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, 1170 insertions, 0 deletions

diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c
new file mode 100644
index 000000000..b9efe66f9
--- /dev/null
+++ b/drivers/counter/counter-sysfs.c
@@ -0,0 +1,1170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Counter sysfs interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#include <linux/counter.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/kfifo.h>
+#include <linux/kstrtox.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include "counter-sysfs.h"
+
+static inline struct counter_device *counter_from_dev(struct device *dev)
+{
+	return container_of(dev, struct counter_device, dev);
+}
+
+/**
+ * struct counter_attribute - Counter sysfs attribute
+ * @dev_attr:	device attribute for sysfs
+ * @l:		node to add Counter attribute to attribute group list
+ * @comp:	Counter component callbacks and data
+ * @scope:	Counter scope of the attribute
+ * @parent:	pointer to the parent component
+ */
+struct counter_attribute {
+	struct device_attribute dev_attr;
+	struct list_head l;
+
+	struct counter_comp comp;
+	enum counter_scope scope;
+	void *parent;
+};
+
+#define to_counter_attribute(_dev_attr) \
+	container_of(_dev_attr, struct counter_attribute, dev_attr)
+
+/**
+ * struct counter_attribute_group - container for attribute group
+ * @name:	name of the attribute group
+ * @attr_list:	list to keep track of created attributes
+ * @num_attr:	number of attributes
+ */
+struct counter_attribute_group {
+	const char *name;
+	struct list_head attr_list;
+	size_t num_attr;
+};
+
+static const char *const counter_function_str[] = {
+	[COUNTER_FUNCTION_INCREASE] = "increase",
+	[COUNTER_FUNCTION_DECREASE] = "decrease",
+	[COUNTER_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
+	[COUNTER_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
+	[COUNTER_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
+	[COUNTER_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
+	[COUNTER_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
+	[COUNTER_FUNCTION_QUADRATURE_X4] = "quadrature x4"
+};
+
+static const char *const counter_signal_value_str[] = {
+	[COUNTER_SIGNAL_LEVEL_LOW] = "low",
+	[COUNTER_SIGNAL_LEVEL_HIGH] = "high"
+};
+
+static const char *const counter_synapse_action_str[] = {
+	[COUNTER_SYNAPSE_ACTION_NONE] = "none",
+	[COUNTER_SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
+	[COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
+	[COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
+};
+
+static const char *const counter_count_direction_str[] = {
+	[COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
+	[COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
+};
+
+static const char *const counter_count_mode_str[] = {
+	[COUNTER_COUNT_MODE_NORMAL] = "normal",
+	[COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
+	[COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
+	[COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
+};
+
+static const char *const counter_signal_polarity_str[] = {
+	[COUNTER_SIGNAL_POLARITY_POSITIVE] = "positive",
+	[COUNTER_SIGNAL_POLARITY_NEGATIVE] = "negative"
+};
+
+static ssize_t counter_comp_u8_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	int err;
+	u8 data = 0;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u8_read(counter, &data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u8_read(counter, a->parent, &data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_u8_read(counter, a->parent, &data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	if (a->comp.type == COUNTER_COMP_BOOL)
+		/* data should already be boolean but ensure just to be safe */
+		data = !!data;
+
+	return sysfs_emit(buf, "%u\n", (unsigned int)data);
+}
+
+static ssize_t counter_comp_u8_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	int err;
+	bool bool_data = 0;
+	u8 data = 0;
+
+	if (a->comp.type == COUNTER_COMP_BOOL) {
+		err = kstrtobool(buf, &bool_data);
+		data = bool_data;
+	} else
+		err = kstrtou8(buf, 0, &data);
+	if (err < 0)
+		return err;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u8_write(counter, data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u8_write(counter, a->parent, data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_u8_write(counter, a->parent, data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return len;
+}
+
+static ssize_t counter_comp_u32_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	const struct counter_available *const avail = a->comp.priv;
+	int err;
+	u32 data = 0;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u32_read(counter, &data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u32_read(counter, a->parent, &data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		if (a->comp.type == COUNTER_COMP_SYNAPSE_ACTION)
+			err = a->comp.action_read(counter, a->parent,
+						  a->comp.priv, &data);
+		else
+			err = a->comp.count_u32_read(counter, a->parent, &data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	switch (a->comp.type) {
+	case COUNTER_COMP_FUNCTION:
+		return sysfs_emit(buf, "%s\n", counter_function_str[data]);
+	case COUNTER_COMP_SIGNAL_LEVEL:
+		return sysfs_emit(buf, "%s\n", counter_signal_value_str[data]);
+	case COUNTER_COMP_SYNAPSE_ACTION:
+		return sysfs_emit(buf, "%s\n", counter_synapse_action_str[data]);
+	case COUNTER_COMP_ENUM:
+		return sysfs_emit(buf, "%s\n", avail->strs[data]);
+	case COUNTER_COMP_COUNT_DIRECTION:
+		return sysfs_emit(buf, "%s\n", counter_count_direction_str[data]);
+	case COUNTER_COMP_COUNT_MODE:
+		return sysfs_emit(buf, "%s\n", counter_count_mode_str[data]);
+	case COUNTER_COMP_SIGNAL_POLARITY:
+		return sysfs_emit(buf, "%s\n", counter_signal_polarity_str[data]);
+	default:
+		return sysfs_emit(buf, "%u\n", (unsigned int)data);
+	}
+}
+
+static int counter_find_enum(u32 *const enum_item, const u32 *const enums,
+			     const size_t num_enums, const char *const buf,
+			     const char *const string_array[])
+{
+	size_t index;
+
+	for (index = 0; index < num_enums; index++) {
+		*enum_item = enums[index];
+		if (sysfs_streq(buf, string_array[*enum_item]))
+			return 0;
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t counter_comp_u32_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t len)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	struct counter_count *const count = a->parent;
+	struct counter_synapse *const synapse = a->comp.priv;
+	const struct counter_available *const avail = a->comp.priv;
+	int err;
+	u32 data = 0;
+
+	switch (a->comp.type) {
+	case COUNTER_COMP_FUNCTION:
+		err = counter_find_enum(&data, count->functions_list,
+					count->num_functions, buf,
+					counter_function_str);
+		break;
+	case COUNTER_COMP_SYNAPSE_ACTION:
+		err = counter_find_enum(&data, synapse->actions_list,
+					synapse->num_actions, buf,
+					counter_synapse_action_str);
+		break;
+	case COUNTER_COMP_ENUM:
+		err = __sysfs_match_string(avail->strs, avail->num_items, buf);
+		data = err;
+		break;
+	case COUNTER_COMP_COUNT_MODE:
+		err = counter_find_enum(&data, avail->enums, avail->num_items,
+					buf, counter_count_mode_str);
+		break;
+	case COUNTER_COMP_SIGNAL_POLARITY:
+		err = counter_find_enum(&data, avail->enums, avail->num_items,
+					buf, counter_signal_polarity_str);
+		break;
+	default:
+		err = kstrtou32(buf, 0, &data);
+		break;
+	}
+	if (err < 0)
+		return err;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u32_write(counter, data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u32_write(counter, a->parent, data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		if (a->comp.type == COUNTER_COMP_SYNAPSE_ACTION)
+			err = a->comp.action_write(counter, count, synapse,
+						   data);
+		else
+			err = a->comp.count_u32_write(counter, count, data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return len;
+}
+
+static ssize_t counter_comp_u64_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	int err;
+	u64 data = 0;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u64_read(counter, &data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u64_read(counter, a->parent, &data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_u64_read(counter, a->parent, &data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)data);
+}
+
+static ssize_t counter_comp_u64_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t len)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	int err;
+	u64 data = 0;
+
+	err = kstrtou64(buf, 0, &data);
+	if (err < 0)
+		return err;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_u64_write(counter, data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_u64_write(counter, a->parent, data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_u64_write(counter, a->parent, data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return len;
+}
+
+static ssize_t counter_comp_array_u32_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	const struct counter_array *const element = a->comp.priv;
+	int err;
+	u32 data = 0;
+
+	if (a->scope != COUNTER_SCOPE_SIGNAL ||
+	    element->type != COUNTER_COMP_SIGNAL_POLARITY)
+		return -EINVAL;
+
+	err = a->comp.signal_array_u32_read(counter, a->parent, element->idx,
+					    &data);
+	if (err < 0)
+		return err;
+
+	return sysfs_emit(buf, "%s\n", counter_signal_polarity_str[data]);
+}
+
+static ssize_t counter_comp_array_u32_store(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t len)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	const struct counter_array *const element = a->comp.priv;
+	int err;
+	u32 data = 0;
+
+	if (element->type != COUNTER_COMP_SIGNAL_POLARITY ||
+	    a->scope != COUNTER_SCOPE_SIGNAL)
+		return -EINVAL;
+
+	err = counter_find_enum(&data, element->avail->enums,
+				element->avail->num_items, buf,
+				counter_signal_polarity_str);
+	if (err < 0)
+		return err;
+
+	err = a->comp.signal_array_u32_write(counter, a->parent, element->idx,
+					     data);
+	if (err < 0)
+		return err;
+
+	return len;
+}
+
+static ssize_t counter_comp_array_u64_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	const struct counter_array *const element = a->comp.priv;
+	int err;
+	u64 data = 0;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_array_u64_read(counter, element->idx,
+						    &data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_array_u64_read(counter, a->parent,
+						    element->idx, &data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_array_u64_read(counter, a->parent,
+						   element->idx, &data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)data);
+}
+
+static ssize_t counter_comp_array_u64_store(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t len)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	struct counter_device *const counter = counter_from_dev(dev);
+	const struct counter_array *const element = a->comp.priv;
+	int err;
+	u64 data = 0;
+
+	err = kstrtou64(buf, 0, &data);
+	if (err < 0)
+		return err;
+
+	switch (a->scope) {
+	case COUNTER_SCOPE_DEVICE:
+		err = a->comp.device_array_u64_write(counter, element->idx,
+						     data);
+		break;
+	case COUNTER_SCOPE_SIGNAL:
+		err = a->comp.signal_array_u64_write(counter, a->parent,
+						     element->idx, data);
+		break;
+	case COUNTER_SCOPE_COUNT:
+		err = a->comp.count_array_u64_write(counter, a->parent,
+						    element->idx, data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	return len;
+}
+
+static ssize_t enums_available_show(const u32 *const enums,
+				    const size_t num_enums,
+				    const char *const strs[], char *buf)
+{
+	size_t len = 0;
+	size_t index;
+
+	for (index = 0; index < num_enums; index++)
+		len += sysfs_emit_at(buf, len, "%s\n", strs[enums[index]]);
+
+	return len;
+}
+
+static ssize_t strs_available_show(const struct counter_available *const avail,
+				   char *buf)
+{
+	size_t len = 0;
+	size_t index;
+
+	for (index = 0; index < avail->num_items; index++)
+		len += sysfs_emit_at(buf, len, "%s\n", avail->strs[index]);
+
+	return len;
+}
+
+static ssize_t counter_comp_available_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	const struct counter_attribute *const a = to_counter_attribute(attr);
+	const struct counter_count *const count = a->parent;
+	const struct counter_synapse *const synapse = a->comp.priv;
+	const struct counter_available *const avail = a->comp.priv;
+
+	switch (a->comp.type) {
+	case COUNTER_COMP_FUNCTION:
+		return enums_available_show(count->functions_list,
+					    count->num_functions,
+					    counter_function_str, buf);
+	case COUNTER_COMP_SYNAPSE_ACTION:
+		return enums_available_show(synapse->actions_list,
+					    synapse->num_actions,
+					    counter_synapse_action_str, buf);
+	case COUNTER_COMP_ENUM:
+		return strs_available_show(avail, buf);
+	case COUNTER_COMP_COUNT_MODE:
+		return enums_available_show(avail->enums, avail->num_items,
+					    counter_count_mode_str, buf);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int counter_avail_attr_create(struct device *const dev,
+	struct counter_attribute_group *const group,
+	const struct counter_comp *const comp, void *const parent)
+{
+	struct counter_attribute *counter_attr;
+	struct device_attribute *dev_attr;
+
+	counter_attr = devm_kzalloc(dev, sizeof(*counter_attr), GFP_KERNEL);
+	if (!counter_attr)
+		return -ENOMEM;
+
+	/* Configure Counter attribute */
+	counter_attr->comp.type = comp->type;
+	counter_attr->comp.priv = comp->priv;
+	counter_attr->parent = parent;
+
+	/* Initialize sysfs attribute */
+	dev_attr = &counter_attr->dev_attr;
+	sysfs_attr_init(&dev_attr->attr);
+
+	/* Configure device attribute */
+	dev_attr->attr.name = devm_kasprintf(dev, GFP_KERNEL, "%s_available",
+					     comp->name);
+	if (!dev_attr->attr.name)
+		return -ENOMEM;
+	dev_attr->attr.mode = 0444;
+	dev_attr->show = counter_comp_available_show;
+
+	/* Store list node */
+	list_add(&counter_attr->l, &group->attr_list);
+	group->num_attr++;
+
+	return 0;
+}
+
+static int counter_attr_create(struct device *const dev,
+			       struct counter_attribute_group *const group,
+			       const struct counter_comp *const comp,
+			       const enum counter_scope scope,
+			       void *const parent)
+{
+	const struct counter_array *const array = comp->priv;
+	struct counter_attribute *counter_attr;
+	struct device_attribute *dev_attr;
+
+	counter_attr = devm_kzalloc(dev, sizeof(*counter_attr), GFP_KERNEL);
+	if (!counter_attr)
+		return -ENOMEM;
+
+	/* Configure Counter attribute */
+	counter_attr->comp = *comp;
+	counter_attr->scope = scope;
+	counter_attr->parent = parent;
+
+	/* Configure device attribute */
+	dev_attr = &counter_attr->dev_attr;
+	sysfs_attr_init(&dev_attr->attr);
+	dev_attr->attr.name = comp->name;
+	switch (comp->type) {
+	case COUNTER_COMP_U8:
+	case COUNTER_COMP_BOOL:
+		if (comp->device_u8_read) {
+			dev_attr->attr.mode |= 0444;
+			dev_attr->show = counter_comp_u8_show;
+		}
+		if (comp->device_u8_write) {
+			dev_attr->attr.mode |= 0200;
+			dev_attr->store = counter_comp_u8_store;
+		}
+		break;
+	case COUNTER_COMP_SIGNAL_LEVEL:
+	case COUNTER_COMP_FUNCTION:
+	case COUNTER_COMP_SYNAPSE_ACTION:
+	case COUNTER_COMP_ENUM:
+	case COUNTER_COMP_COUNT_DIRECTION:
+	case COUNTER_COMP_COUNT_MODE:
+	case COUNTER_COMP_SIGNAL_POLARITY:
+		if (comp->device_u32_read) {
+			dev_attr->attr.mode |= 0444;
+			dev_attr->show = counter_comp_u32_show;
+		}
+		if (comp->device_u32_write) {
+			dev_attr->attr.mode |= 0200;
+			dev_attr->store = counter_comp_u32_store;
+		}
+		break;
+	case COUNTER_COMP_U64:
+		if (comp->device_u64_read) {
+			dev_attr->attr.mode |= 0444;
+			dev_attr->show = counter_comp_u64_show;
+		}
+		if (comp->device_u64_write) {
+			dev_attr->attr.mode |= 0200;
+			dev_attr->store = counter_comp_u64_store;
+		}
+		break;
+	case COUNTER_COMP_ARRAY:
+		switch (array->type) {
+		case COUNTER_COMP_SIGNAL_POLARITY:
+			if (comp->signal_array_u32_read) {
+				dev_attr->attr.mode |= 0444;
+				dev_attr->show = counter_comp_array_u32_show;
+			}
+			if (comp->signal_array_u32_write) {
+				dev_attr->attr.mode |= 0200;
+				dev_attr->store = counter_comp_array_u32_store;
+			}
+			break;
+		case COUNTER_COMP_U64:
+			if (comp->device_array_u64_read) {
+				dev_attr->attr.mode |= 0444;
+				dev_attr->show = counter_comp_array_u64_show;
+			}
+			if (comp->device_array_u64_write) {
+				dev_attr->attr.mode |= 0200;
+				dev_attr->store = counter_comp_array_u64_store;
+			}
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Store list node */
+	list_add(&counter_attr->l, &group->attr_list);
+	group->num_attr++;
+
+	/* Create "*_available" attribute if needed */
+	switch (comp->type) {
+	case COUNTER_COMP_FUNCTION:
+	case COUNTER_COMP_SYNAPSE_ACTION:
+	case COUNTER_COMP_ENUM:
+	case COUNTER_COMP_COUNT_MODE:
+		return counter_avail_attr_create(dev, group, comp, parent);
+	default:
+		return 0;
+	}
+}
+
+static ssize_t counter_comp_name_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%s\n", to_counter_attribute(attr)->comp.name);
+}
+
+static int counter_name_attr_create(struct device *const dev,
+				    struct counter_attribute_group *const group,
+				    const char *const name)
+{
+	struct counter_attribute *counter_attr;
+
+	counter_attr = devm_kzalloc(dev, sizeof(*counter_attr), GFP_KERNEL);
+	if (!counter_attr)
+		return -ENOMEM;
+
+	/* Configure Counter attribute */
+	counter_attr->comp.name = name;
+
+	/* Configure device attribute */
+	sysfs_attr_init(&counter_attr->dev_attr.attr);
+	counter_attr->dev_attr.attr.name = "name";
+	counter_attr->dev_attr.attr.mode = 0444;
+	counter_attr->dev_attr.show = counter_comp_name_show;
+
+	/* Store list node */
+	list_add(&counter_attr->l, &group->attr_list);
+	group->num_attr++;
+
+	return 0;
+}
+
+static ssize_t counter_comp_id_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	const size_t id = (size_t)to_counter_attribute(attr)->comp.priv;
+
+	return sysfs_emit(buf, "%zu\n", id);
+}
+
+static int counter_comp_id_attr_create(struct device *const dev,
+				       struct counter_attribute_group *const group,
+				       const char *name, const size_t id)
+{
+	struct counter_attribute *counter_attr;
+
+	/* Allocate Counter attribute */
+	counter_attr = devm_kzalloc(dev, sizeof(*counter_attr), GFP_KERNEL);
+	if (!counter_attr)
+		return -ENOMEM;
+
+	/* Generate component ID name */
+	name = devm_kasprintf(dev, GFP_KERNEL, "%s_component_id", name);
+	if (!name)
+		return -ENOMEM;
+
+	/* Configure Counter attribute */
+	counter_attr->comp.priv = (void *)id;
+
+	/* Configure device attribute */
+	sysfs_attr_init(&counter_attr->dev_attr.attr);
+	counter_attr->dev_attr.attr.name = name;
+	counter_attr->dev_attr.attr.mode = 0444;
+	counter_attr->dev_attr.show = counter_comp_id_show;
+
+	/* Store list node */
+	list_add(&counter_attr->l, &group->attr_list);
+	group->num_attr++;
+
+	return 0;
+}
+
+static int counter_ext_attrs_create(struct device *const dev,
+				    struct counter_attribute_group *const group,
+				    const struct counter_comp *const ext,
+				    const enum counter_scope scope,
+				    void *const parent, const size_t id)
+{
+	int err;
+
+	/* Create main extension attribute */
+	err = counter_attr_create(dev, group, ext, scope, parent);
+	if (err < 0)
+		return err;
+
+	/* Create extension id attribute */
+	return counter_comp_id_attr_create(dev, group, ext->name, id);
+}
+
+static int counter_array_attrs_create(struct device *const dev,
+				      struct counter_attribute_group *const group,
+				      const struct counter_comp *const comp,
+				      const enum counter_scope scope,
+				      void *const parent, const size_t id)
+{
+	const struct counter_array *const array = comp->priv;
+	struct counter_comp ext = *comp;
+	struct counter_array *element;
+	size_t idx;
+	int err;
+
+	/* Create an attribute for each array element */
+	for (idx = 0; idx < array->length; idx++) {
+		/* Generate array element attribute name */
+		ext.name = devm_kasprintf(dev, GFP_KERNEL, "%s%zu", comp->name,
+					  idx);
+		if (!ext.name)
+			return -ENOMEM;
+
+		/* Allocate and configure array element */
+		element = devm_kzalloc(dev, sizeof(*element), GFP_KERNEL);
+		if (!element)
+			return -ENOMEM;
+		element->type = array->type;
+		element->avail = array->avail;
+		element->idx = idx;
+		ext.priv = element;
+
+		/* Create all attributes associated with the array element */
+		err = counter_ext_attrs_create(dev, group, &ext, scope, parent,
+					       id + idx);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static int counter_sysfs_exts_add(struct device *const dev,
+				  struct counter_attribute_group *const group,
+				  const struct counter_comp *const exts,
+				  const size_t num_ext,
+				  const enum counter_scope scope,
+				  void *const parent)
+{
+	size_t i;
+	const struct counter_comp *ext;
+	int err;
+	size_t id = 0;
+	const struct counter_array *array;
+
+	/* Create attributes for each extension */
+	for (i = 0; i < num_ext; i++) {
+		ext = &exts[i];
+		if (ext->type == COUNTER_COMP_ARRAY) {
+			err = counter_array_attrs_create(dev, group, ext, scope,
+							 parent, id);
+			array = ext->priv;
+			id += array->length;
+		} else {
+			err = counter_ext_attrs_create(dev, group, ext, scope,
+						       parent, id);
+			id++;
+		}
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static struct counter_comp counter_signal_comp = {
+	.type = COUNTER_COMP_SIGNAL_LEVEL,
+	.name = "signal",
+};
+
+static int counter_signal_attrs_create(struct counter_device *const counter,
+	struct counter_attribute_group *const cattr_group,
+	struct counter_signal *const signal)
+{
+	const enum counter_scope scope = COUNTER_SCOPE_SIGNAL;
+	struct device *const dev = &counter->dev;
+	int err;
+	struct counter_comp comp;
+
+	/* Create main Signal attribute */
+	comp = counter_signal_comp;
+	comp.signal_u32_read = counter->ops->signal_read;
+	err = counter_attr_create(dev, cattr_group, &comp, scope, signal);
+	if (err < 0)
+		return err;
+
+	/* Create Signal name attribute */
+	err = counter_name_attr_create(dev, cattr_group, signal->name);
+	if (err < 0)
+		return err;
+
+	/* Add Signal extensions */
+	return counter_sysfs_exts_add(dev, cattr_group, signal->ext,
+				      signal->num_ext, scope, signal);
+}
+
+static int counter_sysfs_signals_add(struct counter_device *const counter,
+	struct counter_attribute_group *const groups)
+{
+	size_t i;
+	int err;
+
+	/* Add each Signal */
+	for (i = 0; i < counter->num_signals; i++) {
+		/* Generate Signal attribute directory name */
+		groups[i].name = devm_kasprintf(&counter->dev, GFP_KERNEL,
+						"signal%zu", i);
+		if (!groups[i].name)
+			return -ENOMEM;
+
+		/* Create all attributes associated with Signal */
+		err = counter_signal_attrs_create(counter, groups + i,
+						  counter->signals + i);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static int counter_sysfs_synapses_add(struct counter_device *const counter,
+	struct counter_attribute_group *const group,
+	struct counter_count *const count)
+{
+	size_t i;
+
+	/* Add each Synapse */
+	for (i = 0; i < count->num_synapses; i++) {
+		struct device *const dev = &counter->dev;
+		struct counter_synapse *synapse;
+		size_t id;
+		struct counter_comp comp;
+		int err;
+
+		synapse = count->synapses + i;
+
+		/* Generate Synapse action name */
+		id = synapse->signal - counter->signals;
+		comp.name = devm_kasprintf(dev, GFP_KERNEL, "signal%zu_action",
+					   id);
+		if (!comp.name)
+			return -ENOMEM;
+
+		/* Create action attribute */
+		comp.type = COUNTER_COMP_SYNAPSE_ACTION;
+		comp.action_read = counter->ops->action_read;
+		comp.action_write = counter->ops->action_write;
+		comp.priv = synapse;
+		err = counter_attr_create(dev, group, &comp,
+					  COUNTER_SCOPE_COUNT, count);
+		if (err < 0)
+			return err;
+
+		/* Create Synapse component ID attribute */
+		err = counter_comp_id_attr_create(dev, group, comp.name, i);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static struct counter_comp counter_count_comp =
+	COUNTER_COMP_COUNT_U64("count", NULL, NULL);
+
+static struct counter_comp counter_function_comp = {
+	.type = COUNTER_COMP_FUNCTION,
+	.name = "function",
+};
+
+static int counter_count_attrs_create(struct counter_device *const counter,
+	struct counter_attribute_group *const cattr_group,
+	struct counter_count *const count)
+{
+	const enum counter_scope scope = COUNTER_SCOPE_COUNT;
+	struct device *const dev = &counter->dev;
+	int err;
+	struct counter_comp comp;
+
+	/* Create main Count attribute */
+	comp = counter_count_comp;
+	comp.count_u64_read = counter->ops->count_read;
+	comp.count_u64_write = counter->ops->count_write;
+	err = counter_attr_create(dev, cattr_group, &comp, scope, count);
+	if (err < 0)
+		return err;
+
+	/* Create Count name attribute */
+	err = counter_name_attr_create(dev, cattr_group, count->name);
+	if (err < 0)
+		return err;
+
+	/* Create Count function attribute */
+	comp = counter_function_comp;
+	comp.count_u32_read = counter->ops->function_read;
+	comp.count_u32_write = counter->ops->function_write;
+	err = counter_attr_create(dev, cattr_group, &comp, scope, count);
+	if (err < 0)
+		return err;
+
+	/* Add Count extensions */
+	return counter_sysfs_exts_add(dev, cattr_group, count->ext,
+				      count->num_ext, scope, count);
+}
+
+static int counter_sysfs_counts_add(struct counter_device *const counter,
+	struct counter_attribute_group *const groups)
+{
+	size_t i;
+	struct counter_count *count;
+	int err;
+
+	/* Add each Count */
+	for (i = 0; i < counter->num_counts; i++) {
+		count = counter->counts + i;
+
+		/* Generate Count attribute directory name */
+		groups[i].name = devm_kasprintf(&counter->dev, GFP_KERNEL,
+						"count%zu", i);
+		if (!groups[i].name)
+			return -ENOMEM;
+
+		/* Add sysfs attributes of the Synapses */
+		err = counter_sysfs_synapses_add(counter, groups + i, count);
+		if (err < 0)
+			return err;
+
+		/* Create all attributes associated with Count */
+		err = counter_count_attrs_create(counter, groups + i, count);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static int counter_num_signals_read(struct counter_device *counter, u8 *val)
+{
+	*val = counter->num_signals;
+	return 0;
+}
+
+static int counter_num_counts_read(struct counter_device *counter, u8 *val)
+{
+	*val = counter->num_counts;
+	return 0;
+}
+
+static int counter_events_queue_size_read(struct counter_device *counter,
+					  u64 *val)
+{
+	*val = kfifo_size(&counter->events);
+	return 0;
+}
+
+static int counter_events_queue_size_write(struct counter_device *counter,
+					   u64 val)
+{
+	DECLARE_KFIFO_PTR(events, struct counter_event);
+	int err;
+	unsigned long flags;
+
+	/* Allocate new events queue */
+	err = kfifo_alloc(&events, val, GFP_KERNEL);
+	if (err)
+		return err;
+
+	/* Swap in new events queue */
+	mutex_lock(&counter->events_out_lock);
+	spin_lock_irqsave(&counter->events_in_lock, flags);
+	kfifo_free(&counter->events);
+	counter->events.kfifo = events.kfifo;
+	spin_unlock_irqrestore(&counter->events_in_lock, flags);
+	mutex_unlock(&counter->events_out_lock);
+
+	return 0;
+}
+
+static struct counter_comp counter_num_signals_comp =
+	COUNTER_COMP_DEVICE_U8("num_signals", counter_num_signals_read, NULL);
+
+static struct counter_comp counter_num_counts_comp =
+	COUNTER_COMP_DEVICE_U8("num_counts", counter_num_counts_read, NULL);
+
+static struct counter_comp counter_events_queue_size_comp =
+	COUNTER_COMP_DEVICE_U64("events_queue_size",
+				counter_events_queue_size_read,
+				counter_events_queue_size_write);
+
+static int counter_sysfs_attr_add(struct counter_device *const counter,
+				  struct counter_attribute_group *cattr_group)
+{
+	const enum counter_scope scope = COUNTER_SCOPE_DEVICE;
+	struct device *const dev = &counter->dev;
+	int err;
+
+	/* Add Signals sysfs attributes */
+	err = counter_sysfs_signals_add(counter, cattr_group);
+	if (err < 0)
+		return err;
+	cattr_group += counter->num_signals;
+
+	/* Add Counts sysfs attributes */
+	err = counter_sysfs_counts_add(counter, cattr_group);
+	if (err < 0)
+		return err;
+	cattr_group += counter->num_counts;
+
+	/* Create name attribute */
+	err = counter_name_attr_create(dev, cattr_group, counter->name);
+	if (err < 0)
+		return err;
+
+	/* Create num_signals attribute */
+	err = counter_attr_create(dev, cattr_group, &counter_num_signals_comp,
+				  scope, NULL);
+	if (err < 0)
+		return err;
+
+	/* Create num_counts attribute */
+	err = counter_attr_create(dev, cattr_group, &counter_num_counts_comp,
+				  scope, NULL);
+	if (err < 0)
+		return err;
+
+	/* Create events_queue_size attribute */
+	err = counter_attr_create(dev, cattr_group,
+				  &counter_events_queue_size_comp, scope, NULL);
+	if (err < 0)
+		return err;
+
+	/* Add device extensions */
+	return counter_sysfs_exts_add(dev, cattr_group, counter->ext,
+				      counter->num_ext, scope, NULL);
+
+	return 0;
+}
+
+/**
+ * counter_sysfs_add - Adds Counter sysfs attributes to the device structure
+ * @counter:	Pointer to the Counter device structure
+ *
+ * Counter sysfs attributes are created and added to the respective device
+ * structure for later registration to the system. Resource-managed memory
+ * allocation is performed by this function, and this memory should be freed
+ * when no longer needed (automatically by a device_unregister call, or
+ * manually by a devres_release_all call).
+ */
+int counter_sysfs_add(struct counter_device *const counter)
+{
+	struct device *const dev = &counter->dev;
+	const size_t num_groups = counter->num_signals + counter->num_counts + 1;
+	struct counter_attribute_group *cattr_groups;
+	size_t i, j;
+	int err;
+	struct attribute_group *groups;
+	struct counter_attribute *p;
+
+	/* Allocate space for attribute groups (signals, counts, and ext) */
+	cattr_groups = devm_kcalloc(dev, num_groups, sizeof(*cattr_groups),
+				    GFP_KERNEL);
+	if (!cattr_groups)
+		return -ENOMEM;
+
+	/* Initialize attribute lists */
+	for (i = 0; i < num_groups; i++)
+		INIT_LIST_HEAD(&cattr_groups[i].attr_list);
+
+	/* Add Counter device sysfs attributes */
+	err = counter_sysfs_attr_add(counter, cattr_groups);
+	if (err < 0)
+		return err;
+
+	/* Allocate attribute group pointers for association with device */
+	dev->groups = devm_kcalloc(dev, num_groups + 1, sizeof(*dev->groups),
+				   GFP_KERNEL);
+	if (!dev->groups)
+		return -ENOMEM;
+
+	/* Allocate space for attribute groups */
+	groups = devm_kcalloc(dev, num_groups, sizeof(*groups), GFP_KERNEL);
+	if (!groups)
+		return -ENOMEM;
+
+	/* Prepare each group of attributes for association */
+	for (i = 0; i < num_groups; i++) {
+		groups[i].name = cattr_groups[i].name;
+
+		/* Allocate space for attribute pointers */
+		groups[i].attrs = devm_kcalloc(dev,
+					       cattr_groups[i].num_attr + 1,
+					       sizeof(*groups[i].attrs),
+					       GFP_KERNEL);
+		if (!groups[i].attrs)
+			return -ENOMEM;
+
+		/* Add attribute pointers to attribute group */
+		j = 0;
+		list_for_each_entry(p, &cattr_groups[i].attr_list, l)
+			groups[i].attrs[j++] = &p->dev_attr.attr;
+
+		/* Associate attribute group */
+		dev->groups[i] = &groups[i];
+	}
+
+	return 0;
+}