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, 422 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c
new file mode 100644
index 000000000..aae40d20d
--- /dev/null
+++ b/drivers/rtc/rtc-stmp3xxx.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Freescale STMP37XX/STMP378X Real Time Clock driver
+ *
+ * Copyright (c) 2007 Sigmatel, Inc.
+ * Peter Hartley, <peter.hartley@sigmatel.com>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ * Copyright 2011 Wolfram Sang, Pengutronix e.K.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/stmp_device.h>
+#include <linux/stmp3xxx_rtc_wdt.h>
+
+#define STMP3XXX_RTC_CTRL			0x0
+#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN		0x00000001
+#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN	0x00000002
+#define STMP3XXX_RTC_CTRL_ALARM_IRQ		0x00000004
+#define STMP3XXX_RTC_CTRL_WATCHDOGEN		0x00000010
+
+#define STMP3XXX_RTC_STAT			0x10
+#define STMP3XXX_RTC_STAT_STALE_SHIFT		16
+#define STMP3XXX_RTC_STAT_RTC_PRESENT		0x80000000
+#define STMP3XXX_RTC_STAT_XTAL32000_PRESENT	0x10000000
+#define STMP3XXX_RTC_STAT_XTAL32768_PRESENT	0x08000000
+
+#define STMP3XXX_RTC_SECONDS			0x30
+
+#define STMP3XXX_RTC_ALARM			0x40
+
+#define STMP3XXX_RTC_WATCHDOG			0x50
+
+#define STMP3XXX_RTC_PERSISTENT0		0x60
+#define STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE		(1 << 0)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN		(1 << 1)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN		(1 << 2)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP	(1 << 4)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP	(1 << 5)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ		(1 << 6)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE		(1 << 7)
+
+#define STMP3XXX_RTC_PERSISTENT1		0x70
+/* missing bitmask in headers */
+#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER	0x80000000
+
+struct stmp3xxx_rtc_data {
+	struct rtc_device *rtc;
+	void __iomem *io;
+	int irq_alarm;
+};
+
+#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
+/**
+ * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
+ * @dev: the parent device of the watchdog (= the RTC)
+ * @timeout: the desired value for the timeout register of the watchdog.
+ *           0 disables the watchdog
+ *
+ * The watchdog needs one register and two bits which are in the RTC domain.
+ * To handle the resource conflict, the RTC driver will create another
+ * platform_device for the watchdog driver as a child of the RTC device.
+ * The watchdog driver is passed the below accessor function via platform_data
+ * to configure the watchdog. Locking is not needed because accessing SET/CLR
+ * registers is atomic.
+ */
+
+static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	if (timeout) {
+		writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
+		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
+		       rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
+		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
+		       rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
+	} else {
+		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
+		       rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
+		       rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
+	}
+}
+
+static struct stmp3xxx_wdt_pdata wdt_pdata = {
+	.wdt_set_timeout = stmp3xxx_wdt_set_timeout,
+};
+
+static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
+{
+	int rc = -1;
+	struct platform_device *wdt_pdev =
+		platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);
+
+	if (wdt_pdev) {
+		wdt_pdev->dev.parent = &rtc_pdev->dev;
+		wdt_pdev->dev.platform_data = &wdt_pdata;
+		rc = platform_device_add(wdt_pdev);
+		if (rc)
+			platform_device_put(wdt_pdev);
+	}
+
+	if (rc)
+		dev_err(&rtc_pdev->dev,
+			"failed to register stmp3xxx_rtc_wdt\n");
+}
+#else
+static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
+{
+}
+#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */
+
+static int stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
+{
+	int timeout = 5000; /* 3ms according to i.MX28 Ref Manual */
+	/*
+	 * The i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
+	 * states:
+	 * | The order in which registers are updated is
+	 * | Persistent 0, 1, 2, 3, 4, 5, Alarm, Seconds.
+	 * | (This list is in bitfield order, from LSB to MSB, as they would
+	 * | appear in the STALE_REGS and NEW_REGS bitfields of the HW_RTC_STAT
+	 * | register. For example, the Seconds register corresponds to
+	 * | STALE_REGS or NEW_REGS containing 0x80.)
+	 */
+	do {
+		if (!(readl(rtc_data->io + STMP3XXX_RTC_STAT) &
+				(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)))
+			return 0;
+		udelay(1);
+	} while (--timeout > 0);
+	return (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
+		(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) ? -ETIME : 0;
+}
+
+/* Time read/write */
+static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
+{
+	int ret;
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	ret = stmp3xxx_wait_time(rtc_data);
+	if (ret)
+		return ret;
+
+	rtc_time64_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
+	return 0;
+}
+
+static int stmp3xxx_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(rtc_tm), rtc_data->io + STMP3XXX_RTC_SECONDS);
+	return stmp3xxx_wait_time(rtc_data);
+}
+
+/* interrupt(s) handler */
+static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
+	u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
+
+	if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+		rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	if (enabled) {
+		writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+				STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
+			rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+				STMP_OFFSET_REG_SET);
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
+	} else {
+		writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+				STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
+			rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+				STMP_OFFSET_REG_CLR);
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+	}
+	return 0;
+}
+
+static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
+	return 0;
+}
+
+static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(&alm->time), rtc_data->io + STMP3XXX_RTC_ALARM);
+
+	stmp3xxx_alarm_irq_enable(dev, alm->enabled);
+
+	return 0;
+}
+
+static const struct rtc_class_ops stmp3xxx_rtc_ops = {
+	.alarm_irq_enable =
+			  stmp3xxx_alarm_irq_enable,
+	.read_time	= stmp3xxx_rtc_gettime,
+	.set_time	= stmp3xxx_rtc_settime,
+	.read_alarm	= stmp3xxx_rtc_read_alarm,
+	.set_alarm	= stmp3xxx_rtc_set_alarm,
+};
+
+static int stmp3xxx_rtc_remove(struct platform_device *pdev)
+{
+	struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
+
+	if (!rtc_data)
+		return 0;
+
+	writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+
+	return 0;
+}
+
+static int stmp3xxx_rtc_probe(struct platform_device *pdev)
+{
+	struct stmp3xxx_rtc_data *rtc_data;
+	struct resource *r;
+	u32 rtc_stat;
+	u32 pers0_set, pers0_clr;
+	u32 crystalfreq = 0;
+	int err;
+
+	rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL);
+	if (!rtc_data)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		dev_err(&pdev->dev, "failed to get resource\n");
+		return -ENXIO;
+	}
+
+	rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (!rtc_data->io) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		return -EIO;
+	}
+
+	rtc_data->irq_alarm = platform_get_irq(pdev, 0);
+
+	rtc_stat = readl(rtc_data->io + STMP3XXX_RTC_STAT);
+	if (!(rtc_stat & STMP3XXX_RTC_STAT_RTC_PRESENT)) {
+		dev_err(&pdev->dev, "no device onboard\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, rtc_data);
+
+	/*
+	 * Resetting the rtc stops the watchdog timer that is potentially
+	 * running. So (assuming it is running on purpose) don't reset if the
+	 * watchdog is enabled.
+	 */
+	if (readl(rtc_data->io + STMP3XXX_RTC_CTRL) &
+	    STMP3XXX_RTC_CTRL_WATCHDOGEN) {
+		dev_info(&pdev->dev,
+			 "Watchdog is running, skip resetting rtc\n");
+	} else {
+		err = stmp_reset_block(rtc_data->io);
+		if (err) {
+			dev_err(&pdev->dev, "stmp_reset_block failed: %d\n",
+				err);
+			return err;
+		}
+	}
+
+	/*
+	 * Obviously the rtc needs a clock input to be able to run.
+	 * This clock can be provided by an external 32k crystal. If that one is
+	 * missing XTAL must not be disabled in suspend which consumes a
+	 * lot of power. Normally the presence and exact frequency (supported
+	 * are 32000 Hz and 32768 Hz) is detectable from fuses, but as reality
+	 * proves these fuses are not blown correctly on all machines, so the
+	 * frequency can be overridden in the device tree.
+	 */
+	if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32000_PRESENT)
+		crystalfreq = 32000;
+	else if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32768_PRESENT)
+		crystalfreq = 32768;
+
+	of_property_read_u32(pdev->dev.of_node, "stmp,crystal-freq",
+			     &crystalfreq);
+
+	switch (crystalfreq) {
+	case 32000:
+		/* keep 32kHz crystal running in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ |
+			STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
+		break;
+	case 32768:
+		/* keep 32.768kHz crystal running in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ;
+		break;
+	default:
+		dev_warn(&pdev->dev,
+			 "invalid crystal-freq specified in device-tree. Assuming no crystal\n");
+		fallthrough;
+	case 0:
+		/* keep XTAL on in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+	}
+
+	writel(pers0_set, rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+			STMP_OFFSET_REG_SET);
+
+	writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE | pers0_clr,
+		rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
+
+	writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
+			STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+
+	rtc_data->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc_data->rtc))
+		return PTR_ERR(rtc_data->rtc);
+
+	err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm,
+			stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
+			rtc_data->irq_alarm);
+		return err;
+	}
+
+	rtc_data->rtc->ops = &stmp3xxx_rtc_ops;
+	rtc_data->rtc->range_max = U32_MAX;
+
+	err = devm_rtc_register_device(rtc_data->rtc);
+	if (err)
+		return err;
+
+	stmp3xxx_wdt_register(pdev);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stmp3xxx_rtc_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int stmp3xxx_rtc_resume(struct device *dev)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	stmp_reset_block(rtc_data->io);
+	writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
+		rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend,
+			stmp3xxx_rtc_resume);
+
+static const struct of_device_id rtc_dt_ids[] = {
+	{ .compatible = "fsl,stmp3xxx-rtc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rtc_dt_ids);
+
+static struct platform_driver stmp3xxx_rtcdrv = {
+	.probe		= stmp3xxx_rtc_probe,
+	.remove		= stmp3xxx_rtc_remove,
+	.driver		= {
+		.name	= "stmp3xxx-rtc",
+		.pm	= &stmp3xxx_rtc_pm_ops,
+		.of_match_table = rtc_dt_ids,
+	},
+};
+
+module_platform_driver(stmp3xxx_rtcdrv);
+
+MODULE_DESCRIPTION("STMP3xxx RTC Driver");
+MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
+		"Wolfram Sang <kernel@pengutronix.de>");
+MODULE_LICENSE("GPL");