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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/pps/kapi.c | |
| download | linux-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/kapi.c')
| -rw-r--r-- | drivers/pps/kapi.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c new file mode 100644 index 000000000..1bf0335a1 --- /dev/null +++ b/drivers/pps/kapi.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * kernel API + * + * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/time.h> +#include <linux/timex.h> +#include <linux/spinlock.h> +#include <linux/fs.h> +#include <linux/pps_kernel.h> +#include <linux/slab.h> + +#include "kc.h" + +/* + * Local functions + */ + +static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) +{ + ts->nsec += offset->nsec; + while (ts->nsec >= NSEC_PER_SEC) { + ts->nsec -= NSEC_PER_SEC; + ts->sec++; + } + while (ts->nsec < 0) { + ts->nsec += NSEC_PER_SEC; + ts->sec--; + } + ts->sec += offset->sec; +} + +static void pps_echo_client_default(struct pps_device *pps, int event, + void *data) +{ + dev_info(&pps->dev, "echo %s %s\n", + event & PPS_CAPTUREASSERT ? "assert" : "", + event & PPS_CAPTURECLEAR ? "clear" : ""); +} + +/* + * Exported functions + */ + +/* pps_register_source - add a PPS source in the system + * @info: the PPS info struct + * @default_params: the default PPS parameters of the new source + * + * This function is used to add a new PPS source in the system. The new + * source is described by info's fields and it will have, as default PPS + * parameters, the ones specified into default_params. + * + * The function returns, in case of success, the PPS device. Otherwise + * ERR_PTR(errno). + */ + +struct pps_device *pps_register_source(struct pps_source_info *info, + int default_params) +{ + struct pps_device *pps; + int err; + + /* Sanity checks */ + if ((info->mode & default_params) != default_params) { + pr_err("%s: unsupported default parameters\n", + info->name); + err = -EINVAL; + goto pps_register_source_exit; + } + if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { + pr_err("%s: unspecified time format\n", + info->name); + err = -EINVAL; + goto pps_register_source_exit; + } + + /* Allocate memory for the new PPS source struct */ + pps = kzalloc_obj(struct pps_device); + if (pps == NULL) { + err = -ENOMEM; + goto pps_register_source_exit; + } + + /* These initializations must be done before calling idr_alloc() + * in order to avoid reces into pps_event(). + */ + pps->params.api_version = PPS_API_VERS; + pps->params.mode = default_params; + pps->info = *info; + + /* check for default echo function */ + if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) && + pps->info.echo == NULL) + pps->info.echo = pps_echo_client_default; + + init_waitqueue_head(&pps->queue); + spin_lock_init(&pps->lock); + + /* Create the char device */ + err = pps_register_cdev(pps); + if (err < 0) { + pr_err("%s: unable to create char device\n", + info->name); + goto pps_register_source_exit; + } + + dev_dbg(&pps->dev, "new PPS source %s\n", info->name); + + return pps; + +pps_register_source_exit: + pr_err("%s: unable to register source\n", info->name); + + return ERR_PTR(err); +} +EXPORT_SYMBOL(pps_register_source); + +/* pps_unregister_source - remove a PPS source from the system + * @pps: the PPS source + * + * This function is used to remove a previously registered PPS source from + * the system. + */ + +void pps_unregister_source(struct pps_device *pps) +{ + pps_kc_remove(pps); + pps_unregister_cdev(pps); + + /* don't have to kfree(pps) here because it will be done on + * device destruction */ +} +EXPORT_SYMBOL(pps_unregister_source); + +/* pps_event - register a PPS event into the system + * @pps: the PPS device + * @ts: the event timestamp + * @event: the event type + * @data: userdef pointer + * + * This function is used by each PPS client in order to register a new + * PPS event into the system (it's usually called inside an IRQ handler). + * + * If an echo function is associated with the PPS device it will be called + * as: + * pps->info.echo(pps, event, data); + */ +void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, + void *data) +{ + unsigned long flags; + int captured = 0; + struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 }; + + /* check event type */ + BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); + + dev_dbg(&pps->dev, "PPS event at %ptSp\n", &ts->ts_real); + + timespec_to_pps_ktime(&ts_real, ts->ts_real); + + spin_lock_irqsave(&pps->lock, flags); + + /* Must call the echo function? */ + if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR))) + pps->info.echo(pps, event, data); + + /* Check the event */ + pps->current_mode = pps->params.mode; + if (event & pps->params.mode & PPS_CAPTUREASSERT) { + /* We have to add an offset? */ + if (pps->params.mode & PPS_OFFSETASSERT) + pps_add_offset(&ts_real, + &pps->params.assert_off_tu); + + /* Save the time stamp */ + pps->assert_tu = ts_real; + pps->assert_sequence++; + dev_dbg(&pps->dev, "capture assert seq #%u\n", + pps->assert_sequence); + + captured = ~0; + } + if (event & pps->params.mode & PPS_CAPTURECLEAR) { + /* We have to add an offset? */ + if (pps->params.mode & PPS_OFFSETCLEAR) + pps_add_offset(&ts_real, + &pps->params.clear_off_tu); + + /* Save the time stamp */ + pps->clear_tu = ts_real; + pps->clear_sequence++; + dev_dbg(&pps->dev, "capture clear seq #%u\n", + pps->clear_sequence); + + captured = ~0; + } + + pps_kc_event(pps, ts, event); + + /* Wake up if captured something */ + if (captured) { + pps->last_ev++; + wake_up_interruptible_all(&pps->queue); + + kill_fasync(&pps->async_queue, SIGIO, POLL_IN); + } + + spin_unlock_irqrestore(&pps->lock, flags); +} +EXPORT_SYMBOL(pps_event); |
