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authorAlexander Gordeev <lasaine@lvk.cs.msu.su>2011-01-12 17:00:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 08:03:21 -0800
commit717c033669ed3ceaee8df57d4562fafcc1a6267a (patch)
tree892e922c08b5f5eee8fbe7c8e0fdc774db660c67 /drivers/pps
parente2c18e49a0d4f822ffc29fb4958943beb1ff08b7 (diff)
downloadtalos-obmc-linux-717c033669ed3ceaee8df57d4562fafcc1a6267a.tar.gz
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pps: add kernel consumer support
Add an optional feature of PPSAPI, kernel consumer support, which uses the added hardpps() function. 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>
Diffstat (limited to 'drivers/pps')
-rw-r--r--drivers/pps/Makefile1
-rw-r--r--drivers/pps/kapi.c6
-rw-r--r--drivers/pps/kc.c122
-rw-r--r--drivers/pps/kc.h46
-rw-r--r--drivers/pps/pps.c38
5 files changed, 212 insertions, 1 deletions
diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile
index 98960ddd3188..77c23457b739 100644
--- a/drivers/pps/Makefile
+++ b/drivers/pps/Makefile
@@ -3,6 +3,7 @@
#
pps_core-y := pps.o kapi.o sysfs.o
+pps_core-$(CONFIG_NTP_PPS) += kc.o
obj-$(CONFIG_PPS) := pps_core.o
obj-y += clients/
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index ebf33746c37c..cba1b43f7519 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -26,11 +26,14 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/time.h>
+#include <linux/timex.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/pps_kernel.h>
#include <linux/slab.h>
+#include "kc.h"
+
/*
* Local functions
*/
@@ -139,6 +142,7 @@ EXPORT_SYMBOL(pps_register_source);
void pps_unregister_source(struct pps_device *pps)
{
+ pps_kc_remove(pps);
pps_unregister_cdev(pps);
/* don't have to kfree(pps) here because it will be done on
@@ -211,6 +215,8 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
captured = ~0;
}
+ pps_kc_event(pps, ts, event);
+
/* Wake up if captured something */
if (captured) {
pps->last_ev++;
diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c
new file mode 100644
index 000000000000..079e930b1938
--- /dev/null
+++ b/drivers/pps/kc.c
@@ -0,0 +1,122 @@
+/*
+ * PPS kernel consumer API
+ *
+ * Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/pps_kernel.h>
+
+#include "kc.h"
+
+/*
+ * Global variables
+ */
+
+/* state variables to bind kernel consumer */
+DEFINE_SPINLOCK(pps_kc_hardpps_lock);
+/* PPS API (RFC 2783): current source and mode for kernel consumer */
+struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */
+int pps_kc_hardpps_mode; /* mode bits for kernel consumer */
+
+/* pps_kc_bind - control PPS kernel consumer binding
+ * @pps: the PPS source
+ * @bind_args: kernel consumer bind parameters
+ *
+ * This function is used to bind or unbind PPS kernel consumer according to
+ * supplied parameters. Should not be called in interrupt context.
+ */
+int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args)
+{
+ /* Check if another consumer is already bound */
+ spin_lock_irq(&pps_kc_hardpps_lock);
+
+ if (bind_args->edge == 0)
+ if (pps_kc_hardpps_dev == pps) {
+ pps_kc_hardpps_mode = 0;
+ pps_kc_hardpps_dev = NULL;
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+ dev_info(pps->dev, "unbound kernel"
+ " consumer\n");
+ } else {
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+ dev_err(pps->dev, "selected kernel consumer"
+ " is not bound\n");
+ return -EINVAL;
+ }
+ else
+ if (pps_kc_hardpps_dev == NULL ||
+ pps_kc_hardpps_dev == pps) {
+ pps_kc_hardpps_mode = bind_args->edge;
+ pps_kc_hardpps_dev = pps;
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+ dev_info(pps->dev, "bound kernel consumer: "
+ "edge=0x%x\n", bind_args->edge);
+ } else {
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+ dev_err(pps->dev, "another kernel consumer"
+ " is already bound\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/* pps_kc_remove - unbind kernel consumer on PPS source removal
+ * @pps: the PPS source
+ *
+ * This function is used to disable kernel consumer on PPS source removal
+ * if this source was bound to PPS kernel consumer. Can be called on any
+ * source safely. Should not be called in interrupt context.
+ */
+void pps_kc_remove(struct pps_device *pps)
+{
+ spin_lock_irq(&pps_kc_hardpps_lock);
+ if (pps == pps_kc_hardpps_dev) {
+ pps_kc_hardpps_mode = 0;
+ pps_kc_hardpps_dev = NULL;
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+ dev_info(pps->dev, "unbound kernel consumer"
+ " on device removal\n");
+ } else
+ spin_unlock_irq(&pps_kc_hardpps_lock);
+}
+
+/* pps_kc_event - call hardpps() on PPS event
+ * @pps: the PPS source
+ * @ts: PPS event timestamp
+ * @event: PPS event edge
+ *
+ * This function calls hardpps() when an event from bound PPS source occurs.
+ */
+void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts,
+ int event)
+{
+ unsigned long flags;
+
+ /* Pass some events to kernel consumer if activated */
+ spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
+ if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
+ hardpps(&ts->ts_real, &ts->ts_raw);
+ spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
+}
diff --git a/drivers/pps/kc.h b/drivers/pps/kc.h
new file mode 100644
index 000000000000..d296fcd0a175
--- /dev/null
+++ b/drivers/pps/kc.h
@@ -0,0 +1,46 @@
+/*
+ * PPS kernel consumer API header
+ *
+ * Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef LINUX_PPS_KC_H
+#define LINUX_PPS_KC_H
+
+#include <linux/errno.h>
+#include <linux/pps_kernel.h>
+
+#ifdef CONFIG_NTP_PPS
+
+extern int pps_kc_bind(struct pps_device *pps,
+ struct pps_bind_args *bind_args);
+extern void pps_kc_remove(struct pps_device *pps);
+extern void pps_kc_event(struct pps_device *pps,
+ struct pps_event_time *ts, int event);
+
+
+#else /* CONFIG_NTP_PPS */
+
+static inline int pps_kc_bind(struct pps_device *pps,
+ struct pps_bind_args *bind_args) { return -EOPNOTSUPP; }
+static inline void pps_kc_remove(struct pps_device *pps) {}
+static inline void pps_kc_event(struct pps_device *pps,
+ struct pps_event_time *ts, int event) {}
+
+#endif /* CONFIG_NTP_PPS */
+
+#endif /* LINUX_PPS_KC_H */
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 9e15cf1da946..2baadd21b7a6 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -33,6 +33,8 @@
#include <linux/pps_kernel.h>
#include <linux/slab.h>
+#include "kc.h"
+
/*
* Local variables
*/
@@ -198,9 +200,43 @@ static long pps_cdev_ioctl(struct file *file,
break;
}
+ case PPS_KC_BIND: {
+ struct pps_bind_args bind_args;
+
+ dev_dbg(pps->dev, "PPS_KC_BIND\n");
+
+ /* Check the capabilities */
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ if (copy_from_user(&bind_args, uarg,
+ sizeof(struct pps_bind_args)))
+ return -EFAULT;
+
+ /* Check for supported capabilities */
+ if ((bind_args.edge & ~pps->info.mode) != 0) {
+ dev_err(pps->dev, "unsupported capabilities (%x)\n",
+ bind_args.edge);
+ return -EINVAL;
+ }
+
+ /* Validate parameters roughly */
+ if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
+ (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
+ bind_args.consumer != PPS_KC_HARDPPS) {
+ dev_err(pps->dev, "invalid kernel consumer bind"
+ " parameters (%x)\n", bind_args.edge);
+ return -EINVAL;
+ }
+
+ err = pps_kc_bind(pps, &bind_args);
+ if (err < 0)
+ return err;
+
+ break;
+ }
default:
return -ENOTTY;
- break;
}
return 0;
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