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authorLinus Torvalds <torvalds@linux-foundation.org>2025-04-01 11:26:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-04-01 11:26:08 -0700
commit25601e85441dd91cf7973b002f27af4c5b8691ea (patch)
tree821267764ed1dbdfb7d08839f7bf0054358eb4f8 /Documentation/driver-api
parent2cd5769fb0b78b8ef583ab4c0015c2c48d525dac (diff)
parent5d1a5c4f121f0ec50327e899c9450978505f1560 (diff)
downloadnet-25601e85441dd91cf7973b002f27af4c5b8691ea.tar.gz
Merge tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / IIO driver updates from Greg KH: "Here is the big set of char, misc, iio, and other smaller driver subsystems for 6.15-rc1. Lots of stuff in here, including: - loads of IIO changes and driver updates - counter driver updates - w1 driver updates - faux conversions for some drivers that were abusing the platform bus interface - coresight driver updates - rust miscdevice binding updates based on real-world-use - other minor driver updates All of these have been in linux-next with no reported issues for quite a while" * tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) samples: rust_misc_device: fix markup in top-level docs Coresight: Fix a NULL vs IS_ERR() bug in probe misc: lis3lv02d: convert to use faux_device tlclk: convert to use faux_device regulator: dummy: convert to use the faux device interface bus: mhi: host: Fix race between unprepare and queue_buf coresight: configfs: Constify struct config_item_type doc: iio: ad7380: describe offload support iio: ad7380: add support for SPI offload iio: light: Add check for array bounds in veml6075_read_int_time_ms iio: adc: ti-ads7924 Drop unnecessary function parameters staging: iio: ad9834: Use devm_regulator_get_enable() staging: iio: ad9832: Use devm_regulator_get_enable() iio: gyro: bmg160_spi: add of_match_table dt-bindings: iio: adc: Add i.MX94 and i.MX95 support iio: adc: ad7768-1: remove unnecessary locking Documentation: ABI: add wideband filter type to sysfs-bus-iio iio: adc: ad7768-1: set MOSI idle state to prevent accidental reset iio: adc: ad7768-1: Fix conversion result sign iio: adc: ad7124: Benefit of dev = indio_dev->dev.parent in ad7124_parse_channel_config() ...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/pps.rst27
1 files changed, 25 insertions, 2 deletions
diff --git a/Documentation/driver-api/pps.rst b/Documentation/driver-api/pps.rst
index 71ad04c82d6cf5..598729f9cd2714 100644
--- a/Documentation/driver-api/pps.rst
+++ b/Documentation/driver-api/pps.rst
@@ -206,8 +206,7 @@ To do so the class pps-gen has been added. PPS generators can be
registered in the kernel by defining a struct pps_gen_source_info as
follows::
- static struct pps_gen_source_info pps_gen_dummy_info = {
- .name = "dummy",
+ static const struct pps_gen_source_info pps_gen_dummy_info = {
.use_system_clock = true,
.get_time = pps_gen_dummy_get_time,
.enable = pps_gen_dummy_enable,
@@ -286,3 +285,27 @@ delay between assert and clear edge as small as possible to reduce system
latencies. But if it is too small slave won't be able to capture clear edge
transition. The default of 30us should be good enough in most situations.
The delay can be selected using 'delay' pps_gen_parport module parameter.
+
+
+Intel Timed I/O PPS signal generator
+------------------------------------
+
+Intel Timed I/O is a high precision device, present on 2019 and newer Intel
+CPUs, that can generate PPS signals.
+
+Timed I/O and system time are both driven by same hardware clock. The signal
+is generated with a precision of ~20 nanoseconds. The generated PPS signal
+is used to synchronize an external device with system clock. For example,
+it can be used to share your clock with a device that receives PPS signal,
+generated by Timed I/O device. There are dedicated Timed I/O pins to deliver
+the PPS signal to an external device.
+
+Usage of Intel Timed I/O as PPS generator:
+
+Start generating PPS signal::
+
+ $echo 1 > /sys/class/pps-gen/pps-genx/enable
+
+Stop generating PPS signal::
+
+ $echo 0 > /sys/class/pps-gen/pps-genx/enable