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, 748 insertions, 0 deletions

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
new file mode 100644
index 000000000..7dd5205ae
--- /dev/null
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * STMicroelectronics st_lsm6dsx FIFO buffer library driver
+ *
+ * LSM6DS3/LSM6DS3H/LSM6DSL/LSM6DSM/ISM330DLC/LSM6DS3TR-C:
+ * The FIFO buffer can be configured to store data from gyroscope and
+ * accelerometer. Samples are queued without any tag according to a
+ * specific pattern based on 'FIFO data sets' (6 bytes each):
+ *  - 1st data set is reserved for gyroscope data
+ *  - 2nd data set is reserved for accelerometer data
+ * The FIFO pattern changes depending on the ODRs and decimation factors
+ * assigned to the FIFO data sets. The first sequence of data stored in FIFO
+ * buffer contains the data of all the enabled FIFO data sets
+ * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated depending on the
+ * value of the decimation factor and ODR set for each FIFO data set.
+ *
+ * LSM6DSO/LSM6DSOX/ASM330LHH/ASM330LHHX/LSM6DSR/LSM6DSRX/ISM330DHCX/
+ * LSM6DST/LSM6DSOP/LSM6DSTX/LSM6DSV:
+ * The FIFO buffer can be configured to store data from gyroscope and
+ * accelerometer. Each sample is queued with a tag (1B) indicating data
+ * source (gyroscope, accelerometer, hw timer).
+ *
+ * FIFO supported modes:
+ *  - BYPASS: FIFO disabled
+ *  - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
+ *    restarts from the beginning and the oldest sample is overwritten
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ * Denis Ciocca <denis.ciocca@st.com>
+ */
+#include <linux/module.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/regmap.h>
+#include <linux/bitfield.h>
+
+#include <linux/platform_data/st_sensors_pdata.h>
+
+#include "st_lsm6dsx.h"
+
+#define ST_LSM6DSX_REG_FIFO_MODE_ADDR		0x0a
+#define ST_LSM6DSX_FIFO_MODE_MASK		GENMASK(2, 0)
+#define ST_LSM6DSX_FIFO_ODR_MASK		GENMASK(6, 3)
+#define ST_LSM6DSX_FIFO_EMPTY_MASK		BIT(12)
+#define ST_LSM6DSX_REG_FIFO_OUTL_ADDR		0x3e
+#define ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR	0x78
+#define ST_LSM6DSX_REG_TS_RESET_ADDR		0x42
+
+#define ST_LSM6DSX_MAX_FIFO_ODR_VAL		0x08
+
+#define ST_LSM6DSX_TS_RESET_VAL			0xaa
+
+struct st_lsm6dsx_decimator_entry {
+	u8 decimator;
+	u8 val;
+};
+
+enum st_lsm6dsx_fifo_tag {
+	ST_LSM6DSX_GYRO_TAG = 0x01,
+	ST_LSM6DSX_ACC_TAG = 0x02,
+	ST_LSM6DSX_TS_TAG = 0x04,
+	ST_LSM6DSX_EXT0_TAG = 0x0f,
+	ST_LSM6DSX_EXT1_TAG = 0x10,
+	ST_LSM6DSX_EXT2_TAG = 0x11,
+};
+
+static const
+struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
+	{  0, 0x0 },
+	{  1, 0x1 },
+	{  2, 0x2 },
+	{  3, 0x3 },
+	{  4, 0x4 },
+	{  8, 0x5 },
+	{ 16, 0x6 },
+	{ 32, 0x7 },
+};
+
+static int
+st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor *sensor, u32 max_odr)
+{
+	const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
+	u32 decimator =  max_odr / sensor->odr;
+	int i;
+
+	if (decimator > 1)
+		decimator = round_down(decimator, 2);
+
+	for (i = 0; i < max_size; i++) {
+		if (st_lsm6dsx_decimator_table[i].decimator == decimator)
+			break;
+	}
+
+	sensor->decimator = decimator;
+	return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
+}
+
+static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
+				       u32 *max_odr, u32 *min_odr)
+{
+	struct st_lsm6dsx_sensor *sensor;
+	int i;
+
+	*max_odr = 0, *min_odr = ~0;
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		if (!hw->iio_devs[i])
+			continue;
+
+		sensor = iio_priv(hw->iio_devs[i]);
+
+		if (!(hw->enable_mask & BIT(sensor->id)))
+			continue;
+
+		*max_odr = max_t(u32, *max_odr, sensor->odr);
+		*min_odr = min_t(u32, *min_odr, sensor->odr);
+	}
+}
+
+static u8 st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor *sensor, u32 min_odr)
+{
+	u8 sip = sensor->odr / min_odr;
+
+	return sip > 1 ? round_down(sip, 2) : sip;
+}
+
+static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
+{
+	const struct st_lsm6dsx_reg *ts_dec_reg;
+	struct st_lsm6dsx_sensor *sensor;
+	u16 sip = 0, ts_sip = 0;
+	u32 max_odr, min_odr;
+	int err = 0, i;
+	u8 data;
+
+	st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		const struct st_lsm6dsx_reg *dec_reg;
+
+		if (!hw->iio_devs[i])
+			continue;
+
+		sensor = iio_priv(hw->iio_devs[i]);
+		/* update fifo decimators and sample in pattern */
+		if (hw->enable_mask & BIT(sensor->id)) {
+			sensor->sip = st_lsm6dsx_get_sip(sensor, min_odr);
+			data = st_lsm6dsx_get_decimator_val(sensor, max_odr);
+		} else {
+			sensor->sip = 0;
+			data = 0;
+		}
+		ts_sip = max_t(u16, ts_sip, sensor->sip);
+
+		dec_reg = &hw->settings->decimator[sensor->id];
+		if (dec_reg->addr) {
+			int val = ST_LSM6DSX_SHIFT_VAL(data, dec_reg->mask);
+
+			err = st_lsm6dsx_update_bits_locked(hw, dec_reg->addr,
+							    dec_reg->mask,
+							    val);
+			if (err < 0)
+				return err;
+		}
+		sip += sensor->sip;
+	}
+	hw->sip = sip + ts_sip;
+	hw->ts_sip = ts_sip;
+
+	/*
+	 * update hw ts decimator if necessary. Decimator for hw timestamp
+	 * is always 1 or 0 in order to have a ts sample for each data
+	 * sample in FIFO
+	 */
+	ts_dec_reg = &hw->settings->ts_settings.decimator;
+	if (ts_dec_reg->addr) {
+		int val, ts_dec = !!hw->ts_sip;
+
+		val = ST_LSM6DSX_SHIFT_VAL(ts_dec, ts_dec_reg->mask);
+		err = st_lsm6dsx_update_bits_locked(hw, ts_dec_reg->addr,
+						    ts_dec_reg->mask, val);
+	}
+	return err;
+}
+
+static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
+				    enum st_lsm6dsx_fifo_mode fifo_mode)
+{
+	unsigned int data;
+
+	data = FIELD_PREP(ST_LSM6DSX_FIFO_MODE_MASK, fifo_mode);
+	return st_lsm6dsx_update_bits_locked(hw, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
+					     ST_LSM6DSX_FIFO_MODE_MASK, data);
+}
+
+static int st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor *sensor,
+				   bool enable)
+{
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	const struct st_lsm6dsx_reg *batch_reg;
+	u8 data;
+
+	batch_reg = &hw->settings->batch[sensor->id];
+	if (batch_reg->addr) {
+		int val;
+
+		if (enable) {
+			int err;
+
+			err = st_lsm6dsx_check_odr(sensor, sensor->odr,
+						   &data);
+			if (err < 0)
+				return err;
+		} else {
+			data = 0;
+		}
+		val = ST_LSM6DSX_SHIFT_VAL(data, batch_reg->mask);
+		return st_lsm6dsx_update_bits_locked(hw, batch_reg->addr,
+						     batch_reg->mask, val);
+	} else {
+		data = hw->enable_mask ? ST_LSM6DSX_MAX_FIFO_ODR_VAL : 0;
+		return st_lsm6dsx_update_bits_locked(hw,
+					ST_LSM6DSX_REG_FIFO_MODE_ADDR,
+					ST_LSM6DSX_FIFO_ODR_MASK,
+					FIELD_PREP(ST_LSM6DSX_FIFO_ODR_MASK,
+						   data));
+	}
+}
+
+int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
+{
+	u16 fifo_watermark = ~0, cur_watermark, fifo_th_mask;
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	struct st_lsm6dsx_sensor *cur_sensor;
+	int i, err, data;
+	__le16 wdata;
+
+	if (!hw->sip)
+		return 0;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		if (!hw->iio_devs[i])
+			continue;
+
+		cur_sensor = iio_priv(hw->iio_devs[i]);
+
+		if (!(hw->enable_mask & BIT(cur_sensor->id)))
+			continue;
+
+		cur_watermark = (cur_sensor == sensor) ? watermark
+						       : cur_sensor->watermark;
+
+		fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
+	}
+
+	fifo_watermark = max_t(u16, fifo_watermark, hw->sip);
+	fifo_watermark = (fifo_watermark / hw->sip) * hw->sip;
+	fifo_watermark = fifo_watermark * hw->settings->fifo_ops.th_wl;
+
+	mutex_lock(&hw->page_lock);
+	err = regmap_read(hw->regmap, hw->settings->fifo_ops.fifo_th.addr + 1,
+			  &data);
+	if (err < 0)
+		goto out;
+
+	fifo_th_mask = hw->settings->fifo_ops.fifo_th.mask;
+	fifo_watermark = ((data << 8) & ~fifo_th_mask) |
+			 (fifo_watermark & fifo_th_mask);
+
+	wdata = cpu_to_le16(fifo_watermark);
+	err = regmap_bulk_write(hw->regmap,
+				hw->settings->fifo_ops.fifo_th.addr,
+				&wdata, sizeof(wdata));
+out:
+	mutex_unlock(&hw->page_lock);
+	return err;
+}
+
+static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw)
+{
+	struct st_lsm6dsx_sensor *sensor;
+	int i, err;
+
+	/* reset hw ts counter */
+	err = st_lsm6dsx_write_locked(hw, ST_LSM6DSX_REG_TS_RESET_ADDR,
+				      ST_LSM6DSX_TS_RESET_VAL);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		if (!hw->iio_devs[i])
+			continue;
+
+		sensor = iio_priv(hw->iio_devs[i]);
+		/*
+		 * store enable buffer timestamp as reference for
+		 * hw timestamp
+		 */
+		sensor->ts_ref = iio_get_time_ns(hw->iio_devs[i]);
+	}
+	return 0;
+}
+
+int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw)
+{
+	int err;
+
+	/* reset hw ts counter */
+	err = st_lsm6dsx_reset_hw_ts(hw);
+	if (err < 0)
+		return err;
+
+	return st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+}
+
+/*
+ * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN/ST_LSM6DSX_MAX_TAGGED_WORD_LEN
+ * in order to avoid a kmalloc for each bus access
+ */
+static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 addr,
+					u8 *data, unsigned int data_len,
+					unsigned int max_word_len)
+{
+	unsigned int word_len, read_len = 0;
+	int err;
+
+	while (read_len < data_len) {
+		word_len = min_t(unsigned int, data_len - read_len,
+				 max_word_len);
+		err = st_lsm6dsx_read_locked(hw, addr, data + read_len,
+					     word_len);
+		if (err < 0)
+			return err;
+		read_len += word_len;
+	}
+	return 0;
+}
+
+#define ST_LSM6DSX_IIO_BUFF_SIZE	(ALIGN(ST_LSM6DSX_SAMPLE_SIZE, \
+					       sizeof(s64)) + sizeof(s64))
+/**
+ * st_lsm6dsx_read_fifo() - hw FIFO read routine
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ *
+ * Read samples from the hw FIFO and push them to IIO buffers.
+ *
+ * Return: Number of bytes read from the FIFO
+ */
+int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
+{
+	struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor, *ext_sensor = NULL;
+	int err, sip, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
+	u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
+	u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
+	bool reset_ts = false;
+	__le16 fifo_status;
+	s64 ts = 0;
+
+	err = st_lsm6dsx_read_locked(hw,
+				     hw->settings->fifo_ops.fifo_diff.addr,
+				     &fifo_status, sizeof(fifo_status));
+	if (err < 0) {
+		dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
+			err);
+		return err;
+	}
+
+	if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
+		return 0;
+
+	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
+		   ST_LSM6DSX_CHAN_SIZE;
+	fifo_len = (fifo_len / pattern_len) * pattern_len;
+
+	acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
+	gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
+	if (hw->iio_devs[ST_LSM6DSX_ID_EXT0])
+		ext_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_EXT0]);
+
+	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
+		err = st_lsm6dsx_read_block(hw, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
+					    hw->buff, pattern_len,
+					    ST_LSM6DSX_MAX_WORD_LEN);
+		if (err < 0) {
+			dev_err(hw->dev,
+				"failed to read pattern from fifo (err=%d)\n",
+				err);
+			return err;
+		}
+
+		/*
+		 * Data are written to the FIFO with a specific pattern
+		 * depending on the configured ODRs. The first sequence of data
+		 * stored in FIFO contains the data of all enabled sensors
+		 * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated
+		 * depending on the value of the decimation factor set for each
+		 * sensor.
+		 *
+		 * Supposing the FIFO is storing data from gyroscope and
+		 * accelerometer at different ODRs:
+		 *   - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
+		 * Since the gyroscope ODR is twice the accelerometer one, the
+		 * following pattern is repeated every 9 samples:
+		 *   - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, ..
+		 */
+		ext_sip = ext_sensor ? ext_sensor->sip : 0;
+		gyro_sip = gyro_sensor->sip;
+		acc_sip = acc_sensor->sip;
+		ts_sip = hw->ts_sip;
+		offset = 0;
+		sip = 0;
+
+		while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) {
+			if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
+				memcpy(hw->scan[ST_LSM6DSX_ID_GYRO].channels,
+				       &hw->buff[offset],
+				       sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels));
+				offset += sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels);
+			}
+			if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
+				memcpy(hw->scan[ST_LSM6DSX_ID_ACC].channels,
+				       &hw->buff[offset],
+				       sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels));
+				offset += sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels);
+			}
+			if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
+				memcpy(hw->scan[ST_LSM6DSX_ID_EXT0].channels,
+				       &hw->buff[offset],
+				       sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels));
+				offset += sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels);
+			}
+
+			if (ts_sip-- > 0) {
+				u8 data[ST_LSM6DSX_SAMPLE_SIZE];
+
+				memcpy(data, &hw->buff[offset], sizeof(data));
+				/*
+				 * hw timestamp is 3B long and it is stored
+				 * in FIFO using 6B as 4th FIFO data set
+				 * according to this schema:
+				 * B0 = ts[15:8], B1 = ts[23:16], B3 = ts[7:0]
+				 */
+				ts = data[1] << 16 | data[0] << 8 | data[3];
+				/*
+				 * check if hw timestamp engine is going to
+				 * reset (the sensor generates an interrupt
+				 * to signal the hw timestamp will reset in
+				 * 1.638s)
+				 */
+				if (!reset_ts && ts >= 0xff0000)
+					reset_ts = true;
+				ts *= hw->ts_gain;
+
+				offset += ST_LSM6DSX_SAMPLE_SIZE;
+			}
+
+			if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
+				iio_push_to_buffers_with_timestamp(
+					hw->iio_devs[ST_LSM6DSX_ID_GYRO],
+					&hw->scan[ST_LSM6DSX_ID_GYRO],
+					gyro_sensor->ts_ref + ts);
+				gyro_sip--;
+			}
+			if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
+				iio_push_to_buffers_with_timestamp(
+					hw->iio_devs[ST_LSM6DSX_ID_ACC],
+					&hw->scan[ST_LSM6DSX_ID_ACC],
+					acc_sensor->ts_ref + ts);
+				acc_sip--;
+			}
+			if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
+				iio_push_to_buffers_with_timestamp(
+					hw->iio_devs[ST_LSM6DSX_ID_EXT0],
+					&hw->scan[ST_LSM6DSX_ID_EXT0],
+					ext_sensor->ts_ref + ts);
+				ext_sip--;
+			}
+			sip++;
+		}
+	}
+
+	if (unlikely(reset_ts)) {
+		err = st_lsm6dsx_reset_hw_ts(hw);
+		if (err < 0) {
+			dev_err(hw->dev, "failed to reset hw ts (err=%d)\n",
+				err);
+			return err;
+		}
+	}
+	return read_len;
+}
+
+#define ST_LSM6DSX_INVALID_SAMPLE	0x7ffd
+static int
+st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag,
+			    u8 *data, s64 ts)
+{
+	s16 val = le16_to_cpu(*(__le16 *)data);
+	struct st_lsm6dsx_sensor *sensor;
+	struct iio_dev *iio_dev;
+
+	/* invalid sample during bootstrap phase */
+	if (val >= ST_LSM6DSX_INVALID_SAMPLE)
+		return -EINVAL;
+
+	/*
+	 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG
+	 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG
+	 * to the second one and ST_LSM6DSX_EXT2_TAG to the last enabled
+	 * channel
+	 */
+	switch (tag) {
+	case ST_LSM6DSX_GYRO_TAG:
+		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_GYRO];
+		break;
+	case ST_LSM6DSX_ACC_TAG:
+		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_ACC];
+		break;
+	case ST_LSM6DSX_EXT0_TAG:
+		if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0))
+			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT0];
+		else if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1))
+			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
+		else
+			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
+		break;
+	case ST_LSM6DSX_EXT1_TAG:
+		if ((hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) &&
+		    (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1)))
+			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
+		else
+			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
+		break;
+	case ST_LSM6DSX_EXT2_TAG:
+		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	sensor = iio_priv(iio_dev);
+	iio_push_to_buffers_with_timestamp(iio_dev, data,
+					   ts + sensor->ts_ref);
+
+	return 0;
+}
+
+/**
+ * st_lsm6dsx_read_tagged_fifo() - tagged hw FIFO read routine
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ *
+ * Read samples from the hw FIFO and push them to IIO buffers.
+ *
+ * Return: Number of bytes read from the FIFO
+ */
+int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
+{
+	u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
+	u16 fifo_len, fifo_diff_mask;
+	/*
+	 * Alignment needed as this can ultimately be passed to a
+	 * call to iio_push_to_buffers_with_timestamp() which
+	 * must be passed a buffer that is aligned to 8 bytes so
+	 * as to allow insertion of a naturally aligned timestamp.
+	 */
+	u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8);
+	u8 tag;
+	bool reset_ts = false;
+	int i, err, read_len;
+	__le16 fifo_status;
+	s64 ts = 0;
+
+	err = st_lsm6dsx_read_locked(hw,
+				     hw->settings->fifo_ops.fifo_diff.addr,
+				     &fifo_status, sizeof(fifo_status));
+	if (err < 0) {
+		dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
+			err);
+		return err;
+	}
+
+	fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
+	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
+		   ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
+	if (!fifo_len)
+		return 0;
+
+	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
+		err = st_lsm6dsx_read_block(hw,
+					    ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,
+					    hw->buff, pattern_len,
+					    ST_LSM6DSX_MAX_TAGGED_WORD_LEN);
+		if (err < 0) {
+			dev_err(hw->dev,
+				"failed to read pattern from fifo (err=%d)\n",
+				err);
+			return err;
+		}
+
+		for (i = 0; i < pattern_len;
+		     i += ST_LSM6DSX_TAGGED_SAMPLE_SIZE) {
+			memcpy(iio_buff, &hw->buff[i + ST_LSM6DSX_TAG_SIZE],
+			       ST_LSM6DSX_SAMPLE_SIZE);
+
+			tag = hw->buff[i] >> 3;
+			if (tag == ST_LSM6DSX_TS_TAG) {
+				/*
+				 * hw timestamp is 4B long and it is stored
+				 * in FIFO according to this schema:
+				 * B0 = ts[7:0], B1 = ts[15:8], B2 = ts[23:16],
+				 * B3 = ts[31:24]
+				 */
+				ts = le32_to_cpu(*((__le32 *)iio_buff));
+				/*
+				 * check if hw timestamp engine is going to
+				 * reset (the sensor generates an interrupt
+				 * to signal the hw timestamp will reset in
+				 * 1.638s)
+				 */
+				if (!reset_ts && ts >= 0xffff0000)
+					reset_ts = true;
+				ts *= hw->ts_gain;
+			} else {
+				st_lsm6dsx_push_tagged_data(hw, tag, iio_buff,
+							    ts);
+			}
+		}
+	}
+
+	if (unlikely(reset_ts)) {
+		err = st_lsm6dsx_reset_hw_ts(hw);
+		if (err < 0)
+			return err;
+	}
+	return read_len;
+}
+
+int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
+{
+	int err;
+
+	if (!hw->settings->fifo_ops.read_fifo)
+		return -ENOTSUPP;
+
+	mutex_lock(&hw->fifo_lock);
+
+	hw->settings->fifo_ops.read_fifo(hw);
+	err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
+
+	mutex_unlock(&hw->fifo_lock);
+
+	return err;
+}
+
+int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
+{
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	u8 fifo_mask;
+	int err;
+
+	mutex_lock(&hw->conf_lock);
+
+	if (enable)
+		fifo_mask = hw->fifo_mask | BIT(sensor->id);
+	else
+		fifo_mask = hw->fifo_mask & ~BIT(sensor->id);
+
+	if (hw->fifo_mask) {
+		err = st_lsm6dsx_flush_fifo(hw);
+		if (err < 0)
+			goto out;
+	}
+
+	err = st_lsm6dsx_device_set_enable(sensor, enable);
+	if (err < 0)
+		goto out;
+
+	err = st_lsm6dsx_set_fifo_odr(sensor, enable);
+	if (err < 0)
+		goto out;
+
+	err = st_lsm6dsx_update_decimators(hw);
+	if (err < 0)
+		goto out;
+
+	err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
+	if (err < 0)
+		goto out;
+
+	if (fifo_mask) {
+		err = st_lsm6dsx_resume_fifo(hw);
+		if (err < 0)
+			goto out;
+	}
+
+	hw->fifo_mask = fifo_mask;
+
+out:
+	mutex_unlock(&hw->conf_lock);
+
+	return err;
+}
+
+static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+
+	if (!hw->settings->fifo_ops.update_fifo)
+		return -ENOTSUPP;
+
+	return hw->settings->fifo_ops.update_fifo(sensor, true);
+}
+
+static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+
+	if (!hw->settings->fifo_ops.update_fifo)
+		return -ENOTSUPP;
+
+	return hw->settings->fifo_ops.update_fifo(sensor, false);
+}
+
+static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
+	.preenable = st_lsm6dsx_buffer_preenable,
+	.postdisable = st_lsm6dsx_buffer_postdisable,
+};
+
+int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
+{
+	int i, ret;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		if (!hw->iio_devs[i])
+			continue;
+
+		ret = devm_iio_kfifo_buffer_setup(hw->dev, hw->iio_devs[i],
+						  &st_lsm6dsx_buffer_ops);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}