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, 758 insertions, 0 deletions

diff --git a/tools/iio/iio_generic_buffer.c b/tools/iio/iio_generic_buffer.c
new file mode 100644
index 000000000..f8deae4e2
--- /dev/null
+++ b/tools/iio/iio_generic_buffer.c
@@ -0,0 +1,758 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Industrialio buffer test code.
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is primarily intended as an example application.
+ * Reads the current buffer setup from sysfs and starts a short capture
+ * from the specified device, pretty printing the result after appropriate
+ * conversion.
+ *
+ * Command line parameters
+ * generic_buffer -n <device_name> -t <trigger_name>
+ * If trigger name is not specified the program assumes you want a dataready
+ * trigger associated with the device and goes looking for it.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/dir.h>
+#include <linux/types.h>
+#include <string.h>
+#include <poll.h>
+#include <endian.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <linux/iio/buffer.h>
+#include "iio_utils.h"
+
+/**
+ * enum autochan - state for the automatic channel enabling mechanism
+ */
+enum autochan {
+	AUTOCHANNELS_DISABLED,
+	AUTOCHANNELS_ENABLED,
+	AUTOCHANNELS_ACTIVE,
+};
+
+/**
+ * size_from_channelarray() - calculate the storage size of a scan
+ * @channels:		the channel info array
+ * @num_channels:	number of channels
+ *
+ * Has the side effect of filling the channels[i].location values used
+ * in processing the buffer output.
+ **/
+static int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
+{
+	int bytes = 0;
+	int i = 0;
+
+	while (i < num_channels) {
+		if (bytes % channels[i].bytes == 0)
+			channels[i].location = bytes;
+		else
+			channels[i].location = bytes - bytes % channels[i].bytes
+					       + channels[i].bytes;
+
+		bytes = channels[i].location + channels[i].bytes;
+		i++;
+	}
+
+	return bytes;
+}
+
+static void print1byte(uint8_t input, struct iio_channel_info *info)
+{
+	/*
+	 * Shift before conversion to avoid sign extension
+	 * of left aligned data
+	 */
+	input >>= info->shift;
+	input &= info->mask;
+	if (info->is_signed) {
+		int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
+			     (8 - info->bits_used);
+		printf("%05f ", ((float)val + info->offset) * info->scale);
+	} else {
+		printf("%05f ", ((float)input + info->offset) * info->scale);
+	}
+}
+
+static void print2byte(uint16_t input, struct iio_channel_info *info)
+{
+	/* First swap if incorrect endian */
+	if (info->be)
+		input = be16toh(input);
+	else
+		input = le16toh(input);
+
+	/*
+	 * Shift before conversion to avoid sign extension
+	 * of left aligned data
+	 */
+	input >>= info->shift;
+	input &= info->mask;
+	if (info->is_signed) {
+		int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
+			      (16 - info->bits_used);
+		printf("%05f ", ((float)val + info->offset) * info->scale);
+	} else {
+		printf("%05f ", ((float)input + info->offset) * info->scale);
+	}
+}
+
+static void print4byte(uint32_t input, struct iio_channel_info *info)
+{
+	/* First swap if incorrect endian */
+	if (info->be)
+		input = be32toh(input);
+	else
+		input = le32toh(input);
+
+	/*
+	 * Shift before conversion to avoid sign extension
+	 * of left aligned data
+	 */
+	input >>= info->shift;
+	input &= info->mask;
+	if (info->is_signed) {
+		int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
+			      (32 - info->bits_used);
+		printf("%05f ", ((float)val + info->offset) * info->scale);
+	} else {
+		printf("%05f ", ((float)input + info->offset) * info->scale);
+	}
+}
+
+static void print8byte(uint64_t input, struct iio_channel_info *info)
+{
+	/* First swap if incorrect endian */
+	if (info->be)
+		input = be64toh(input);
+	else
+		input = le64toh(input);
+
+	/*
+	 * Shift before conversion to avoid sign extension
+	 * of left aligned data
+	 */
+	input >>= info->shift;
+	input &= info->mask;
+	if (info->is_signed) {
+		int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
+			      (64 - info->bits_used);
+		/* special case for timestamp */
+		if (info->scale == 1.0f && info->offset == 0.0f)
+			printf("%" PRId64 " ", val);
+		else
+			printf("%05f ",
+			       ((float)val + info->offset) * info->scale);
+	} else {
+		printf("%05f ", ((float)input + info->offset) * info->scale);
+	}
+}
+
+/**
+ * process_scan() - print out the values in SI units
+ * @data:		pointer to the start of the scan
+ * @channels:		information about the channels.
+ *			Note: size_from_channelarray must have been called first
+ *			      to fill the location offsets.
+ * @num_channels:	number of channels
+ **/
+static void process_scan(char *data, struct iio_channel_info *channels,
+			 int num_channels)
+{
+	int k;
+
+	for (k = 0; k < num_channels; k++)
+		switch (channels[k].bytes) {
+			/* only a few cases implemented so far */
+		case 1:
+			print1byte(*(uint8_t *)(data + channels[k].location),
+				   &channels[k]);
+			break;
+		case 2:
+			print2byte(*(uint16_t *)(data + channels[k].location),
+				   &channels[k]);
+			break;
+		case 4:
+			print4byte(*(uint32_t *)(data + channels[k].location),
+				   &channels[k]);
+			break;
+		case 8:
+			print8byte(*(uint64_t *)(data + channels[k].location),
+				   &channels[k]);
+			break;
+		default:
+			break;
+		}
+	printf("\n");
+}
+
+static int enable_disable_all_channels(char *dev_dir_name, int buffer_idx, int enable)
+{
+	const struct dirent *ent;
+	char scanelemdir[256];
+	DIR *dp;
+	int ret;
+
+	snprintf(scanelemdir, sizeof(scanelemdir),
+		 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name, buffer_idx);
+	scanelemdir[sizeof(scanelemdir)-1] = '\0';
+
+	dp = opendir(scanelemdir);
+	if (!dp) {
+		fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
+			scanelemdir);
+		return -EIO;
+	}
+
+	ret = -ENOENT;
+	while (ent = readdir(dp), ent) {
+		if (iioutils_check_suffix(ent->d_name, "_en")) {
+			printf("%sabling: %s\n",
+			       enable ? "En" : "Dis",
+			       ent->d_name);
+			ret = write_sysfs_int(ent->d_name, scanelemdir,
+					      enable);
+			if (ret < 0)
+				fprintf(stderr, "Failed to enable/disable %s\n",
+					ent->d_name);
+		}
+	}
+
+	if (closedir(dp) == -1) {
+		perror("Enabling/disabling channels: "
+		       "Failed to close directory");
+		return -errno;
+	}
+	return 0;
+}
+
+static void print_usage(void)
+{
+	fprintf(stderr, "Usage: generic_buffer [options]...\n"
+		"Capture, convert and output data from IIO device buffer\n"
+		"  -a         Auto-activate all available channels\n"
+		"  -A         Force-activate ALL channels\n"
+		"  -b <n>     The buffer which to open (by index), default 0\n"
+		"  -c <n>     Do n conversions, or loop forever if n < 0\n"
+		"  -e         Disable wait for event (new data)\n"
+		"  -g         Use trigger-less mode\n"
+		"  -l <n>     Set buffer length to n samples\n"
+		"  --device-name -n <name>\n"
+		"  --device-num -N <num>\n"
+		"        Set device by name or number (mandatory)\n"
+		"  --trigger-name -t <name>\n"
+		"  --trigger-num -T <num>\n"
+		"        Set trigger by name or number\n"
+		"  -w <n>     Set delay between reads in us (event-less mode)\n");
+}
+
+static enum autochan autochannels = AUTOCHANNELS_DISABLED;
+static char *dev_dir_name = NULL;
+static char *buf_dir_name = NULL;
+static int buffer_idx = 0;
+static bool current_trigger_set = false;
+
+static void cleanup(void)
+{
+	int ret;
+
+	/* Disable trigger */
+	if (dev_dir_name && current_trigger_set) {
+		/* Disconnect the trigger - just write a dummy name. */
+		ret = write_sysfs_string("trigger/current_trigger",
+					 dev_dir_name, "NULL");
+		if (ret < 0)
+			fprintf(stderr, "Failed to disable trigger: %s\n",
+				strerror(-ret));
+		current_trigger_set = false;
+	}
+
+	/* Disable buffer */
+	if (buf_dir_name) {
+		ret = write_sysfs_int("enable", buf_dir_name, 0);
+		if (ret < 0)
+			fprintf(stderr, "Failed to disable buffer: %s\n",
+				strerror(-ret));
+	}
+
+	/* Disable channels if auto-enabled */
+	if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
+		ret = enable_disable_all_channels(dev_dir_name, buffer_idx, 0);
+		if (ret)
+			fprintf(stderr, "Failed to disable all channels\n");
+		autochannels = AUTOCHANNELS_DISABLED;
+	}
+}
+
+static void sig_handler(int signum)
+{
+	fprintf(stderr, "Caught signal %d\n", signum);
+	cleanup();
+	exit(-signum);
+}
+
+static void register_cleanup(void)
+{
+	struct sigaction sa = { .sa_handler = sig_handler };
+	const int signums[] = { SIGINT, SIGTERM, SIGABRT };
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(signums); ++i) {
+		ret = sigaction(signums[i], &sa, NULL);
+		if (ret) {
+			perror("Failed to register signal handler");
+			exit(-1);
+		}
+	}
+}
+
+static const struct option longopts[] = {
+	{ "device-name",	1, 0, 'n' },
+	{ "device-num",		1, 0, 'N' },
+	{ "trigger-name",	1, 0, 't' },
+	{ "trigger-num",	1, 0, 'T' },
+	{ },
+};
+
+int main(int argc, char **argv)
+{
+	long long num_loops = 2;
+	unsigned long timedelay = 1000000;
+	unsigned long buf_len = 128;
+
+	ssize_t i;
+	unsigned long long j;
+	unsigned long toread;
+	int ret, c;
+	struct stat st;
+	int fd = -1;
+	int buf_fd = -1;
+
+	int num_channels = 0;
+	char *trigger_name = NULL, *device_name = NULL;
+
+	char *data = NULL;
+	ssize_t read_size;
+	int dev_num = -1, trig_num = -1;
+	char *buffer_access = NULL;
+	int scan_size;
+	int noevents = 0;
+	int notrigger = 0;
+	char *dummy;
+	bool force_autochannels = false;
+
+	struct iio_channel_info *channels = NULL;
+
+	register_cleanup();
+
+	while ((c = getopt_long(argc, argv, "aAb:c:egl:n:N:t:T:w:?", longopts,
+				NULL)) != -1) {
+		switch (c) {
+		case 'a':
+			autochannels = AUTOCHANNELS_ENABLED;
+			break;
+		case 'A':
+			autochannels = AUTOCHANNELS_ENABLED;
+			force_autochannels = true;
+			break;
+		case 'b':
+			errno = 0;
+			buffer_idx = strtoll(optarg, &dummy, 10);
+			if (errno) {
+				ret = -errno;
+				goto error;
+			}
+			if (buffer_idx < 0) {
+				ret = -ERANGE;
+				goto error;
+			}
+
+			break;
+		case 'c':
+			errno = 0;
+			num_loops = strtoll(optarg, &dummy, 10);
+			if (errno) {
+				ret = -errno;
+				goto error;
+			}
+
+			break;
+		case 'e':
+			noevents = 1;
+			break;
+		case 'g':
+			notrigger = 1;
+			break;
+		case 'l':
+			errno = 0;
+			buf_len = strtoul(optarg, &dummy, 10);
+			if (errno) {
+				ret = -errno;
+				goto error;
+			}
+
+			break;
+		case 'n':
+			device_name = strdup(optarg);
+			break;
+		case 'N':
+			errno = 0;
+			dev_num = strtoul(optarg, &dummy, 10);
+			if (errno) {
+				ret = -errno;
+				goto error;
+			}
+			break;
+		case 't':
+			trigger_name = strdup(optarg);
+			break;
+		case 'T':
+			errno = 0;
+			trig_num = strtoul(optarg, &dummy, 10);
+			if (errno)
+				return -errno;
+			break;
+		case 'w':
+			errno = 0;
+			timedelay = strtoul(optarg, &dummy, 10);
+			if (errno) {
+				ret = -errno;
+				goto error;
+			}
+			break;
+		case '?':
+			print_usage();
+			ret = -1;
+			goto error;
+		}
+	}
+
+	/* Find the device requested */
+	if (dev_num < 0 && !device_name) {
+		fprintf(stderr, "Device not set\n");
+		print_usage();
+		ret = -1;
+		goto error;
+	} else if (dev_num >= 0 && device_name) {
+		fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
+		print_usage();
+		ret = -1;
+		goto error;
+	} else if (dev_num < 0) {
+		dev_num = find_type_by_name(device_name, "iio:device");
+		if (dev_num < 0) {
+			fprintf(stderr, "Failed to find the %s\n", device_name);
+			ret = dev_num;
+			goto error;
+		}
+	}
+	printf("iio device number being used is %d\n", dev_num);
+
+	ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
+	if (ret < 0)
+		return -ENOMEM;
+	/* Fetch device_name if specified by number */
+	if (!device_name) {
+		device_name = malloc(IIO_MAX_NAME_LENGTH);
+		if (!device_name) {
+			ret = -ENOMEM;
+			goto error;
+		}
+		ret = read_sysfs_string("name", dev_dir_name, device_name);
+		if (ret < 0) {
+			fprintf(stderr, "Failed to read name of device %d\n", dev_num);
+			goto error;
+		}
+	}
+
+	if (notrigger) {
+		printf("trigger-less mode selected\n");
+	} else if (trig_num >= 0) {
+		char *trig_dev_name;
+		ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
+		if (ret < 0) {
+			return -ENOMEM;
+		}
+		trigger_name = malloc(IIO_MAX_NAME_LENGTH);
+		ret = read_sysfs_string("name", trig_dev_name, trigger_name);
+		free(trig_dev_name);
+		if (ret < 0) {
+			fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
+			return ret;
+		}
+		printf("iio trigger number being used is %d\n", trig_num);
+	} else {
+		if (!trigger_name) {
+			/*
+			 * Build the trigger name. If it is device associated
+			 * its name is <device_name>_dev[n] where n matches
+			 * the device number found above.
+			 */
+			ret = asprintf(&trigger_name,
+				       "%s-dev%d", device_name, dev_num);
+			if (ret < 0) {
+				ret = -ENOMEM;
+				goto error;
+			}
+		}
+
+		/* Look for this "-devN" trigger */
+		trig_num = find_type_by_name(trigger_name, "trigger");
+		if (trig_num < 0) {
+			/* OK try the simpler "-trigger" suffix instead */
+			free(trigger_name);
+			ret = asprintf(&trigger_name,
+				       "%s-trigger", device_name);
+			if (ret < 0) {
+				ret = -ENOMEM;
+				goto error;
+			}
+		}
+
+		trig_num = find_type_by_name(trigger_name, "trigger");
+		if (trig_num < 0) {
+			fprintf(stderr, "Failed to find the trigger %s\n",
+				trigger_name);
+			ret = trig_num;
+			goto error;
+		}
+
+		printf("iio trigger number being used is %d\n", trig_num);
+	}
+
+	/*
+	 * Parse the files in scan_elements to identify what channels are
+	 * present
+	 */
+	ret = build_channel_array(dev_dir_name, buffer_idx, &channels, &num_channels);
+	if (ret) {
+		fprintf(stderr, "Problem reading scan element information\n"
+			"diag %s\n", dev_dir_name);
+		goto error;
+	}
+	if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
+	    !force_autochannels) {
+		fprintf(stderr, "Auto-channels selected but some channels "
+			"are already activated in sysfs\n");
+		fprintf(stderr, "Proceeding without activating any channels\n");
+	}
+
+	if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
+	    (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
+		fprintf(stderr, "Enabling all channels\n");
+
+		ret = enable_disable_all_channels(dev_dir_name, buffer_idx, 1);
+		if (ret) {
+			fprintf(stderr, "Failed to enable all channels\n");
+			goto error;
+		}
+
+		/* This flags that we need to disable the channels again */
+		autochannels = AUTOCHANNELS_ACTIVE;
+
+		ret = build_channel_array(dev_dir_name, buffer_idx, &channels,
+					  &num_channels);
+		if (ret) {
+			fprintf(stderr, "Problem reading scan element "
+				"information\n"
+				"diag %s\n", dev_dir_name);
+			goto error;
+		}
+		if (!num_channels) {
+			fprintf(stderr, "Still no channels after "
+				"auto-enabling, giving up\n");
+			goto error;
+		}
+	}
+
+	if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
+		fprintf(stderr,
+			"No channels are enabled, we have nothing to scan.\n");
+		fprintf(stderr, "Enable channels manually in "
+			FORMAT_SCAN_ELEMENTS_DIR
+			"/*_en or pass -a to autoenable channels and "
+			"try again.\n", dev_dir_name, buffer_idx);
+		ret = -ENOENT;
+		goto error;
+	}
+
+	/*
+	 * Construct the directory name for the associated buffer.
+	 * As we know that the lis3l02dq has only one buffer this may
+	 * be built rather than found.
+	 */
+	ret = asprintf(&buf_dir_name,
+		       "%siio:device%d/buffer%d", iio_dir, dev_num, buffer_idx);
+	if (ret < 0) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	if (stat(buf_dir_name, &st)) {
+		fprintf(stderr, "Could not stat() '%s', got error %d: %s\n",
+			buf_dir_name, errno, strerror(errno));
+		ret = -errno;
+		goto error;
+	}
+
+	if (!S_ISDIR(st.st_mode)) {
+		fprintf(stderr, "File '%s' is not a directory\n", buf_dir_name);
+		ret = -EFAULT;
+		goto error;
+	}
+
+	if (!notrigger) {
+		printf("%s %s\n", dev_dir_name, trigger_name);
+		/*
+		 * Set the device trigger to be the data ready trigger found
+		 * above
+		 */
+		ret = write_sysfs_string_and_verify("trigger/current_trigger",
+						    dev_dir_name,
+						    trigger_name);
+		if (ret < 0) {
+			fprintf(stderr,
+				"Failed to write current_trigger file\n");
+			goto error;
+		}
+	}
+
+	ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
+	if (ret < 0) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* Attempt to open non blocking the access dev */
+	fd = open(buffer_access, O_RDONLY | O_NONBLOCK);
+	if (fd == -1) { /* TODO: If it isn't there make the node */
+		ret = -errno;
+		fprintf(stderr, "Failed to open %s\n", buffer_access);
+		goto error;
+	}
+
+	/* specify for which buffer index we want an FD */
+	buf_fd = buffer_idx;
+
+	ret = ioctl(fd, IIO_BUFFER_GET_FD_IOCTL, &buf_fd);
+	if (ret == -1 || buf_fd == -1) {
+		ret = -errno;
+		if (ret == -ENODEV || ret == -EINVAL)
+			fprintf(stderr,
+				"Device does not have this many buffers\n");
+		else
+			fprintf(stderr, "Failed to retrieve buffer fd\n");
+
+		goto error;
+	}
+
+	/* Setup ring buffer parameters */
+	ret = write_sysfs_int("length", buf_dir_name, buf_len);
+	if (ret < 0)
+		goto error;
+
+	/* Enable the buffer */
+	ret = write_sysfs_int("enable", buf_dir_name, 1);
+	if (ret < 0) {
+		fprintf(stderr,
+			"Failed to enable buffer '%s': %s\n",
+			buf_dir_name, strerror(-ret));
+		goto error;
+	}
+
+	scan_size = size_from_channelarray(channels, num_channels);
+	data = malloc(scan_size * buf_len);
+	if (!data) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/**
+	 * This check is being done here for sanity reasons, however it
+	 * should be omitted under normal operation.
+	 * If this is buffer0, we check that we get EBUSY after this point.
+	 */
+	if (buffer_idx == 0) {
+		errno = 0;
+		read_size = read(fd, data, 1);
+		if (read_size > -1 || errno != EBUSY) {
+			ret = -EFAULT;
+			perror("Reading from '%s' should not be possible after ioctl()");
+			goto error;
+		}
+	}
+
+	/* close now the main chardev FD and let the buffer FD work */
+	if (close(fd) == -1)
+		perror("Failed to close character device file");
+	fd = -1;
+
+	for (j = 0; j < num_loops || num_loops < 0; j++) {
+		if (!noevents) {
+			struct pollfd pfd = {
+				.fd = buf_fd,
+				.events = POLLIN,
+			};
+
+			ret = poll(&pfd, 1, -1);
+			if (ret < 0) {
+				ret = -errno;
+				goto error;
+			} else if (ret == 0) {
+				continue;
+			}
+
+		} else {
+			usleep(timedelay);
+		}
+
+		toread = buf_len;
+
+		read_size = read(buf_fd, data, toread * scan_size);
+		if (read_size < 0) {
+			if (errno == EAGAIN) {
+				fprintf(stderr, "nothing available\n");
+				continue;
+			} else {
+				break;
+			}
+		}
+		for (i = 0; i < read_size / scan_size; i++)
+			process_scan(data + scan_size * i, channels,
+				     num_channels);
+	}
+
+error:
+	cleanup();
+
+	if (fd >= 0 && close(fd) == -1)
+		perror("Failed to close character device");
+	if (buf_fd >= 0 && close(buf_fd) == -1)
+		perror("Failed to close buffer");
+	free(buffer_access);
+	free(data);
+	free(buf_dir_name);
+	for (i = num_channels - 1; i >= 0; i--) {
+		free(channels[i].name);
+		free(channels[i].generic_name);
+	}
+	free(channels);
+	free(trigger_name);
+	free(device_name);
+	free(dev_dir_name);
+
+	return ret;
+}