewire transaction. */
+	mutex_lock(&sl->master->bus_mutex);
+
+	/* Select DS28E17. */
+	if (w1_reset_select_slave(sl)) {
+		i = -EIO;
+		goto error;
+	}
+
+	/* Loop while there are still messages to transfer. */
+	while (i < num) {
+		/*
+		 * Check for special case: Small write followed
+		 * by read to same I2C device.
+		 */
+		if (i < (num-1)
+			&& msgs[i].addr == msgs[i+1].addr
+			&& !(msgs[i].flags & I2C_M_RD)
+			&& (msgs[i+1].flags & I2C_M_RD)
+			&& (msgs[i].len <= W1_F19_WRITE_DATA_LIMIT)) {
+			/*
+			 * The DS28E17 has a combined transfer
+			 * for small write+read.
+			 */
+			result = w1_f19_i2c_write_read(sl, msgs[i].addr,
+				msgs[i].buf, msgs[i].len,
+				msgs[i+1].buf, msgs[i+1].len);
+			if (result < 0) {
+				i = result;
+				goto error;
+			}
+
+			/*
+			 * Check if we should interpret the read data
+			 * as a length byte. The DS28E17 unfortunately
+			 * has no read without stop, so we can just do
+			 * another simple read in that case.
+			 */
+			if (msgs[i+1].flags & I2C_M_RECV_LEN) {
+				result = w1_f19_i2c_read(sl, msgs[i+1].addr,
+					&(msgs[i+1].buf[1]), msgs[i+1].buf[0]);
+				if (result < 0) {
+					i = result;
+					goto error;
+				}
+			}
+
+			/* Eat up read message, too. */
+			i++;
+		} else if (msgs[i].flags & I2C_M_RD) {
+			/* Read transfer. */
+			result = w1_f19_i2c_read(sl, msgs[i].addr,
+				msgs[i].buf, msgs[i].len);
+			if (result < 0) {
+				i = result;
+				goto error;
+			}
+
+			/*
+			 * Check if we should interpret the read data
+			 * as a length byte. The DS28E17 unfortunately
+			 * has no read without stop, so we can just do
+			 * another simple read in that case.
+			 */
+			if (msgs[i].flags & I2C_M_RECV_LEN) {
+				result = w1_f19_i2c_read(sl,
+					msgs[i].addr,
+					&(msgs[i].buf[1]),
+					msgs[i].buf[0]);
+				if (result < 0) {
+					i = result;
+					goto error;
+				}
+			}
+		} else {
+			/*
+			 * Write transfer.
+			 * Stop condition only for last
+			 * transfer.
+			 */
+			result = w1_f19_i2c_write(sl,
+				msgs[i].addr,
+				msgs[i].buf,
+				msgs[i].len,
+				i == (num-1));
+			if (result < 0) {
+				i = result;
+				goto error;
+			}
+		}
+
+		/* Next message. */
+		i++;
+
+		/* Are there still messages to send/receive? */
+		if (i < num) {
+			/* Yes. Resume to same DS28E17. */
+			if (w1_reset_resume_command(sl->master)) {
+				i = -EIO;
+				goto error;
+			}
+		}
+	}
+
+error:
+	/* End onewire transaction. */
+	mutex_unlock(&sl->master->bus_mutex);
+
+	/* Return number of messages processed or error. */
+	return i;
+}
+
+
+/* Get I2C adapter functionality. */
+static u32 w1_f19_i2c_functionality(struct i2c_adapter *adapter)
+{
+	/*
+	 * Plain I2C functions only.
+	 * SMBus is emulated by the kernel's I2C layer.
+	 * No "I2C_FUNC_SMBUS_QUICK"
+	 * No "I2C_FUNC_SMBUS_READ_BLOCK_DATA"
+	 * No "I2C_FUNC_SMBUS_BLOCK_PROC_CALL"
+	 */
+	return I2C_FUNC_I2C |
+		I2C_FUNC_SMBUS_BYTE |
+		I2C_FUNC_SMBUS_BYTE_DATA |
+		I2C_FUNC_SMBUS_WORD_DATA |
+		I2C_FUNC_SMBUS_PROC_CALL |
+		I2C_FUNC_SMBUS_WRITE_BLOCK_DATA |
+		I2C_FUNC_SMBUS_I2C_BLOCK |
+		I2C_FUNC_SMBUS_PEC;
+}
+
+
+/* I2C adapter quirks. */
+static const struct i2c_adapter_quirks w1_f19_i2c_adapter_quirks = {
+	.max_read_len = W1_F19_READ_DATA_LIMIT,
+};
+
+/* I2C algorithm. */
+static const struct i2c_algorithm w1_f19_i2c_algorithm = {
+	.master_xfer    = w1_f19_i2c_master_transfer,
+	.functionality  = w1_f19_i2c_functionality,
+};
+
+
+/* Read I2C speed from DS28E17. */
+static int w1_f19_get_i2c_speed(struct w1_slave *sl)
+{
+	struct w1_f19_data *data = sl->family_data;
+	int result = -EIO;
+
+	/* Start onewire transaction. */
+	mutex_lock(&sl->master->bus_mutex);
+
+	/* Select slave. */
+	if (w1_reset_select_slave(sl))
+		goto error;
+
+	/* Read slave configuration byte. */
+	w1_write_8(sl->master, W1_F19_READ_CONFIGURATION);
+	result = w1_read_8(sl->master);
+	if (result < 0 || result > 2) {
+		result = -EIO;
+		goto error;
+	}
+
+	/* Update speed in slave specific data. */
+	data->speed = result;
+
+error:
+	/* End onewire transaction. */
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return result;
+}
+
+
+/* Set I2C speed on DS28E17. */
+static int __w1_f19_set_i2c_speed(struct w1_slave *sl, u8 speed)
+{
+	struct w1_f19_data *data = sl->family_data;
+	const int i2c_speeds[3] = { 100, 400, 900 };
+	u8 w1_buf[2];
+
+	/* Select slave. */
+	if (w1_reset_select_slave(sl))
+		return -EIO;
+
+	w1_buf[0] = W1_F19_WRITE_CONFIGURATION;
+	w1_buf[1] = speed;
+	w1_write_block(sl->master, w1_buf, 2);
+
+	/* Update speed in slave specific data. */
+	data->speed = speed;
+
+	dev_info(&sl->dev, "i2c speed set to %d kBaud\n", i2c_speeds[speed]);
+
+	return 0;
+}
+
+static int w1_f19_set_i2c_speed(struct w1_slave *sl, u8 speed)
+{
+	int result;
+
+	/* Start onewire transaction. */
+	mutex_lock(&sl->master->bus_mutex);
+
+	/* Set I2C speed on DS28E17. */
+	result = __w1_f19_set_i2c_speed(sl, speed);
+
+	/* End onewire transaction. */
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return result;
+}
+
+
+/* Sysfs attributes. */
+
+/* I2C speed attribute for a single chip. */
+static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct w1_slave *sl = dev_to_w1_slave(dev);
+	int result;
+
+	/* Read current speed from slave. Updates data->speed. */
+	result = w1_f19_get_i2c_speed(sl);
+	if (result < 0)
+		return result;
+
+	/* Return current speed value. */
+	return sprintf(buf, "%d\n", result);
+}
+
+static ssize_t speed_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct w1_slave *sl = dev_to_w1_slave(dev);
+	int error;
+
+	/* Valid values are: "100", "400", "900" */
+	if (count < 3 || count > 4 || !buf)
+		return -EINVAL;
+	if (count == 4 && buf[3] != '\n')
+		return -EINVAL;
+	if (buf[1] != '0' || buf[2] != '0')
+		return -EINVAL;
+
+	/* Set speed on slave. */
+	switch (buf[0]) {
+	case '1':
+		error = w1_f19_set_i2c_speed(sl, 0);
+		break;
+	case '4':
+		error = w1_f19_set_i2c_speed(sl, 1);
+		break;
+	case '9':
+		error = w1_f19_set_i2c_speed(sl, 2);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (error < 0)
+		return error;
+
+	/* Return bytes written. */
+	return count;
+}
+
+static DEVICE_ATTR_RW(speed);
+
+
+/* Busy stretch attribute for a single chip. */
+static ssize_t stretch_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct w1_slave *sl = dev_to_w1_slave(dev);
+	struct w1_f19_data *data = sl->family_data;
+
+	/* Return current stretch value. */
+	return sprintf(buf, "%d\n", data->stretch);
+}
+
+static ssize_t stretch_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct w1_slave *sl = dev_to_w1_slave(dev);
+	struct w1_f19_data *data = sl->family_data;
+
+	/* Valid values are '1' to '9' */
+	if (count < 1 || count > 2 || !buf)
+		return -EINVAL;
+	if (count == 2 && buf[1] != '\n')
+		return -EINVAL;
+	if (buf[0] < '1' || buf[0] > '9')
+		return -EINVAL;
+
+	/* Set busy stretch value. */
+	data->stretch = buf[0] & 0x0F;
+
+	/* Return bytes written. */
+	return count;
+}
+
+static DEVICE_ATTR_RW(stretch);
+
+
+/* All attributes. */
+static struct attribute *w1_f19_attrs[] = {
+	&dev_attr_speed.attr,
+	&dev_attr_stretch.attr,
+	NULL,
+};
+
+static const struct attribute_group w1_f19_group = {
+	.attrs		= w1_f19_attrs,
+};
+
+static const struct attribute_group *w1_f19_groups[] = {
+	&w1_f19_group,
+	NULL,
+};
+
+
+/* Slave add and remove functions. */
+static int w1_f19_add_slave(struct w1_slave *sl)
+{
+	struct w1_f19_data *data = NULL;
+
+	/* Allocate memory for slave specific data. */
+	data = devm_kzalloc(&sl->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	sl->family_data = data;
+
+	/* Setup default I2C speed on slave. */
+	switch (i2c_speed) {
+	case 100:
+		__w1_f19_set_i2c_speed(sl, 0);
+		break;
+	case 400:
+		__w1_f19_set_i2c_speed(sl, 1);
+		break;
+	case 900:
+		__w1_f19_set_i2c_speed(sl, 2);
+		break;
+	default:
+		/*
+		 * A i2c_speed module parameter of anything else
+		 * than 100, 400, 900 means not to touch the
+		 * speed of the DS28E17.
+		 * We assume 400kBaud, the power-on value.
+		 */
+		data->speed = 1;
+	}
+
+	/*
+	 * Setup default busy stretch
+	 * configuration for the DS28E17.
+	 */
+	data->stretch = i2c_stretch;
+
+	/* Setup I2C adapter. */
+	data->adapter.owner      = THIS_MODULE;
+	data->adapter.algo       = &w1_f19_i2c_algorithm;
+	data->adapter.algo_data  = sl;
+	strcpy(data->adapter.name, "w1-");
+	strcat(data->adapter.name, sl->name);
+	data->adapter.dev.parent = &sl->dev;
+	data->adapter.quirks     = &w1_f19_i2c_adapter_quirks;
+
+	return i2c_add_adapter(&data->adapter);
+}
+
+static void w1_f19_remove_slave(struct w1_slave *sl)
+{
+	struct w1_f19_data *family_data = sl->family_data;
+
+	/* Delete I2C adapter. */
+	i2c_del_adapter(&family_data->adapter);
+
+	/* Free slave specific data. */
+	devm_kfree(&sl->dev, family_data);
+	sl->family_data = NULL;
+}
+
+
+/* Declarations within the w1 subsystem. */
+static const struct w1_family_ops w1_f19_fops = {
+	.add_slave = w1_f19_add_slave,
+	.remove_slave = w1_f19_remove_slave,
+	.groups = w1_f19_groups,
+};
+
+static struct w1_family w1_family_19 = {
+	.fid = W1_FAMILY_DS28E17,
+	.fops = &w1_f19_fops,
+};
+
+module_w1_family(w1_family_19);