From patchwork Mon Aug 16 11:17:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Cochran X-Patchwork-Id: 61789 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 1D6E1B7527 for ; Mon, 16 Aug 2010 21:17:33 +1000 (EST) Received: from mail-bw0-f51.google.com (mail-bw0-f51.google.com [209.85.214.51]) by ozlabs.org (Postfix) with ESMTP id 68AF6B6F0D; Mon, 16 Aug 2010 21:17:19 +1000 (EST) Received: by mail-bw0-f51.google.com with SMTP id 10so1971450bwz.38 for ; Mon, 16 Aug 2010 04:17:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:references:mime-version:content-type:content-disposition :in-reply-to:user-agent; bh=R/4DTWOsg9aoOYWq885CCg1E3QJX+QyUWDNZLKqO6io=; b=CTjay5OE0hB0beFBvVh9A6a/kKzl0xeJxXLXRu+Gc8PSkZLiKn+gwldC+rsu0EDE3T qJ3vzd0OppTLxVfTlIbQ6Ck/NkQYQ+THVbvSMRpAu3/7xV7HK5quHWGAvLuEoQRVdntR RMjhLv2fnviDPB1MomKhzUaw0H3BzIaxwKt3Q= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=Y22oRSjxWjp4aWG/nNq66wwh+jL9CryRmGZOrjUNTjhdVUrGhGHHKvEx/hCvZJTCMr JGEPCZVE/yngFIMWPiWe+7/aorlZGFNbszOOfeD05Cddxnb6X027QudkqWFa+B0LMS7q B7JIFQWxeTgTQ/eSt5A9TjRGdXGLeOFgThdQw= Received: by 10.204.120.130 with SMTP id d2mr1962546bkr.9.1281957437073; Mon, 16 Aug 2010 04:17:17 -0700 (PDT) Received: from riccoc20.at.omicron.at (vs162244.vserver.de [62.75.162.244]) by mx.google.com with ESMTPS id f10sm4225252bkl.17.2010.08.16.04.17.09 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 16 Aug 2010 04:17:16 -0700 (PDT) Date: Mon, 16 Aug 2010 13:17:36 +0200 From: Richard Cochran To: netdev@vger.kernel.org Subject: [PATCH 1/5] ptp: Added a brand new class driver for ptp clocks. Message-ID: <363bd749a38d0b785d8431e591bf54c38db4c2d7.1281956490.git.richard.cochran@omicron.at> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Cc: linuxppc-dev@lists.ozlabs.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Rodolfo Giometti , linux-arm-kernel@lists.infradead.org, Krzysztof Halasa X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org 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 exposed to user space as a character device with ioctls that allow tuning of the PTP clock. Signed-off-by: Richard Cochran --- Documentation/ptp/ptp.txt | 95 +++++++ Documentation/ptp/testptp.c | 306 ++++++++++++++++++++++ Documentation/ptp/testptp.mk | 33 +++ drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/ptp/Kconfig | 27 ++ drivers/ptp/Makefile | 5 + drivers/ptp/ptp_clock.c | 514 ++++++++++++++++++++++++++++++++++++++ include/linux/Kbuild | 1 + include/linux/ptp_clock.h | 79 ++++++ include/linux/ptp_clock_kernel.h | 137 ++++++++++ 11 files changed, 1200 insertions(+), 0 deletions(-) create mode 100644 Documentation/ptp/ptp.txt create mode 100644 Documentation/ptp/testptp.c create mode 100644 Documentation/ptp/testptp.mk create mode 100644 drivers/ptp/Kconfig create mode 100644 drivers/ptp/Makefile create mode 100644 drivers/ptp/ptp_clock.c create mode 100644 include/linux/ptp_clock.h create mode 100644 include/linux/ptp_clock_kernel.h diff --git a/Documentation/ptp/ptp.txt b/Documentation/ptp/ptp.txt new file mode 100644 index 0000000..46858b3 --- /dev/null +++ b/Documentation/ptp/ptp.txt @@ -0,0 +1,95 @@ + +* PTP infrastructure for Linux + + This patch set introduces support for IEEE 1588 PTP clocks in + Linux. Together with the SO_TIMESTAMPING socket options, this + presents a standardized method for developing PTP user space + programs, synchronizing Linux with external clocks, and using the + ancillary features of PTP hardware clocks. + + A new class driver exports a kernel interface for specific clock + drivers and a user space interface. The infrastructure supports a + complete set of PTP functionality. + + + Basic clock operations + - Set time + - Get time + - Shift the clock by a given offset atomically + - Adjust clock frequency + + + Ancillary clock features + - One short or periodic alarms, with signal delivery to user program + - Time stamp external events + - Period output signals configurable from user space + - Synchronization of the Linux system time via the PPS subsystem + +** PTP kernel API + + A PTP clock driver registers itself with the class driver. The + class driver handles all of the dealings with user space. The + author of a clock driver need only implement the details of + programming the clock hardware. The clock driver notifies the class + driver of asynchronous events (alarms and external time stamps) via + a simple message passing interface. + + The class driver supports multiple PTP clock drivers. In normal use + cases, only one PTP clock is needed. However, for testing and + development, it can be useful to have more than one clock in a + single system, in order to allow performance comparisons. + +** PTP user space API + + The class driver creates a character device for each registered PTP + clock. User space programs may control the clock using standardized + ioctls. A program may query, enable, configure, and disable the + ancillary clock features. User space can receive time stamped + events via blocking read() and poll(). One shot and periodic + signals may be configured via an ioctl API with semantics similar + to the POSIX timer_settime() system call. + + As an real life example, the following two patches for ptpd version + 1.0.0 demonstrate how the API works. + + https://sourceforge.net/tracker/?func=detail&aid=2992845&group_id=139814&atid=744634 + + https://sourceforge.net/tracker/?func=detail&aid=2992847&group_id=139814&atid=744634 + +** Writing clock drivers + + Clock drivers include include/linux/ptp_clock_kernel.h and register + themselves by presenting a 'struct ptp_clock_info' to the + registration method. Clock drivers must implement all of the + functions in the interface. If a clock does not offer a particular + ancillary feature, then the driver should just return -EOPNOTSUPP + from those functions. + + Drivers must ensure that all of the methods in interface are + reentrant. Since most hardware implementations treat the time value + as a 64 bit integer accessed as two 32 bit registers, drivers + should use spin_lock_irqsave/spin_unlock_irqrestore to protect + against concurrent access. This locking cannot be accomplished in + class driver, since the lock may also be needed by the clock + driver's interrupt service routine. + +** Supported hardware + + + Standard Linux system timer + - No special PTP features + - For use with software time stamping + + + Freescale eTSEC gianfar + - 2 Time stamp external triggers, programmable polarity (opt. interrupt) + - 2 Alarm registers (optional interrupt) + - 3 Periodic signals (optional interrupt) + + + National DP83640 + - 6 GPIOs programmable as inputs or outputs + - 6 GPIOs with dedicated functions (LED/JTAG/clock) can also be + used as general inputs or outputs + - GPIO inputs can time stamp external triggers + - GPIO outputs can produce periodic signals + - 1 interrupt pin + + + Intel IXP465 + - Auxiliary Slave/Master Mode Snapshot (optional interrupt) + - Target Time (optional interrupt) diff --git a/Documentation/ptp/testptp.c b/Documentation/ptp/testptp.c new file mode 100644 index 0000000..41a9839 --- /dev/null +++ b/Documentation/ptp/testptp.c @@ -0,0 +1,306 @@ +/* + * PTP 1588 clock support - User space test program + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +static void handle_alarm(int s) +{ + printf("received signal %d\n", s); +} + +static int install_handler(int signum, void (*handler)(int)) +{ + struct sigaction action; + sigset_t mask; + + /* Unblock the signal. */ + sigemptyset(&mask); + sigaddset(&mask, signum); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + + /* Install the signal handler. */ + action.sa_handler = handler; + action.sa_flags = 0; + sigemptyset(&action.sa_mask); + sigaction(signum, &action, NULL); + + return 0; +} + +static void usage(char *progname) +{ + fprintf(stderr, + "usage: %s [options]\n" + " -a val request a one-shot alarm after 'val' seconds\n" + " -A val request a periodic alarm every 'val' seconds\n" + " -c query the ptp clock's capabilities\n" + " -d name device to open\n" + " -e val read 'val' external time stamp events\n" + " -f val adjust the ptp clock frequency by 'val' PPB\n" + " -g get the ptp clock time\n" + " -h prints this message\n" + " -p val enable output with a period of 'val' nanoseconds\n" + " -P val enable or disable (val=1|0) the system clock PPS\n" + " -s set the ptp clock time from the system time\n" + " -t val shift the ptp clock time by 'val' seconds\n" + " -v query the ptp clock api version\n", + progname); +} + +int main(int argc, char *argv[]) +{ + struct ptp_clock_caps caps; + struct ptp_clock_timer timer; + struct ptp_extts_event event; + struct ptp_clock_request request; + struct timespec ts; + char *progname; + int c, cnt, fd, val = 0; + + char *device = "/dev/ptp_clock_0"; + int adjfreq = 0x7fffffff; + int adjtime = 0; + int capabilities = 0; + int extts = 0; + int gettime = 0; + int oneshot = 0; + int periodic = 0; + int perout = -1; + int pps = -1; + int settime = 0; + int version = 0; + + progname = strrchr(argv[0], '/'); + progname = progname ? 1+progname : argv[0]; + while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghp:P:st:v"))) { + switch (c) { + case 'a': + oneshot = atoi(optarg); + break; + case 'A': + periodic = atoi(optarg); + break; + case 'c': + capabilities = 1; + break; + case 'd': + device = optarg; + break; + case 'e': + extts = atoi(optarg); + break; + case 'f': + adjfreq = atoi(optarg); + break; + case 'g': + gettime = 1; + break; + case 'p': + perout = atoi(optarg); + break; + case 'P': + pps = atoi(optarg); + break; + case 's': + settime = 1; + break; + case 't': + adjtime = atoi(optarg); + break; + case 'v': + version = 1; + break; + case 'h': + usage(progname); + return 0; + case '?': + default: + usage(progname); + return -1; + } + } + + fd = open(device, O_RDWR); + if (fd < 0) { + fprintf(stderr, "cannot open %s: %s", device, strerror(errno)); + return -1; + } + + if (version) { + if (ioctl(fd, PTP_CLOCK_APIVERS, &val)) { + perror("PTP_CLOCK_APIVERS"); + } else { + printf("version = 0x%08x\n", val); + } + } + + if (capabilities) { + if (ioctl(fd, PTP_CLOCK_GETCAPS, &caps)) { + perror("PTP_CLOCK_GETCAPS"); + } else { + printf("capabilities:\n" + " %d maximum frequency adjustment (PPB)\n" + " %d programmable alarms\n" + " %d external time stamp channels\n" + " %d programmable periodic signals\n" + " %d pulse per second\n", + caps.max_adj, + caps.n_alarm, + caps.n_ext_ts, + caps.n_per_out, + caps.pps); + } + } + + if (0x7fffffff != adjfreq) { + if (ioctl(fd, PTP_CLOCK_ADJFREQ, adjfreq)) { + perror("PTP_CLOCK_ADJFREQ"); + } else { + puts("frequency adjustment okay"); + } + } + + if (adjtime) { + ts.tv_sec = adjtime; + ts.tv_nsec = 0; + if (ioctl(fd, PTP_CLOCK_ADJTIME, &ts)) { + perror("PTP_CLOCK_ADJTIME"); + } else { + puts("time shift okay"); + } + } + + if (gettime) { + if (ioctl(fd, PTP_CLOCK_GETTIME, &ts)) { + perror("PTP_CLOCK_GETTIME"); + } else { + printf("clock time: %ld.%09ld or %s", + ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec)); + } + } + + if (settime) { + clock_gettime(CLOCK_REALTIME, &ts); + if (ioctl(fd, PTP_CLOCK_SETTIME, &ts)) { + perror("PTP_CLOCK_SETTIME"); + } else { + puts("set time okay"); + } + } + + if (extts) { + memset(&request, 0, sizeof(request)); + request.type = PTP_REQUEST_EXTTS; + request.index = 0; + request.flags = PTP_ENABLE_FEATURE; + if (ioctl(fd, PTP_FEATURE_REQUEST, &request)) { + perror("PTP_FEATURE_REQUEST"); + extts = 0; + } else { + puts("external time stamp request okay"); + } + for (; extts; extts--) { + cnt = read(fd, &event, sizeof(event)); + if (cnt != sizeof(event)) { + perror("read"); + break; + } + printf("event index %d at %ld.%09ld\n", event.index, + event.ts.tv_sec, event.ts.tv_nsec); + fflush(stdout); + } + /* Disable the feature again. */ + request.flags = 0; + if (ioctl(fd, PTP_FEATURE_REQUEST, &request)) { + perror("PTP_FEATURE_REQUEST"); + } + } + + if (oneshot) { + install_handler(SIGALRM, handle_alarm); + memset(&timer, 0, sizeof(timer)); + timer.signum = SIGALRM; + timer.tsp.it_value.tv_sec = oneshot; + if (ioctl(fd, PTP_CLOCK_SETTIMER, &timer)) { + perror("PTP_CLOCK_SETTIMER"); + } else { + puts("set timer okay"); + } + pause(); + } + + if (periodic) { + install_handler(SIGALRM, handle_alarm); + memset(&timer, 0, sizeof(timer)); + timer.signum = SIGALRM; + timer.tsp.it_value.tv_sec = periodic; + timer.tsp.it_interval.tv_sec = periodic; + if (ioctl(fd, PTP_CLOCK_SETTIMER, &timer)) { + perror("PTP_CLOCK_SETTIMER"); + } else { + puts("set timer okay"); + } + while (1) { + pause(); + } + } + + if (perout >= 0) { + memset(&request, 0, sizeof(request)); + request.type = PTP_REQUEST_PEROUT; + request.index = 0; + request.ts.tv_sec = 0; + request.ts.tv_nsec = perout; + request.flags = perout ? PTP_ENABLE_FEATURE : 0; + if (ioctl(fd, PTP_FEATURE_REQUEST, &request)) { + perror("PTP_FEATURE_REQUEST"); + extts = 0; + } else { + puts("periodic output request okay"); + } + } + + if (pps != -1) { + memset(&request, 0, sizeof(request)); + request.type = PTP_REQUEST_PPS; + request.flags = perout ? PTP_ENABLE_FEATURE : 0; + if (ioctl(fd, PTP_FEATURE_REQUEST, &request)) { + perror("PTP_FEATURE_REQUEST"); + } else { + puts("pps for system time request okay"); + } + } + + close(fd); + return 0; +} diff --git a/Documentation/ptp/testptp.mk b/Documentation/ptp/testptp.mk new file mode 100644 index 0000000..4ef2d97 --- /dev/null +++ b/Documentation/ptp/testptp.mk @@ -0,0 +1,33 @@ +# PTP 1588 clock support - User space test program +# +# 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. + +CC = $(CROSS_COMPILE)gcc +INC = -I$(KBUILD_OUTPUT)/usr/include +CFLAGS = -Wall $(INC) +LDLIBS = -lrt +PROGS = testptp + +all: $(PROGS) + +testptp: testptp.o + +clean: + rm -f testptp.o + +distclean: clean + rm -f $(PROGS) diff --git a/drivers/Kconfig b/drivers/Kconfig index a2b902f..774fbd7 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -52,6 +52,8 @@ source "drivers/spi/Kconfig" source "drivers/pps/Kconfig" +source "drivers/ptp/Kconfig" + source "drivers/gpio/Kconfig" source "drivers/w1/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 91874e0..6d12b48 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_I2O) += message/ obj-$(CONFIG_RTC_LIB) += rtc/ obj-y += i2c/ media/ obj-$(CONFIG_PPS) += pps/ +obj-$(CONFIG_PTP_1588_CLOCK) += ptp/ obj-$(CONFIG_W1) += w1/ obj-$(CONFIG_POWER_SUPPLY) += power/ obj-$(CONFIG_HWMON) += hwmon/ diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig new file mode 100644 index 0000000..cd7becb --- /dev/null +++ b/drivers/ptp/Kconfig @@ -0,0 +1,27 @@ +# +# PTP clock support configuration +# + +menu "PTP clock support" + +config PTP_1588_CLOCK + tristate "PTP clock support" + depends on EXPERIMENTAL + depends on PPS + help + The IEEE 1588 standard defines a method to precisely + synchronize distributed clocks over Ethernet networks. The + standard defines a Precision Time Protocol (PTP), which can + be used to achieve synchronization within a few dozen + microseconds. In addition, with the help of special hardware + time stamping units, it can be possible to achieve + synchronization to within a few hundred nanoseconds. + + This driver adds support for PTP clocks as character + devices. If you want to use a PTP clock, then you should + also enable at least one clock driver as well. + + To compile this driver as a module, choose M here: the module + will be called ptp_clock. + +endmenu diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile new file mode 100644 index 0000000..b86695c --- /dev/null +++ b/drivers/ptp/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for PTP 1588 clock support. +# + +obj-$(CONFIG_PTP_1588_CLOCK) += ptp_clock.o diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c new file mode 100644 index 0000000..1ebb4b0 --- /dev/null +++ b/drivers/ptp/ptp_clock.c @@ -0,0 +1,514 @@ +/* + * PTP 1588 clock support + * + * Partially adapted from the Linux PPS driver. + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define PTP_MAX_ALARMS 4 +#define PTP_MAX_CLOCKS BITS_PER_LONG +#define PTP_MAX_TIMESTAMPS 128 +#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT) +#define PTP_PPS_EVENT PPS_CAPTUREASSERT +#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC) + +struct alarm { + struct pid *pid; + int sig; +}; + +struct timestamp_event_queue { + struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS]; + int head; + int tail; + int overflow; +}; + +struct ptp_clock { + struct list_head list; + struct cdev cdev; + struct device *dev; + struct ptp_clock_info *info; + dev_t devid; + int index; /* index into clocks.map, also the minor number */ + int pps_source; + + struct alarm alarm[PTP_MAX_ALARMS]; + struct mutex alarm_mux; /* one process at a time setting an alarm */ + + struct timestamp_event_queue tsevq; /* simple fifo for time stamps */ + struct mutex tsevq_mux; /* one process at a time reading the fifo */ + wait_queue_head_t tsev_wq; +}; + +/* private globals */ + +static const struct file_operations ptp_fops; +static dev_t ptp_devt; +static struct class *ptp_class; + +static struct { + struct list_head list; + DECLARE_BITMAP(map, PTP_MAX_CLOCKS); +} clocks; +static DEFINE_MUTEX(clocks_mux); /* protects 'clocks' */ + +/* time stamp event queue operations */ + +static inline int queue_cnt(struct timestamp_event_queue *q) +{ + int cnt = q->tail - q->head; + return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt; +} + +static inline int queue_free(struct timestamp_event_queue *q) +{ + return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1; +} + +static void enqueue_external_timestamp(struct timestamp_event_queue *queue, + struct ptp_clock_event *src) +{ + struct ptp_extts_event *dst; + u32 remainder; + + dst = &queue->buf[queue->tail]; + + dst->index = src->index; + dst->ts.tv_sec = div_u64_rem(src->timestamp, 1000000000, &remainder); + dst->ts.tv_nsec = remainder; + + if (!queue_free(queue)) + queue->overflow++; + + queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS; +} + +/* public interface */ + +struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info) +{ + struct ptp_clock *ptp; + int err = 0, index, major = MAJOR(ptp_devt); + + if (info->n_alarm > PTP_MAX_ALARMS) + return ERR_PTR(-EINVAL); + + /* Find a free clock slot and reserve it. */ + err = -EBUSY; + mutex_lock(&clocks_mux); + index = find_first_zero_bit(clocks.map, PTP_MAX_CLOCKS); + if (index < PTP_MAX_CLOCKS) + set_bit(index, clocks.map); + else + goto no_clock; + + /* Initialize a clock structure. */ + err = -ENOMEM; + ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); + if (ptp == NULL) + goto no_memory; + + ptp->info = info; + ptp->devid = MKDEV(major, index); + ptp->index = index; + mutex_init(&ptp->alarm_mux); + mutex_init(&ptp->tsevq_mux); + init_waitqueue_head(&ptp->tsev_wq); + + /* Create a new device in our class. */ + ptp->dev = device_create(ptp_class, NULL, ptp->devid, ptp, + "ptp_clock_%d", ptp->index); + if (IS_ERR(ptp->dev)) + goto no_device; + + dev_set_drvdata(ptp->dev, ptp); + + /* Register a character device. */ + cdev_init(&ptp->cdev, &ptp_fops); + ptp->cdev.owner = info->owner; + err = cdev_add(&ptp->cdev, ptp->devid, 1); + if (err) + goto no_cdev; + + /* Register a new PPS source. */ + if (info->pps) { + struct pps_source_info pps; + memset(&pps, 0, sizeof(pps)); + snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); + pps.mode = PTP_PPS_MODE; + pps.owner = info->owner; + pps.dev = ptp->dev; + err = pps_register_source(&pps, PTP_PPS_DEFAULTS); + if (err < 0) { + pr_err("failed to register pps source\n"); + goto no_pps; + } else + ptp->pps_source = err; + } + + /* Clock is ready, add it into the list. */ + list_add(&ptp->list, &clocks.list); + + mutex_unlock(&clocks_mux); + return ptp; + +no_pps: +no_cdev: + device_destroy(ptp_class, ptp->devid); +no_device: + mutex_destroy(&ptp->alarm_mux); + mutex_destroy(&ptp->tsevq_mux); + kfree(ptp); +no_memory: + clear_bit(index, clocks.map); +no_clock: + mutex_unlock(&clocks_mux); + return ERR_PTR(err); +} +EXPORT_SYMBOL(ptp_clock_register); + +int ptp_clock_unregister(struct ptp_clock *ptp) +{ + /* Release the clock's resources. */ + if (ptp->info->pps) + pps_unregister_source(ptp->pps_source); + cdev_del(&ptp->cdev); + device_destroy(ptp_class, ptp->devid); + mutex_destroy(&ptp->alarm_mux); + mutex_destroy(&ptp->tsevq_mux); + + /* Remove the clock from the list. */ + mutex_lock(&clocks_mux); + list_del(&ptp->list); + clear_bit(ptp->index, clocks.map); + mutex_unlock(&clocks_mux); + + kfree(ptp); + + return 0; +} +EXPORT_SYMBOL(ptp_clock_unregister); + +void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) +{ + struct timespec ts; + struct pps_ktime pps_ts; + + switch (event->type) { + + case PTP_CLOCK_ALARM: + kill_pid(ptp->alarm[event->index].pid, + ptp->alarm[event->index].sig, 1); + break; + + case PTP_CLOCK_EXTTS: + enqueue_external_timestamp(&ptp->tsevq, event); + wake_up_interruptible(&ptp->tsev_wq); + break; + + case PTP_CLOCK_PPS: + getnstimeofday(&ts); + pps_ts.sec = ts.tv_sec; + pps_ts.nsec = ts.tv_nsec; + pps_event(ptp->pps_source, &pps_ts, PTP_PPS_EVENT, NULL); + break; + } +} +EXPORT_SYMBOL(ptp_clock_event); + +/* character device operations */ + +static int ptp_ioctl(struct inode *node, struct file *fp, + unsigned int cmd, unsigned long arg) +{ + struct ptp_clock_caps caps; + struct ptp_clock_request req; + struct ptp_clock_timer timer; + struct ptp_clock *ptp = fp->private_data; + struct ptp_clock_info *ops = ptp->info; + void *priv = ops->priv; + struct timespec ts; + int flags, index; + int err = 0; + s32 ppb; + + switch (cmd) { + + case PTP_CLOCK_APIVERS: + err = put_user(PTP_CLOCK_VERSION, (u32 __user *)arg); + break; + + case PTP_CLOCK_ADJFREQ: + if (!capable(CAP_SYS_TIME)) + return -EPERM; + ppb = arg; + if (ppb > ops->max_adj || ppb < -ops->max_adj) + return -EINVAL; + err = ops->adjfreq(priv, ppb); + break; + + case PTP_CLOCK_ADJTIME: + if (!capable(CAP_SYS_TIME)) + return -EPERM; + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) + err = -EFAULT; + else + err = ops->adjtime(priv, &ts); + break; + + case PTP_CLOCK_GETTIME: + err = ops->gettime(priv, &ts); + if (err) + break; + err = copy_to_user((void __user *)arg, &ts, sizeof(ts)); + break; + + case PTP_CLOCK_SETTIME: + if (!capable(CAP_SYS_TIME)) + return -EPERM; + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) + err = -EFAULT; + else + err = ops->settime(priv, &ts); + break; + + case PTP_CLOCK_GETCAPS: + memset(&caps, 0, sizeof(caps)); + caps.max_adj = ptp->info->max_adj; + caps.n_alarm = ptp->info->n_alarm; + caps.n_ext_ts = ptp->info->n_ext_ts; + caps.n_per_out = ptp->info->n_per_out; + caps.pps = ptp->info->pps; + err = copy_to_user((void __user *)arg, &caps, sizeof(caps)); + break; + + case PTP_CLOCK_GETTIMER: + if (copy_from_user(&timer, (void __user *)arg, sizeof(timer))) { + err = -EFAULT; + break; + } + index = timer.alarm_index; + if (index < 0 || index >= ptp->info->n_alarm) { + err = -EINVAL; + break; + } + err = ops->gettimer(priv, index, &timer.tsp); + if (err) + break; + err = copy_to_user((void __user *)arg, &timer, sizeof(timer)); + break; + + case PTP_CLOCK_SETTIMER: + if (copy_from_user(&timer, (void __user *)arg, sizeof(timer))) { + err = -EFAULT; + break; + } + index = timer.alarm_index; + if (index < 0 || index >= ptp->info->n_alarm) { + err = -EINVAL; + break; + } + if (!valid_signal(timer.signum)) + return -EINVAL; + flags = timer.flags; + if (flags & (flags != TIMER_ABSTIME)) { + err = -EINVAL; + break; + } + if (mutex_lock_interruptible(&ptp->alarm_mux)) + return -ERESTARTSYS; + + if (ptp->alarm[index].pid) + put_pid(ptp->alarm[index].pid); + + ptp->alarm[index].pid = get_pid(task_pid(current)); + ptp->alarm[index].sig = timer.signum; + err = ops->settimer(priv, index, flags, &timer.tsp); + + mutex_unlock(&ptp->alarm_mux); + break; + + case PTP_FEATURE_REQUEST: + if (copy_from_user(&req, (void __user *)arg, sizeof(req))) { + err = -EFAULT; + break; + } + switch (req.type) { + case PTP_REQUEST_EXTTS: + case PTP_REQUEST_PEROUT: + break; + case PTP_REQUEST_PPS: + if (!capable(CAP_SYS_TIME)) + return -EPERM; + break; + default: + err = -EINVAL; + break; + } + if (err) + break; + err = ops->enable(priv, &req, + req.flags & PTP_ENABLE_FEATURE ? 1 : 0); + break; + + default: + err = -ENOTTY; + break; + } + return err; +} + +static int ptp_open(struct inode *inode, struct file *fp) +{ + struct ptp_clock *ptp; + ptp = container_of(inode->i_cdev, struct ptp_clock, cdev); + + fp->private_data = ptp; + + return 0; +} + +static unsigned int ptp_poll(struct file *fp, poll_table *wait) +{ + struct ptp_clock *ptp = fp->private_data; + + poll_wait(fp, &ptp->tsev_wq, wait); + + return queue_cnt(&ptp->tsevq) ? POLLIN : 0; +} + +static ssize_t ptp_read(struct file *fp, char __user *buf, + size_t cnt, loff_t *off) +{ + struct ptp_clock *ptp = fp->private_data; + struct timestamp_event_queue *queue = &ptp->tsevq; + struct ptp_extts_event *event; + size_t qcnt; + + if (mutex_lock_interruptible(&ptp->tsevq_mux)) + return -ERESTARTSYS; + + cnt = cnt / sizeof(struct ptp_extts_event); + + if (wait_event_interruptible(ptp->tsev_wq, + (qcnt = queue_cnt(&ptp->tsevq)))) { + mutex_unlock(&ptp->tsevq_mux); + return -ERESTARTSYS; + } + + if (cnt > qcnt) + cnt = qcnt; + + event = &queue->buf[queue->head]; + + if (copy_to_user(buf, event, cnt * sizeof(struct ptp_extts_event))) { + mutex_unlock(&ptp->tsevq_mux); + return -EFAULT; + } + queue->head = (queue->head + cnt) % PTP_MAX_TIMESTAMPS; + + mutex_unlock(&ptp->tsevq_mux); + + return cnt * sizeof(struct ptp_extts_event); +} + +static int ptp_release(struct inode *inode, struct file *fp) +{ + struct ptp_clock *ptp; + struct itimerspec ts = { + {0, 0}, {0, 0} + }; + int i; + + ptp = container_of(inode->i_cdev, struct ptp_clock, cdev); + + for (i = 0; i < ptp->info->n_alarm; i++) { + if (ptp->alarm[i].pid) { + ptp->info->settimer(ptp->info->priv, i, 0, &ts); + put_pid(ptp->alarm[i].pid); + ptp->alarm[i].pid = NULL; + } + } + return 0; +} + +static const struct file_operations ptp_fops = { + .owner = THIS_MODULE, + .ioctl = ptp_ioctl, + .open = ptp_open, + .poll = ptp_poll, + .read = ptp_read, + .release = ptp_release, +}; + +/* module operations */ + +static void __exit ptp_exit(void) +{ + class_destroy(ptp_class); + unregister_chrdev_region(ptp_devt, PTP_MAX_CLOCKS); +} + +static int __init ptp_init(void) +{ + int err; + + INIT_LIST_HEAD(&clocks.list); + + ptp_class = class_create(THIS_MODULE, "ptp"); + if (!ptp_class) { + printk(KERN_ERR "ptp: failed to allocate class\n"); + return -ENOMEM; + } + + err = alloc_chrdev_region(&ptp_devt, 0, PTP_MAX_CLOCKS, "ptp"); + if (err < 0) { + printk(KERN_ERR "ptp: failed to allocate char device region\n"); + goto no_region; + } + + pr_info("PTP clock support registered\n"); + return 0; + +no_region: + class_destroy(ptp_class); + return err; +} + +subsys_initcall(ptp_init); +module_exit(ptp_exit); + +MODULE_AUTHOR("Richard Cochran "); +MODULE_DESCRIPTION("PTP clocks support"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 9aa9bca..471205a 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -140,6 +140,7 @@ header-y += pkt_sched.h header-y += posix_types.h header-y += ppdev.h header-y += prctl.h +header-y += ptp_clock.h header-y += qnxtypes.h header-y += qnx4_fs.h header-y += radeonfb.h diff --git a/include/linux/ptp_clock.h b/include/linux/ptp_clock.h new file mode 100644 index 0000000..5a509c5 --- /dev/null +++ b/include/linux/ptp_clock.h @@ -0,0 +1,79 @@ +/* + * 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 +#include + +#define PTP_ENABLE_FEATURE (1<<0) +#define PTP_RISING_EDGE (1<<1) +#define PTP_FALLING_EDGE (1<<2) + +enum ptp_request_types { + PTP_REQUEST_EXTTS, + PTP_REQUEST_PEROUT, + PTP_REQUEST_PPS, +}; + +struct ptp_clock_caps { + __s32 max_adj; /* Maximum frequency adjustment, 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. */ +}; + +struct ptp_clock_timer { + int alarm_index; /* Which alarm to query or configure. */ + int signum; /* Requested signal. */ + int flags; /* Zero or TIMER_ABSTIME, see TIMER_SETTIME(2) */ + struct itimerspec tsp; /* See TIMER_SETTIME(2) */ +}; + +struct ptp_clock_request { + int type; /* One of the ptp_request_types enumeration values. */ + int index; /* Which channel to configure. */ + struct timespec ts; /* For period signals, the desired period. */ + int flags; /* Bit field for PTP_ENABLE_FEATURE or other flags. */ +}; + +struct ptp_extts_event { + int index; + struct timespec ts; +}; + +#define PTP_CLOCK_VERSION 0x00000001 + +#define PTP_CLK_MAGIC '=' + +#define PTP_CLOCK_APIVERS _IOR (PTP_CLK_MAGIC, 1, __u32) +#define PTP_CLOCK_ADJFREQ _IO (PTP_CLK_MAGIC, 2) +#define PTP_CLOCK_ADJTIME _IOW (PTP_CLK_MAGIC, 3, struct timespec) +#define PTP_CLOCK_GETTIME _IOR (PTP_CLK_MAGIC, 4, struct timespec) +#define PTP_CLOCK_SETTIME _IOW (PTP_CLK_MAGIC, 5, struct timespec) + +#define PTP_CLOCK_GETCAPS _IOR (PTP_CLK_MAGIC, 6, struct ptp_clock_caps) +#define PTP_CLOCK_GETTIMER _IOWR (PTP_CLK_MAGIC, 7, struct ptp_clock_timer) +#define PTP_CLOCK_SETTIMER _IOW (PTP_CLK_MAGIC, 8, struct ptp_clock_timer) +#define PTP_FEATURE_REQUEST _IOW (PTP_CLK_MAGIC, 9, struct ptp_clock_request) + +#endif diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h new file mode 100644 index 0000000..d6cc158 --- /dev/null +++ b/include/linux/ptp_clock_kernel.h @@ -0,0 +1,137 @@ +/* + * PTP 1588 clock support + * + * 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_KERNEL_H_ +#define _PTP_CLOCK_KERNEL_H_ + +#include + +/** + * struct ptp_clock_info - decribes a PTP hardware clock + * + * @owner: The clock driver should set to THIS_MODULE. + * @name: A short name to identify the clock. + * @max_adj: The maximum possible frequency adjustment, in parts per billon. + * @n_alarm: The number of programmable alarms. + * @n_ext_ts: The number of external time stamp channels. + * @n_per_out: The number of programmable periodic signals. + * @pps: Indicates whether the clock supports a PPS callback. + * @priv: Passed to the clock operations, for the driver's private use. + * + * clock operations + * + * @adjfreq: Adjusts the frequency of the hardware clock. + * parameter delta: Desired period change in parts per billion. + * + * @adjtime: Shifts the time of the hardware clock. + * parameter ts: Desired change in seconds and nanoseconds. + * + * @gettime: Reads the current time from the hardware clock. + * parameter ts: Holds the result. + * + * @settime: Set the current time on the hardware clock. + * parameter ts: Time value to set. + * + * @gettimer: Reads the time remaining from the given timer. + * parameter index: Which alarm to query. + * parameter ts: Holds the result. + * + * @settimer: Arms the given timer for periodic or one shot operation. + * parameter index: Which alarm to set. + * parameter abs: TIMER_ABSTIME, or zero for relative timer. + * parameter ts: Alarm time and period to set. + * + * @enable: Request driver to enable or disable an ancillary feature. + * parameter request: Desired resource to enable or disable. + * parameter on: Caller passes one to enable or zero to disable. + * + * The callbacks must all return zero on success, non-zero otherwise. + */ + +struct ptp_clock_info { + struct module *owner; + char name[16]; + s32 max_adj; + int n_alarm; + int n_ext_ts; + int n_per_out; + int pps; + void *priv; + int (*adjfreq)(void *priv, s32 delta); + int (*adjtime)(void *priv, struct timespec *ts); + int (*gettime)(void *priv, struct timespec *ts); + int (*settime)(void *priv, struct timespec *ts); + int (*gettimer)(void *priv, int index, struct itimerspec *ts); + int (*settimer)(void *priv, int index, int abs, struct itimerspec *ts); + int (*enable)(void *priv, struct ptp_clock_request *request, int on); +}; + +struct ptp_clock; + +/** + * ptp_clock_register() - register a PTP hardware clock driver + * + * @info: Structure describing the new clock. + */ + +extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info); + +/** + * ptp_clock_unregister() - unregister a PTP hardware clock driver + * + * @ptp: The clock to remove from service. + */ + +extern int ptp_clock_unregister(struct ptp_clock *ptp); + + +enum ptp_clock_events { + PTP_CLOCK_ALARM, + PTP_CLOCK_EXTTS, + PTP_CLOCK_PPS, +}; + +/** + * struct ptp_clock_event - decribes a PTP hardware clock event + * + * @type: One of the ptp_clock_events enumeration values. + * @index: Identifies the source of the event. + * @timestamp: When the event occured. + */ + +struct ptp_clock_event { + int type; + int index; + u64 timestamp; +}; + +/** + * ptp_clock_event() - notify the PTP layer about an event + * + * This function should only be called from interrupt context. + * + * @ptp: The clock obtained from ptp_clock_register(). + * @event: Message structure describing the event. + */ + +extern void ptp_clock_event(struct ptp_clock *ptp, + struct ptp_clock_event *event); + +#endif