From 717c033669ed3ceaee8df57d4562fafcc1a6267a Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 12 Jan 2011 17:00:58 -0800 Subject: 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 Acked-by: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/pps/Makefile | 1 + drivers/pps/kapi.c | 6 +++ drivers/pps/kc.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/pps/kc.h | 46 +++++++++++++++++++ drivers/pps/pps.c | 38 +++++++++++++++- 5 files changed, 212 insertions(+), 1 deletion(-) create mode 100644 drivers/pps/kc.c create mode 100644 drivers/pps/kc.h (limited to 'drivers/pps') diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile index 98960dd..77c23457 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 ebf3374..cba1b43 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -26,11 +26,14 @@ #include #include #include +#include #include #include #include #include +#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 0000000..079e930 --- /dev/null +++ b/drivers/pps/kc.c @@ -0,0 +1,122 @@ +/* + * PPS kernel consumer API + * + * Copyright (C) 2009-2010 Alexander Gordeev + * + * 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 +#include +#include +#include +#include +#include + +#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 0000000..d296fcd --- /dev/null +++ b/drivers/pps/kc.h @@ -0,0 +1,46 @@ +/* + * PPS kernel consumer API header + * + * Copyright (C) 2009-2010 Alexander Gordeev + * + * 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 +#include + +#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 9e15cf1..2baadd2 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -33,6 +33,8 @@ #include #include +#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; -- cgit v1.1