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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/pps/clients/pps-ldisc.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/pps/clients/pps-ldisc.c')
-rw-r--r--drivers/pps/clients/pps-ldisc.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
new file mode 100644
index 000000000..fa5660f3c
--- /dev/null
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pps-ldisc.c -- PPS line discipline
+ *
+ * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/pps_kernel.h>
+#include <linux/bug.h>
+
+static void pps_tty_dcd_change(struct tty_struct *tty, bool active)
+{
+ struct pps_device *pps;
+ struct pps_event_time ts;
+
+ pps_get_ts(&ts);
+
+ pps = pps_lookup_dev(tty);
+ /*
+ * This should never fail, but the ldisc locking is very
+ * convoluted, so don't crash just in case.
+ */
+ if (WARN_ON_ONCE(pps == NULL))
+ return;
+
+ /* Now do the PPS event report */
+ pps_event(pps, &ts, active ? PPS_CAPTUREASSERT :
+ PPS_CAPTURECLEAR, NULL);
+
+ dev_dbg(&pps->dev, "PPS %s at %lu\n",
+ active ? "assert" : "clear", jiffies);
+}
+
+static int (*alias_n_tty_open)(struct tty_struct *tty);
+
+static int pps_tty_open(struct tty_struct *tty)
+{
+ struct pps_source_info info;
+ struct tty_driver *drv = tty->driver;
+ int index = tty->index + drv->name_base;
+ struct pps_device *pps;
+ int ret;
+
+ info.owner = THIS_MODULE;
+ info.dev = NULL;
+ snprintf(info.name, PPS_MAX_NAME_LEN, "%s%d", drv->driver_name, index);
+ snprintf(info.path, PPS_MAX_NAME_LEN, "/dev/%s%d", drv->name, index);
+ info.mode = PPS_CAPTUREBOTH | \
+ PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
+ PPS_CANWAIT | PPS_TSFMT_TSPEC;
+
+ pps = pps_register_source(&info, PPS_CAPTUREBOTH | \
+ PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
+ if (IS_ERR(pps)) {
+ pr_err("cannot register PPS source \"%s\"\n", info.path);
+ return PTR_ERR(pps);
+ }
+ pps->lookup_cookie = tty;
+
+ /* Now open the base class N_TTY ldisc */
+ ret = alias_n_tty_open(tty);
+ if (ret < 0) {
+ pr_err("cannot open tty ldisc \"%s\"\n", info.path);
+ goto err_unregister;
+ }
+
+ dev_dbg(&pps->dev, "source \"%s\" added\n", info.path);
+
+ return 0;
+
+err_unregister:
+ pps_unregister_source(pps);
+ return ret;
+}
+
+static void (*alias_n_tty_close)(struct tty_struct *tty);
+
+static void pps_tty_close(struct tty_struct *tty)
+{
+ struct pps_device *pps = pps_lookup_dev(tty);
+
+ alias_n_tty_close(tty);
+
+ if (WARN_ON(!pps))
+ return;
+
+ dev_info(&pps->dev, "removed\n");
+ pps_unregister_source(pps);
+}
+
+static struct tty_ldisc_ops pps_ldisc_ops;
+
+/*
+ * Module stuff
+ */
+
+static int __init pps_tty_init(void)
+{
+ int err;
+
+ /* Inherit the N_TTY's ops */
+ n_tty_inherit_ops(&pps_ldisc_ops);
+
+ /* Save N_TTY's open()/close() methods */
+ alias_n_tty_open = pps_ldisc_ops.open;
+ alias_n_tty_close = pps_ldisc_ops.close;
+
+ /* Init PPS_TTY data */
+ pps_ldisc_ops.owner = THIS_MODULE;
+ pps_ldisc_ops.num = N_PPS;
+ pps_ldisc_ops.name = "pps_tty";
+ pps_ldisc_ops.dcd_change = pps_tty_dcd_change;
+ pps_ldisc_ops.open = pps_tty_open;
+ pps_ldisc_ops.close = pps_tty_close;
+
+ err = tty_register_ldisc(&pps_ldisc_ops);
+ if (err)
+ pr_err("can't register PPS line discipline\n");
+ else
+ pr_info("PPS line discipline registered\n");
+
+ return err;
+}
+
+static void __exit pps_tty_cleanup(void)
+{
+ tty_unregister_ldisc(&pps_ldisc_ops);
+}
+
+module_init(pps_tty_init);
+module_exit(pps_tty_cleanup);
+
+MODULE_ALIAS_LDISC(N_PPS);
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("PPS TTY device driver");
+MODULE_LICENSE("GPL");