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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/iio/adc/envelope-detector.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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/iio/adc/envelope-detector.c')
-rw-r--r--drivers/iio/adc/envelope-detector.c408
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/iio/adc/envelope-detector.c b/drivers/iio/adc/envelope-detector.c
new file mode 100644
index 000000000..e911c25d1
--- /dev/null
+++ b/drivers/iio/adc/envelope-detector.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for an envelope detector using a DAC and a comparator
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * Author: Peter Rosin <peda@axentia.se>
+ */
+
+/*
+ * The DAC is used to find the peak level of an alternating voltage input
+ * signal by a binary search using the output of a comparator wired to
+ * an interrupt pin. Like so:
+ * _
+ * | \
+ * input +------>-------|+ \
+ * | \
+ * .-------. | }---.
+ * | | | / |
+ * | dac|-->--|- / |
+ * | | |_/ |
+ * | | |
+ * | | |
+ * | irq|------<-------'
+ * | |
+ * '-------'
+ */
+
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+
+struct envelope {
+ spinlock_t comp_lock; /* protects comp */
+ int comp;
+
+ struct mutex read_lock; /* protects everything else */
+
+ int comp_irq;
+ u32 comp_irq_trigger;
+ u32 comp_irq_trigger_inv;
+
+ struct iio_channel *dac;
+ struct delayed_work comp_timeout;
+
+ unsigned int comp_interval;
+ bool invert;
+ u32 dac_max;
+
+ int high;
+ int level;
+ int low;
+
+ struct completion done;
+};
+
+/*
+ * The envelope_detector_comp_latch function works together with the compare
+ * interrupt service routine below (envelope_detector_comp_isr) as a latch
+ * (one-bit memory) for if the interrupt has triggered since last calling
+ * this function.
+ * The ..._comp_isr function disables the interrupt so that the cpu does not
+ * need to service a possible interrupt flood from the comparator when no-one
+ * cares anyway, and this ..._comp_latch function reenables them again if
+ * needed.
+ */
+static int envelope_detector_comp_latch(struct envelope *env)
+{
+ int comp;
+
+ spin_lock_irq(&env->comp_lock);
+ comp = env->comp;
+ env->comp = 0;
+ spin_unlock_irq(&env->comp_lock);
+
+ if (!comp)
+ return 0;
+
+ /*
+ * The irq was disabled, and is reenabled just now.
+ * But there might have been a pending irq that
+ * happened while the irq was disabled that fires
+ * just as the irq is reenabled. That is not what
+ * is desired.
+ */
+ enable_irq(env->comp_irq);
+
+ /* So, synchronize this possibly pending irq... */
+ synchronize_irq(env->comp_irq);
+
+ /* ...and redo the whole dance. */
+ spin_lock_irq(&env->comp_lock);
+ comp = env->comp;
+ env->comp = 0;
+ spin_unlock_irq(&env->comp_lock);
+
+ if (comp)
+ enable_irq(env->comp_irq);
+
+ return 1;
+}
+
+static irqreturn_t envelope_detector_comp_isr(int irq, void *ctx)
+{
+ struct envelope *env = ctx;
+
+ spin_lock(&env->comp_lock);
+ env->comp = 1;
+ disable_irq_nosync(env->comp_irq);
+ spin_unlock(&env->comp_lock);
+
+ return IRQ_HANDLED;
+}
+
+static void envelope_detector_setup_compare(struct envelope *env)
+{
+ int ret;
+
+ /*
+ * Do a binary search for the peak input level, and stop
+ * when that level is "trapped" between two adjacent DAC
+ * values.
+ * When invert is active, use the midpoint floor so that
+ * env->level ends up as env->low when the termination
+ * criteria below is fulfilled, and use the midpoint
+ * ceiling when invert is not active so that env->level
+ * ends up as env->high in that case.
+ */
+ env->level = (env->high + env->low + !env->invert) / 2;
+
+ if (env->high == env->low + 1) {
+ complete(&env->done);
+ return;
+ }
+
+ /* Set a "safe" DAC level (if there is such a thing)... */
+ ret = iio_write_channel_raw(env->dac, env->invert ? 0 : env->dac_max);
+ if (ret < 0)
+ goto err;
+
+ /* ...clear the comparison result... */
+ envelope_detector_comp_latch(env);
+
+ /* ...set the real DAC level... */
+ ret = iio_write_channel_raw(env->dac, env->level);
+ if (ret < 0)
+ goto err;
+
+ /* ...and wait for a bit to see if the latch catches anything. */
+ schedule_delayed_work(&env->comp_timeout,
+ msecs_to_jiffies(env->comp_interval));
+ return;
+
+err:
+ env->level = ret;
+ complete(&env->done);
+}
+
+static void envelope_detector_timeout(struct work_struct *work)
+{
+ struct envelope *env = container_of(work, struct envelope,
+ comp_timeout.work);
+
+ /* Adjust low/high depending on the latch content... */
+ if (!envelope_detector_comp_latch(env) ^ !env->invert)
+ env->low = env->level;
+ else
+ env->high = env->level;
+
+ /* ...and continue the search. */
+ envelope_detector_setup_compare(env);
+}
+
+static int envelope_detector_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct envelope *env = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /*
+ * When invert is active, start with high=max+1 and low=0
+ * since we will end up with the low value when the
+ * termination criteria is fulfilled (rounding down). And
+ * start with high=max and low=-1 when invert is not active
+ * since we will end up with the high value in that case.
+ * This ensures that the returned value in both cases are
+ * in the same range as the DAC and is a value that has not
+ * triggered the comparator.
+ */
+ mutex_lock(&env->read_lock);
+ env->high = env->dac_max + env->invert;
+ env->low = -1 + env->invert;
+ envelope_detector_setup_compare(env);
+ wait_for_completion(&env->done);
+ if (env->level < 0) {
+ ret = env->level;
+ goto err_unlock;
+ }
+ *val = env->invert ? env->dac_max - env->level : env->level;
+ mutex_unlock(&env->read_lock);
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ return iio_read_channel_scale(env->dac, val, val2);
+ }
+
+ return -EINVAL;
+
+err_unlock:
+ mutex_unlock(&env->read_lock);
+ return ret;
+}
+
+static ssize_t envelope_show_invert(struct iio_dev *indio_dev,
+ uintptr_t private,
+ struct iio_chan_spec const *ch, char *buf)
+{
+ struct envelope *env = iio_priv(indio_dev);
+
+ return sprintf(buf, "%u\n", env->invert);
+}
+
+static ssize_t envelope_store_invert(struct iio_dev *indio_dev,
+ uintptr_t private,
+ struct iio_chan_spec const *ch,
+ const char *buf, size_t len)
+{
+ struct envelope *env = iio_priv(indio_dev);
+ unsigned long invert;
+ int ret;
+ u32 trigger;
+
+ ret = kstrtoul(buf, 0, &invert);
+ if (ret < 0)
+ return ret;
+ if (invert > 1)
+ return -EINVAL;
+
+ trigger = invert ? env->comp_irq_trigger_inv : env->comp_irq_trigger;
+
+ mutex_lock(&env->read_lock);
+ if (invert != env->invert)
+ ret = irq_set_irq_type(env->comp_irq, trigger);
+ if (!ret) {
+ env->invert = invert;
+ ret = len;
+ }
+ mutex_unlock(&env->read_lock);
+
+ return ret;
+}
+
+static ssize_t envelope_show_comp_interval(struct iio_dev *indio_dev,
+ uintptr_t private,
+ struct iio_chan_spec const *ch,
+ char *buf)
+{
+ struct envelope *env = iio_priv(indio_dev);
+
+ return sprintf(buf, "%u\n", env->comp_interval);
+}
+
+static ssize_t envelope_store_comp_interval(struct iio_dev *indio_dev,
+ uintptr_t private,
+ struct iio_chan_spec const *ch,
+ const char *buf, size_t len)
+{
+ struct envelope *env = iio_priv(indio_dev);
+ unsigned long interval;
+ int ret;
+
+ ret = kstrtoul(buf, 0, &interval);
+ if (ret < 0)
+ return ret;
+ if (interval > 1000)
+ return -EINVAL;
+
+ mutex_lock(&env->read_lock);
+ env->comp_interval = interval;
+ mutex_unlock(&env->read_lock);
+
+ return len;
+}
+
+static const struct iio_chan_spec_ext_info envelope_detector_ext_info[] = {
+ { .name = "invert",
+ .read = envelope_show_invert,
+ .write = envelope_store_invert, },
+ { .name = "compare_interval",
+ .read = envelope_show_comp_interval,
+ .write = envelope_store_comp_interval, },
+ { /* sentinel */ }
+};
+
+static const struct iio_chan_spec envelope_detector_iio_channel = {
+ .type = IIO_ALTVOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+ | BIT(IIO_CHAN_INFO_SCALE),
+ .ext_info = envelope_detector_ext_info,
+ .indexed = 1,
+};
+
+static const struct iio_info envelope_detector_info = {
+ .read_raw = &envelope_detector_read_raw,
+};
+
+static int envelope_detector_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iio_dev *indio_dev;
+ struct envelope *env;
+ enum iio_chan_type type;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*env));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, indio_dev);
+ env = iio_priv(indio_dev);
+ env->comp_interval = 50; /* some sensible default? */
+
+ spin_lock_init(&env->comp_lock);
+ mutex_init(&env->read_lock);
+ init_completion(&env->done);
+ INIT_DELAYED_WORK(&env->comp_timeout, envelope_detector_timeout);
+
+ indio_dev->name = dev_name(dev);
+ indio_dev->info = &envelope_detector_info;
+ indio_dev->channels = &envelope_detector_iio_channel;
+ indio_dev->num_channels = 1;
+
+ env->dac = devm_iio_channel_get(dev, "dac");
+ if (IS_ERR(env->dac))
+ return dev_err_probe(dev, PTR_ERR(env->dac),
+ "failed to get dac input channel\n");
+
+ env->comp_irq = platform_get_irq_byname(pdev, "comp");
+ if (env->comp_irq < 0)
+ return env->comp_irq;
+
+ ret = devm_request_irq(dev, env->comp_irq, envelope_detector_comp_isr,
+ 0, "envelope-detector", env);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request interrupt\n");
+
+ env->comp_irq_trigger = irq_get_trigger_type(env->comp_irq);
+ if (env->comp_irq_trigger & IRQF_TRIGGER_RISING)
+ env->comp_irq_trigger_inv |= IRQF_TRIGGER_FALLING;
+ if (env->comp_irq_trigger & IRQF_TRIGGER_FALLING)
+ env->comp_irq_trigger_inv |= IRQF_TRIGGER_RISING;
+ if (env->comp_irq_trigger & IRQF_TRIGGER_HIGH)
+ env->comp_irq_trigger_inv |= IRQF_TRIGGER_LOW;
+ if (env->comp_irq_trigger & IRQF_TRIGGER_LOW)
+ env->comp_irq_trigger_inv |= IRQF_TRIGGER_HIGH;
+
+ ret = iio_get_channel_type(env->dac, &type);
+ if (ret < 0)
+ return ret;
+
+ if (type != IIO_VOLTAGE) {
+ dev_err(dev, "dac is of the wrong type\n");
+ return -EINVAL;
+ }
+
+ ret = iio_read_max_channel_raw(env->dac, &env->dac_max);
+ if (ret < 0) {
+ dev_err(dev, "dac does not indicate its raw maximum value\n");
+ return ret;
+ }
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id envelope_detector_match[] = {
+ { .compatible = "axentia,tse850-envelope-detector", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, envelope_detector_match);
+
+static struct platform_driver envelope_detector_driver = {
+ .probe = envelope_detector_probe,
+ .driver = {
+ .name = "iio-envelope-detector",
+ .of_match_table = envelope_detector_match,
+ },
+};
+module_platform_driver(envelope_detector_driver);
+
+MODULE_DESCRIPTION("Envelope detector using a DAC and a comparator");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");