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().
  ...

5 files changed, 1023 insertions, 0 deletions

diff --git a/drivers/iio/amplifiers/Kconfig b/drivers/iio/amplifiers/Kconfig
new file mode 100644
index 000000000..f217a2a1e
--- /dev/null
+++ b/drivers/iio/amplifiers/Kconfig
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Gain Amplifiers, etc.
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Amplifiers"
+
+config AD8366
+	tristate "Analog Devices AD8366 and similar Gain Amplifiers"
+	depends on SPI
+	depends on GPIOLIB
+	select BITREVERSE
+	help
+	  Say yes here to build support for Analog Devices AD8366 and similar
+	  gain amplifiers. This driver supports the following gain amplifiers
+	  from Analog Devices:
+	    AD8366 Dual-Digital Variable Gain Amplifier (VGA)
+	    ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
+	    ADL5240 Digitally controlled variable gain amplifier (VGA)
+	    HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad8366.
+
+config ADA4250
+	tristate "Analog Devices ADA4250 Instrumentation Amplifier"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices ADA4250
+	  SPI Amplifier's support. The driver provides direct access via
+	  sysfs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ada4250.
+
+config HMC425
+	tristate "Analog Devices HMC425A and similar GPIO Gain Amplifiers"
+	depends on GPIOLIB
+	help
+	  Say yes here to build support for Analog Devices HMC425A and similar
+	  gain amplifiers or step attenuators.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hmc425a.
+
+endmenu
diff --git a/drivers/iio/amplifiers/Makefile b/drivers/iio/amplifiers/Makefile
new file mode 100644
index 000000000..212633112
--- /dev/null
+++ b/drivers/iio/amplifiers/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile iio/amplifiers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD8366) += ad8366.o
+obj-$(CONFIG_ADA4250) += ada4250.o
+obj-$(CONFIG_HMC425) += hmc425a.o
diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
new file mode 100644
index 000000000..f2c2ea79a
--- /dev/null
+++ b/drivers/iio/amplifiers/ad8366.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD8366 and similar Gain Amplifiers
+ * This driver supports the following gain amplifiers:
+ *   AD8366 Dual-Digital Variable Gain Amplifier (VGA)
+ *   ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
+ *   ADL5240 Digitally controlled variable gain amplifier (VGA)
+ *   HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
+ *
+ * Copyright 2012-2019 Analog Devices Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/bitrev.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+enum ad8366_type {
+	ID_AD8366,
+	ID_ADA4961,
+	ID_ADL5240,
+	ID_HMC1119,
+};
+
+struct ad8366_info {
+	int gain_min;
+	int gain_max;
+};
+
+struct ad8366_state {
+	struct spi_device	*spi;
+	struct regulator	*reg;
+	struct mutex            lock; /* protect sensor state */
+	struct gpio_desc	*reset_gpio;
+	unsigned char		ch[2];
+	enum ad8366_type	type;
+	struct ad8366_info	*info;
+	/*
+	 * DMA (thus cache coherency maintenance) may require the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	unsigned char		data[2] __aligned(IIO_DMA_MINALIGN);
+};
+
+static struct ad8366_info ad8366_infos[] = {
+	[ID_AD8366] = {
+		.gain_min = 4500,
+		.gain_max = 20500,
+	},
+	[ID_ADA4961] = {
+		.gain_min = -6000,
+		.gain_max = 15000,
+	},
+	[ID_ADL5240] = {
+		.gain_min = -11500,
+		.gain_max = 20000,
+	},
+	[ID_HMC1119] = {
+		.gain_min = -31750,
+		.gain_max = 0,
+	},
+};
+
+static int ad8366_write(struct iio_dev *indio_dev,
+			unsigned char ch_a, unsigned char ch_b)
+{
+	struct ad8366_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (st->type) {
+	case ID_AD8366:
+		ch_a = bitrev8(ch_a & 0x3F);
+		ch_b = bitrev8(ch_b & 0x3F);
+
+		st->data[0] = ch_b >> 4;
+		st->data[1] = (ch_b << 4) | (ch_a >> 2);
+		break;
+	case ID_ADA4961:
+		st->data[0] = ch_a & 0x1F;
+		break;
+	case ID_ADL5240:
+		st->data[0] = (ch_a & 0x3F);
+		break;
+	case ID_HMC1119:
+		st->data[0] = ch_a;
+		break;
+	}
+
+	ret = spi_write(st->spi, st->data, indio_dev->num_channels);
+	if (ret < 0)
+		dev_err(&indio_dev->dev, "write failed (%d)", ret);
+
+	return ret;
+}
+
+static int ad8366_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad8366_state *st = iio_priv(indio_dev);
+	int ret;
+	int code, gain = 0;
+
+	mutex_lock(&st->lock);
+	switch (m) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		code = st->ch[chan->channel];
+
+		switch (st->type) {
+		case ID_AD8366:
+			gain = code * 253 + 4500;
+			break;
+		case ID_ADA4961:
+			gain = 15000 - code * 1000;
+			break;
+		case ID_ADL5240:
+			gain = 20000 - 31500 + code * 500;
+			break;
+		case ID_HMC1119:
+			gain = -1 * code * 250;
+			break;
+		}
+
+		/* Values in dB */
+		*val = gain / 1000;
+		*val2 = (gain % 1000) * 1000;
+
+		ret = IIO_VAL_INT_PLUS_MICRO_DB;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+};
+
+static int ad8366_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long mask)
+{
+	struct ad8366_state *st = iio_priv(indio_dev);
+	struct ad8366_info *inf = st->info;
+	int code = 0, gain;
+	int ret;
+
+	/* Values in dB */
+	if (val < 0)
+		gain = (val * 1000) - (val2 / 1000);
+	else
+		gain = (val * 1000) + (val2 / 1000);
+
+	if (gain > inf->gain_max || gain < inf->gain_min)
+		return -EINVAL;
+
+	switch (st->type) {
+	case ID_AD8366:
+		code = (gain - 4500) / 253;
+		break;
+	case ID_ADA4961:
+		code = (15000 - gain) / 1000;
+		break;
+	case ID_ADL5240:
+		code = ((gain - 500 - 20000) / 500) & 0x3F;
+		break;
+	case ID_HMC1119:
+		code = (abs(gain) / 250) & 0x7F;
+		break;
+	}
+
+	mutex_lock(&st->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		st->ch[chan->channel] = code;
+		ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad8366_write_raw_get_fmt(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan,
+				    long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return IIO_VAL_INT_PLUS_MICRO_DB;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ad8366_info = {
+	.read_raw = &ad8366_read_raw,
+	.write_raw = &ad8366_write_raw,
+	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
+};
+
+#define AD8366_CHAN(_channel) {				\
+	.type = IIO_VOLTAGE,				\
+	.output = 1,					\
+	.indexed = 1,					\
+	.channel = _channel,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
+}
+
+static const struct iio_chan_spec ad8366_channels[] = {
+	AD8366_CHAN(0),
+	AD8366_CHAN(1),
+};
+
+static const struct iio_chan_spec ada4961_channels[] = {
+	AD8366_CHAN(0),
+};
+
+static int ad8366_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct ad8366_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->reg = devm_regulator_get(&spi->dev, "vcc");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret)
+			return ret;
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+	mutex_init(&st->lock);
+	st->spi = spi;
+	st->type = spi_get_device_id(spi)->driver_data;
+
+	switch (st->type) {
+	case ID_AD8366:
+		indio_dev->channels = ad8366_channels;
+		indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
+		break;
+	case ID_ADA4961:
+	case ID_ADL5240:
+	case ID_HMC1119:
+		st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_HIGH);
+		if (IS_ERR(st->reset_gpio)) {
+			ret = PTR_ERR(st->reset_gpio);
+			goto error_disable_reg;
+		}
+		indio_dev->channels = ada4961_channels;
+		indio_dev->num_channels = ARRAY_SIZE(ada4961_channels);
+		break;
+	default:
+		dev_err(&spi->dev, "Invalid device ID\n");
+		ret = -EINVAL;
+		goto error_disable_reg;
+	}
+
+	st->info = &ad8366_infos[st->type];
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &ad8366_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = ad8366_write(indio_dev, 0 , 0);
+	if (ret < 0)
+		goto error_disable_reg;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_disable_reg;
+
+	return 0;
+
+error_disable_reg:
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+
+	return ret;
+}
+
+static void ad8366_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad8366_state *st = iio_priv(indio_dev);
+	struct regulator *reg = st->reg;
+
+	iio_device_unregister(indio_dev);
+
+	if (!IS_ERR(reg))
+		regulator_disable(reg);
+}
+
+static const struct spi_device_id ad8366_id[] = {
+	{"ad8366",  ID_AD8366},
+	{"ada4961", ID_ADA4961},
+	{"adl5240", ID_ADL5240},
+	{"hmc1119", ID_HMC1119},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad8366_id);
+
+static struct spi_driver ad8366_driver = {
+	.driver = {
+		.name	= KBUILD_MODNAME,
+	},
+	.probe		= ad8366_probe,
+	.remove		= ad8366_remove,
+	.id_table	= ad8366_id,
+};
+
+module_spi_driver(ad8366_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD8366 and similar Gain Amplifiers");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/amplifiers/ada4250.c b/drivers/iio/amplifiers/ada4250.c
new file mode 100644
index 000000000..4b32d350d
--- /dev/null
+++ b/drivers/iio/amplifiers/ada4250.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ADA4250 driver
+ *
+ * Copyright 2022 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <asm/unaligned.h>
+
+/* ADA4250 Register Map */
+#define ADA4250_REG_GAIN_MUX        0x00
+#define ADA4250_REG_REFBUF_EN       0x01
+#define ADA4250_REG_RESET           0x02
+#define ADA4250_REG_SNSR_CAL_VAL    0x04
+#define ADA4250_REG_SNSR_CAL_CNFG   0x05
+#define ADA4250_REG_DIE_REV         0x18
+#define ADA4250_REG_CHIP_ID         0x19
+
+/* ADA4250_REG_GAIN_MUX Map */
+#define ADA4250_GAIN_MUX_MSK        GENMASK(2, 0)
+
+/* ADA4250_REG_REFBUF Map */
+#define ADA4250_REFBUF_MSK          BIT(0)
+
+/* ADA4250_REG_RESET Map */
+#define ADA4250_RESET_MSK           BIT(0)
+
+/* ADA4250_REG_SNSR_CAL_VAL Map */
+#define ADA4250_CAL_CFG_BIAS_MSK    GENMASK(7, 0)
+
+/* ADA4250_REG_SNSR_CAL_CNFG Bit Definition */
+#define ADA4250_BIAS_SET_MSK        GENMASK(3, 2)
+#define ADA4250_RANGE_SET_MSK       GENMASK(1, 0)
+
+/* Miscellaneous definitions */
+#define ADA4250_CHIP_ID             0x4250
+#define ADA4250_RANGE1              0
+#define	ADA4250_RANGE4              3
+
+/* ADA4250 current bias set */
+enum ada4250_current_bias {
+	ADA4250_BIAS_DISABLED,
+	ADA4250_BIAS_BANDGAP,
+	ADA4250_BIAS_AVDD,
+};
+
+struct ada4250_state {
+	struct spi_device	*spi;
+	struct regmap		*regmap;
+	struct regulator	*reg;
+	/* Protect against concurrent accesses to the device and data content */
+	struct mutex		lock;
+	u8			bias;
+	u8			gain;
+	int			offset_uv;
+	bool			refbuf_en;
+};
+
+/* ADA4250 Current Bias Source Settings: Disabled, Bandgap Reference, AVDD */
+static const int calibbias_table[] = {0, 1, 2};
+
+/* ADA4250 Gain (V/V) values: 1, 2, 4, 8, 16, 32, 64, 128 */
+static const int hwgain_table[] = {1, 2, 4, 8, 16, 32, 64, 128};
+
+static const struct regmap_config ada4250_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = BIT(7),
+	.max_register = 0x1A,
+};
+
+static int ada4250_set_offset_uv(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan,
+				 int offset_uv)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+
+	int i, ret, x[8], max_vos, min_vos, voltage_v, vlsb = 0;
+	u8 offset_raw, range = ADA4250_RANGE1;
+	u32 lsb_coeff[6] = {1333, 2301, 4283, 8289, 16311, 31599};
+
+	if (st->bias == 0 || st->bias == 3)
+		return -EINVAL;
+
+	voltage_v = regulator_get_voltage(st->reg);
+	voltage_v = DIV_ROUND_CLOSEST(voltage_v, 1000000);
+
+	if (st->bias == ADA4250_BIAS_AVDD)
+		x[0] = voltage_v;
+	else
+		x[0] = 5;
+
+	x[1] = 126 * (x[0] - 1);
+
+	for (i = 0; i < 6; i++)
+		x[i + 2] = DIV_ROUND_CLOSEST(x[1] * 1000, lsb_coeff[i]);
+
+	if (st->gain == 0)
+		return -EINVAL;
+
+	/*
+	 * Compute Range and Voltage per LSB for the Sensor Offset Calibration
+	 * Example of computation for Range 1 and Range 2 (Curren Bias Set = AVDD):
+	 *                     Range 1                            Range 2
+	 *   Gain   | Max Vos(mV) |   LSB(mV)        |  Max Vos(mV)  | LSB(mV) |
+	 *    2     |    X1*127   | X1=0.126(AVDD-1) |   X1*3*127    |  X1*3   |
+	 *    4     |    X2*127   | X2=X1/1.3333     |   X2*3*127    |  X2*3   |
+	 *    8     |    X3*127   | X3=X1/2.301      |   X3*3*127    |  X3*3   |
+	 *    16    |    X4*127   | X4=X1/4.283      |   X4*3*127    |  X4*3   |
+	 *    32    |    X5*127   | X5=X1/8.289      |   X5*3*127    |  X5*3   |
+	 *    64    |    X6*127   | X6=X1/16.311     |   X6*3*127    |  X6*3   |
+	 *    128   |    X7*127   | X7=X1/31.599     |   X7*3*127    |  X7*3   |
+	 */
+	for (i = ADA4250_RANGE1; i <= ADA4250_RANGE4; i++) {
+		max_vos = x[st->gain] *  127 * ((1 << (i + 1)) - 1);
+		min_vos = -1 * max_vos;
+		if (offset_uv > min_vos && offset_uv < max_vos) {
+			range = i;
+			vlsb = x[st->gain] * ((1 << (i + 1)) - 1);
+			break;
+		}
+	}
+
+	if (vlsb <= 0)
+		return -EINVAL;
+
+	offset_raw = DIV_ROUND_CLOSEST(abs(offset_uv), vlsb);
+
+	mutex_lock(&st->lock);
+	ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,
+				 ADA4250_RANGE_SET_MSK,
+				 FIELD_PREP(ADA4250_RANGE_SET_MSK, range));
+	if (ret)
+		goto exit;
+
+	st->offset_uv = offset_raw * vlsb;
+
+	/*
+	 * To set the offset calibration value, use bits [6:0] and bit 7 as the
+	 * polarity bit (set to "0" for a negative offset and "1" for a positive
+	 * offset).
+	 */
+	if (offset_uv < 0) {
+		offset_raw |= BIT(7);
+		st->offset_uv *= (-1);
+	}
+
+	ret = regmap_write(st->regmap, ADA4250_REG_SNSR_CAL_VAL, offset_raw);
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ada4250_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long info)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = regmap_read(st->regmap, ADA4250_REG_GAIN_MUX, val);
+		if (ret)
+			return ret;
+
+		*val = BIT(*val);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = st->offset_uv;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = regmap_read(st->regmap, ADA4250_REG_SNSR_CAL_CNFG, val);
+		if (ret)
+			return ret;
+
+		*val = FIELD_GET(ADA4250_BIAS_SET_MSK, *val);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1;
+		*val2 = 1000000;
+
+		return IIO_VAL_FRACTIONAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long info)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = regmap_write(st->regmap, ADA4250_REG_GAIN_MUX,
+				   FIELD_PREP(ADA4250_GAIN_MUX_MSK, ilog2(val)));
+		if (ret)
+			return ret;
+
+		st->gain = ilog2(val);
+
+		return ret;
+	case IIO_CHAN_INFO_OFFSET:
+		return ada4250_set_offset_uv(indio_dev, chan, val);
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,
+					 ADA4250_BIAS_SET_MSK,
+					 FIELD_PREP(ADA4250_BIAS_SET_MSK, val));
+		if (ret)
+			return ret;
+
+		st->bias = val;
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		*vals = calibbias_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(calibbias_table);
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		*vals = hwgain_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(hwgain_table);
+
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_reg_access(struct iio_dev *indio_dev,
+			      unsigned int reg,
+			      unsigned int write_val,
+			      unsigned int *read_val)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+
+	if (read_val)
+		return regmap_read(st->regmap, reg, read_val);
+	else
+		return regmap_write(st->regmap, reg, write_val);
+}
+
+static const struct iio_info ada4250_info = {
+	.read_raw = ada4250_read_raw,
+	.write_raw = ada4250_write_raw,
+	.read_avail = &ada4250_read_avail,
+	.debugfs_reg_access = &ada4250_reg_access,
+};
+
+static const struct iio_chan_spec ada4250_channels[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.output = 1,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN) |
+				BIT(IIO_CHAN_INFO_OFFSET) |
+				BIT(IIO_CHAN_INFO_CALIBBIAS) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS) |
+						BIT(IIO_CHAN_INFO_HARDWAREGAIN),
+	}
+};
+
+static void ada4250_reg_disable(void *data)
+{
+	regulator_disable(data);
+}
+
+static int ada4250_init(struct ada4250_state *st)
+{
+	int ret;
+	u16 chip_id;
+	u8 data[2] __aligned(8) = {};
+	struct spi_device *spi = st->spi;
+
+	st->refbuf_en = device_property_read_bool(&spi->dev, "adi,refbuf-enable");
+
+	st->reg = devm_regulator_get(&spi->dev, "avdd");
+	if (IS_ERR(st->reg))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->reg),
+				     "failed to get the AVDD voltage\n");
+
+	ret = regulator_enable(st->reg);
+	if (ret) {
+		dev_err(&spi->dev, "Failed to enable specified AVDD supply\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&spi->dev, ada4250_reg_disable, st->reg);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->regmap, ADA4250_REG_RESET,
+			   FIELD_PREP(ADA4250_RESET_MSK, 1));
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(st->regmap, ADA4250_REG_CHIP_ID, data, 2);
+	if (ret)
+		return ret;
+
+	chip_id = get_unaligned_le16(data);
+
+	if (chip_id != ADA4250_CHIP_ID) {
+		dev_err(&spi->dev, "Invalid chip ID.\n");
+		return -EINVAL;
+	}
+
+	return regmap_write(st->regmap, ADA4250_REG_REFBUF_EN,
+			    FIELD_PREP(ADA4250_REFBUF_MSK, st->refbuf_en));
+}
+
+static int ada4250_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	struct ada4250_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	regmap = devm_regmap_init_spi(spi, &ada4250_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	st = iio_priv(indio_dev);
+	st->regmap = regmap;
+	st->spi = spi;
+
+	indio_dev->info = &ada4250_info;
+	indio_dev->name = "ada4250";
+	indio_dev->channels = ada4250_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ada4250_channels);
+
+	mutex_init(&st->lock);
+
+	ret = ada4250_init(st);
+	if (ret) {
+		dev_err(&spi->dev, "ADA4250 init failed\n");
+		return ret;
+	}
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ada4250_id[] = {
+	{ "ada4250", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ada4250_id);
+
+static const struct of_device_id ada4250_of_match[] = {
+	{ .compatible = "adi,ada4250" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ada4250_of_match);
+
+static struct spi_driver ada4250_driver = {
+	.driver = {
+			.name = "ada4250",
+			.of_match_table = ada4250_of_match,
+		},
+	.probe = ada4250_probe,
+	.id_table = ada4250_id,
+};
+module_spi_driver(ada4250_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
+MODULE_DESCRIPTION("Analog Devices ADA4250");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/amplifiers/hmc425a.c b/drivers/iio/amplifiers/hmc425a.c
new file mode 100644
index 000000000..108f0f168
--- /dev/null
+++ b/drivers/iio/amplifiers/hmc425a.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HMC425A and similar Gain Amplifiers
+ *
+ * Copyright 2020 Analog Devices Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+
+enum hmc425a_type {
+	ID_HMC425A,
+};
+
+struct hmc425a_chip_info {
+	const char			*name;
+	const struct iio_chan_spec	*channels;
+	unsigned int			num_channels;
+	unsigned int			num_gpios;
+	int				gain_min;
+	int				gain_max;
+	int				default_gain;
+};
+
+struct hmc425a_state {
+	struct	mutex lock; /* protect sensor state */
+	struct	hmc425a_chip_info *chip_info;
+	struct	gpio_descs *gpios;
+	enum	hmc425a_type type;
+	u32	gain;
+};
+
+static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	DECLARE_BITMAP(values, BITS_PER_TYPE(value));
+
+	values[0] = value;
+
+	gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios->desc,
+				       NULL, values);
+	return 0;
+}
+
+static int hmc425a_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long m)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	int code, gain = 0;
+	int ret;
+
+	mutex_lock(&st->lock);
+	switch (m) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		code = st->gain;
+
+		switch (st->type) {
+		case ID_HMC425A:
+			gain = ~code * -500;
+			break;
+		}
+
+		*val = gain / 1000;
+		*val2 = (gain % 1000) * 1000;
+
+		ret = IIO_VAL_INT_PLUS_MICRO_DB;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+};
+
+static int hmc425a_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int val,
+			     int val2, long mask)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	struct hmc425a_chip_info *inf = st->chip_info;
+	int code = 0, gain;
+	int ret;
+
+	if (val < 0)
+		gain = (val * 1000) - (val2 / 1000);
+	else
+		gain = (val * 1000) + (val2 / 1000);
+
+	if (gain > inf->gain_max || gain < inf->gain_min)
+		return -EINVAL;
+
+	switch (st->type) {
+	case ID_HMC425A:
+		code = ~((abs(gain) / 500) & 0x3F);
+		break;
+	}
+
+	mutex_lock(&st->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		st->gain = code;
+
+		ret = hmc425a_write(indio_dev, st->gain);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int hmc425a_write_raw_get_fmt(struct iio_dev *indio_dev,
+				     struct iio_chan_spec const *chan,
+				     long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return IIO_VAL_INT_PLUS_MICRO_DB;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info hmc425a_info = {
+	.read_raw = &hmc425a_read_raw,
+	.write_raw = &hmc425a_write_raw,
+	.write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
+};
+
+#define HMC425A_CHAN(_channel)						\
+{									\
+	.type = IIO_VOLTAGE,						\
+	.output = 1,							\
+	.indexed = 1,							\
+	.channel = _channel,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
+}
+
+static const struct iio_chan_spec hmc425a_channels[] = {
+	HMC425A_CHAN(0),
+};
+
+/* Match table for of_platform binding */
+static const struct of_device_id hmc425a_of_match[] = {
+	{ .compatible = "adi,hmc425a", .data = (void *)ID_HMC425A },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hmc425a_of_match);
+
+static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
+	[ID_HMC425A] = {
+		.name = "hmc425a",
+		.channels = hmc425a_channels,
+		.num_channels = ARRAY_SIZE(hmc425a_channels),
+		.num_gpios = 6,
+		.gain_min = -31500,
+		.gain_max = 0,
+		.default_gain = -0x40, /* set default gain -31.5db*/
+	},
+};
+
+static int hmc425a_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct hmc425a_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->type = (uintptr_t)device_get_match_data(&pdev->dev);
+
+	st->chip_info = &hmc425a_chip_info_tbl[st->type];
+	indio_dev->num_channels = st->chip_info->num_channels;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->name = st->chip_info->name;
+	st->gain = st->chip_info->default_gain;
+
+	st->gpios = devm_gpiod_get_array(&pdev->dev, "ctrl", GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpios))
+		return dev_err_probe(&pdev->dev, PTR_ERR(st->gpios),
+				     "failed to get gpios\n");
+
+	if (st->gpios->ndescs != st->chip_info->num_gpios) {
+		dev_err(&pdev->dev, "%d GPIOs needed to operate\n",
+			st->chip_info->num_gpios);
+		return -ENODEV;
+	}
+
+	ret = devm_regulator_get_enable(&pdev->dev, "vcc-supply");
+	if (ret)
+		return ret;
+
+	mutex_init(&st->lock);
+
+	indio_dev->info = &hmc425a_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static struct platform_driver hmc425a_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = hmc425a_of_match,
+	},
+	.probe = hmc425a_probe,
+};
+module_platform_driver(hmc425a_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
+MODULE_LICENSE("GPL v2");