#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/poll.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/syscalls.h>
#include <linux/time.h>
#include <linux/unistd.h>
#include <linux/wait.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <asm/atomic.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <nidas/linux/ver_macros.h>
#include <nidas/linux/irigclock.h>
#include <nidas/linux/isa_bus.h>
#include <nidas/linux/Revision.h>
#include <nidas/linux/klog.h>
#include "pc104sg.h"

Classes
struct	clockSnapShot
	One a second, or when clockAction == RESET_COUNTERS, the interrupt service routine grabs a snapshot of the following values. More...

struct	irig_device
	Device structure used in the file operations of the character device which provides IRIG samples. More...

struct	pc104sg_board
	Everything needed to access the board. More...

Macros
#define	REPO_REVISION "unknown"

#define	IRQF_SHARED SA_SHIRQ

#define	INTERRUPT_RATE 100

#define	MSEC_PER_INTERRUPT (MSECS_PER_SEC / INTERRUPT_RATE)
	number of milliseconds per interrupt

#define	TMSEC_PER_INTERRUPT (TMSECS_PER_SEC / INTERRUPT_RATE)
	number of 1/10ths of milliseconds per interrupt

#define	INTERRUPTS_PER_TASKLET 1
	We schedule the bottom-half tasklet after every INTERRUPTS_PER_TASKLET interrupts.

#define	TMSEC_PER_SOFT_TIC
	Increment of the software clock on each schedule of the tasklet.

#define	MAX_TASKLET_COUNTER (10 * INTERRUPT_RATE * INTERRUPTS_PER_TASKLET)
	Allow for counting up to 10 seconds, so that we can do 0.1hz callbacks.

#define	CALLBACK_POOL_SIZE 64 /* number of callbacks we can support */

#define	PC104SG_SAMPLE_QUEUE_SIZE 16
	Length of the circular buffer of output samples.

#define	MAX_TMSEC_SINCE_LAST_SYNC (5 * TMSECS_PER_SEC)
	Values that are used to detect whether the bottom half tasklet has gotten out of sync with real-time.

#define	SECS_PER_HOUR (60 * 60)
	macros borrowed from glibc/time functions

#define	SECS_PER_DAY (SECS_PER_HOUR * 24)

#define	my_isleap(year) ((year) % 4 == 0 && ((year) % 100 != 0 \|\| (year) % 400 == 0))

#define	DIV(a, b) ((a) / (b) - ((a) % (b) < 0))

#define	LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))

Enumerations
enum	clockAction { RESET_COUNTERS , NO_ACTION }
	What to do with the with the software clock and loop counter in the bottom-half tasklet. More...

enum	clockState { SYNCD_SET , UNSYNCD_SET }
	Enumeration of the state of the software clock. More...

enum	notifyClients { NO_NOTIFY , NOTIFY_CLIENTS }
	Whether to notify callback clients if clockAction is RESET_COUNTERS. More...

Functions
	MODULE_AUTHOR ("Gordon Maclean <maclean@ucar.edu>")

	MODULE_DESCRIPTION ("PC104-SG IRIG Card Driver")

	MODULE_LICENSE ("GPL")

	MODULE_VERSION (REPO_REVISION)

	module_param (Irq, int, 0)

	module_param (IoPort, int, 0)

	module_param (A2DClockFreq, int, 0)

	EXPORT_SYMBOL (TMsecClock)

	EXPORT_SYMBOL (ReadClock)

static const char *	clockStateString (void)

struct irig_callback *	register_irig_callback (irig_callback_func callback, irig_callback_func resync, enum irigClockRates rate, void privateData, int errp)
	Module function that allows other modules to register their callback function to be called at the given rate.

	EXPORT_SYMBOL (register_irig_callback)

int	unregister_irig_callback (struct irig_callback *cb)
	Modules call this function to dequeue their callbacks.

	EXPORT_SYMBOL (unregister_irig_callback)

int	flush_irig_callbacks (void)

	EXPORT_SYMBOL (flush_irig_callbacks)

static void	handlePendingCallbacks (void)
	Handle pending adds and removes of callbacks from the active list for the appropriate rate.

static void	free_callbacks (void)
	Cleanup function that un-registers all callbacks.

static void	resetHeartBeatLatch (void)
	After receiving a heartbeat interrupt, one must reset the heartbeat latch in the handler.

static void	enableHeartBeatInt (void)
	Enable heart beat interrupts.

static void	resetMatchLatch (void)
	After receiving a match interrupt, one must reset the match flag in order to receive further interrupts.

static void	disableAllInts (void)

static int	readDPRAM (unsigned char addr, unsigned char *val)
	Read dual port RAM.

static void	requestDPRAM (unsigned char addr)
	The requestDPRAM()/getRequestedDPRAM() pair allow us to break a dual-port read into two parts.

static void	getRequestedDPRAM (unsigned char *val)

static int	writeDPRAM (unsigned char addr, unsigned char value)
	Set a value in dual port RAM.

static int	setHeartBeatOutput (int rate)

static int	setPrimarySyncReference (unsigned char val)
	Set the primary time reference.

static int	setTimeCodeInputSelect (unsigned char val)

int	setRate2Output (int rate)

static int	counterRejam (void)

static void	getTimeRegisters (struct irigTime *ti, int offset)
	Read time from the registers.

int	getTimeUsec ()
	Read sub-second time fields from the card, return microseconds.

static void	timespecToirig (const thiskernel_timespec_t ts, struct irigTime ti)
	Break a timespec into the fields of a struct irigTime.

static void	irigTotimespec (const struct irigTime ti, thiskernel_timespec_t ts)
	Convert a struct irigTime into a thiskernel_timespec_t.

static int64_t	irigTousec (const struct irigTime *ti)
	Convert a struct irigTime to a int64_t time in microseconds.

static void	irigTotimeval32 (const struct irigTime ti, struct timeval32 tv)
	Convert a struct irigTime into a struct timeval32.

static void	get_irig_time_nolock (struct irigTime *ti)
	Get value of on-board clock.

static void	get_irig_timespec_nolock (thiskernel_timespec_t *ts)

void	irig_clock_gettime (thiskernel_timespec_t *tp)
	This function is available for use by external modules.

	EXPORT_SYMBOL (irig_clock_gettime)

int	get_msec_clock_resolution ()

static int	setYear (int val)
	set the year fields in Dual Port RAM.

static int	setMajorTime (struct irigTime *ti)
	The major time consists of the day-of-year, hour, minute and second fields.

static int	setSoftTickers (const thiskernel_timespec_t *ts, int round)
	Set the software clock and the tasklet loop counter based on a clock value in a timespec struct.

static void	checkSoftTicker (int newClock, int currClock, int scale, int notify)
	Try to determine if our software clock and client callbacks are keeping up with real-time.

static void	doCallbacklist (int rate)
	Invoke the callback functions for a given rate.

static void	doResyncCallbacks (void)
	Invoke all resync callback functions.

static void	pc104sg_bh_100Hz (unsigned long dev)
	Tasklet called 100 times/second in softare interrupt context.

static void	oneHzFunction (void *ptr)

static void	requestExtendedStatus (void)

static irqreturn_t	pc104sg_isr (int irq, void *callbackPtr)

static int	pc104sg_open (struct inode inode, struct file filp)

static int	pc104sg_release (struct inode inode, struct file filp)

static unsigned int	pc104sg_poll (struct file filp, poll_table wait)

static ssize_t	pc104sg_read (struct file filp, char __user buf, size_t count, loff_t *f_pos)

static long	setIRIGclock (int64_t usec)
	Set the IRIG hardware clock fields in DPRAM.

static long	pc104sg_ioctl (struct file *filp, unsigned int cmd, unsigned long arg)

static void	pc104sg_cleanup (void)

static int __init	pc104sg_init (void)

	module_init (pc104sg_init)

	module_exit (pc104sg_cleanup)

Variables
static char *	driver_name = "pc104sg"

static unsigned int	A2DClockFreq = 10000

static unsigned int	Irq = 10

static unsigned int	IoPort = 0x2a0

int	TMsecClock [2] = { 0, 0 }
	A toggle buffer containing the current clock value in tenths of milliseconds since UTC midnight.

int	ReadClock = 0
	Index into TMsecClock of the value to be read.

static struct pc104sg_board	board

static int	StaticYear
	The year field in the pc104sg time registers ranges from 0-99, so we keep track of the century.

static struct file_operations	pc104sg_fops

Macro Definition Documentation

◆ CALLBACK_POOL_SIZE

#define CALLBACK_POOL_SIZE 64 /* number of callbacks we can support */

Referenced by init_gpio_timer(), and pc104sg_init().

◆ DIV

#define DIV	(		a,
			b ) ((a) / (b) - ((a) % (b) < 0))

◆ INTERRUPT_RATE

#define INTERRUPT_RATE 100

Referenced by pc104sg_init().

◆ INTERRUPTS_PER_TASKLET

#define INTERRUPTS_PER_TASKLET 1

We schedule the bottom-half tasklet after every INTERRUPTS_PER_TASKLET interrupts.

◆ IRQF_SHARED

#define IRQF_SHARED SA_SHIRQ

◆ LEAPS_THRU_END_OF

#define LEAPS_THRU_END_OF ( y ) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))

Referenced by irigTotimespec(), irigTousec(), and timespecToirig().

◆ MAX_TASKLET_COUNTER

#define MAX_TASKLET_COUNTER (10 * INTERRUPT_RATE * INTERRUPTS_PER_TASKLET)

Allow for counting up to 10 seconds, so that we can do 0.1hz callbacks.

Referenced by pc104sg_bh_100Hz(), and setSoftTickers().

◆ MAX_TMSEC_SINCE_LAST_SYNC

#define MAX_TMSEC_SINCE_LAST_SYNC (5 * TMSECS_PER_SEC)

Values that are used to detect whether the bottom half tasklet has gotten out of sync with real-time.

Referenced by oneHzFunction().

◆ MSEC_PER_INTERRUPT

#define MSEC_PER_INTERRUPT (MSECS_PER_SEC / INTERRUPT_RATE)

number of milliseconds per interrupt

Referenced by get_msec_clock_resolution().

◆ my_isleap

#define my_isleap ( year ) ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))

Referenced by timespecToirig().

◆ PC104SG_SAMPLE_QUEUE_SIZE

#define PC104SG_SAMPLE_QUEUE_SIZE 16

Length of the circular buffer of output samples.

Referenced by oneHzFunction(), and pc104sg_open().

◆ REPO_REVISION

#define REPO_REVISION "unknown"

Referenced by pc104sg_init().

◆ SECS_PER_DAY

#define SECS_PER_DAY (SECS_PER_HOUR * 24)

Referenced by nidas::core::SampleClock::addSampleDate(), get_irig_time_nolock(), irigTotimespec(), irigTousec(), oneHzFunction(), setSoftTickers(), timespecToirig(), and nidas::dynld::isff::WisardMote::unpack10thSec().

◆ SECS_PER_HOUR

#define SECS_PER_HOUR (60 * 60)

macros borrowed from glibc/time functions

Referenced by timespecToirig().

◆ TMSEC_PER_INTERRUPT

#define TMSEC_PER_INTERRUPT (TMSECS_PER_SEC / INTERRUPT_RATE)

number of 1/10ths of milliseconds per interrupt

◆ TMSEC_PER_SOFT_TIC

#define TMSEC_PER_SOFT_TIC

Value:

(TMSEC_PER_INTERRUPT * \

INTERRUPTS_PER_TASKLET)

TMSEC_PER_INTERRUPT

#define TMSEC_PER_INTERRUPT

number of 1/10ths of milliseconds per interrupt

Definition pc104sg.c:172

INTERRUPTS_PER_TASKLET

#define INTERRUPTS_PER_TASKLET

We schedule the bottom-half tasklet after every INTERRUPTS_PER_TASKLET interrupts.

Definition pc104sg.c:178

Increment of the software clock on each schedule of the tasklet.

Referenced by checkSoftTicker(), pc104sg_bh_100Hz(), and setSoftTickers().

Enumeration Type Documentation

◆ clockAction

enum clockAction

What to do with the with the software clock and loop counter in the bottom-half tasklet.

Enumerator
RESET_COUNTERS
NO_ACTION

◆ clockState

enum clockState

Enumeration of the state of the software clock.

Enumerator
SYNCD_SET
UNSYNCD_SET

◆ notifyClients

enum notifyClients

Whether to notify callback clients if clockAction is RESET_COUNTERS.

Enumerator
NO_NOTIFY
NOTIFY_CLIENTS

Function Documentation

◆ checkSoftTicker()

static void checkSoftTicker	(	int	newClock,
		int	currClock,
		int	scale,
		int	notify )

static

Try to determine if our software clock and client callbacks are keeping up with real-time.

Other pc104 cards are receiving clock signals from this pc104sg card. If they want to do polling, or other periodic things, they register with this module for their callbacks to be called at a given rate by the 100Hz tasklet. We want to avoid missing a callback if at all possible.

It seems to happen, especially on vulcans, that a CPU card can miss one or more IRIG interrupts. When that happens, then one or more schedules of the bottom half tasklet are missed, which means that the software clock and the callbacks get behind.

This function compares the difference between the newClock value which was calculated from either the irig or unix clock, and currClock, which is the current software clock we provide to other modules. The difference is calculated as a number of 0.01 second delta-Ts.

This dT check is performed once a second.

If the clock difference is within limits of (IRIG_MAX_DT_DIFF / scale : IRIG_MIN_DT_DIFF / scale) then the pendingH100Hz counter is adjusted by the difference, so that the tasklet will be either scheduled more or less rapidly than 100 Hz for a period.

If the difference is negative, it is likely that a previous positive result was in error, or that spurious interrupts occurred. The latter doesn't seem to happen.

The hope is that in either case the software clock and callback loop counter get back in sync with the clock signals that were sent from the IRIG card to the other cards.

If the difference is outside those limits, then set clockAction is set to RESET_COUNTERS, so that the tasklet will reset the loop counter and the software clock the next time it is scheduled, and also call the resync callbacks of the clients, so that they could possibly resync their processing.

If the out-of-sync condition is caused by missed interrupts, or a temporary glitch in the irig clock, where it later recovers to be in sync with the output signals, this method should fix the problem.

Since we don't have any other details about the clock signals that were sent to other cards, we only have the value of the irig clock and unix clock to try to re-synchronize.

Another side issue arises when we are running without an IRIG source. This should only happen when bench testing. The pc104sg card still generates signals and interrupts, but they are based on an internal oscillator, which slowly drifts relative to the unix clock. In that case is is harder to determine what to do if a disagreement dTs is seen.

References board, clockStateString(), IRIG_MAX_DT_DIFF, IRIG_MIN_DT_DIFF, RESET_COUNTERS, TMSEC_PER_SOFT_TIC, and TMSECS_PER_DAY.

Referenced by oneHzFunction().

◆ clockStateString()

static const char * clockStateString ( void )

static

References board, SYNCD_SET, and UNSYNCD_SET.

Referenced by checkSoftTicker().

◆ counterRejam()

static int counterRejam ( void )

static

References writeDPRAM().

Referenced by pc104sg_init().

◆ disableAllInts()

static void disableAllInts ( void )

static

References board.

Referenced by pc104sg_cleanup(), and pc104sg_init().

◆ doCallbacklist()

static void doCallbacklist ( int rate )

inlinestatic

Invoke the callback functions for a given rate.

References board, and rate.

Referenced by pc104sg_bh_100Hz().

◆ doResyncCallbacks()

static void doResyncCallbacks ( void )

static

Invoke all resync callback functions.

References board, IRIG_NUM_RATES, and rate.

Referenced by pc104sg_bh_100Hz().

◆ enableHeartBeatInt()

static void enableHeartBeatInt ( void )

static

Enable heart beat interrupts.

References board, and resetHeartBeatLatch().

Referenced by pc104sg_init().

◆ EXPORT_SYMBOL() [1/6]

EXPORT_SYMBOL ( flush_irig_callbacks )

◆ EXPORT_SYMBOL() [2/6]

EXPORT_SYMBOL ( irig_clock_gettime )

◆ EXPORT_SYMBOL() [3/6]

EXPORT_SYMBOL ( ReadClock )

◆ EXPORT_SYMBOL() [4/6]

EXPORT_SYMBOL ( register_irig_callback )

◆ EXPORT_SYMBOL() [5/6]

EXPORT_SYMBOL ( TMsecClock )

◆ EXPORT_SYMBOL() [6/6]

EXPORT_SYMBOL ( unregister_irig_callback )

◆ flush_irig_callbacks()

int flush_irig_callbacks ( void )

References board.

Referenced by close_ports(), ncar_a2d_cleanup(), resetBoard(), and stopBoard().

◆ free_callbacks()

static void free_callbacks ( void )

static

Cleanup function that un-registers all callbacks.

References board, handlePendingCallbacks(), and IRIG_NUM_RATES.

Referenced by pc104sg_cleanup().

◆ get_irig_time_nolock()

static void get_irig_time_nolock ( struct irigTime * ti )

static

Get value of on-board clock.

References board, getTimeRegisters(), irigTotimespec(), NSECS_PER_TMSEC, SECS_PER_DAY, and TMSECS_PER_SEC.

Referenced by get_irig_timespec_nolock(), irig_clock_gettime(), and pc104sg_ioctl().

◆ get_irig_timespec_nolock()

static void get_irig_timespec_nolock ( thiskernel_timespec_t * ts )

static

References get_irig_time_nolock(), and irigTotimespec().

Referenced by pc104sg_init(), and pc104sg_isr().

◆ get_msec_clock_resolution()

int get_msec_clock_resolution ( )

References MSEC_PER_INTERRUPT.

◆ getRequestedDPRAM()

static void getRequestedDPRAM ( unsigned char * val )

inlinestatic

References board.

Referenced by requestExtendedStatus().

◆ getTimeRegisters()

static void getTimeRegisters	(	struct irigTime *	ti,
		int	offset )

static

Read time from the registers.

Set offset to 0 to read main clock. Set offset to 0x10 to read time of external pulse.

Data are stored in BCD form as 4 byte niblets, containing ones, tens or hundreds value for the respective time fields.

Called by: get_irig_time_nolock(&ti) from the ISR ioctls, from user space irig_clock_gettime(struct timespec* tp) other modules

Since reading the Usec1_Nsec100 value latches the other digits, all these calls hold a spin_lock before calling getTimeRegisters().

References board, and StaticYear.

Referenced by get_irig_time_nolock().

◆ getTimeUsec()

int getTimeUsec ( )

Read sub-second time fields from the card, return microseconds.

May be useful for watching-the-clock when debugging.

References board, and USECS_PER_MSEC.

◆ handlePendingCallbacks()

static void handlePendingCallbacks ( void )

static

Handle pending adds and removes of callbacks from the active list for the appropriate rate.

References board.

Referenced by free_callbacks(), gpio_mm_timer_bottom_half(), and pc104sg_bh_100Hz().

◆ irig_clock_gettime()

void irig_clock_gettime ( thiskernel_timespec_t * tp )

This function is available for use by external modules.

Note that it disables interrupts.

References board, get_irig_time_nolock(), and irigTotimespec().

◆ irigTotimespec()

static void irigTotimespec	(	const struct irigTime *	ti,
		thiskernel_timespec_t *	ts )

static

Convert a struct irigTime into a thiskernel_timespec_t.

References LEAPS_THRU_END_OF, NSECS_PER_MSEC, NSECS_PER_USEC, and SECS_PER_DAY.

Referenced by get_irig_time_nolock(), get_irig_timespec_nolock(), irig_clock_gettime(), and irigTotimeval32().

◆ irigTotimeval32()

static void irigTotimeval32	(	const struct irigTime *	ti,
		struct timeval32 *	tv )

static

Convert a struct irigTime into a struct timeval32.

Not 2038 compatible.

References irigTotimespec(), and NSECS_PER_USEC.

Referenced by pc104sg_ioctl().

◆ irigTousec()

static int64_t irigTousec ( const struct irigTime * ti )

static

Convert a struct irigTime to a int64_t time in microseconds.

References LEAPS_THRU_END_OF, SECS_PER_DAY, USECS_PER_MSEC, and USECS_PER_SEC.

Referenced by pc104sg_ioctl().

◆ MODULE_AUTHOR()

MODULE_AUTHOR ( "Gordon Maclean <maclean@ucar.edu>" )

◆ MODULE_DESCRIPTION()

MODULE_DESCRIPTION ( "PC104-SG IRIG Card Driver" )

◆ module_exit()

module_exit ( pc104sg_cleanup )

◆ module_init()

module_init ( pc104sg_init )

◆ MODULE_LICENSE()

MODULE_LICENSE ( "GPL" )

◆ module_param() [1/3]

module_param	(	A2DClockFreq	,
		int	,
		0	)

◆ module_param() [2/3]

module_param	(	IoPort	,
		int	,
		0	)

◆ module_param() [3/3]

module_param	(	Irq	,
		int	,
		0	)

◆ MODULE_VERSION()

MODULE_VERSION ( REPO_REVISION )

◆ oneHzFunction()

static void oneHzFunction ( void * ptr )

static

◆ pc104sg_bh_100Hz()

static void pc104sg_bh_100Hz ( unsigned long dev )

static

Tasklet called 100 times/second in softare interrupt context.

This tasklet maintains the software clock and performs requested regular callbacks.

References board, CLOCK_STATUS_NOSYNC, CLOCK_SYNC_NOT_OK, doCallbacklist(), doResyncCallbacks(), handlePendingCallbacks(), IRIG_0_1_HZ, IRIG_100_HZ, IRIG_10_HZ, IRIG_1_HZ, IRIG_20_HZ, IRIG_25_HZ, IRIG_2_HZ, IRIG_4_HZ, IRIG_50_HZ, IRIG_5_HZ, MAX_TASKLET_COUNTER, NO_ACTION, NO_NOTIFY, NOTIFY_CLIENTS, ReadClock, RESET_COUNTERS, setSoftTickers(), SYNCD_SET, TMSEC_PER_SOFT_TIC, TMsecClock, TMSECS_PER_DAY, and UNSYNCD_SET.

Referenced by pc104sg_init().

◆ pc104sg_cleanup()

static void pc104sg_cleanup ( void )

static

References board, disableAllInts(), free_callbacks(), and unregister_irig_callback().

Referenced by pc104sg_init().

◆ pc104sg_init()

static int __init pc104sg_init ( void )

static

◆ pc104sg_ioctl()

static long pc104sg_ioctl	(	struct file *	filp,
		unsigned int	cmd,
		unsigned long	arg )

static

References board, get_irig_time_nolock(), IRIG_GET_CLOCK, IRIG_GET_CLOCK64, IRIG_GET_STATUS, IRIG_IOC_MAGIC, IRIG_SET_CLOCK, IRIG_SET_CLOCK64, irigTotimeval32(), irigTousec(), len, setIRIGclock(), and USECS_PER_SEC.

◆ pc104sg_isr()

static irqreturn_t pc104sg_isr	(	int	irq,
		void *	callbackPtr )

static

References board, CLOCK_SYNC_NOT_OK, get_irig_timespec_nolock(), requestExtendedStatus(), RESET_COUNTERS, and resetHeartBeatLatch().

Referenced by pc104sg_init().

◆ pc104sg_open()

static int pc104sg_open	(	struct inode *	inode,
		struct file *	filp )

static

References board, PC104SG_SAMPLE_QUEUE_SIZE, realloc_dsm_circ_buf(), irig_device::rwaitq, and irig_device::samples.

◆ pc104sg_poll()

static unsigned int pc104sg_poll	(	struct file *	filp,
		poll_table *	wait )

static

References irig_device::read_state, irig_device::rwaitq, and irig_device::samples.

◆ pc104sg_read()

static ssize_t pc104sg_read	(	struct file *	filp,
		char __user *	buf,
		size_t	count,
		loff_t *	f_pos )

static

References nidas_circbuf_read(), irig_device::read_state, irig_device::rwaitq, and irig_device::samples.

◆ pc104sg_release()

static int pc104sg_release	(	struct inode *	inode,
		struct file *	filp )

static

References board, free_dsm_circ_buf(), and irig_device::samples.

◆ readDPRAM()

static int readDPRAM	(	unsigned char	addr,
		unsigned char *	val )

static

Read dual port RAM.

Parameters

addr	dual-port RAM address to read

Called by (all by module init) setHeartBeatOutput(int rate) setPrimarySyncReference(unsigned char val) setRate2Output(int rate) init

References board.

Referenced by setHeartBeatOutput(), setPrimarySyncReference(), and setRate2Output().

◆ register_irig_callback()

struct irig_callback * register_irig_callback	(	irig_callback_func *	callback,
		irig_callback_func *	resync,
		enum irigClockRates	rate,
		void *	privateData,
		int *	errp )

Module function that allows other modules to register their callback function to be called at the given rate.

register_irig_callback can be called at anytime. Note that register_irig_callback and unregister_irig_callback do not alter the active callback lists but instead add requests to a group of pending requests. The loop function, pc104sg_bh_100Hz, does not do any locking on the active list. Once on each pass through the loop it acts on the pending requests.

References board, IRIG_NUM_RATES, and rate.

Referenced by mesa_ioctl(), pc104sg_init(), resetBoard(), and waitFor1PPS().

◆ requestDPRAM()

static void requestDPRAM ( unsigned char addr )

inlinestatic

The requestDPRAM()/getRequestedDPRAM() pair allow us to break a dual-port read into two parts.

This is used by the interrupt service routine. Each entry into the ISR reads the value ready from the previous request, then issues another request. In this way, the necessary delay between requesting dual-port RAM and actually getting the value happens between interrupts, rather than by a busy wait.

If non ISR code wants to access dual ported RAM, it should do the following, which prevents the ISR from accessing it, without disabling interrupts while accessing the DP ram: spin_lock_irqsave(&board.lock, flags); board.DP_RamExtStatusEnabled = 0; board.DP_RamExtStatusRequested = 0; spin_unlock_irqrestore(&board.lock, flags); Then access the RAM, for example: setYear(n); ... Then re-enable access by the ISR spin_lock_irqsave(&board.lock, flags); board.DP_RamExtStatusEnabled = 1; spin_unlock_irqrestore(&board.lock, flags);

References board.

Referenced by pc104sg_init(), and requestExtendedStatus().

◆ requestExtendedStatus()

static void requestExtendedStatus ( void )

inlinestatic

References board, getRequestedDPRAM(), and requestDPRAM().

Referenced by pc104sg_isr().

◆ resetHeartBeatLatch()

static void resetHeartBeatLatch ( void )

inlinestatic

After receiving a heartbeat interrupt, one must reset the heartbeat latch in the handler.

Otherwise either of two bad things will happen, depending on how the system is configured to handle interrupt levels:

the interrupt handler will be called again immediately after it returns, resulting in a system lockup.
you won't get any further interrupts.

References board.

Referenced by enableHeartBeatInt(), and pc104sg_isr().

◆ resetMatchLatch()

static void resetMatchLatch ( void )

inlinestatic

After receiving a match interrupt, one must reset the match flag in order to receive further interrupts.

References board.

◆ setHeartBeatOutput()

static int setHeartBeatOutput ( int rate )

static

References rate, readDPRAM(), and writeDPRAM().

Referenced by pc104sg_init().

◆ setIRIGclock()

static long setIRIGclock ( int64_t usec )

static

Set the IRIG hardware clock fields in DPRAM.

Interrupts are disabled when writing to DPRAM.

References board, NSECS_PER_USEC, RESET_COUNTERS, setMajorTime(), setYear(), timespecToirig(), and USECS_PER_SEC.

Referenced by pc104sg_ioctl().

◆ setMajorTime()

static int setMajorTime ( struct irigTime * ti )

static

The major time consists of the day-of-year, hour, minute and second fields.

Ideally they are set via the time-code input, but this function can be used if there is no time-code.

The sub-second values are determined from the PPS input, and I see no way to change them if there is no PPS or time-code.

References board, setYear(), and writeDPRAM().

Referenced by pc104sg_init(), and setIRIGclock().

◆ setPrimarySyncReference()

static int setPrimarySyncReference ( unsigned char val )

static

Set the primary time reference.

Parameters

val	0=PPS is primary time reference, 1=time code is primary

References readDPRAM(), and writeDPRAM().

Referenced by pc104sg_init().

◆ setRate2Output()

int setRate2Output ( int rate )

References rate, readDPRAM(), and writeDPRAM().

Referenced by pc104sg_init().

◆ setSoftTickers()

static int setSoftTickers	(	const thiskernel_timespec_t *	ts,
		int	round )

static

Set the software clock and the tasklet loop counter based on a clock value in a timespec struct.

This function is called by the bottom half tasklet if clockAction==RESET_COUNTERS.

Note: we are seeing sub-millisecond agreement between the IRIG register clocks and the system clock (conditioned by NTP), with a GPS-conditioned timeserver providing the IRIG and NTP references.

This function sets TMsecClockTicker from the timespec.

References board, MAX_TASKLET_COUNTER, NSECS_PER_TMSEC, SECS_PER_DAY, TMSEC_PER_SOFT_TIC, TMSECS_PER_DAY, and TMSECS_PER_SEC.

Referenced by pc104sg_bh_100Hz().

◆ setTimeCodeInputSelect()

static int setTimeCodeInputSelect ( unsigned char val )

static

References writeDPRAM().

Referenced by pc104sg_init().

◆ setYear()

static int setYear ( int val )

static

set the year fields in Dual Port RAM.

References StaticYear, and writeDPRAM().

Referenced by setIRIGclock(), and setMajorTime().

◆ timespecToirig()

static void timespecToirig	(	const thiskernel_timespec_t *	ts,
		struct irigTime *	ti )

static

Break a timespec into the fields of a struct irigTime.

This uses some code from glibc/time routines.

References LEAPS_THRU_END_OF, my_isleap, NSECS_PER_MSEC, NSECS_PER_USEC, SECS_PER_DAY, and SECS_PER_HOUR.

Referenced by pc104sg_init(), and setIRIGclock().

◆ unregister_irig_callback()

int unregister_irig_callback ( struct irig_callback * cb )

Modules call this function to dequeue their callbacks.

A callback function can cancel itself, or any other callback function.

Returns: 0: OK, but callback might be called once more. Do flush_irig_callback to wait until it is definitely finished. <0: errno

References board, and IRIG_NUM_RATES.

Referenced by close_ports(), mesa_ioctl(), ncar_a2d_cleanup(), pc104sg_cleanup(), resetBoard(), stopBoard(), and waitFor1PPS().

◆ writeDPRAM()

static int writeDPRAM	(	unsigned char	addr,
		unsigned char	value )

static

Set a value in dual port RAM.

Parameters

addr	dual-port RAM address to write Note that it disables interrupts.

Called by: setHeartBeatOutput(int rate) setPrimarySyncReference(unsigned char val) setTimeCodeInputSelect(unsigned char val) setRate2Output(int rate) counterRejam(void) module init setYear(int val) setMajorTime(struct irigTime* ti) ioctl

References board.

Referenced by counterRejam(), setHeartBeatOutput(), setMajorTime(), setPrimarySyncReference(), setRate2Output(), setTimeCodeInputSelect(), and setYear().

Variable Documentation

◆ A2DClockFreq

unsigned int A2DClockFreq = 10000

static

Referenced by pc104sg_init().

◆ board

◆ driver_name

char* driver_name = "pc104sg"

static

Referenced by pc104sg_init().

◆ IoPort

unsigned int IoPort = 0x2a0

static

Referenced by pc104sg_init().

◆ Irq

unsigned int Irq = 10

static

Referenced by pc104sg_init().

◆ pc104sg_fops

struct file_operations pc104sg_fops

static

Initial value:

= {
        .owner = THIS_MODULE,
        .read = pc104sg_read,
        .poll = pc104sg_poll,
        .open = pc104sg_open,
        .unlocked_ioctl = pc104sg_ioctl,
        .release = pc104sg_release,
        .llseek  = no_llseek,
}

Referenced by pc104sg_init().

◆ ReadClock

int ReadClock = 0

Index into TMsecClock of the value to be read.

Referenced by pc104sg_bh_100Hz(), and pc104sg_init().

◆ StaticYear

int StaticYear

static

The year field in the pc104sg time registers ranges from 0-99, so we keep track of the century.

Referenced by getTimeRegisters(), and setYear().

◆ TMsecClock

int TMsecClock[2] = { 0, 0 }

A toggle buffer containing the current clock value in tenths of milliseconds since UTC midnight.

Referenced by pc104sg_bh_100Hz(), and pc104sg_init().

Classes

Macros

Enumerations

Functions

Variables

Macro Definition Documentation

◆ CALLBACK_POOL_SIZE

◆ DIV

◆ INTERRUPT_RATE

◆ INTERRUPTS_PER_TASKLET

◆ IRQF_SHARED

◆ LEAPS_THRU_END_OF

◆ MAX_TASKLET_COUNTER

◆ MAX_TMSEC_SINCE_LAST_SYNC

◆ MSEC_PER_INTERRUPT

◆ my_isleap

◆ PC104SG_SAMPLE_QUEUE_SIZE

◆ REPO_REVISION

◆ SECS_PER_DAY

◆ SECS_PER_HOUR

◆ TMSEC_PER_INTERRUPT

◆ TMSEC_PER_SOFT_TIC

Enumeration Type Documentation

◆ clockAction

◆ clockState

◆ notifyClients

Function Documentation

◆ checkSoftTicker()

◆ clockStateString()

◆ counterRejam()

◆ disableAllInts()

◆ doCallbacklist()

◆ doResyncCallbacks()

◆ enableHeartBeatInt()

◆ EXPORT_SYMBOL() [1/6]

◆ EXPORT_SYMBOL() [2/6]

◆ EXPORT_SYMBOL() [3/6]

◆ EXPORT_SYMBOL() [4/6]

◆ EXPORT_SYMBOL() [5/6]

◆ EXPORT_SYMBOL() [6/6]

◆ flush_irig_callbacks()

◆ free_callbacks()

◆ get_irig_time_nolock()

◆ get_irig_timespec_nolock()

◆ get_msec_clock_resolution()

◆ getRequestedDPRAM()

◆ getTimeRegisters()

◆ getTimeUsec()

◆ handlePendingCallbacks()

◆ irig_clock_gettime()

◆ irigTotimespec()

◆ irigTotimeval32()

◆ irigTousec()

◆ MODULE_AUTHOR()

◆ MODULE_DESCRIPTION()

◆ module_exit()

◆ module_init()

◆ MODULE_LICENSE()

◆ module_param() [1/3]

◆ module_param() [2/3]

◆ module_param() [3/3]

◆ MODULE_VERSION()

◆ oneHzFunction()

◆ pc104sg_bh_100Hz()

◆ pc104sg_cleanup()

◆ pc104sg_init()

◆ pc104sg_ioctl()

◆ pc104sg_isr()

◆ pc104sg_open()

◆ pc104sg_poll()

◆ pc104sg_read()

◆ pc104sg_release()

◆ readDPRAM()

◆ register_irig_callback()

◆ requestDPRAM()

◆ requestExtendedStatus()

◆ resetHeartBeatLatch()

◆ resetMatchLatch()

◆ setHeartBeatOutput()

◆ setIRIGclock()