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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/reset/core.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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(). ...
Diffstat (limited to 'drivers/reset/core.c')
-rw-r--r--drivers/reset/core.c1289
1 files changed, 1289 insertions, 0 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
new file mode 100644
index 000000000..f0a076e94
--- /dev/null
+++ b/drivers/reset/core.c
@@ -0,0 +1,1289 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Reset Controller framework
+ *
+ * Copyright 2013 Philipp Zabel, Pengutronix
+ */
+#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/acpi.h>
+#include <linux/reset.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+
+static DEFINE_MUTEX(reset_list_mutex);
+static LIST_HEAD(reset_controller_list);
+
+static DEFINE_MUTEX(reset_lookup_mutex);
+static LIST_HEAD(reset_lookup_list);
+
+/**
+ * struct reset_control - a reset control
+ * @rcdev: a pointer to the reset controller device
+ * this reset control belongs to
+ * @list: list entry for the rcdev's reset controller list
+ * @id: ID of the reset controller in the reset
+ * controller device
+ * @refcnt: Number of gets of this reset_control
+ * @acquired: Only one reset_control may be acquired for a given rcdev and id.
+ * @shared: Is this a shared (1), or an exclusive (0) reset_control?
+ * @array: Is this an array of reset controls (1)?
+ * @deassert_count: Number of times this reset line has been deasserted
+ * @triggered_count: Number of times this reset line has been reset. Currently
+ * only used for shared resets, which means that the value
+ * will be either 0 or 1.
+ */
+struct reset_control {
+ struct reset_controller_dev *rcdev;
+ struct list_head list;
+ unsigned int id;
+ struct kref refcnt;
+ bool acquired;
+ bool shared;
+ bool array;
+ atomic_t deassert_count;
+ atomic_t triggered_count;
+};
+
+/**
+ * struct reset_control_array - an array of reset controls
+ * @base: reset control for compatibility with reset control API functions
+ * @num_rstcs: number of reset controls
+ * @rstc: array of reset controls
+ */
+struct reset_control_array {
+ struct reset_control base;
+ unsigned int num_rstcs;
+ struct reset_control *rstc[];
+};
+
+static const char *rcdev_name(struct reset_controller_dev *rcdev)
+{
+ if (rcdev->dev)
+ return dev_name(rcdev->dev);
+
+ if (rcdev->of_node)
+ return rcdev->of_node->full_name;
+
+ return NULL;
+}
+
+/**
+ * of_reset_simple_xlate - translate reset_spec to the reset line number
+ * @rcdev: a pointer to the reset controller device
+ * @reset_spec: reset line specifier as found in the device tree
+ *
+ * This static translation function is used by default if of_xlate in
+ * :c:type:`reset_controller_dev` is not set. It is useful for all reset
+ * controllers with 1:1 mapping, where reset lines can be indexed by number
+ * without gaps.
+ */
+static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *reset_spec)
+{
+ if (reset_spec->args[0] >= rcdev->nr_resets)
+ return -EINVAL;
+
+ return reset_spec->args[0];
+}
+
+/**
+ * reset_controller_register - register a reset controller device
+ * @rcdev: a pointer to the initialized reset controller device
+ */
+int reset_controller_register(struct reset_controller_dev *rcdev)
+{
+ if (!rcdev->of_xlate) {
+ rcdev->of_reset_n_cells = 1;
+ rcdev->of_xlate = of_reset_simple_xlate;
+ }
+
+ INIT_LIST_HEAD(&rcdev->reset_control_head);
+
+ mutex_lock(&reset_list_mutex);
+ list_add(&rcdev->list, &reset_controller_list);
+ mutex_unlock(&reset_list_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_controller_register);
+
+/**
+ * reset_controller_unregister - unregister a reset controller device
+ * @rcdev: a pointer to the reset controller device
+ */
+void reset_controller_unregister(struct reset_controller_dev *rcdev)
+{
+ mutex_lock(&reset_list_mutex);
+ list_del(&rcdev->list);
+ mutex_unlock(&reset_list_mutex);
+}
+EXPORT_SYMBOL_GPL(reset_controller_unregister);
+
+static void devm_reset_controller_release(struct device *dev, void *res)
+{
+ reset_controller_unregister(*(struct reset_controller_dev **)res);
+}
+
+/**
+ * devm_reset_controller_register - resource managed reset_controller_register()
+ * @dev: device that is registering this reset controller
+ * @rcdev: a pointer to the initialized reset controller device
+ *
+ * Managed reset_controller_register(). For reset controllers registered by
+ * this function, reset_controller_unregister() is automatically called on
+ * driver detach. See reset_controller_register() for more information.
+ */
+int devm_reset_controller_register(struct device *dev,
+ struct reset_controller_dev *rcdev)
+{
+ struct reset_controller_dev **rcdevp;
+ int ret;
+
+ rcdevp = devres_alloc(devm_reset_controller_release, sizeof(*rcdevp),
+ GFP_KERNEL);
+ if (!rcdevp)
+ return -ENOMEM;
+
+ ret = reset_controller_register(rcdev);
+ if (ret) {
+ devres_free(rcdevp);
+ return ret;
+ }
+
+ *rcdevp = rcdev;
+ devres_add(dev, rcdevp);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_reset_controller_register);
+
+/**
+ * reset_controller_add_lookup - register a set of lookup entries
+ * @lookup: array of reset lookup entries
+ * @num_entries: number of entries in the lookup array
+ */
+void reset_controller_add_lookup(struct reset_control_lookup *lookup,
+ unsigned int num_entries)
+{
+ struct reset_control_lookup *entry;
+ unsigned int i;
+
+ mutex_lock(&reset_lookup_mutex);
+ for (i = 0; i < num_entries; i++) {
+ entry = &lookup[i];
+
+ if (!entry->dev_id || !entry->provider) {
+ pr_warn("%s(): reset lookup entry badly specified, skipping\n",
+ __func__);
+ continue;
+ }
+
+ list_add_tail(&entry->list, &reset_lookup_list);
+ }
+ mutex_unlock(&reset_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(reset_controller_add_lookup);
+
+static inline struct reset_control_array *
+rstc_to_array(struct reset_control *rstc) {
+ return container_of(rstc, struct reset_control_array, base);
+}
+
+static int reset_control_array_reset(struct reset_control_array *resets)
+{
+ int ret, i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ ret = reset_control_reset(resets->rstc[i]);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int reset_control_array_rearm(struct reset_control_array *resets)
+{
+ struct reset_control *rstc;
+ int i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (!rstc)
+ continue;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+ return -EINVAL;
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+ }
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (rstc && rstc->shared)
+ WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+ }
+
+ return 0;
+}
+
+static int reset_control_array_assert(struct reset_control_array *resets)
+{
+ int ret, i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ ret = reset_control_assert(resets->rstc[i]);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (i--)
+ reset_control_deassert(resets->rstc[i]);
+ return ret;
+}
+
+static int reset_control_array_deassert(struct reset_control_array *resets)
+{
+ int ret, i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ ret = reset_control_deassert(resets->rstc[i]);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (i--)
+ reset_control_assert(resets->rstc[i]);
+ return ret;
+}
+
+static int reset_control_array_acquire(struct reset_control_array *resets)
+{
+ unsigned int i;
+ int err;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ err = reset_control_acquire(resets->rstc[i]);
+ if (err < 0)
+ goto release;
+ }
+
+ return 0;
+
+release:
+ while (i--)
+ reset_control_release(resets->rstc[i]);
+
+ return err;
+}
+
+static void reset_control_array_release(struct reset_control_array *resets)
+{
+ unsigned int i;
+
+ for (i = 0; i < resets->num_rstcs; i++)
+ reset_control_release(resets->rstc[i]);
+}
+
+static inline bool reset_control_is_array(struct reset_control *rstc)
+{
+ return rstc->array;
+}
+
+/**
+ * reset_control_reset - reset the controlled device
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance: for all but the first caller this is
+ * a no-op.
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset has been used.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
+ */
+int reset_control_reset(struct reset_control *rstc)
+{
+ int ret;
+
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_reset(rstc_to_array(rstc));
+
+ if (!rstc->rcdev->ops->reset)
+ return -ENOTSUPP;
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+ return -EINVAL;
+
+ if (atomic_inc_return(&rstc->triggered_count) != 1)
+ return 0;
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+
+ ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
+ if (rstc->shared && ret)
+ atomic_dec(&rstc->triggered_count);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_reset);
+
+/**
+ * reset_control_bulk_reset - reset the controlled devices in order
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ *
+ * Issue a reset on all provided reset controls, in order.
+ *
+ * See also: reset_control_reset()
+ */
+int reset_control_bulk_reset(int num_rstcs,
+ struct reset_control_bulk_data *rstcs)
+{
+ int ret, i;
+
+ for (i = 0; i < num_rstcs; i++) {
+ ret = reset_control_reset(rstcs[i].rstc);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_reset);
+
+/**
+ * reset_control_rearm - allow shared reset line to be re-triggered"
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance, except if this call is used.
+ *
+ * Calls to this function must be balanced with calls to reset_control_reset,
+ * a warning is thrown in case triggered_count ever dips below 0.
+ *
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset or reset_control_rearm have been used.
+ *
+ * If rstc is NULL the function will just return 0.
+ */
+int reset_control_rearm(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_rearm(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+ return -EINVAL;
+
+ WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_rearm);
+
+/**
+ * reset_control_assert - asserts the reset line
+ * @rstc: reset controller
+ *
+ * Calling this on an exclusive reset controller guarantees that the reset
+ * will be asserted. When called on a shared reset controller the line may
+ * still be deasserted, as long as other users keep it so.
+ *
+ * For shared reset controls a driver cannot expect the hw's registers and
+ * internal state to be reset, but must be prepared for this to happen.
+ * Consumers must not use reset_control_reset on shared reset lines when
+ * reset_control_(de)assert has been used.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
+ */
+int reset_control_assert(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_assert(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
+ return -EINVAL;
+
+ if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))
+ return -EINVAL;
+
+ if (atomic_dec_return(&rstc->deassert_count) != 0)
+ return 0;
+
+ /*
+ * Shared reset controls allow the reset line to be in any state
+ * after this call, so doing nothing is a valid option.
+ */
+ if (!rstc->rcdev->ops->assert)
+ return 0;
+ } else {
+ /*
+ * If the reset controller does not implement .assert(), there
+ * is no way to guarantee that the reset line is asserted after
+ * this call.
+ */
+ if (!rstc->rcdev->ops->assert)
+ return -ENOTSUPP;
+
+ if (!rstc->acquired) {
+ WARN(1, "reset %s (ID: %u) is not acquired\n",
+ rcdev_name(rstc->rcdev), rstc->id);
+ return -EPERM;
+ }
+ }
+
+ return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
+}
+EXPORT_SYMBOL_GPL(reset_control_assert);
+
+/**
+ * reset_control_bulk_assert - asserts the reset lines in order
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ *
+ * Assert the reset lines for all provided reset controls, in order.
+ * If an assertion fails, already asserted resets are deasserted again.
+ *
+ * See also: reset_control_assert()
+ */
+int reset_control_bulk_assert(int num_rstcs,
+ struct reset_control_bulk_data *rstcs)
+{
+ int ret, i;
+
+ for (i = 0; i < num_rstcs; i++) {
+ ret = reset_control_assert(rstcs[i].rstc);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (i--)
+ reset_control_deassert(rstcs[i].rstc);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_assert);
+
+/**
+ * reset_control_deassert - deasserts the reset line
+ * @rstc: reset controller
+ *
+ * After calling this function, the reset is guaranteed to be deasserted.
+ * Consumers must not use reset_control_reset on shared reset lines when
+ * reset_control_(de)assert has been used.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
+ */
+int reset_control_deassert(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_deassert(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
+ return -EINVAL;
+
+ if (atomic_inc_return(&rstc->deassert_count) != 1)
+ return 0;
+ } else {
+ if (!rstc->acquired) {
+ WARN(1, "reset %s (ID: %u) is not acquired\n",
+ rcdev_name(rstc->rcdev), rstc->id);
+ return -EPERM;
+ }
+ }
+
+ /*
+ * If the reset controller does not implement .deassert(), we assume
+ * that it handles self-deasserting reset lines via .reset(). In that
+ * case, the reset lines are deasserted by default. If that is not the
+ * case, the reset controller driver should implement .deassert() and
+ * return -ENOTSUPP.
+ */
+ if (!rstc->rcdev->ops->deassert)
+ return 0;
+
+ return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
+}
+EXPORT_SYMBOL_GPL(reset_control_deassert);
+
+/**
+ * reset_control_bulk_deassert - deasserts the reset lines in reverse order
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ *
+ * Deassert the reset lines for all provided reset controls, in reverse order.
+ * If a deassertion fails, already deasserted resets are asserted again.
+ *
+ * See also: reset_control_deassert()
+ */
+int reset_control_bulk_deassert(int num_rstcs,
+ struct reset_control_bulk_data *rstcs)
+{
+ int ret, i;
+
+ for (i = num_rstcs - 1; i >= 0; i--) {
+ ret = reset_control_deassert(rstcs[i].rstc);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (i < num_rstcs)
+ reset_control_assert(rstcs[i++].rstc);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_deassert);
+
+/**
+ * reset_control_status - returns a negative errno if not supported, a
+ * positive value if the reset line is asserted, or zero if the reset
+ * line is not asserted or if the desc is NULL (optional reset).
+ * @rstc: reset controller
+ */
+int reset_control_status(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc))
+ return -EINVAL;
+
+ if (rstc->rcdev->ops->status)
+ return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
+
+ return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(reset_control_status);
+
+/**
+ * reset_control_acquire() - acquires a reset control for exclusive use
+ * @rstc: reset control
+ *
+ * This is used to explicitly acquire a reset control for exclusive use. Note
+ * that exclusive resets are requested as acquired by default. In order for a
+ * second consumer to be able to control the reset, the first consumer has to
+ * release it first. Typically the easiest way to achieve this is to call the
+ * reset_control_get_exclusive_released() to obtain an instance of the reset
+ * control. Such reset controls are not acquired by default.
+ *
+ * Consumers implementing shared access to an exclusive reset need to follow
+ * a specific protocol in order to work together. Before consumers can change
+ * a reset they must acquire exclusive access using reset_control_acquire().
+ * After they are done operating the reset, they must release exclusive access
+ * with a call to reset_control_release(). Consumers are not granted exclusive
+ * access to the reset as long as another consumer hasn't released a reset.
+ *
+ * See also: reset_control_release()
+ */
+int reset_control_acquire(struct reset_control *rstc)
+{
+ struct reset_control *rc;
+
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_acquire(rstc_to_array(rstc));
+
+ mutex_lock(&reset_list_mutex);
+
+ if (rstc->acquired) {
+ mutex_unlock(&reset_list_mutex);
+ return 0;
+ }
+
+ list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {
+ if (rstc != rc && rstc->id == rc->id) {
+ if (rc->acquired) {
+ mutex_unlock(&reset_list_mutex);
+ return -EBUSY;
+ }
+ }
+ }
+
+ rstc->acquired = true;
+
+ mutex_unlock(&reset_list_mutex);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_acquire);
+
+/**
+ * reset_control_bulk_acquire - acquires reset controls for exclusive use
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ *
+ * This is used to explicitly acquire reset controls requested with
+ * reset_control_bulk_get_exclusive_release() for temporary exclusive use.
+ *
+ * See also: reset_control_acquire(), reset_control_bulk_release()
+ */
+int reset_control_bulk_acquire(int num_rstcs,
+ struct reset_control_bulk_data *rstcs)
+{
+ int ret, i;
+
+ for (i = 0; i < num_rstcs; i++) {
+ ret = reset_control_acquire(rstcs[i].rstc);
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ while (i--)
+ reset_control_release(rstcs[i].rstc);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_acquire);
+
+/**
+ * reset_control_release() - releases exclusive access to a reset control
+ * @rstc: reset control
+ *
+ * Releases exclusive access right to a reset control previously obtained by a
+ * call to reset_control_acquire(). Until a consumer calls this function, no
+ * other consumers will be granted exclusive access.
+ *
+ * See also: reset_control_acquire()
+ */
+void reset_control_release(struct reset_control *rstc)
+{
+ if (!rstc || WARN_ON(IS_ERR(rstc)))
+ return;
+
+ if (reset_control_is_array(rstc))
+ reset_control_array_release(rstc_to_array(rstc));
+ else
+ rstc->acquired = false;
+}
+EXPORT_SYMBOL_GPL(reset_control_release);
+
+/**
+ * reset_control_bulk_release() - releases exclusive access to reset controls
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ *
+ * Releases exclusive access right to reset controls previously obtained by a
+ * call to reset_control_bulk_acquire().
+ *
+ * See also: reset_control_release(), reset_control_bulk_acquire()
+ */
+void reset_control_bulk_release(int num_rstcs,
+ struct reset_control_bulk_data *rstcs)
+{
+ int i;
+
+ for (i = 0; i < num_rstcs; i++)
+ reset_control_release(rstcs[i].rstc);
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_release);
+
+static struct reset_control *
+__reset_control_get_internal(struct reset_controller_dev *rcdev,
+ unsigned int index, bool shared, bool acquired)
+{
+ struct reset_control *rstc;
+
+ lockdep_assert_held(&reset_list_mutex);
+
+ list_for_each_entry(rstc, &rcdev->reset_control_head, list) {
+ if (rstc->id == index) {
+ /*
+ * Allow creating a secondary exclusive reset_control
+ * that is initially not acquired for an already
+ * controlled reset line.
+ */
+ if (!rstc->shared && !shared && !acquired)
+ break;
+
+ if (WARN_ON(!rstc->shared || !shared))
+ return ERR_PTR(-EBUSY);
+
+ kref_get(&rstc->refcnt);
+ return rstc;
+ }
+ }
+
+ rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
+ if (!rstc)
+ return ERR_PTR(-ENOMEM);
+
+ if (!try_module_get(rcdev->owner)) {
+ kfree(rstc);
+ return ERR_PTR(-ENODEV);
+ }
+
+ rstc->rcdev = rcdev;
+ list_add(&rstc->list, &rcdev->reset_control_head);
+ rstc->id = index;
+ kref_init(&rstc->refcnt);
+ rstc->acquired = acquired;
+ rstc->shared = shared;
+
+ return rstc;
+}
+
+static void __reset_control_release(struct kref *kref)
+{
+ struct reset_control *rstc = container_of(kref, struct reset_control,
+ refcnt);
+
+ lockdep_assert_held(&reset_list_mutex);
+
+ module_put(rstc->rcdev->owner);
+
+ list_del(&rstc->list);
+ kfree(rstc);
+}
+
+static void __reset_control_put_internal(struct reset_control *rstc)
+{
+ lockdep_assert_held(&reset_list_mutex);
+
+ kref_put(&rstc->refcnt, __reset_control_release);
+}
+
+struct reset_control *
+__of_reset_control_get(struct device_node *node, const char *id, int index,
+ bool shared, bool optional, bool acquired)
+{
+ struct reset_control *rstc;
+ struct reset_controller_dev *r, *rcdev;
+ struct of_phandle_args args;
+ int rstc_id;
+ int ret;
+
+ if (!node)
+ return ERR_PTR(-EINVAL);
+
+ if (id) {
+ index = of_property_match_string(node,
+ "reset-names", id);
+ if (index == -EILSEQ)
+ return ERR_PTR(index);
+ if (index < 0)
+ return optional ? NULL : ERR_PTR(-ENOENT);
+ }
+
+ ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
+ index, &args);
+ if (ret == -EINVAL)
+ return ERR_PTR(ret);
+ if (ret)
+ return optional ? NULL : ERR_PTR(ret);
+
+ mutex_lock(&reset_list_mutex);
+ rcdev = NULL;
+ list_for_each_entry(r, &reset_controller_list, list) {
+ if (args.np == r->of_node) {
+ rcdev = r;
+ break;
+ }
+ }
+
+ if (!rcdev) {
+ rstc = ERR_PTR(-EPROBE_DEFER);
+ goto out;
+ }
+
+ if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
+ rstc = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ rstc_id = rcdev->of_xlate(rcdev, &args);
+ if (rstc_id < 0) {
+ rstc = ERR_PTR(rstc_id);
+ goto out;
+ }
+
+ /* reset_list_mutex also protects the rcdev's reset_control list */
+ rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);
+
+out:
+ mutex_unlock(&reset_list_mutex);
+ of_node_put(args.np);
+
+ return rstc;
+}
+EXPORT_SYMBOL_GPL(__of_reset_control_get);
+
+static struct reset_controller_dev *
+__reset_controller_by_name(const char *name)
+{
+ struct reset_controller_dev *rcdev;
+
+ lockdep_assert_held(&reset_list_mutex);
+
+ list_for_each_entry(rcdev, &reset_controller_list, list) {
+ if (!rcdev->dev)
+ continue;
+
+ if (!strcmp(name, dev_name(rcdev->dev)))
+ return rcdev;
+ }
+
+ return NULL;
+}
+
+static struct reset_control *
+__reset_control_get_from_lookup(struct device *dev, const char *con_id,
+ bool shared, bool optional, bool acquired)
+{
+ const struct reset_control_lookup *lookup;
+ struct reset_controller_dev *rcdev;
+ const char *dev_id = dev_name(dev);
+ struct reset_control *rstc = NULL;
+
+ mutex_lock(&reset_lookup_mutex);
+
+ list_for_each_entry(lookup, &reset_lookup_list, list) {
+ if (strcmp(lookup->dev_id, dev_id))
+ continue;
+
+ if ((!con_id && !lookup->con_id) ||
+ ((con_id && lookup->con_id) &&
+ !strcmp(con_id, lookup->con_id))) {
+ mutex_lock(&reset_list_mutex);
+ rcdev = __reset_controller_by_name(lookup->provider);
+ if (!rcdev) {
+ mutex_unlock(&reset_list_mutex);
+ mutex_unlock(&reset_lookup_mutex);
+ /* Reset provider may not be ready yet. */
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ rstc = __reset_control_get_internal(rcdev,
+ lookup->index,
+ shared, acquired);
+ mutex_unlock(&reset_list_mutex);
+ break;
+ }
+ }
+
+ mutex_unlock(&reset_lookup_mutex);
+
+ if (!rstc)
+ return optional ? NULL : ERR_PTR(-ENOENT);
+
+ return rstc;
+}
+
+struct reset_control *__reset_control_get(struct device *dev, const char *id,
+ int index, bool shared, bool optional,
+ bool acquired)
+{
+ if (WARN_ON(shared && acquired))
+ return ERR_PTR(-EINVAL);
+
+ if (dev->of_node)
+ return __of_reset_control_get(dev->of_node, id, index, shared,
+ optional, acquired);
+
+ return __reset_control_get_from_lookup(dev, id, shared, optional,
+ acquired);
+}
+EXPORT_SYMBOL_GPL(__reset_control_get);
+
+int __reset_control_bulk_get(struct device *dev, int num_rstcs,
+ struct reset_control_bulk_data *rstcs,
+ bool shared, bool optional, bool acquired)
+{
+ int ret, i;
+
+ for (i = 0; i < num_rstcs; i++) {
+ rstcs[i].rstc = __reset_control_get(dev, rstcs[i].id, 0,
+ shared, optional, acquired);
+ if (IS_ERR(rstcs[i].rstc)) {
+ ret = PTR_ERR(rstcs[i].rstc);
+ goto err;
+ }
+ }
+
+ return 0;
+
+err:
+ mutex_lock(&reset_list_mutex);
+ while (i--)
+ __reset_control_put_internal(rstcs[i].rstc);
+ mutex_unlock(&reset_list_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__reset_control_bulk_get);
+
+static void reset_control_array_put(struct reset_control_array *resets)
+{
+ int i;
+
+ mutex_lock(&reset_list_mutex);
+ for (i = 0; i < resets->num_rstcs; i++)
+ __reset_control_put_internal(resets->rstc[i]);
+ mutex_unlock(&reset_list_mutex);
+ kfree(resets);
+}
+
+/**
+ * reset_control_put - free the reset controller
+ * @rstc: reset controller
+ */
+void reset_control_put(struct reset_control *rstc)
+{
+ if (IS_ERR_OR_NULL(rstc))
+ return;
+
+ if (reset_control_is_array(rstc)) {
+ reset_control_array_put(rstc_to_array(rstc));
+ return;
+ }
+
+ mutex_lock(&reset_list_mutex);
+ __reset_control_put_internal(rstc);
+ mutex_unlock(&reset_list_mutex);
+}
+EXPORT_SYMBOL_GPL(reset_control_put);
+
+/**
+ * reset_control_bulk_put - free the reset controllers
+ * @num_rstcs: number of entries in rstcs array
+ * @rstcs: array of struct reset_control_bulk_data with reset controls set
+ */
+void reset_control_bulk_put(int num_rstcs, struct reset_control_bulk_data *rstcs)
+{
+ mutex_lock(&reset_list_mutex);
+ while (num_rstcs--) {
+ if (IS_ERR_OR_NULL(rstcs[num_rstcs].rstc))
+ continue;
+ __reset_control_put_internal(rstcs[num_rstcs].rstc);
+ }
+ mutex_unlock(&reset_list_mutex);
+}
+EXPORT_SYMBOL_GPL(reset_control_bulk_put);
+
+static void devm_reset_control_release(struct device *dev, void *res)
+{
+ reset_control_put(*(struct reset_control **)res);
+}
+
+struct reset_control *
+__devm_reset_control_get(struct device *dev, const char *id, int index,
+ bool shared, bool optional, bool acquired)
+{
+ struct reset_control **ptr, *rstc;
+
+ ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ rstc = __reset_control_get(dev, id, index, shared, optional, acquired);
+ if (IS_ERR_OR_NULL(rstc)) {
+ devres_free(ptr);
+ return rstc;
+ }
+
+ *ptr = rstc;
+ devres_add(dev, ptr);
+
+ return rstc;
+}
+EXPORT_SYMBOL_GPL(__devm_reset_control_get);
+
+struct reset_control_bulk_devres {
+ int num_rstcs;
+ struct reset_control_bulk_data *rstcs;
+};
+
+static void devm_reset_control_bulk_release(struct device *dev, void *res)
+{
+ struct reset_control_bulk_devres *devres = res;
+
+ reset_control_bulk_put(devres->num_rstcs, devres->rstcs);
+}
+
+int __devm_reset_control_bulk_get(struct device *dev, int num_rstcs,
+ struct reset_control_bulk_data *rstcs,
+ bool shared, bool optional, bool acquired)
+{
+ struct reset_control_bulk_devres *ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_reset_control_bulk_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ret = __reset_control_bulk_get(dev, num_rstcs, rstcs, shared, optional, acquired);
+ if (ret < 0) {
+ devres_free(ptr);
+ return ret;
+ }
+
+ ptr->num_rstcs = num_rstcs;
+ ptr->rstcs = rstcs;
+ devres_add(dev, ptr);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__devm_reset_control_bulk_get);
+
+/**
+ * __device_reset - find reset controller associated with the device
+ * and perform reset
+ * @dev: device to be reset by the controller
+ * @optional: whether it is optional to reset the device
+ *
+ * Convenience wrapper for __reset_control_get() and reset_control_reset().
+ * This is useful for the common case of devices with single, dedicated reset
+ * lines. _RST firmware method will be called for devices with ACPI.
+ */
+int __device_reset(struct device *dev, bool optional)
+{
+ struct reset_control *rstc;
+ int ret;
+
+#ifdef CONFIG_ACPI
+ acpi_handle handle = ACPI_HANDLE(dev);
+
+ if (handle) {
+ if (!acpi_has_method(handle, "_RST"))
+ return optional ? 0 : -ENOENT;
+ if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL,
+ NULL)))
+ return -EIO;
+ }
+#endif
+
+ rstc = __reset_control_get(dev, NULL, 0, 0, optional, true);
+ if (IS_ERR(rstc))
+ return PTR_ERR(rstc);
+
+ ret = reset_control_reset(rstc);
+
+ reset_control_put(rstc);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__device_reset);
+
+/*
+ * APIs to manage an array of reset controls.
+ */
+
+/**
+ * of_reset_control_get_count - Count number of resets available with a device
+ *
+ * @node: device node that contains 'resets'.
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+static int of_reset_control_get_count(struct device_node *node)
+{
+ int count;
+
+ if (!node)
+ return -EINVAL;
+
+ count = of_count_phandle_with_args(node, "resets", "#reset-cells");
+ if (count == 0)
+ count = -ENOENT;
+
+ return count;
+}
+
+/**
+ * of_reset_control_array_get - Get a list of reset controls using
+ * device node.
+ *
+ * @np: device node for the device that requests the reset controls array
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ * @acquired: only one reset control may be acquired for a given controller
+ * and ID
+ *
+ * Returns pointer to allocated reset_control on success or error on failure
+ */
+struct reset_control *
+of_reset_control_array_get(struct device_node *np, bool shared, bool optional,
+ bool acquired)
+{
+ struct reset_control_array *resets;
+ struct reset_control *rstc;
+ int num, i;
+
+ num = of_reset_control_get_count(np);
+ if (num < 0)
+ return optional ? NULL : ERR_PTR(num);
+
+ resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL);
+ if (!resets)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < num; i++) {
+ rstc = __of_reset_control_get(np, NULL, i, shared, optional,
+ acquired);
+ if (IS_ERR(rstc))
+ goto err_rst;
+ resets->rstc[i] = rstc;
+ }
+ resets->num_rstcs = num;
+ resets->base.array = true;
+
+ return &resets->base;
+
+err_rst:
+ mutex_lock(&reset_list_mutex);
+ while (--i >= 0)
+ __reset_control_put_internal(resets->rstc[i]);
+ mutex_unlock(&reset_list_mutex);
+
+ kfree(resets);
+
+ return rstc;
+}
+EXPORT_SYMBOL_GPL(of_reset_control_array_get);
+
+/**
+ * devm_reset_control_array_get - Resource managed reset control array get
+ *
+ * @dev: device that requests the list of reset controls
+ * @shared: whether reset controls are shared or not
+ * @optional: whether it is optional to get the reset controls
+ *
+ * The reset control array APIs are intended for a list of resets
+ * that just have to be asserted or deasserted, without any
+ * requirements on the order.
+ *
+ * Returns pointer to allocated reset_control on success or error on failure
+ */
+struct reset_control *
+devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
+{
+ struct reset_control **ptr, *rstc;
+
+ ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);
+ if (IS_ERR_OR_NULL(rstc)) {
+ devres_free(ptr);
+ return rstc;
+ }
+
+ *ptr = rstc;
+ devres_add(dev, ptr);
+
+ return rstc;
+}
+EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
+
+static int reset_control_get_count_from_lookup(struct device *dev)
+{
+ const struct reset_control_lookup *lookup;
+ const char *dev_id;
+ int count = 0;
+
+ if (!dev)
+ return -EINVAL;
+
+ dev_id = dev_name(dev);
+ mutex_lock(&reset_lookup_mutex);
+
+ list_for_each_entry(lookup, &reset_lookup_list, list) {
+ if (!strcmp(lookup->dev_id, dev_id))
+ count++;
+ }
+
+ mutex_unlock(&reset_lookup_mutex);
+
+ if (count == 0)
+ count = -ENOENT;
+
+ return count;
+}
+
+/**
+ * reset_control_get_count - Count number of resets available with a device
+ *
+ * @dev: device for which to return the number of resets
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+int reset_control_get_count(struct device *dev)
+{
+ if (dev->of_node)
+ return of_reset_control_get_count(dev->of_node);
+
+ return reset_control_get_count_from_lookup(dev);
+}
+EXPORT_SYMBOL_GPL(reset_control_get_count);