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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/spi/spi-mux.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/spi/spi-mux.c')
-rw-r--r--drivers/spi/spi-mux.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/spi/spi-mux.c b/drivers/spi/spi-mux.c
new file mode 100644
index 000000000..0709e987b
--- /dev/null
+++ b/drivers/spi/spi-mux.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// General Purpose SPI multiplexer
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mux/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#define SPI_MUX_NO_CS ((unsigned int)-1)
+
+/**
+ * DOC: Driver description
+ *
+ * This driver supports a MUX on an SPI bus. This can be useful when you need
+ * more chip selects than the hardware peripherals support, or than are
+ * available in a particular board setup.
+ *
+ * The driver will create an additional SPI controller. Devices added under the
+ * mux will be handled as 'chip selects' on this controller.
+ */
+
+/**
+ * struct spi_mux_priv - the basic spi_mux structure
+ * @spi: pointer to the device struct attached to the parent
+ * spi controller
+ * @current_cs: The current chip select set in the mux
+ * @child_msg_complete: The mux replaces the complete callback in the child's
+ * message to its own callback; this field is used by the
+ * driver to store the child's callback during a transfer
+ * @child_msg_context: Used to store the child's context to the callback
+ * @child_msg_dev: Used to store the spi_device pointer to the child
+ * @mux: mux_control structure used to provide chip selects for
+ * downstream spi devices
+ */
+struct spi_mux_priv {
+ struct spi_device *spi;
+ unsigned int current_cs;
+
+ void (*child_msg_complete)(void *context);
+ void *child_msg_context;
+ struct spi_device *child_msg_dev;
+ struct mux_control *mux;
+};
+
+/* should not get called when the parent controller is doing a transfer */
+static int spi_mux_select(struct spi_device *spi)
+{
+ struct spi_mux_priv *priv = spi_controller_get_devdata(spi->controller);
+ int ret;
+
+ ret = mux_control_select(priv->mux, spi->chip_select);
+ if (ret)
+ return ret;
+
+ if (priv->current_cs == spi->chip_select)
+ return 0;
+
+ dev_dbg(&priv->spi->dev, "setting up the mux for cs %d\n",
+ spi->chip_select);
+
+ /* copy the child device's settings except for the cs */
+ priv->spi->max_speed_hz = spi->max_speed_hz;
+ priv->spi->mode = spi->mode;
+ priv->spi->bits_per_word = spi->bits_per_word;
+
+ priv->current_cs = spi->chip_select;
+
+ return 0;
+}
+
+static int spi_mux_setup(struct spi_device *spi)
+{
+ struct spi_mux_priv *priv = spi_controller_get_devdata(spi->controller);
+
+ /*
+ * can be called multiple times, won't do a valid setup now but we will
+ * change the settings when we do a transfer (necessary because we
+ * can't predict from which device it will be anyway)
+ */
+ return spi_setup(priv->spi);
+}
+
+static void spi_mux_complete_cb(void *context)
+{
+ struct spi_mux_priv *priv = (struct spi_mux_priv *)context;
+ struct spi_controller *ctlr = spi_get_drvdata(priv->spi);
+ struct spi_message *m = ctlr->cur_msg;
+
+ m->complete = priv->child_msg_complete;
+ m->context = priv->child_msg_context;
+ m->spi = priv->child_msg_dev;
+ spi_finalize_current_message(ctlr);
+ mux_control_deselect(priv->mux);
+}
+
+static int spi_mux_transfer_one_message(struct spi_controller *ctlr,
+ struct spi_message *m)
+{
+ struct spi_mux_priv *priv = spi_controller_get_devdata(ctlr);
+ struct spi_device *spi = m->spi;
+ int ret;
+
+ ret = spi_mux_select(spi);
+ if (ret)
+ return ret;
+
+ /*
+ * Replace the complete callback, context and spi_device with our own
+ * pointers. Save originals
+ */
+ priv->child_msg_complete = m->complete;
+ priv->child_msg_context = m->context;
+ priv->child_msg_dev = m->spi;
+
+ m->complete = spi_mux_complete_cb;
+ m->context = priv;
+ m->spi = priv->spi;
+
+ /* do the transfer */
+ return spi_async(priv->spi, m);
+}
+
+static int spi_mux_probe(struct spi_device *spi)
+{
+ struct spi_controller *ctlr;
+ struct spi_mux_priv *priv;
+ int ret;
+
+ ctlr = spi_alloc_master(&spi->dev, sizeof(*priv));
+ if (!ctlr)
+ return -ENOMEM;
+
+ spi_set_drvdata(spi, ctlr);
+ priv = spi_controller_get_devdata(ctlr);
+ priv->spi = spi;
+
+ /*
+ * Increase lockdep class as these lock are taken while the parent bus
+ * already holds their instance's lock.
+ */
+ lockdep_set_subclass(&ctlr->io_mutex, 1);
+ lockdep_set_subclass(&ctlr->add_lock, 1);
+
+ priv->mux = devm_mux_control_get(&spi->dev, NULL);
+ if (IS_ERR(priv->mux)) {
+ ret = dev_err_probe(&spi->dev, PTR_ERR(priv->mux),
+ "failed to get control-mux\n");
+ goto err_put_ctlr;
+ }
+
+ priv->current_cs = SPI_MUX_NO_CS;
+
+ /* supported modes are the same as our parent's */
+ ctlr->mode_bits = spi->controller->mode_bits;
+ ctlr->flags = spi->controller->flags;
+ ctlr->transfer_one_message = spi_mux_transfer_one_message;
+ ctlr->setup = spi_mux_setup;
+ ctlr->num_chipselect = mux_control_states(priv->mux);
+ ctlr->bus_num = -1;
+ ctlr->dev.of_node = spi->dev.of_node;
+ ctlr->must_async = true;
+
+ ret = devm_spi_register_controller(&spi->dev, ctlr);
+ if (ret)
+ goto err_put_ctlr;
+
+ return 0;
+
+err_put_ctlr:
+ spi_controller_put(ctlr);
+
+ return ret;
+}
+
+static const struct spi_device_id spi_mux_id[] = {
+ { "spi-mux" },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, spi_mux_id);
+
+static const struct of_device_id spi_mux_of_match[] = {
+ { .compatible = "spi-mux" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, spi_mux_of_match);
+
+static struct spi_driver spi_mux_driver = {
+ .probe = spi_mux_probe,
+ .driver = {
+ .name = "spi-mux",
+ .of_match_table = spi_mux_of_match,
+ },
+ .id_table = spi_mux_id,
+};
+
+module_spi_driver(spi_mux_driver);
+
+MODULE_DESCRIPTION("SPI multiplexer");
+MODULE_LICENSE("GPL");