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, 644 insertions, 0 deletions

diff --git a/drivers/hwmon/ina238.c b/drivers/hwmon/ina238.c
new file mode 100644
index 000000000..50eb9c5e1
--- /dev/null
+++ b/drivers/hwmon/ina238.c
@@ -0,0 +1,644 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Texas Instruments INA238 power monitor chip
+ * Datasheet: https://www.ti.com/product/ina238
+ *
+ * Copyright (C) 2021 Nathan Rossi <nathan.rossi@digi.com>
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#include <linux/platform_data/ina2xx.h>
+
+/* INA238 register definitions */
+#define INA238_CONFIG			0x0
+#define INA238_ADC_CONFIG		0x1
+#define INA238_SHUNT_CALIBRATION	0x2
+#define INA238_SHUNT_VOLTAGE		0x4
+#define INA238_BUS_VOLTAGE		0x5
+#define INA238_DIE_TEMP			0x6
+#define INA238_CURRENT			0x7
+#define INA238_POWER			0x8
+#define INA238_DIAG_ALERT		0xb
+#define INA238_SHUNT_OVER_VOLTAGE	0xc
+#define INA238_SHUNT_UNDER_VOLTAGE	0xd
+#define INA238_BUS_OVER_VOLTAGE		0xe
+#define INA238_BUS_UNDER_VOLTAGE	0xf
+#define INA238_TEMP_LIMIT		0x10
+#define INA238_POWER_LIMIT		0x11
+#define INA238_DEVICE_ID		0x3f
+
+#define INA238_CONFIG_ADCRANGE		BIT(4)
+
+#define INA238_DIAG_ALERT_TMPOL		BIT(7)
+#define INA238_DIAG_ALERT_SHNTOL	BIT(6)
+#define INA238_DIAG_ALERT_SHNTUL	BIT(5)
+#define INA238_DIAG_ALERT_BUSOL		BIT(4)
+#define INA238_DIAG_ALERT_BUSUL		BIT(3)
+#define INA238_DIAG_ALERT_POL		BIT(2)
+
+#define INA238_REGISTERS		0x11
+
+#define INA238_RSHUNT_DEFAULT		10000 /* uOhm */
+
+/* Default configuration of device on reset. */
+#define INA238_CONFIG_DEFAULT		0
+/* 16 sample averaging, 1052us conversion time, continuous mode */
+#define INA238_ADC_CONFIG_DEFAULT	0xfb6a
+/* Configure alerts to be based on averaged value (SLOWALERT) */
+#define INA238_DIAG_ALERT_DEFAULT	0x2000
+/*
+ * This driver uses a fixed calibration value in order to scale current/power
+ * based on a fixed shunt resistor value. This allows for conversion within the
+ * device to avoid integer limits whilst current/power accuracy is scaled
+ * relative to the shunt resistor value within the driver. This is similar to
+ * how the ina2xx driver handles current/power scaling.
+ *
+ * The end result of this is that increasing shunt values (from a fixed 20 mOhm
+ * shunt) increase the effective current/power accuracy whilst limiting the
+ * range and decreasing shunt values decrease the effective accuracy but
+ * increase the range.
+ *
+ * The value of the Current register is calculated given the following:
+ *   Current (A) = (shunt voltage register * 5) * calibration / 81920
+ *
+ * The maximum shunt voltage is 163.835 mV (0x7fff, ADC_RANGE = 0, gain = 4).
+ * With the maximum current value of 0x7fff and a fixed shunt value results in
+ * a calibration value of 16384 (0x4000).
+ *
+ *   0x7fff = (0x7fff * 5) * calibration / 81920
+ *   calibration = 0x4000
+ *
+ * Equivalent calibration is applied for the Power register (maximum value for
+ * bus voltage is 102396.875 mV, 0x7fff), where the maximum power that can
+ * occur is ~16776192 uW (register value 0x147a8):
+ *
+ * This scaling means the resulting values for Current and Power registers need
+ * to be scaled by the difference between the fixed shunt resistor and the
+ * actual shunt resistor:
+ *
+ *  shunt = 0x4000 / (819.2 * 10^6) / 0.001 = 20000 uOhms (with 1mA/lsb)
+ *
+ *  Current (mA) = register value * 20000 / rshunt / 4 * gain
+ *  Power (W) = 0.2 * register value * 20000 / rshunt / 4 * gain
+ */
+#define INA238_CALIBRATION_VALUE	16384
+#define INA238_FIXED_SHUNT		20000
+
+#define INA238_SHUNT_VOLTAGE_LSB	5 /* 5 uV/lsb */
+#define INA238_BUS_VOLTAGE_LSB		3125 /* 3.125 mV/lsb */
+#define INA238_DIE_TEMP_LSB		125 /* 125 mC/lsb */
+
+static struct regmap_config ina238_regmap_config = {
+	.max_register = INA238_REGISTERS,
+	.reg_bits = 8,
+	.val_bits = 16,
+};
+
+struct ina238_data {
+	struct i2c_client *client;
+	struct mutex config_lock;
+	struct regmap *regmap;
+	u32 rshunt;
+	int gain;
+};
+
+static int ina238_read_reg24(const struct i2c_client *client, u8 reg, u32 *val)
+{
+	u8 data[3];
+	int err;
+
+	/* 24-bit register read */
+	err = i2c_smbus_read_i2c_block_data(client, reg, 3, data);
+	if (err < 0)
+		return err;
+	if (err != 3)
+		return -EIO;
+	*val = (data[0] << 16) | (data[1] << 8) | data[2];
+
+	return 0;
+}
+
+static int ina238_read_in(struct device *dev, u32 attr, int channel,
+			  long *val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int reg, mask;
+	int regval;
+	int err;
+
+	switch (channel) {
+	case 0:
+		switch (attr) {
+		case hwmon_in_input:
+			reg = INA238_SHUNT_VOLTAGE;
+			break;
+		case hwmon_in_max:
+			reg = INA238_SHUNT_OVER_VOLTAGE;
+			break;
+		case hwmon_in_min:
+			reg = INA238_SHUNT_UNDER_VOLTAGE;
+			break;
+		case hwmon_in_max_alarm:
+			reg = INA238_DIAG_ALERT;
+			mask = INA238_DIAG_ALERT_SHNTOL;
+			break;
+		case hwmon_in_min_alarm:
+			reg = INA238_DIAG_ALERT;
+			mask = INA238_DIAG_ALERT_SHNTUL;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	case 1:
+		switch (attr) {
+		case hwmon_in_input:
+			reg = INA238_BUS_VOLTAGE;
+			break;
+		case hwmon_in_max:
+			reg = INA238_BUS_OVER_VOLTAGE;
+			break;
+		case hwmon_in_min:
+			reg = INA238_BUS_UNDER_VOLTAGE;
+			break;
+		case hwmon_in_max_alarm:
+			reg = INA238_DIAG_ALERT;
+			mask = INA238_DIAG_ALERT_BUSOL;
+			break;
+		case hwmon_in_min_alarm:
+			reg = INA238_DIAG_ALERT;
+			mask = INA238_DIAG_ALERT_BUSUL;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	err = regmap_read(data->regmap, reg, &regval);
+	if (err < 0)
+		return err;
+
+	switch (attr) {
+	case hwmon_in_input:
+	case hwmon_in_max:
+	case hwmon_in_min:
+		/* signed register, value in mV */
+		regval = (s16)regval;
+		if (channel == 0)
+			/* gain of 1 -> LSB / 4 */
+			*val = (regval * INA238_SHUNT_VOLTAGE_LSB) /
+			       (1000 * (4 - data->gain + 1));
+		else
+			*val = (regval * INA238_BUS_VOLTAGE_LSB) / 1000;
+		break;
+	case hwmon_in_max_alarm:
+	case hwmon_in_min_alarm:
+		*val = !!(regval & mask);
+		break;
+	}
+
+	return 0;
+}
+
+static int ina238_write_in(struct device *dev, u32 attr, int channel,
+			   long val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int regval;
+
+	if (attr != hwmon_in_max && attr != hwmon_in_min)
+		return -EOPNOTSUPP;
+
+	/* convert decimal to register value */
+	switch (channel) {
+	case 0:
+		/* signed value, clamp to max range +/-163 mV */
+		regval = clamp_val(val, -163, 163);
+		regval = (regval * 1000 * (4 - data->gain + 1)) /
+			 INA238_SHUNT_VOLTAGE_LSB;
+		regval = clamp_val(regval, S16_MIN, S16_MAX);
+
+		switch (attr) {
+		case hwmon_in_max:
+			return regmap_write(data->regmap,
+					    INA238_SHUNT_OVER_VOLTAGE, regval);
+		case hwmon_in_min:
+			return regmap_write(data->regmap,
+					    INA238_SHUNT_UNDER_VOLTAGE, regval);
+		default:
+			return -EOPNOTSUPP;
+		}
+	case 1:
+		/* signed value, positive values only. Clamp to max 102.396 V */
+		regval = clamp_val(val, 0, 102396);
+		regval = (regval * 1000) / INA238_BUS_VOLTAGE_LSB;
+		regval = clamp_val(regval, 0, S16_MAX);
+
+		switch (attr) {
+		case hwmon_in_max:
+			return regmap_write(data->regmap,
+					    INA238_BUS_OVER_VOLTAGE, regval);
+		case hwmon_in_min:
+			return regmap_write(data->regmap,
+					    INA238_BUS_UNDER_VOLTAGE, regval);
+		default:
+			return -EOPNOTSUPP;
+		}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina238_read_current(struct device *dev, u32 attr, long *val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int regval;
+	int err;
+
+	switch (attr) {
+	case hwmon_curr_input:
+		err = regmap_read(data->regmap, INA238_CURRENT, &regval);
+		if (err < 0)
+			return err;
+
+		/* Signed register, fixed 1mA current lsb. result in mA */
+		*val = div_s64((s16)regval * INA238_FIXED_SHUNT * data->gain,
+			       data->rshunt * 4);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int ina238_read_power(struct device *dev, u32 attr, long *val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	long long power;
+	int regval;
+	int err;
+
+	switch (attr) {
+	case hwmon_power_input:
+		err = ina238_read_reg24(data->client, INA238_POWER, &regval);
+		if (err)
+			return err;
+
+		/* Fixed 1mA lsb, scaled by 1000000 to have result in uW */
+		power = div_u64(regval * 1000ULL * INA238_FIXED_SHUNT *
+				data->gain, 20 * data->rshunt);
+		/* Clamp value to maximum value of long */
+		*val = clamp_val(power, 0, LONG_MAX);
+		break;
+	case hwmon_power_max:
+		err = regmap_read(data->regmap, INA238_POWER_LIMIT, &regval);
+		if (err)
+			return err;
+
+		/*
+		 * Truncated 24-bit compare register, lower 8-bits are
+		 * truncated. Same conversion to/from uW as POWER register.
+		 */
+		power = div_u64((regval << 8) * 1000ULL * INA238_FIXED_SHUNT *
+			       data->gain, 20 * data->rshunt);
+		/* Clamp value to maximum value of long */
+		*val = clamp_val(power, 0, LONG_MAX);
+		break;
+	case hwmon_power_max_alarm:
+		err = regmap_read(data->regmap, INA238_DIAG_ALERT, &regval);
+		if (err)
+			return err;
+
+		*val = !!(regval & INA238_DIAG_ALERT_POL);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int ina238_write_power(struct device *dev, u32 attr, long val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	long regval;
+
+	if (attr != hwmon_power_max)
+		return -EOPNOTSUPP;
+
+	/*
+	 * Unsigned postive values. Compared against the 24-bit power register,
+	 * lower 8-bits are truncated. Same conversion to/from uW as POWER
+	 * register.
+	 */
+	regval = clamp_val(val, 0, LONG_MAX);
+	regval = div_u64(val * 20ULL * data->rshunt,
+			 1000ULL * INA238_FIXED_SHUNT * data->gain);
+	regval = clamp_val(regval >> 8, 0, U16_MAX);
+
+	return regmap_write(data->regmap, INA238_POWER_LIMIT, regval);
+}
+
+static int ina238_read_temp(struct device *dev, u32 attr, long *val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int regval;
+	int err;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		err = regmap_read(data->regmap, INA238_DIE_TEMP, &regval);
+		if (err)
+			return err;
+
+		/* Signed, bits 15-4 of register, result in mC */
+		*val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB;
+		break;
+	case hwmon_temp_max:
+		err = regmap_read(data->regmap, INA238_TEMP_LIMIT, &regval);
+		if (err)
+			return err;
+
+		/* Signed, bits 15-4 of register, result in mC */
+		*val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB;
+		break;
+	case hwmon_temp_max_alarm:
+		err = regmap_read(data->regmap, INA238_DIAG_ALERT, &regval);
+		if (err)
+			return err;
+
+		*val = !!(regval & INA238_DIAG_ALERT_TMPOL);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int ina238_write_temp(struct device *dev, u32 attr, long val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int regval;
+
+	if (attr != hwmon_temp_max)
+		return -EOPNOTSUPP;
+
+	/* Signed, bits 15-4 of register */
+	regval = (val / INA238_DIE_TEMP_LSB) << 4;
+	regval = clamp_val(regval, S16_MIN, S16_MAX) & 0xfff0;
+
+	return regmap_write(data->regmap, INA238_TEMP_LIMIT, regval);
+}
+
+static int ina238_read(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_in:
+		return ina238_read_in(dev, attr, channel, val);
+	case hwmon_curr:
+		return ina238_read_current(dev, attr, val);
+	case hwmon_power:
+		return ina238_read_power(dev, attr, val);
+	case hwmon_temp:
+		return ina238_read_temp(dev, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ina238_write(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long val)
+{
+	struct ina238_data *data = dev_get_drvdata(dev);
+	int err;
+
+	mutex_lock(&data->config_lock);
+
+	switch (type) {
+	case hwmon_in:
+		err = ina238_write_in(dev, attr, channel, val);
+		break;
+	case hwmon_power:
+		err = ina238_write_power(dev, attr, val);
+		break;
+	case hwmon_temp:
+		err = ina238_write_temp(dev, attr, val);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&data->config_lock);
+	return err;
+}
+
+static umode_t ina238_is_visible(const void *drvdata,
+				 enum hwmon_sensor_types type,
+				 u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+		case hwmon_in_max_alarm:
+		case hwmon_in_min_alarm:
+			return 0444;
+		case hwmon_in_max:
+		case hwmon_in_min:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+			return 0444;
+		default:
+			return 0;
+		}
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+		case hwmon_power_max_alarm:
+			return 0444;
+		case hwmon_power_max:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_max_alarm:
+			return 0444;
+		case hwmon_temp_max:
+			return 0644;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+#define INA238_HWMON_IN_CONFIG (HWMON_I_INPUT | \
+				HWMON_I_MAX | HWMON_I_MAX_ALARM | \
+				HWMON_I_MIN | HWMON_I_MIN_ALARM)
+
+static const struct hwmon_channel_info *ina238_info[] = {
+	HWMON_CHANNEL_INFO(in,
+			   /* 0: shunt voltage */
+			   INA238_HWMON_IN_CONFIG,
+			   /* 1: bus voltage */
+			   INA238_HWMON_IN_CONFIG),
+	HWMON_CHANNEL_INFO(curr,
+			   /* 0: current through shunt */
+			   HWMON_C_INPUT),
+	HWMON_CHANNEL_INFO(power,
+			   /* 0: power */
+			   HWMON_P_INPUT | HWMON_P_MAX | HWMON_P_MAX_ALARM),
+	HWMON_CHANNEL_INFO(temp,
+			   /* 0: die temperature */
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops ina238_hwmon_ops = {
+	.is_visible = ina238_is_visible,
+	.read = ina238_read,
+	.write = ina238_write,
+};
+
+static const struct hwmon_chip_info ina238_chip_info = {
+	.ops = &ina238_hwmon_ops,
+	.info = ina238_info,
+};
+
+static int ina238_probe(struct i2c_client *client)
+{
+	struct ina2xx_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct ina238_data *data;
+	int config;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	mutex_init(&data->config_lock);
+
+	data->regmap = devm_regmap_init_i2c(client, &ina238_regmap_config);
+	if (IS_ERR(data->regmap)) {
+		dev_err(dev, "failed to allocate register map\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	/* load shunt value */
+	data->rshunt = INA238_RSHUNT_DEFAULT;
+	if (device_property_read_u32(dev, "shunt-resistor", &data->rshunt) < 0 && pdata)
+		data->rshunt = pdata->shunt_uohms;
+	if (data->rshunt == 0) {
+		dev_err(dev, "invalid shunt resister value %u\n", data->rshunt);
+		return -EINVAL;
+	}
+
+	/* load shunt gain value */
+	if (device_property_read_u32(dev, "ti,shunt-gain", &data->gain) < 0)
+		data->gain = 4; /* Default of ADCRANGE = 0 */
+	if (data->gain != 1 && data->gain != 4) {
+		dev_err(dev, "invalid shunt gain value %u\n", data->gain);
+		return -EINVAL;
+	}
+
+	/* Setup CONFIG register */
+	config = INA238_CONFIG_DEFAULT;
+	if (data->gain == 1)
+		config |= INA238_CONFIG_ADCRANGE; /* ADCRANGE = 1 is /1 */
+	ret = regmap_write(data->regmap, INA238_CONFIG, config);
+	if (ret < 0) {
+		dev_err(dev, "error configuring the device: %d\n", ret);
+		return -ENODEV;
+	}
+
+	/* Setup ADC_CONFIG register */
+	ret = regmap_write(data->regmap, INA238_ADC_CONFIG,
+			   INA238_ADC_CONFIG_DEFAULT);
+	if (ret < 0) {
+		dev_err(dev, "error configuring the device: %d\n", ret);
+		return -ENODEV;
+	}
+
+	/* Setup SHUNT_CALIBRATION register with fixed value */
+	ret = regmap_write(data->regmap, INA238_SHUNT_CALIBRATION,
+			   INA238_CALIBRATION_VALUE);
+	if (ret < 0) {
+		dev_err(dev, "error configuring the device: %d\n", ret);
+		return -ENODEV;
+	}
+
+	/* Setup alert/alarm configuration */
+	ret = regmap_write(data->regmap, INA238_DIAG_ALERT,
+			   INA238_DIAG_ALERT_DEFAULT);
+	if (ret < 0) {
+		dev_err(dev, "error configuring the device: %d\n", ret);
+		return -ENODEV;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
+							 &ina238_chip_info,
+							 NULL);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n",
+		 client->name, data->rshunt, data->gain);
+
+	return 0;
+}
+
+static const struct i2c_device_id ina238_id[] = {
+	{ "ina238", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ina238_id);
+
+static const struct of_device_id __maybe_unused ina238_of_match[] = {
+	{ .compatible = "ti,ina238" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ina238_of_match);
+
+static struct i2c_driver ina238_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "ina238",
+		.of_match_table = of_match_ptr(ina238_of_match),
+	},
+	.probe_new	= ina238_probe,
+	.id_table	= ina238_id,
+};
+
+module_i2c_driver(ina238_driver);
+
+MODULE_AUTHOR("Nathan Rossi <nathan.rossi@digi.com>");
+MODULE_DESCRIPTION("ina238 driver");
+MODULE_LICENSE("GPL");