Commit 5e196d34 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Linus Torvalds
Browse files

pps: access pps device by direct pointer 



Using device index as a pointer needs some unnecessary work to be done
every time the pointer is needed (in irq handler for example).  Using a
direct pointer is much more easy (and safe as well).

Signed-off-by: default avatarAlexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: default avatarRodolfo Giometti <giometti@linux.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6f4229b5

drivers/pps/clients/pps-ktimer.c

+13 −17
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ 
 * Global variables

 */



static int source;

static struct pps_device *pps;

static struct timer_list ktimer;



/*
@@ -47,7 +47,7 @@ static void pps_ktimer_event(unsigned long ptr) 


	pr_info("PPS event at %lu\n", jiffies);



	pps_event(source, &ts, PPS_CAPTUREASSERT, NULL);

	pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);



	mod_timer(&ktimer, jiffies + HZ);

}
@@ -56,12 +56,11 @@ static void pps_ktimer_event(unsigned long ptr) 
 * The echo function

 */



static void pps_ktimer_echo(int source, int event, void *data)

static void pps_ktimer_echo(struct pps_device *pps, int event, void *data)

{

	pr_info("echo %s %s for source %d\n",

	dev_info(pps->dev, "echo %s %s\n",

		event & PPS_CAPTUREASSERT ? "assert" : "",

		event & PPS_CAPTURECLEAR ? "clear" : "",

		source);

		event & PPS_CAPTURECLEAR ? "clear" : "");

}



/*
@@ -84,28 +83,25 @@ static struct pps_source_info pps_ktimer_info = { 


static void __exit pps_ktimer_exit(void)

{

	del_timer_sync(&ktimer);

	pps_unregister_source(source);

	dev_info(pps->dev, "ktimer PPS source unregistered\n");



	pr_info("ktimer PPS source unregistered\n");

	del_timer_sync(&ktimer);

	pps_unregister_source(pps);

}



static int __init pps_ktimer_init(void)

{

	int ret;



	ret = pps_register_source(&pps_ktimer_info,

	pps = pps_register_source(&pps_ktimer_info,

				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);

	if (ret < 0) {

	if (pps == NULL) {

		printk(KERN_ERR "cannot register ktimer source\n");

		return ret;

		return -ENOMEM;

	}

	source = ret;



	setup_timer(&ktimer, pps_ktimer_event, 0);

	mod_timer(&ktimer, jiffies + HZ);



	pr_info("ktimer PPS source registered at %d\n", source);

	dev_info(pps->dev, "ktimer PPS source registered\n");



	return 0;

}

drivers/pps/clients/pps-ldisc.c

+26 −15
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ 
static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,

				struct pps_event_time *ts)

{

	int id = (long)tty->disc_data;

	struct pps_device *pps = (struct pps_device *)tty->disc_data;

	struct pps_event_time __ts;



	/* First of all we get the time stamp... */
@@ -39,12 +39,14 @@ static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status, 
	if (!ts)	/* No. Do it ourself! */

		ts = &__ts;



	BUG_ON(pps == NULL);



	/* Now do the PPS event report */

	pps_event(id, ts, status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR,

			NULL);

	pps_event(pps, ts, status ? PPS_CAPTUREASSERT :

			PPS_CAPTURECLEAR, NULL);



	pr_debug("PPS %s at %lu on source #%d\n",

			status ? "assert" : "clear", jiffies, id);

	dev_dbg(pps->dev, "PPS %s at %lu\n",

			status ? "assert" : "clear", jiffies);

}



static int (*alias_n_tty_open)(struct tty_struct *tty);
@@ -54,6 +56,7 @@ 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;
@@ -64,34 +67,42 @@ static int pps_tty_open(struct tty_struct *tty) 
			PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \

			PPS_CANWAIT | PPS_TSFMT_TSPEC;



	ret = pps_register_source(&info, PPS_CAPTUREBOTH | \

	pps = pps_register_source(&info, PPS_CAPTUREBOTH | \

				PPS_OFFSETASSERT | PPS_OFFSETCLEAR);

	if (ret < 0) {

	if (pps == NULL) {

		pr_err("cannot register PPS source \"%s\"\n", info.path);

		return ret;

		return -ENOMEM;

	}

	tty->disc_data = (void *)(long)ret;

	tty->disc_data = pps;



	/* Should open N_TTY ldisc too */

	ret = alias_n_tty_open(tty);

	if (ret < 0)

		pps_unregister_source((long)tty->disc_data);

	if (ret < 0) {

		pr_err("cannot open tty ldisc \"%s\"\n", info.path);

		goto err_unregister;

	}



	pr_info("PPS source #%d \"%s\" added\n", ret, info.path);

	dev_info(pps->dev, "source \"%s\" added\n", info.path);



	return 0;



err_unregister:

	tty->disc_data = NULL;

	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)

{

	int id = (long)tty->disc_data;

	struct pps_device *pps = (struct pps_device *)tty->disc_data;



	pps_unregister_source(id);

	alias_n_tty_close(tty);



	pr_info("PPS source #%d removed\n", id);

	tty->disc_data = NULL;

	dev_info(pps->dev, "removed\n");

	pps_unregister_source(pps);

}



static struct tty_ldisc_ops pps_ldisc_ops;

drivers/pps/kapi.c

+28 −96
Original line number Diff line number Diff line
@@ -32,11 +32,11 @@ 
#include <linux/slab.h>



/*

 * Global variables

 * Local variables

 */



DEFINE_SPINLOCK(pps_idr_lock);

DEFINE_IDR(pps_idr);

static DEFINE_SPINLOCK(pps_idr_lock);

static DEFINE_IDR(pps_idr);



/*

 * Local functions
@@ -60,60 +60,6 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) 
 * Exported functions

 */



/* pps_get_source - find a PPS source

 * @source: the PPS source ID.

 *

 * This function is used to find an already registered PPS source into the

 * system.

 *

 * The function returns NULL if found nothing, otherwise it returns a pointer

 * to the PPS source data struct (the refcounter is incremented by 1).

 */



struct pps_device *pps_get_source(int source)

{

	struct pps_device *pps;

	unsigned long flags;



	spin_lock_irqsave(&pps_idr_lock, flags);



	pps = idr_find(&pps_idr, source);

	if (pps != NULL)

		atomic_inc(&pps->usage);



	spin_unlock_irqrestore(&pps_idr_lock, flags);



	return pps;

}



/* pps_put_source - free the PPS source data

 * @pps: a pointer to the PPS source.

 *

 * This function is used to free a PPS data struct if its refcount is 0.

 */



void pps_put_source(struct pps_device *pps)

{

	unsigned long flags;



	spin_lock_irqsave(&pps_idr_lock, flags);

	BUG_ON(atomic_read(&pps->usage) == 0);



	if (!atomic_dec_and_test(&pps->usage)) {

		pps = NULL;

		goto exit;

	}



	/* No more reference to the PPS source. We can safely remove the

	 * PPS data struct.

	 */

	idr_remove(&pps_idr, pps->id);



exit:

	spin_unlock_irqrestore(&pps_idr_lock, flags);

	kfree(pps);

}



/* 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
@@ -122,10 +68,11 @@ exit: 
 * 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 source ID.

 * The function returns, in case of success, the PPS device. Otherwise NULL.

 */



int pps_register_source(struct pps_source_info *info, int default_params)

struct pps_device *pps_register_source(struct pps_source_info *info,

		int default_params)

{

	struct pps_device *pps;

	int id;
@@ -168,7 +115,6 @@ int pps_register_source(struct pps_source_info *info, int default_params) 


	init_waitqueue_head(&pps->queue);

	spin_lock_init(&pps->lock);

	atomic_set(&pps->usage, 1);



	/* Get new ID for the new PPS source */

	if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) {
@@ -211,7 +157,7 @@ int pps_register_source(struct pps_source_info *info, int default_params) 


	pr_info("new PPS source %s at ID %d\n", info->name, id);



	return id;

	return pps;



free_idr:

	spin_lock_irq(&pps_idr_lock);
@@ -224,38 +170,33 @@ kfree_pps: 
pps_register_source_exit:

	printk(KERN_ERR "pps: %s: unable to register source\n", info->name);



	return err;

	return NULL;

}

EXPORT_SYMBOL(pps_register_source);



/* pps_unregister_source - remove a PPS source from the system

 * @source: the PPS source ID

 * @pps: the PPS source

 *

 * This function is used to remove a previously registered PPS source from

 * the system.

 */



void pps_unregister_source(int source)

void pps_unregister_source(struct pps_device *pps)

{

	struct pps_device *pps;

	unsigned int id = pps->id;



	spin_lock_irq(&pps_idr_lock);

	pps = idr_find(&pps_idr, source);

	pps_unregister_cdev(pps);



	if (!pps) {

		BUG();

		spin_unlock_irq(&pps_idr_lock);

		return;

	}

	spin_lock_irq(&pps_idr_lock);

	idr_remove(&pps_idr, pps->id);

	spin_unlock_irq(&pps_idr_lock);



	pps_unregister_cdev(pps);

	pps_put_source(pps);

	kfree(pps);

}

EXPORT_SYMBOL(pps_unregister_source);



/* pps_event - register a PPS event into the system

 * @source: the PPS source ID

 * @pps: the PPS device

 * @ts: the event timestamp

 * @event: the event type

 * @data: userdef pointer
@@ -263,30 +204,24 @@ EXPORT_SYMBOL(pps_unregister_source); 
 * 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 source it will be called

 * If an echo function is associated with the PPS device it will be called

 * as:

 *	pps->info.echo(source, event, data);

 *	pps->info.echo(pps, event, data);

 */



void pps_event(int source, struct pps_event_time *ts, int event, void *data)

void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,

		void *data)

{

	struct pps_device *pps;

	unsigned long flags;

	int captured = 0;

	struct pps_ktime ts_real;



	if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {

		printk(KERN_ERR "pps: unknown event (%x) for source %d\n",

			event, source);

		dev_err(pps->dev, "unknown event (%x)\n", event);

		return;

	}



	pps = pps_get_source(source);

	if (!pps)

		return;



	pr_debug("PPS event on source %d at %ld.%09ld\n",

			pps->id, ts->ts_real.tv_sec, ts->ts_real.tv_nsec);

	dev_dbg(pps->dev, "PPS event at %ld.%09ld\n",

			ts->ts_real.tv_sec, ts->ts_real.tv_nsec);



	timespec_to_pps_ktime(&ts_real, ts->ts_real);
@@ -294,7 +229,7 @@ void pps_event(int source, struct pps_event_time *ts, int event, void *data) 


	/* Must call the echo function? */

	if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))

		pps->info.echo(source, event, data);

		pps->info.echo(pps, event, data);



	/* Check the event */

	pps->current_mode = pps->params.mode;
@@ -308,8 +243,8 @@ void pps_event(int source, struct pps_event_time *ts, int event, void *data) 
		/* Save the time stamp */

		pps->assert_tu = ts_real;

		pps->assert_sequence++;

		pr_debug("capture assert seq #%u for source %d\n",

			pps->assert_sequence, source);

		dev_dbg(pps->dev, "capture assert seq #%u\n",

			pps->assert_sequence);



		captured = ~0;

	}
@@ -323,8 +258,8 @@ void pps_event(int source, struct pps_event_time *ts, int event, void *data) 
		/* Save the time stamp */

		pps->clear_tu = ts_real;

		pps->clear_sequence++;

		pr_debug("capture clear seq #%u for source %d\n",

			pps->clear_sequence, source);

		dev_dbg(pps->dev, "capture clear seq #%u\n",

			pps->clear_sequence);



		captured = ~0;

	}
@@ -338,8 +273,5 @@ void pps_event(int source, struct pps_event_time *ts, int event, void *data) 
	}



	spin_unlock_irqrestore(&pps->lock, flags);



	/* Now we can release the PPS source for (possible) deregistration */

	pps_put_source(pps);

}

EXPORT_SYMBOL(pps_event);

drivers/pps/pps.c

+6 −16
Original line number Diff line number Diff line
@@ -204,12 +204,6 @@ static int pps_cdev_open(struct inode *inode, struct file *file) 
{

	struct pps_device *pps = container_of(inode->i_cdev,

						struct pps_device, cdev);

	int found;



	found = pps_get_source(pps->id) != 0;

	if (!found)

		return -ENODEV;



	file->private_data = pps;



	return 0;
@@ -217,11 +211,6 @@ static int pps_cdev_open(struct inode *inode, struct file *file) 


static int pps_cdev_release(struct inode *inode, struct file *file)

{

	struct pps_device *pps = file->private_data;



	/* Free the PPS source and wake up (possible) deregistration */

	pps_put_source(pps);



	return 0;

}
@@ -242,22 +231,23 @@ static const struct file_operations pps_cdev_fops = { 
int pps_register_cdev(struct pps_device *pps)

{

	int err;

	dev_t devt;



	devt = MKDEV(MAJOR(pps_devt), pps->id);



	pps->devno = MKDEV(MAJOR(pps_devt), pps->id);

	cdev_init(&pps->cdev, &pps_cdev_fops);

	pps->cdev.owner = pps->info.owner;



	err = cdev_add(&pps->cdev, pps->devno, 1);

	err = cdev_add(&pps->cdev, devt, 1);

	if (err) {

		printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",

				pps->info.name, MAJOR(pps_devt), pps->id);

		return err;

	}

	pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL,

	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,

							"pps%d", pps->id);

	if (IS_ERR(pps->dev))

		goto del_cdev;

	dev_set_drvdata(pps->dev, pps);



	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,

			MAJOR(pps_devt), pps->id);
@@ -272,7 +262,7 @@ del_cdev: 


void pps_unregister_cdev(struct pps_device *pps)

{

	device_destroy(pps_class, pps->devno);

	device_destroy(pps_class, pps->dev->devt);

	cdev_del(&pps->cdev);

}

include/linux/pps_kernel.h

+9 −14
Original line number Diff line number Diff line
@@ -31,13 +31,16 @@ 
 * Global defines

 */



struct pps_device;



/* The specific PPS source info */

struct pps_source_info {

	char name[PPS_MAX_NAME_LEN];		/* simbolic name */

	char path[PPS_MAX_NAME_LEN];		/* path of connected device */

	int mode;				/* PPS's allowed mode */



	void (*echo)(int source, int event, void *data); /* PPS echo function */

	void (*echo)(struct pps_device *pps,

			int event, void *data);	/* PPS echo function */



	struct module *owner;

	struct device *dev;
@@ -65,35 +68,27 @@ struct pps_device { 
	unsigned int id;			/* PPS source unique ID */

	struct cdev cdev;

	struct device *dev;

	int devno;

	struct fasync_struct *async_queue;	/* fasync method */

	spinlock_t lock;



	atomic_t usage;				/* usage count */

};



/*

 * Global variables

 */



extern spinlock_t pps_idr_lock;

extern struct idr pps_idr;



extern struct device_attribute pps_attrs[];



/*

 * Exported functions

 */



struct pps_device *pps_get_source(int source);

extern void pps_put_source(struct pps_device *pps);

extern int pps_register_source(struct pps_source_info *info,

				int default_params);

extern void pps_unregister_source(int source);

extern struct pps_device *pps_register_source(

		struct pps_source_info *info, int default_params);

extern void pps_unregister_source(struct pps_device *pps);

extern int pps_register_cdev(struct pps_device *pps);

extern void pps_unregister_cdev(struct pps_device *pps);

extern void pps_event(int source, struct pps_event_time *ts, int event,

		void *data);

extern void pps_event(struct pps_device *pps,

		struct pps_event_time *ts, int event, void *data);



static inline void timespec_to_pps_ktime(struct pps_ktime *kt,

		struct timespec ts)

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