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: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index b431d83..98d4012 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -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 @@
* 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 @@
* 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 @@
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 @@
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 @@
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;
-
- spin_lock_irq(&pps_idr_lock);
- pps = idr_find(&pps_idr, source);
-
- if (!pps) {
- BUG();
- spin_unlock_irq(&pps_idr_lock);
- return;
- }
- spin_unlock_irq(&pps_idr_lock);
+ unsigned int id = pps->id;
pps_unregister_cdev(pps);
- pps_put_source(pps);
+
+ spin_lock_irq(&pps_idr_lock);
+ idr_remove(&pps_idr, pps->id);
+ spin_unlock_irq(&pps_idr_lock);
+
+ 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 @@
* 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 @@
/* 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 @@
/* 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 @@
/* 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 @@
}
spin_unlock_irqrestore(&pps->lock, flags);
-
- /* Now we can release the PPS source for (possible) deregistration */
- pps_put_source(pps);
}
EXPORT_SYMBOL(pps_event);