ptp: Added a brand new class driver for ptp clocks.

This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.

The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 84 insertions, 0 deletions

diff --git a/include/linux/ptp_clock.h b/include/linux/ptp_clock.h
new file mode 100644
index 000000000000..94e981f810a2
--- /dev/null
+++ b/include/linux/ptp_clock.h
@@ -0,0 +1,84 @@
+/*
+ * PTP 1588 clock support - user space interface
+ *
+ * Copyright (C) 2010 OMICRON electronics GmbH
+ *
+ *  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 _PTP_CLOCK_H_
+#define _PTP_CLOCK_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/* PTP_xxx bits, for the flags field within the request structures. */
+#define PTP_ENABLE_FEATURE (1<<0)
+#define PTP_RISING_EDGE    (1<<1)
+#define PTP_FALLING_EDGE   (1<<2)
+
+/*
+ * struct ptp_clock_time - represents a time value
+ *
+ * The sign of the seconds field applies to the whole value. The
+ * nanoseconds field is always unsigned. The reserved field is
+ * included for sub-nanosecond resolution, should the demand for
+ * this ever appear.
+ *
+ */
+struct ptp_clock_time {
+        __s64 sec;  /* seconds */
+        __u32 nsec; /* nanoseconds */
+        __u32 reserved;
+};
+
+struct ptp_clock_caps {
+        int max_adj;   /* Maximum frequency adjustment in parts per billon. */
+        int n_alarm;   /* Number of programmable alarms. */
+        int n_ext_ts;  /* Number of external time stamp channels. */
+        int n_per_out; /* Number of programmable periodic signals. */
+        int pps;       /* Whether the clock supports a PPS callback. */
+        int rsv[15];   /* Reserved for future use. */
+};
+
+struct ptp_extts_request {
+        unsigned int index;  /* Which channel to configure. */
+        unsigned int flags;  /* Bit field for PTP_xxx flags. */
+        unsigned int rsv[2]; /* Reserved for future use. */
+};
+
+struct ptp_perout_request {
+        struct ptp_clock_time start;  /* Absolute start time. */
+        struct ptp_clock_time period; /* Desired period, zero means disable. */
+        unsigned int index;           /* Which channel to configure. */
+        unsigned int flags;           /* Reserved for future use. */
+        unsigned int rsv[4];          /* Reserved for future use. */
+};
+
+#define PTP_CLK_MAGIC '='
+
+#define PTP_CLOCK_GETCAPS  _IOR(PTP_CLK_MAGIC, 1, struct ptp_clock_caps)
+#define PTP_EXTTS_REQUEST  _IOW(PTP_CLK_MAGIC, 2, struct ptp_extts_request)
+#define PTP_PEROUT_REQUEST _IOW(PTP_CLK_MAGIC, 3, struct ptp_perout_request)
+#define PTP_ENABLE_PPS     _IOW(PTP_CLK_MAGIC, 4, int)
+
+struct ptp_extts_event {
+        struct ptp_clock_time t; /* Time event occured. */
+        unsigned int index;      /* Which channel produced the event. */
+        unsigned int flags;      /* Reserved for future use. */
+        unsigned int rsv[2];     /* Reserved for future use. */
+};
+
+#endif