PTP update notification framework

Bug 1823033

Change-Id: I345e707455e5e64ad316143e3cea085b20588110
Signed-off-by: Rajesh Hosakote <rhosakote@nvidia.com>
Reviewed-on: http://git-master/r/1237704
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Dmitry Pervushin <dpervushin@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sumeet Gupta <sumeetg@nvidia.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/include/linux/platform/tegra/ptp-notifier.h b/include/linux/platform/tegra/ptp-notifier.h
new file mode 100644
index 000000000..fa9681278
--- /dev/null
+++ b/include/linux/platform/tegra/ptp-notifier.h
@@ -0,0 +1,81 @@
+/*
+ * include/linux/platform/tegra/ptp-notifier.h
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __PTP_NOTIFIER_H
+#define __PTP_NOTIFIER_H
+
+#ifdef CONFIG_TEGRA_PTP_NOTIFIER
+/* register / unregister HW time source */
+void tegra_register_hwtime_source(u64 (*func)(void));
+void tegra_unregister_hwtime_source(void);
+
+/* clients registering / unregistering for time update events */
+int tegra_register_hwtime_notifier(struct notifier_block *nb);
+int tegra_unregister_hwtime_notifier(struct notifier_block *nb);
+
+/* Notify time updates to registered clients */
+int tegra_hwtime_notifier_call_chain(unsigned int val, void *v);
+
+/*
+ * Get HW time counter.
+ * Clients may call the API every anytime PTP time is needed.
+ * If HW time source is not registered, returns ktime_get_real instead
+ */
+u64 get_ptp_hwtime(void);
+
+#else /* CONFIG_TEGRA_PTP_NOTIFIER */
+
+/* register / unregister HW time source */
+static inline void tegra_register_hwtime_source(u64 (*func)(void))
+{
+}
+
+static inline void tegra_unregister_hwtime_source(void)
+{
+}
+
+/* clients registering / unregistering for time update events */
+static inline int tegra_register_hwtime_notifier(struct notifier_block *nb)
+{
+        return 0;
+}
+
+static inline int tegra_unregister_hwtime_notifier(struct notifier_block *nb)
+{
+        return -ENOENT;
+}
+
+/* Notify time updates to registered clients */
+static inline int tegra_hwtime_notifier_call_chain(unsigned int val, void *v)
+{
+        return notifier_to_errno(NOTIFY_DONE);
+}
+
+/*
+ * Get HW time counter.
+ * Clients may call the API every anytime PTP time is needed.
+ * If HW time source is not registered, returns ktime_get_real instead
+ */
+static inline u64 get_ptp_hwtime(void)
+{
+        return ktime_to_ns(ktime_get_real());
+}
+
+#endif /* CONFIG_TEGRA_PTP_NOTIFIER */
+
+#endif /* __PTP_NOTIFIER_H */