[PATCH] Aesthetic tweaks to PPS-related content

From: Robert P. J. Day
Date: Sat Aug 26 2017 - 10:36:25 EST

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Collection of aesthetic adjustments to various PPS-related files,
directories and Documentation, some quite minor just for the sake of
consistency, including:

* Updated example of pps device tree node (courtesy Rodolfo G.)
* "PPS-API" -> "PPS API"
* "pps_source_info_s" -> "pps_source_info"
* "ktimer driver" -> "pps-ktimer driver"
* "ppstest /dev/pps0" -> "ppstest /dev/pps1" to match example
* Add missing PPS-related entries to MAINTAINERS file
* Other trivialities

Diff stat:

Documentation/devicetree/bindings/pps/pps-gpio.txt | 8 ++++++--
Documentation/pps/pps.txt | 44 +++++++++++++++++++++++---------------------
MAINTAINERS | 3 +++
include/linux/pps-gpio.h | 2 +-
include/linux/pps_kernel.h | 16 +++++++---------
include/uapi/linux/pps.h | 4 ++--
kernel/time/timekeeping.c | 2 +-
7 files changed, 43 insertions(+), 36 deletions(-)

Signed-off-by: Robert P. J. Day <rpjday@xxxxxxxxxxxxxx>
---

any other changes worth throwing in?

diff --git a/Documentation/devicetree/bindings/pps/pps-gpio.txt b/Documentation/devicetree/bindings/pps/pps-gpio.txt
index 40bf9c3..0de23b7 100644
--- a/Documentation/devicetree/bindings/pps/pps-gpio.txt
+++ b/Documentation/devicetree/bindings/pps/pps-gpio.txt
@@ -13,8 +13,12 @@ Optional properties:

Example:
pps {
- compatible = "pps-gpio";
- gpios = <&gpio2 6 0>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_pps>;

+ gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;
assert-falling-edge;
+
+ compatible = "pps-gpio";
+ status = "okay";
};
diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt
index 1fdbd54..99f5d8c 100644
--- a/Documentation/pps/pps.txt
+++ b/Documentation/pps/pps.txt
@@ -48,12 +48,12 @@ problem:
time_pps_create().

This implies that the source has a /dev/... entry. This assumption is
-ok for the serial and parallel port, where you can do something
+OK for the serial and parallel port, where you can do something
useful besides(!) the gathering of timestamps as it is the central
-task for a PPS-API. But this assumption does not work for a single
+task for a PPS API. But this assumption does not work for a single
purpose GPIO line. In this case even basic file-related functionality
(like read() and write()) makes no sense at all and should not be a
-precondition for the use of a PPS-API.
+precondition for the use of a PPS API.

The problem can be simply solved if you consider that a PPS source is
not always connected with a GPS data source.
@@ -88,13 +88,13 @@ Coding example
--------------

To register a PPS source into the kernel you should define a struct
-pps_source_info_s as follows:
+pps_source_info as follows:

static struct pps_source_info pps_ktimer_info = {
.name = "ktimer",
.path = "",
- .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
- PPS_ECHOASSERT | \
+ .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
+ PPS_ECHOASSERT |
PPS_CANWAIT | PPS_TSFMT_TSPEC,
.echo = pps_ktimer_echo,
.owner = THIS_MODULE,
@@ -108,13 +108,13 @@ initialization routine as follows:

The pps_register_source() prototype is:

- int pps_register_source(struct pps_source_info_s *info, int default_params)
+ int pps_register_source(struct pps_source_info *info, int default_params)

where "info" is a pointer to a structure that describes a particular
PPS source, "default_params" tells the system what the initial default
parameters for the device should be (it is obvious that these parameters
must be a subset of ones defined in the struct
-pps_source_info_s which describe the capabilities of the driver).
+pps_source_info which describe the capabilities of the driver).

Once you have registered a new PPS source into the system you can
signal an assert event (for example in the interrupt handler routine)
@@ -142,8 +142,10 @@ If the SYSFS filesystem is enabled in the kernel it provides a new class:
Every directory is the ID of a PPS sources defined in the system and
inside you find several files:

- $ ls /sys/class/pps/pps0/
- assert clear echo mode name path subsystem@ uevent
+ $ ls -F /sys/class/pps/pps0/
+ assert dev mode path subsystem@
+ clear echo name power/ uevent
+

Inside each "assert" and "clear" file you can find the timestamp and a
sequence number:
@@ -154,32 +156,32 @@ sequence number:
Where before the "#" is the timestamp in seconds; after it is the
sequence number. Other files are:

-* echo: reports if the PPS source has an echo function or not;
+ * echo: reports if the PPS source has an echo function or not;

-* mode: reports available PPS functioning modes;
+ * mode: reports available PPS functioning modes;

-* name: reports the PPS source's name;
+ * name: reports the PPS source's name;

-* path: reports the PPS source's device path, that is the device the
- PPS source is connected to (if it exists).
+ * path: reports the PPS source's device path, that is the device the
+ PPS source is connected to (if it exists).

Testing the PPS support
-----------------------

In order to test the PPS support even without specific hardware you can use
-the ktimer driver (see the client subsection in the PPS configuration menu)
+the pps-ktimer driver (see the client subsection in the PPS configuration menu)
and the userland tools available in your distribution's pps-tools package,
-http://linuxpps.org , or https://github.com/ago/pps-tools .
+http://linuxpps.org , or https://github.com/redlab-i/pps-tools.

-Once you have enabled the compilation of ktimer just modprobe it (if
+Once you have enabled the compilation of pps-ktimer just modprobe it (if
not statically compiled):

- # modprobe ktimer
+ # modprobe pps-ktimer

and the run ppstest as follow:

- $ ./ppstest /dev/pps0
+ $ ./ppstest /dev/pps1
trying PPS source "/dev/pps1"
found PPS source "/dev/pps1"
ok, found 1 source(s), now start fetching data...
@@ -187,7 +189,7 @@ and the run ppstest as follow:
source 0 - assert 1186592700.388931295, sequence: 365 - clear 0.000000000, sequence: 0
source 0 - assert 1186592701.389032765, sequence: 366 - clear 0.000000000, sequence: 0

-Please, note that to compile userland programs you need the file timepps.h .
+Please note that to compile userland programs, you need the file timepps.h.
This is available in the pps-tools repository mentioned above.

diff --git a/MAINTAINERS b/MAINTAINERS
index 1c3feff..c4c0ed6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10579,8 +10579,11 @@ W: http://wiki.enneenne.com/index.php/LinuxPPS_support
L: linuxpps@xxxxxxxxxxxxxxx (subscribers-only)
S: Maintained
F: Documentation/pps/
+F: Documentation/devicetree/bindings/pps/pps-gpio.txt
+F: Documentation/ABI/testing/sysfs-pps
F: drivers/pps/
F: include/linux/pps*.h
+F: include/uapi/linux/pps.h

PPTP DRIVER
M: Dmitry Kozlov <xeb@xxxxxxx>
diff --git a/include/linux/pps-gpio.h b/include/linux/pps-gpio.h
index 0035abe..56f35dd 100644
--- a/include/linux/pps-gpio.h
+++ b/include/linux/pps-gpio.h
@@ -29,4 +29,4 @@ struct pps_gpio_platform_data {
const char *gpio_label;
};

-#endif
+#endif /* _PPS_GPIO_H */
diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
index 35ac903..80a980c 100644
--- a/include/linux/pps_kernel.h
+++ b/include/linux/pps_kernel.h
@@ -22,7 +22,6 @@
#define LINUX_PPS_KERNEL_H

#include <linux/pps.h>
-
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/time.h>
@@ -35,9 +34,9 @@ struct pps_device;

/* The specific PPS source info */
struct pps_source_info {
- char name[PPS_MAX_NAME_LEN]; /* simbolic name */
+ char name[PPS_MAX_NAME_LEN]; /* symbolic name */
char path[PPS_MAX_NAME_LEN]; /* path of connected device */
- int mode; /* PPS's allowed mode */
+ int mode; /* PPS allowed mode */

void (*echo)(struct pps_device *pps,
int event, void *data); /* PPS echo function */
@@ -57,10 +56,10 @@ struct pps_event_time {
struct pps_device {
struct pps_source_info info; /* PSS source info */

- struct pps_kparams params; /* PPS's current params */
+ struct pps_kparams params; /* PPS current params */

- __u32 assert_sequence; /* PPS' assert event seq # */
- __u32 clear_sequence; /* PPS' clear event seq # */
+ __u32 assert_sequence; /* PPS assert event seq # */
+ __u32 clear_sequence; /* PPS clear event seq # */
struct pps_ktime assert_tu;
struct pps_ktime clear_tu;
int current_mode; /* PPS mode at event time */
@@ -69,7 +68,7 @@ struct pps_device {
wait_queue_head_t queue; /* PPS event queue */

unsigned int id; /* PPS source unique ID */
- void const *lookup_cookie; /* pps_lookup_dev only */
+ void const *lookup_cookie; /* For pps_lookup_dev() only */
struct cdev cdev;
struct device *dev;
struct fasync_struct *async_queue; /* fasync method */
@@ -101,7 +100,7 @@ extern struct pps_device *pps_register_source(
extern void pps_unregister_source(struct pps_device *pps);
extern void pps_event(struct pps_device *pps,
struct pps_event_time *ts, int event, void *data);
-/* Look up a pps device by magic cookie */
+/* Look up a pps_device by magic cookie */
struct pps_device *pps_lookup_dev(void const *cookie);

static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
@@ -132,4 +131,3 @@ static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta
}

#endif /* LINUX_PPS_KERNEL_H */
-
diff --git a/include/uapi/linux/pps.h b/include/uapi/linux/pps.h
index c1cb382..c29d6b7 100644
--- a/include/uapi/linux/pps.h
+++ b/include/uapi/linux/pps.h
@@ -95,8 +95,8 @@ struct pps_kparams {
#define PPS_CAPTURECLEAR 0x02 /* capture clear events */
#define PPS_CAPTUREBOTH 0x03 /* capture assert and clear events */

-#define PPS_OFFSETASSERT 0x10 /* apply compensation for assert ev. */
-#define PPS_OFFSETCLEAR 0x20 /* apply compensation for clear ev. */
+#define PPS_OFFSETASSERT 0x10 /* apply compensation for assert event */
+#define PPS_OFFSETCLEAR 0x20 /* apply compensation for clear event */

#define PPS_CANWAIT 0x100 /* can we wait for an event? */
#define PPS_CANPOLL 0x200 /* bit reserved for future use */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cedafa0..66dbabb 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -2318,7 +2318,7 @@ void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
}
EXPORT_SYMBOL(hardpps);
-#endif
+#endif /* CONFIG_NTP_PPS */

/**
* xtime_update() - advances the timekeeping infrastructure

--

========================================================================
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca

Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
========================================================================

Next message: Larry Finger: "Re: [PATCH] Staging rtlwifi efuse fix up a warning kzalloc"
Previous message: Thomas Gleixner: "Re: a25339d553 ("x86/idt: Hide set_intr_gate()"): WARNING: CPU: 0 PID: 0 at arch/x86/kernel/idt.c:355 update_intr_gate"
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