diff options
Diffstat (limited to 'drivers/pps')
| -rw-r--r-- | drivers/pps/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/pps/Makefile | 3 | ||||
| -rw-r--r-- | drivers/pps/clients/Kconfig | 18 | ||||
| -rw-r--r-- | drivers/pps/clients/Makefile | 6 | ||||
| -rw-r--r-- | drivers/pps/clients/pps-gpio.c | 213 | ||||
| -rw-r--r-- | drivers/pps/clients/pps-ktimer.c | 50 | ||||
| -rw-r--r-- | drivers/pps/clients/pps-ldisc.c | 73 | ||||
| -rw-r--r-- | drivers/pps/clients/pps_parport.c | 250 | ||||
| -rw-r--r-- | drivers/pps/generators/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/pps/generators/Makefile | 9 | ||||
| -rw-r--r-- | drivers/pps/generators/pps_gen_parport.c | 277 | ||||
| -rw-r--r-- | drivers/pps/kapi.c | 228 | ||||
| -rw-r--r-- | drivers/pps/kc.c | 122 | ||||
| -rw-r--r-- | drivers/pps/kc.h | 46 | ||||
| -rw-r--r-- | drivers/pps/pps.c | 201 | ||||
| -rw-r--r-- | drivers/pps/sysfs.c | 55 |
16 files changed, 1277 insertions, 303 deletions
diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig index 1afe4e03440..7512e98e931 100644 --- a/drivers/pps/Kconfig +++ b/drivers/pps/Kconfig @@ -6,7 +6,6 @@ menu "PPS support" config PPS tristate "PPS support" - depends on EXPERIMENTAL ---help--- PPS (Pulse Per Second) is a special pulse provided by some GPS antennae. Userland can use it to get a high-precision time @@ -21,15 +20,28 @@ config PPS To compile this driver as a module, choose M here: the module will be called pps_core.ko. +if PPS config PPS_DEBUG bool "PPS debugging messages" - depends on PPS help Say Y here if you want the PPS support to produce a bunch of debug messages to the system log. Select this if you are having a problem with PPS support and want to see more of what is going on. +config NTP_PPS + bool "PPS kernel consumer support" + depends on !NO_HZ + help + This option adds support for direct in-kernel time + synchronization using an external PPS signal. + + It doesn't work on tickless systems at the moment. + +endif + source drivers/pps/clients/Kconfig +source drivers/pps/generators/Kconfig + endmenu diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile index 98960ddd318..4483eaadadd 100644 --- a/drivers/pps/Makefile +++ b/drivers/pps/Makefile @@ -3,7 +3,8 @@ # 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/ +obj-y += clients/ generators/ ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig index 4e801bd7254..0c9f2805d07 100644 --- a/drivers/pps/clients/Kconfig +++ b/drivers/pps/clients/Kconfig @@ -17,9 +17,25 @@ config PPS_CLIENT_KTIMER config PPS_CLIENT_LDISC tristate "PPS line discipline" - depends on PPS + depends on PPS && TTY help If you say yes here you get support for a PPS source connected with the CD (Carrier Detect) pin of your serial port. +config PPS_CLIENT_PARPORT + tristate "Parallel port PPS client" + depends on PPS && PARPORT + help + If you say yes here you get support for a PPS source connected + with the interrupt pin of your parallel port. + +config PPS_CLIENT_GPIO + tristate "PPS client using GPIO" + depends on PPS + help + If you say yes here you get support for a PPS source using + GPIO. To be useful you must also register a platform device + specifying the GPIO pin and other options, usually in your board + setup. + endif diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile index 812c9b19b43..a461d15f4a2 100644 --- a/drivers/pps/clients/Makefile +++ b/drivers/pps/clients/Makefile @@ -4,7 +4,7 @@ obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o +obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o +obj-$(CONFIG_PPS_CLIENT_GPIO) += pps-gpio.o -ifeq ($(CONFIG_PPS_DEBUG),y) -EXTRA_CFLAGS += -DDEBUG -endif +ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c new file mode 100644 index 00000000000..f41bacfdc3d --- /dev/null +++ b/drivers/pps/clients/pps-gpio.c @@ -0,0 +1,213 @@ +/* + * pps-gpio.c -- PPS client driver using GPIO + * + * + * Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt> + * Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca> + * + * 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 PPS_GPIO_NAME "pps-gpio" +#define pr_fmt(fmt) PPS_GPIO_NAME ": " fmt + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/pps_kernel.h> +#include <linux/pps-gpio.h> +#include <linux/gpio.h> +#include <linux/list.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> + +/* Info for each registered platform device */ +struct pps_gpio_device_data { + int irq; /* IRQ used as PPS source */ + struct pps_device *pps; /* PPS source device */ + struct pps_source_info info; /* PPS source information */ + bool assert_falling_edge; + bool capture_clear; + unsigned int gpio_pin; +}; + +/* + * Report the PPS event + */ + +static irqreturn_t pps_gpio_irq_handler(int irq, void *data) +{ + const struct pps_gpio_device_data *info; + struct pps_event_time ts; + int rising_edge; + + /* Get the time stamp first */ + pps_get_ts(&ts); + + info = data; + + rising_edge = gpio_get_value(info->gpio_pin); + if ((rising_edge && !info->assert_falling_edge) || + (!rising_edge && info->assert_falling_edge)) + pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL); + else if (info->capture_clear && + ((rising_edge && info->assert_falling_edge) || + (!rising_edge && !info->assert_falling_edge))) + pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL); + + return IRQ_HANDLED; +} + +static unsigned long +get_irqf_trigger_flags(const struct pps_gpio_device_data *data) +{ + unsigned long flags = data->assert_falling_edge ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; + + if (data->capture_clear) { + flags |= ((flags & IRQF_TRIGGER_RISING) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING); + } + + return flags; +} + +static int pps_gpio_probe(struct platform_device *pdev) +{ + struct pps_gpio_device_data *data; + const char *gpio_label; + int ret; + int pps_default_params; + const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data; + struct device_node *np = pdev->dev.of_node; + + /* allocate space for device info */ + data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + if (pdata) { + data->gpio_pin = pdata->gpio_pin; + gpio_label = pdata->gpio_label; + + data->assert_falling_edge = pdata->assert_falling_edge; + data->capture_clear = pdata->capture_clear; + } else { + ret = of_get_gpio(np, 0); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get GPIO from device tree\n"); + return ret; + } + data->gpio_pin = ret; + gpio_label = PPS_GPIO_NAME; + + if (of_get_property(np, "assert-falling-edge", NULL)) + data->assert_falling_edge = true; + } + + /* GPIO setup */ + ret = devm_gpio_request(&pdev->dev, data->gpio_pin, gpio_label); + if (ret) { + dev_err(&pdev->dev, "failed to request GPIO %u\n", + data->gpio_pin); + return ret; + } + + ret = gpio_direction_input(data->gpio_pin); + if (ret) { + dev_err(&pdev->dev, "failed to set pin direction\n"); + return -EINVAL; + } + + /* IRQ setup */ + ret = gpio_to_irq(data->gpio_pin); + if (ret < 0) { + dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret); + return -EINVAL; + } + data->irq = ret; + + /* initialize PPS specific parts of the bookkeeping data structure. */ + data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | + PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC; + if (data->capture_clear) + data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR | + PPS_ECHOCLEAR; + data->info.owner = THIS_MODULE; + snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d", + pdev->name, pdev->id); + + /* register PPS source */ + pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT; + if (data->capture_clear) + pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR; + data->pps = pps_register_source(&data->info, pps_default_params); + if (data->pps == NULL) { + dev_err(&pdev->dev, "failed to register IRQ %d as PPS source\n", + data->irq); + return -EINVAL; + } + + /* register IRQ interrupt handler */ + ret = devm_request_irq(&pdev->dev, data->irq, pps_gpio_irq_handler, + get_irqf_trigger_flags(data), data->info.name, data); + if (ret) { + pps_unregister_source(data->pps); + dev_err(&pdev->dev, "failed to acquire IRQ %d\n", data->irq); + return -EINVAL; + } + + platform_set_drvdata(pdev, data); + dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", + data->irq); + + return 0; +} + +static int pps_gpio_remove(struct platform_device *pdev) +{ + struct pps_gpio_device_data *data = platform_get_drvdata(pdev); + + pps_unregister_source(data->pps); + dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq); + return 0; +} + +static const struct of_device_id pps_gpio_dt_ids[] = { + { .compatible = "pps-gpio", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, pps_gpio_dt_ids); + +static struct platform_driver pps_gpio_driver = { + .probe = pps_gpio_probe, + .remove = pps_gpio_remove, + .driver = { + .name = PPS_GPIO_NAME, + .owner = THIS_MODULE, + .of_match_table = pps_gpio_dt_ids, + }, +}; + +module_platform_driver(pps_gpio_driver); +MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>"); +MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>"); +MODULE_DESCRIPTION("Use GPIO pin as PPS source"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.0.0"); diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c index e7ef5b8186d..436b4e4e71a 100644 --- a/drivers/pps/clients/pps-ktimer.c +++ b/drivers/pps/clients/pps-ktimer.c @@ -19,6 +19,7 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/module.h> @@ -31,7 +32,7 @@ * Global variables */ -static int source; +static struct pps_device *pps; static struct timer_list ktimer; /* @@ -40,36 +41,17 @@ static struct timer_list ktimer; static void pps_ktimer_event(unsigned long ptr) { - struct timespec __ts; - struct pps_ktime ts; + struct pps_event_time ts; /* First of all we get the time stamp... */ - getnstimeofday(&__ts); + pps_get_ts(&ts); - pr_info("PPS event at %lu\n", jiffies); - - /* ... and translate it to PPS time data struct */ - ts.sec = __ts.tv_sec; - ts.nsec = __ts.tv_nsec; - - pps_event(source, &ts, PPS_CAPTUREASSERT, NULL); + pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL); mod_timer(&ktimer, jiffies + HZ); } /* - * The echo function - */ - -static void pps_ktimer_echo(int source, int event, void *data) -{ - pr_info("echo %s %s for source %d\n", - event & PPS_CAPTUREASSERT ? "assert" : "", - event & PPS_CAPTURECLEAR ? "clear" : "", - source); -} - -/* * The PPS info struct */ @@ -79,7 +61,6 @@ static struct pps_source_info pps_ktimer_info = { .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC, - .echo = pps_ktimer_echo, .owner = THIS_MODULE, }; @@ -89,30 +70,27 @@ static struct pps_source_info pps_ktimer_info = { static void __exit pps_ktimer_exit(void) { - del_timer_sync(&ktimer); - pps_unregister_source(source); + dev_info(pps->dev, "ktimer PPS source unregistered\n"); - pr_info("ktimer PPS source unregistered\n"); + del_timer_sync(&ktimer); + pps_unregister_source(pps); } static int __init pps_ktimer_init(void) { - int ret; - - ret = pps_register_source(&pps_ktimer_info, + pps = pps_register_source(&pps_ktimer_info, PPS_CAPTUREASSERT | PPS_OFFSETASSERT); - if (ret < 0) { - printk(KERN_ERR "cannot register ktimer source\n"); - return ret; + if (pps == NULL) { + pr_err("cannot register PPS source\n"); + return -ENOMEM; } - source = ret; setup_timer(&ktimer, pps_ktimer_event, 0); mod_timer(&ktimer, jiffies + HZ); - pr_info("ktimer PPS source registered at %d\n", source); + dev_info(pps->dev, "ktimer PPS source registered\n"); - return 0; + return 0; } module_init(pps_ktimer_init); diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c index 8e1932d29fd..73bd3bb4d93 100644 --- a/drivers/pps/clients/pps-ldisc.c +++ b/drivers/pps/clients/pps-ldisc.c @@ -19,38 +19,37 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/module.h> #include <linux/serial_core.h> #include <linux/tty.h> #include <linux/pps_kernel.h> +#include <linux/bug.h> #define PPS_TTY_MAGIC 0x0001 -static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status, - struct timespec *ts) +static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status) { - int id = (long)tty->disc_data; - struct timespec __ts; - struct pps_ktime pps_ts; - - /* First of all we get the time stamp... */ - getnstimeofday(&__ts); - - /* Does caller give us a timestamp? */ - if (ts) { /* Yes. Let's use it! */ - pps_ts.sec = ts->tv_sec; - pps_ts.nsec = ts->tv_nsec; - } else { /* No. Do it ourself! */ - pps_ts.sec = __ts.tv_sec; - pps_ts.nsec = __ts.tv_nsec; - } + struct pps_device *pps; + struct pps_event_time ts; + + pps_get_ts(&ts); + + pps = pps_lookup_dev(tty); + /* + * This should never fail, but the ldisc locking is very + * convoluted, so don't crash just in case. + */ + if (WARN_ON_ONCE(pps == NULL)) + return; /* Now do the PPS event report */ - pps_event(id, &pps_ts, status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR, - NULL); + pps_event(pps, &ts, status ? PPS_CAPTUREASSERT : + PPS_CAPTURECLEAR, NULL); - pr_debug("PPS %s at %lu on source #%d\n", - status ? "assert" : "clear", jiffies, id); + dev_dbg(pps->dev, "PPS %s at %lu\n", + status ? "assert" : "clear", jiffies); } static int (*alias_n_tty_open)(struct tty_struct *tty); @@ -60,6 +59,7 @@ static int pps_tty_open(struct tty_struct *tty) struct pps_source_info info; struct tty_driver *drv = tty->driver; int index = tty->index + drv->name_base; + struct pps_device *pps; int ret; info.owner = THIS_MODULE; @@ -70,34 +70,43 @@ static int pps_tty_open(struct tty_struct *tty) PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \ PPS_CANWAIT | PPS_TSFMT_TSPEC; - ret = pps_register_source(&info, PPS_CAPTUREBOTH | \ + pps = pps_register_source(&info, PPS_CAPTUREBOTH | \ PPS_OFFSETASSERT | PPS_OFFSETCLEAR); - if (ret < 0) { + if (pps == NULL) { pr_err("cannot register PPS source \"%s\"\n", info.path); - return ret; + return -ENOMEM; } - tty->disc_data = (void *)(long)ret; + pps->lookup_cookie = tty; - /* Should open N_TTY ldisc too */ + /* Now open the base class N_TTY ldisc */ ret = alias_n_tty_open(tty); - if (ret < 0) - pps_unregister_source((long)tty->disc_data); + if (ret < 0) { + pr_err("cannot open tty ldisc \"%s\"\n", info.path); + goto err_unregister; + } - pr_info("PPS source #%d \"%s\" added\n", ret, info.path); + dev_info(pps->dev, "source \"%s\" added\n", info.path); return 0; + +err_unregister: + pps_unregister_source(pps); + return ret; } static void (*alias_n_tty_close)(struct tty_struct *tty); static void pps_tty_close(struct tty_struct *tty) { - int id = (long)tty->disc_data; + struct pps_device *pps = pps_lookup_dev(tty); - pps_unregister_source(id); alias_n_tty_close(tty); - pr_info("PPS source #%d removed\n", id); + if (WARN_ON(!pps)) + return; + + dev_info(pps->dev, "removed\n"); + pps_unregister_source(pps); } static struct tty_ldisc_ops pps_ldisc_ops; diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c new file mode 100644 index 00000000000..38a8bbe7481 --- /dev/null +++ b/drivers/pps/clients/pps_parport.c @@ -0,0 +1,250 @@ +/* + * pps_parport.c -- kernel parallel port PPS client + * + * + * Copyright (C) 2009 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. + */ + + +/* + * TODO: + * implement echo over SEL pin + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/irqnr.h> +#include <linux/time.h> +#include <linux/slab.h> +#include <linux/parport.h> +#include <linux/pps_kernel.h> + +#define DRVDESC "parallel port PPS client" + +/* module parameters */ + +#define CLEAR_WAIT_MAX 100 +#define CLEAR_WAIT_MAX_ERRORS 5 + +static unsigned int clear_wait = 100; +MODULE_PARM_DESC(clear_wait, + "Maximum number of port reads when polling for signal clear," + " zero turns clear edge capture off entirely"); +module_param(clear_wait, uint, 0); + + +/* internal per port structure */ +struct pps_client_pp { + struct pardevice *pardev; /* parport device */ + struct pps_device *pps; /* PPS device */ + unsigned int cw; /* port clear timeout */ + unsigned int cw_err; /* number of timeouts */ +}; + +static inline int signal_is_set(struct parport *port) +{ + return (port->ops->read_status(port) & PARPORT_STATUS_ACK) != 0; +} + +/* parport interrupt handler */ +static void parport_irq(void *handle) +{ + struct pps_event_time ts_assert, ts_clear; + struct pps_client_pp *dev = handle; + struct parport *port = dev->pardev->port; + unsigned int i; + unsigned long flags; + + /* first of all we get the time stamp... */ + pps_get_ts(&ts_assert); + + if (dev->cw == 0) + /* clear edge capture disabled */ + goto out_assert; + + /* try capture the clear edge */ + + /* We have to disable interrupts here. The idea is to prevent + * other interrupts on the same processor to introduce random + * lags while polling the port. Reading from IO port is known + * to take approximately 1us while other interrupt handlers can + * take much more potentially. + * + * Interrupts won't be disabled for a long time because the + * number of polls is limited by clear_wait parameter which is + * kept rather low. So it should never be an issue. + */ + local_irq_save(flags); + /* check the signal (no signal means the pulse is lost this time) */ + if (!signal_is_set(port)) { + local_irq_restore(flags); + dev_err(dev->pps->dev, "lost the signal\n"); + goto out_assert; + } + + /* poll the port until the signal is unset */ + for (i = dev->cw; i; i--) + if (!signal_is_set(port)) { + pps_get_ts(&ts_clear); + local_irq_restore(flags); + dev->cw_err = 0; + goto out_both; + } + local_irq_restore(flags); + + /* timeout */ + dev->cw_err++; + if (dev->cw_err >= CLEAR_WAIT_MAX_ERRORS) { + dev_err(dev->pps->dev, "disabled clear edge capture after %d" + " timeouts\n", dev->cw_err); + dev->cw = 0; + dev->cw_err = 0; + } + +out_assert: + /* fire assert event */ + pps_event(dev->pps, &ts_assert, + PPS_CAPTUREASSERT, NULL); + return; + +out_both: + /* fire assert event */ + pps_event(dev->pps, &ts_assert, + PPS_CAPTUREASSERT, NULL); + /* fire clear event */ + pps_event(dev->pps, &ts_clear, + PPS_CAPTURECLEAR, NULL); + return; +} + +static void parport_attach(struct parport *port) +{ + struct pps_client_pp *device; + struct pps_source_info info = { + .name = KBUILD_MODNAME, + .path = "", + .mode = PPS_CAPTUREBOTH | \ + PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \ + PPS_ECHOASSERT | PPS_ECHOCLEAR | \ + PPS_CANWAIT | PPS_TSFMT_TSPEC, + .owner = THIS_MODULE, + .dev = NULL + }; + + device = kzalloc(sizeof(struct pps_client_pp), GFP_KERNEL); + if (!device) { + pr_err("memory allocation failed, not attaching\n"); + return; + } + + device->pardev = parport_register_device(port, KBUILD_MODNAME, + NULL, NULL, parport_irq, PARPORT_FLAG_EXCL, device); + if (!device->pardev) { + pr_err("couldn't register with %s\n", port->name); + goto err_free; + } + + if (parport_claim_or_block(device->pardev) < 0) { + pr_err("couldn't claim %s\n", port->name); + goto err_unregister_dev; + } + + device->pps = pps_register_source(&info, + PPS_CAPTUREBOTH | PPS_OFFSETASSERT | PPS_OFFSETCLEAR); + if (device->pps == NULL) { + pr_err("couldn't register PPS source\n"); + goto err_release_dev; + } + + device->cw = clear_wait; + + port->ops->enable_irq(port); + + pr_info("attached to %s\n", port->name); + + return; + +err_release_dev: + parport_release(device->pardev); +err_unregister_dev: + parport_unregister_device(device->pardev); +err_free: + kfree(device); +} + +static void parport_detach(struct parport *port) +{ + struct pardevice *pardev = port->cad; + struct pps_client_pp *device; + + /* FIXME: oooh, this is ugly! */ + if (strcmp(pardev->name, KBUILD_MODNAME)) + /* not our port */ + return; + + device = pardev->private; + + port->ops->disable_irq(port); + pps_unregister_source(device->pps); + parport_release(pardev); + parport_unregister_device(pardev); + kfree(device); +} + +static struct parport_driver pps_parport_driver = { + .name = KBUILD_MODNAME, + .attach = parport_attach, + .detach = parport_detach, +}; + +/* module staff */ + +static int __init pps_parport_init(void) +{ + int ret; + + pr_info(DRVDESC "\n"); + + if (clear_wait > CLEAR_WAIT_MAX) { + pr_err("clear_wait value should be not greater" + " then %d\n", CLEAR_WAIT_MAX); + return -EINVAL; + } + + ret = parport_register_driver(&pps_parport_driver); + if (ret) { + pr_err("unable to register with parport\n"); + return ret; + } + + return 0; +} + +static void __exit pps_parport_exit(void) +{ + parport_unregister_driver(&pps_parport_driver); +} + +module_init(pps_parport_init); +module_exit(pps_parport_exit); + +MODULE_AUTHOR("Alexander Gordeev <lasaine@lvk.cs.msu.su>"); +MODULE_DESCRIPTION(DRVDESC); +MODULE_LICENSE("GPL"); diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig new file mode 100644 index 00000000000..e4c4f3dc072 --- /dev/null +++ b/drivers/pps/generators/Kconfig @@ -0,0 +1,13 @@ +# +# PPS generators configuration +# + +comment "PPS generators support" + +config PPS_GENERATOR_PARPORT + tristate "Parallel port PPS signal generator" + depends on PARPORT && BROKEN + help + If you say yes here you get support for a PPS signal generator which + utilizes STROBE pin of a parallel port to send PPS signals. It uses + parport abstraction layer and hrtimers to precisely control the signal. diff --git a/drivers/pps/generators/Makefile b/drivers/pps/generators/Makefile new file mode 100644 index 00000000000..303304a6b8e --- /dev/null +++ b/drivers/pps/generators/Makefile @@ -0,0 +1,9 @@ +# +# Makefile for PPS generators. +# + +obj-$(CONFIG_PPS_GENERATOR_PARPORT) += pps_gen_parport.o + +ifeq ($(CONFIG_PPS_DEBUG),y) +EXTRA_CFLAGS += -DDEBUG +endif diff --git a/drivers/pps/generators/pps_gen_parport.c b/drivers/pps/generators/pps_gen_parport.c new file mode 100644 index 00000000000..dcd39fba6dd --- /dev/null +++ b/drivers/pps/generators/pps_gen_parport.c @@ -0,0 +1,277 @@ +/* + * pps_gen_parport.c -- kernel parallel port PPS signal generator + * + * + * Copyright (C) 2009 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. + */ + + +/* + * TODO: + * fix issues when realtime clock is adjusted in a leap + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/time.h> +#include <linux/hrtimer.h> +#include <linux/parport.h> + +#define DRVDESC "parallel port PPS signal generator" + +#define SIGNAL 0 +#define NO_SIGNAL PARPORT_CONTROL_STROBE + +/* module parameters */ + +#define SEND_DELAY_MAX 100000 + +static unsigned int send_delay = 30000; +MODULE_PARM_DESC(delay, + "Delay between setting and dropping the signal (ns)"); +module_param_named(delay, send_delay, uint, 0); + + +#define SAFETY_INTERVAL 3000 /* set the hrtimer earlier for safety (ns) */ + +/* internal per port structure */ +struct pps_generator_pp { + struct pardevice *pardev; /* parport device */ + struct hrtimer timer; + long port_write_time; /* calibrated port write time (ns) */ +}; + +static struct pps_generator_pp device = { + .pardev = NULL, +}; + +static int attached; + +/* calibrated time between a hrtimer event and the reaction */ +static long hrtimer_error = SAFETY_INTERVAL; + +/* the kernel hrtimer event */ +static enum hrtimer_restart hrtimer_event(struct hrtimer *timer) +{ + struct timespec expire_time, ts1, ts2, ts3, dts; + struct pps_generator_pp *dev; + struct parport *port; + long lim, delta; + unsigned long flags; + + /* We have to disable interrupts here. The idea is to prevent + * other interrupts on the same processor to introduce random + * lags while polling the clock. getnstimeofday() takes <1us on + * most machines while other interrupt handlers can take much + * more potentially. + * + * NB: approx time with blocked interrupts = + * send_delay + 3 * SAFETY_INTERVAL + */ + local_irq_save(flags); + + /* first of all we get the time stamp... */ + getnstimeofday(&ts1); + expire_time = ktime_to_timespec(hrtimer_get_softexpires(timer)); + dev = container_of(timer, struct pps_generator_pp, timer); + lim = NSEC_PER_SEC - send_delay - dev->port_write_time; + + /* check if we are late */ + if (expire_time.tv_sec != ts1.tv_sec || ts1.tv_nsec > lim) { + local_irq_restore(flags); + pr_err("we are late this time %ld.%09ld\n", + ts1.tv_sec, ts1.tv_nsec); + goto done; + } + + /* busy loop until the time is right for an assert edge */ + do { + getnstimeofday(&ts2); + } while (expire_time.tv_sec == ts2.tv_sec && ts2.tv_nsec < lim); + + /* set the signal */ + port = dev->pardev->port; + port->ops->write_control(port, SIGNAL); + + /* busy loop until the time is right for a clear edge */ + lim = NSEC_PER_SEC - dev->port_write_time; + do { + getnstimeofday(&ts2); + } while (expire_time.tv_sec == ts2.tv_sec && ts2.tv_nsec < lim); + + /* unset the signal */ + port->ops->write_control(port, NO_SIGNAL); + + getnstimeofday(&ts3); + + local_irq_restore(flags); + + /* update calibrated port write time */ + dts = timespec_sub(ts3, ts2); + dev->port_write_time = + (dev->port_write_time + timespec_to_ns(&dts)) >> 1; + +done: + /* update calibrated hrtimer error */ + dts = timespec_sub(ts1, expire_time); + delta = timespec_to_ns(&dts); + /* If the new error value is bigger then the old, use the new + * value, if not then slowly move towards the new value. This + * way it should be safe in bad conditions and efficient in + * good conditions. + */ + if (delta >= hrtimer_error) + hrtimer_error = delta; + else + hrtimer_error = (3 * hrtimer_error + delta) >> 2; + + /* update the hrtimer expire time */ + hrtimer_set_expires(timer, + ktime_set(expire_time.tv_sec + 1, + NSEC_PER_SEC - (send_delay + + dev->port_write_time + SAFETY_INTERVAL + + 2 * hrtimer_error))); + + return HRTIMER_RESTART; +} + +/* calibrate port write time */ +#define PORT_NTESTS_SHIFT 5 +static void calibrate_port(struct pps_generator_pp *dev) +{ + struct parport *port = dev->pardev->port; + int i; + long acc = 0; + + for (i = 0; i < (1 << PORT_NTESTS_SHIFT); i++) { + struct timespec a, b; + unsigned long irq_flags; + + local_irq_save(irq_flags); + getnstimeofday(&a); + port->ops->write_control(port, NO_SIGNAL); + getnstimeofday(&b); + local_irq_restore(irq_flags); + + b = timespec_sub(b, a); + acc += timespec_to_ns(&b); + } + + dev->port_write_time = acc >> PORT_NTESTS_SHIFT; + pr_info("port write takes %ldns\n", dev->port_write_time); +} + +static inline ktime_t next_intr_time(struct pps_generator_pp *dev) +{ + struct timespec ts; + + getnstimeofday(&ts); + + return ktime_set(ts.tv_sec + + ((ts.tv_nsec > 990 * NSEC_PER_MSEC) ? 1 : 0), + NSEC_PER_SEC - (send_delay + + dev->port_write_time + 3 * SAFETY_INTERVAL)); +} + +static void parport_attach(struct parport *port) +{ + if (attached) { + /* we already have a port */ + return; + } + + device.pardev = parport_register_device(port, KBUILD_MODNAME, + NULL, NULL, NULL, PARPORT_FLAG_EXCL, &device); + if (!device.pardev) { + pr_err("couldn't register with %s\n", port->name); + return; + } + + if (parport_claim_or_block(device.pardev) < 0) { + pr_err("couldn't claim %s\n", port->name); + goto err_unregister_dev; + } + + pr_info("attached to %s\n", port->name); + attached = 1; + + calibrate_port(&device); + + hrtimer_init(&device.timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); + device.timer.function = hrtimer_event; + hrtimer_start(&device.timer, next_intr_time(&device), HRTIMER_MODE_ABS); + + return; + +err_unregister_dev: + parport_unregister_device(device.pardev); +} + +static void parport_detach(struct parport *port) +{ + if (port->cad != device.pardev) + return; /* not our port */ + + hrtimer_cancel(&device.timer); + parport_release(device.pardev); + parport_unregister_device(device.pardev); +} + +static struct parport_driver pps_gen_parport_driver = { + .name = KBUILD_MODNAME, + .attach = parport_attach, + .detach = parport_detach, +}; + +/* module staff */ + +static int __init pps_gen_parport_init(void) +{ + int ret; + + pr_info(DRVDESC "\n"); + + if (send_delay > SEND_DELAY_MAX) { + pr_err("delay value should be not greater" + " then %d\n", SEND_DELAY_MAX); + return -EINVAL; + } + + ret = parport_register_driver(&pps_gen_parport_driver); + if (ret) { + pr_err("unable to register with parport\n"); + return ret; + } + + return 0; +} + +static void __exit pps_gen_parport_exit(void) +{ + parport_unregister_driver(&pps_gen_parport_driver); + pr_info("hrtimer avg error is %ldns\n", hrtimer_error); +} + +module_init(pps_gen_parport_init); +module_exit(pps_gen_parport_exit); + +MODULE_AUTHOR("Alexander Gordeev <lasaine@lvk.cs.msu.su>"); +MODULE_DESCRIPTION(DRVDESC); +MODULE_LICENSE("GPL"); diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index 1aa02db3ff4..cdad4d95b20 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -19,24 +19,20 @@ * 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/init.h> #include <linux/sched.h> #include <linux/time.h> +#include <linux/timex.h> #include <linux/spinlock.h> -#include <linux/idr.h> #include <linux/fs.h> #include <linux/pps_kernel.h> #include <linux/slab.h> -/* - * Global variables - */ - -DEFINE_SPINLOCK(pps_idr_lock); -DEFINE_IDR(pps_idr); +#include "kc.h" /* * Local functions @@ -56,64 +52,18 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset) ts->sec += offset->sec; } -/* - * Exported functions - */ - -/* pps_get_source - find a PPS source - * @source: the PPS source ID. - * - * This function is used to find an already registered PPS source into the - * system. - * - * The function returns NULL if found nothing, otherwise it returns a pointer - * to the PPS source data struct (the refcounter is incremented by 1). - */ - -struct pps_device *pps_get_source(int source) +static void pps_echo_client_default(struct pps_device *pps, int event, + void *data) { - struct pps_device *pps; - unsigned long flags; - - spin_lock_irqsave(&pps_idr_lock, flags); - - pps = idr_find(&pps_idr, source); - if (pps != NULL) - atomic_inc(&pps->usage); - - spin_unlock_irqrestore(&pps_idr_lock, flags); - - return pps; + dev_info(pps->dev, "echo %s %s\n", + event & PPS_CAPTUREASSERT ? "assert" : "", + event & PPS_CAPTURECLEAR ? "clear" : ""); } -/* pps_put_source - free the PPS source data - * @pps: a pointer to the PPS source. - * - * This function is used to free a PPS data struct if its refcount is 0. +/* + * Exported functions */ -void pps_put_source(struct pps_device *pps) -{ - unsigned long flags; - - spin_lock_irqsave(&pps_idr_lock, flags); - BUG_ON(atomic_read(&pps->usage) == 0); - - if (!atomic_dec_and_test(&pps->usage)) { - pps = NULL; - goto exit; - } - - /* No more reference to the PPS source. We can safely remove the - * PPS data struct. - */ - idr_remove(&pps_idr, pps->id); - -exit: - spin_unlock_irqrestore(&pps_idr_lock, flags); - kfree(pps); -} - /* pps_register_source - add a PPS source in the system * @info: the PPS info struct * @default_params: the default PPS parameters of the new source @@ -122,31 +72,24 @@ exit: * source is described by info's fields and it will have, as default PPS * parameters, the ones specified into default_params. * - * The function returns, in case of success, the PPS source ID. + * The function returns, in case of success, the PPS device. Otherwise NULL. */ -int pps_register_source(struct pps_source_info *info, int default_params) +struct pps_device *pps_register_source(struct pps_source_info *info, + int default_params) { struct pps_device *pps; - int id; int err; /* Sanity checks */ if ((info->mode & default_params) != default_params) { - printk(KERN_ERR "pps: %s: unsupported default parameters\n", - info->name); - err = -EINVAL; - goto pps_register_source_exit; - } - if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 && - info->echo == NULL) { - printk(KERN_ERR "pps: %s: echo function is not defined\n", + pr_err("%s: unsupported default parameters\n", info->name); err = -EINVAL; goto pps_register_source_exit; } if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { - printk(KERN_ERR "pps: %s: unspecified time format\n", + pr_err("%s: unspecified time format\n", info->name); err = -EINVAL; goto pps_register_source_exit; @@ -159,103 +102,62 @@ int pps_register_source(struct pps_source_info *info, int default_params) goto pps_register_source_exit; } - /* These initializations must be done before calling idr_get_new() + /* These initializations must be done before calling idr_alloc() * in order to avoid reces into pps_event(). */ pps->params.api_version = PPS_API_VERS; pps->params.mode = default_params; pps->info = *info; + /* check for default echo function */ + if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) && + pps->info.echo == NULL) + pps->info.echo = pps_echo_client_default; + init_waitqueue_head(&pps->queue); spin_lock_init(&pps->lock); - atomic_set(&pps->usage, 1); - - /* Get new ID for the new PPS source */ - if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) { - err = -ENOMEM; - goto kfree_pps; - } - - spin_lock_irq(&pps_idr_lock); - - /* Now really allocate the PPS source. - * After idr_get_new() calling the new source will be freely available - * into the kernel. - */ - err = idr_get_new(&pps_idr, pps, &id); - if (err < 0) { - spin_unlock_irq(&pps_idr_lock); - goto kfree_pps; - } - - id = id & MAX_ID_MASK; - if (id >= PPS_MAX_SOURCES) { - spin_unlock_irq(&pps_idr_lock); - - printk(KERN_ERR "pps: %s: too many PPS sources in the system\n", - info->name); - err = -EBUSY; - goto free_idr; - } - pps->id = id; - - spin_unlock_irq(&pps_idr_lock); /* Create the char device */ err = pps_register_cdev(pps); if (err < 0) { - printk(KERN_ERR "pps: %s: unable to create char device\n", + pr_err("%s: unable to create char device\n", info->name); - goto free_idr; + goto kfree_pps; } - pr_info("new PPS source %s at ID %d\n", info->name, id); - - return id; + dev_info(pps->dev, "new PPS source %s\n", info->name); -free_idr: - spin_lock_irq(&pps_idr_lock); - idr_remove(&pps_idr, id); - spin_unlock_irq(&pps_idr_lock); + return pps; kfree_pps: kfree(pps); pps_register_source_exit: - printk(KERN_ERR "pps: %s: unable to register source\n", info->name); + pr_err("%s: unable to register source\n", info->name); - return err; + return NULL; } EXPORT_SYMBOL(pps_register_source); /* pps_unregister_source - remove a PPS source from the system - * @source: the PPS source ID + * @pps: the PPS source * * This function is used to remove a previously registered PPS source from * the system. */ -void pps_unregister_source(int source) +void pps_unregister_source(struct pps_device *pps) { - struct pps_device *pps; - - spin_lock_irq(&pps_idr_lock); - pps = idr_find(&pps_idr, source); - - if (!pps) { - BUG(); - spin_unlock_irq(&pps_idr_lock); - return; - } - spin_unlock_irq(&pps_idr_lock); - + pps_kc_remove(pps); pps_unregister_cdev(pps); - pps_put_source(pps); + + /* don't have to kfree(pps) here because it will be done on + * device destruction */ } EXPORT_SYMBOL(pps_unregister_source); /* pps_event - register a PPS event into the system - * @source: the PPS source ID + * @pps: the PPS device * @ts: the event timestamp * @event: the event type * @data: userdef pointer @@ -263,78 +165,72 @@ EXPORT_SYMBOL(pps_unregister_source); * This function is used by each PPS client in order to register a new * PPS event into the system (it's usually called inside an IRQ handler). * - * If an echo function is associated with the PPS source it will be called + * If an echo function is associated with the PPS device it will be called * as: - * pps->info.echo(source, event, data); + * pps->info.echo(pps, event, data); */ - -void pps_event(int source, struct pps_ktime *ts, int event, void *data) +void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event, + void *data) { - struct pps_device *pps; unsigned long flags; int captured = 0; + struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 }; - if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) { - printk(KERN_ERR "pps: unknown event (%x) for source %d\n", - event, source); - return; - } + /* check event type */ + BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0); - pps = pps_get_source(source); - if (!pps) - return; + dev_dbg(pps->dev, "PPS event at %ld.%09ld\n", + ts->ts_real.tv_sec, ts->ts_real.tv_nsec); - pr_debug("PPS event on source %d at %llu.%06u\n", - pps->id, (unsigned long long) ts->sec, ts->nsec); + timespec_to_pps_ktime(&ts_real, ts->ts_real); spin_lock_irqsave(&pps->lock, flags); /* Must call the echo function? */ if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR))) - pps->info.echo(source, event, data); + pps->info.echo(pps, event, data); /* Check the event */ pps->current_mode = pps->params.mode; - if ((event & PPS_CAPTUREASSERT) & - (pps->params.mode & PPS_CAPTUREASSERT)) { + if (event & pps->params.mode & PPS_CAPTUREASSERT) { /* We have to add an offset? */ if (pps->params.mode & PPS_OFFSETASSERT) - pps_add_offset(ts, &pps->params.assert_off_tu); + pps_add_offset(&ts_real, + &pps->params.assert_off_tu); /* Save the time stamp */ - pps->assert_tu = *ts; + pps->assert_tu = ts_real; pps->assert_sequence++; - pr_debug("capture assert seq #%u for source %d\n", - pps->assert_sequence, source); + dev_dbg(pps->dev, "capture assert seq #%u\n", + pps->assert_sequence); captured = ~0; } - if ((event & PPS_CAPTURECLEAR) & - (pps->params.mode & PPS_CAPTURECLEAR)) { + if (event & pps->params.mode & PPS_CAPTURECLEAR) { /* We have to add an offset? */ if (pps->params.mode & PPS_OFFSETCLEAR) - pps_add_offset(ts, &pps->params.clear_off_tu); + pps_add_offset(&ts_real, + &pps->params.clear_off_tu); /* Save the time stamp */ - pps->clear_tu = *ts; + pps->clear_tu = ts_real; pps->clear_sequence++; - pr_debug("capture clear seq #%u for source %d\n", - pps->clear_sequence, source); + dev_dbg(pps->dev, "capture clear seq #%u\n", + pps->clear_sequence); captured = ~0; } - /* Wake up iif captured somthing */ + pps_kc_event(pps, ts, event); + + /* Wake up if captured something */ if (captured) { - pps->go = ~0; - wake_up_interruptible(&pps->queue); + pps->last_ev++; + wake_up_interruptible_all(&pps->queue); kill_fasync(&pps->async_queue, SIGIO, POLL_IN); } spin_unlock_irqrestore(&pps->lock, flags); - - /* Now we can release the PPS source for (possible) deregistration */ - pps_put_source(pps); } EXPORT_SYMBOL(pps_event); diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c new file mode 100644 index 00000000000..e219db1f1c8 --- /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 */ +static DEFINE_SPINLOCK(pps_kc_hardpps_lock); +/* PPS API (RFC 2783): current source and mode for kernel consumer */ +static struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */ +static 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 00000000000..d296fcd0a17 --- /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 ca5183bdad8..2f07cd61566 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -19,6 +19,7 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/module.h> @@ -26,9 +27,13 @@ #include <linux/sched.h> #include <linux/uaccess.h> #include <linux/idr.h> +#include <linux/mutex.h> #include <linux/cdev.h> #include <linux/poll.h> #include <linux/pps_kernel.h> +#include <linux/slab.h> + +#include "kc.h" /* * Local variables @@ -37,6 +42,9 @@ static dev_t pps_devt; static struct class *pps_class; +static DEFINE_MUTEX(pps_idr_lock); +static DEFINE_IDR(pps_idr); + /* * Char device methods */ @@ -61,15 +69,13 @@ static long pps_cdev_ioctl(struct file *file, { struct pps_device *pps = file->private_data; struct pps_kparams params; - struct pps_fdata fdata; - unsigned long ticks; void __user *uarg = (void __user *) arg; int __user *iuarg = (int __user *) arg; int err; switch (cmd) { case PPS_GETPARAMS: - pr_debug("PPS_GETPARAMS: source %d\n", pps->id); + dev_dbg(pps->dev, "PPS_GETPARAMS\n"); spin_lock_irq(&pps->lock); @@ -85,7 +91,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_SETPARAMS: - pr_debug("PPS_SETPARAMS: source %d\n", pps->id); + dev_dbg(pps->dev, "PPS_SETPARAMS\n"); /* Check the capabilities */ if (!capable(CAP_SYS_TIME)) @@ -95,14 +101,14 @@ static long pps_cdev_ioctl(struct file *file, if (err) return -EFAULT; if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { - pr_debug("capture mode unspecified (%x)\n", + dev_dbg(pps->dev, "capture mode unspecified (%x)\n", params.mode); return -EINVAL; } /* Check for supported capabilities */ if ((params.mode & ~pps->info.mode) != 0) { - pr_debug("unsupported capabilities (%x)\n", + dev_dbg(pps->dev, "unsupported capabilities (%x)\n", params.mode); return -EINVAL; } @@ -115,7 +121,7 @@ static long pps_cdev_ioctl(struct file *file, /* Restore the read only parameters */ if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { /* section 3.3 of RFC 2783 interpreted */ - pr_debug("time format unspecified (%x)\n", + dev_dbg(pps->dev, "time format unspecified (%x)\n", params.mode); pps->params.mode |= PPS_TSFMT_TSPEC; } @@ -128,7 +134,7 @@ static long pps_cdev_ioctl(struct file *file, break; case PPS_GETCAP: - pr_debug("PPS_GETCAP: source %d\n", pps->id); + dev_dbg(pps->dev, "PPS_GETCAP\n"); err = put_user(pps->info.mode, iuarg); if (err) @@ -136,20 +142,26 @@ static long pps_cdev_ioctl(struct file *file, break; - case PPS_FETCH: - pr_debug("PPS_FETCH: source %d\n", pps->id); + case PPS_FETCH: { + struct pps_fdata fdata; + unsigned int ev; + + dev_dbg(pps->dev, "PPS_FETCH\n"); err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); if (err) return -EFAULT; - pps->go = 0; + ev = pps->last_ev; /* Manage the timeout */ if (fdata.timeout.flags & PPS_TIME_INVALID) - err = wait_event_interruptible(pps->queue, pps->go); + err = wait_event_interruptible(pps->queue, + ev != pps->last_ev); else { - pr_debug("timeout %lld.%09d\n", + unsigned long ticks; + + dev_dbg(pps->dev, "timeout %lld.%09d\n", (long long) fdata.timeout.sec, fdata.timeout.nsec); ticks = fdata.timeout.sec * HZ; @@ -157,7 +169,9 @@ static long pps_cdev_ioctl(struct file *file, if (ticks != 0) { err = wait_event_interruptible_timeout( - pps->queue, pps->go, ticks); + pps->queue, + ev != pps->last_ev, + ticks); if (err == 0) return -ETIMEDOUT; } @@ -165,7 +179,7 @@ static long pps_cdev_ioctl(struct file *file, /* Check for pending signals */ if (err == -ERESTARTSYS) { - pr_debug("pending signal caught\n"); + dev_dbg(pps->dev, "pending signal caught\n"); return -EINTR; } @@ -185,10 +199,44 @@ static long pps_cdev_ioctl(struct file *file, return -EFAULT; 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; @@ -198,24 +246,16 @@ static int pps_cdev_open(struct inode *inode, struct file *file) { struct pps_device *pps = container_of(inode->i_cdev, struct pps_device, cdev); - int found; - - found = pps_get_source(pps->id) != 0; - if (!found) - return -ENODEV; - file->private_data = pps; - + kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = file->private_data; - - /* Free the PPS source and wake up (possible) deregistration */ - pps_put_source(pps); - + struct pps_device *pps = container_of(inode->i_cdev, + struct pps_device, cdev); + kobject_put(&pps->dev->kobj); return 0; } @@ -233,25 +273,64 @@ static const struct file_operations pps_cdev_fops = { .release = pps_cdev_release, }; +static void pps_device_destruct(struct device *dev) +{ + struct pps_device *pps = dev_get_drvdata(dev); + + cdev_del(&pps->cdev); + + /* Now we can release the ID for re-use */ + pr_debug("deallocating pps%d\n", pps->id); + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); + mutex_unlock(&pps_idr_lock); + + kfree(dev); + kfree(pps); +} + int pps_register_cdev(struct pps_device *pps) { int err; + dev_t devt; + + mutex_lock(&pps_idr_lock); + /* + * Get new ID for the new PPS source. After idr_alloc() calling + * the new source will be freely available into the kernel. + */ + err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL); + if (err < 0) { + if (err == -ENOSPC) { + pr_err("%s: too many PPS sources in the system\n", + pps->info.name); + err = -EBUSY; + } + goto out_unlock; + } + pps->id = err; + mutex_unlock(&pps_idr_lock); + + devt = MKDEV(MAJOR(pps_devt), pps->id); - pps->devno = MKDEV(MAJOR(pps_devt), pps->id); cdev_init(&pps->cdev, &pps_cdev_fops); pps->cdev.owner = pps->info.owner; - err = cdev_add(&pps->cdev, pps->devno, 1); + err = cdev_add(&pps->cdev, devt, 1); if (err) { - printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n", + pr_err("%s: failed to add char device %d:%d\n", pps->info.name, MAJOR(pps_devt), pps->id); - return err; + goto free_idr; } - pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL, + pps->dev = device_create(pps_class, pps->info.dev, devt, pps, "pps%d", pps->id); - if (IS_ERR(pps->dev)) + if (IS_ERR(pps->dev)) { + err = PTR_ERR(pps->dev); goto del_cdev; - dev_set_drvdata(pps->dev, pps); + } + + /* Override the release function with our own */ + pps->dev->release = pps_device_destruct; pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, MAJOR(pps_devt), pps->id); @@ -261,14 +340,52 @@ int pps_register_cdev(struct pps_device *pps) del_cdev: cdev_del(&pps->cdev); +free_idr: + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); +out_unlock: + mutex_unlock(&pps_idr_lock); return err; } void pps_unregister_cdev(struct pps_device *pps) { - device_destroy(pps_class, pps->devno); - cdev_del(&pps->cdev); + pr_debug("unregistering pps%d\n", pps->id); + pps->lookup_cookie = NULL; + device_destroy(pps_class, pps->dev->devt); +} + +/* + * Look up a pps device by magic cookie. + * The cookie is usually a pointer to some enclosing device, but this + * code doesn't care; you should never be dereferencing it. + * + * This is a bit of a kludge that is currently used only by the PPS + * serial line discipline. It may need to be tweaked when a second user + * is found. + * + * There is no function interface for setting the lookup_cookie field. + * It's initialized to NULL when the pps device is created, and if a + * client wants to use it, just fill it in afterward. + * + * The cookie is automatically set to NULL in pps_unregister_source() + * so that it will not be used again, even if the pps device cannot + * be removed from the idr due to pending references holding the minor + * number in use. + */ +struct pps_device *pps_lookup_dev(void const *cookie) +{ + struct pps_device *pps; + unsigned id; + + rcu_read_lock(); + idr_for_each_entry(&pps_idr, pps, id) + if (cookie == pps->lookup_cookie) + break; + rcu_read_unlock(); + return pps; } +EXPORT_SYMBOL(pps_lookup_dev); /* * Module stuff @@ -285,15 +402,15 @@ static int __init pps_init(void) int err; pps_class = class_create(THIS_MODULE, "pps"); - if (!pps_class) { - printk(KERN_ERR "pps: failed to allocate class\n"); - return -ENOMEM; + if (IS_ERR(pps_class)) { + pr_err("failed to allocate class\n"); + return PTR_ERR(pps_class); } - pps_class->dev_attrs = pps_attrs; + pps_class->dev_groups = pps_groups; err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); if (err < 0) { - printk(KERN_ERR "pps: failed to allocate char device region\n"); + pr_err("failed to allocate char device region\n"); goto remove_class; } diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c index ef0978c71ee..aefb75d6709 100644 --- a/drivers/pps/sysfs.c +++ b/drivers/pps/sysfs.c @@ -29,8 +29,8 @@ * Attribute functions */ -static ssize_t pps_show_assert(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t assert_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); @@ -41,9 +41,10 @@ static ssize_t pps_show_assert(struct device *dev, (long long) pps->assert_tu.sec, pps->assert_tu.nsec, pps->assert_sequence); } +static DEVICE_ATTR_RO(assert); -static ssize_t pps_show_clear(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t clear_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); @@ -54,45 +55,59 @@ static ssize_t pps_show_clear(struct device *dev, (long long) pps->clear_tu.sec, pps->clear_tu.nsec, pps->clear_sequence); } +static DEVICE_ATTR_RO(clear); -static ssize_t pps_show_mode(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t mode_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); return sprintf(buf, "%4x\n", pps->info.mode); } +static DEVICE_ATTR_RO(mode); -static ssize_t pps_show_echo(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t echo_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); return sprintf(buf, "%d\n", !!pps->info.echo); } +static DEVICE_ATTR_RO(echo); -static ssize_t pps_show_name(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t name_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); return sprintf(buf, "%s\n", pps->info.name); } +static DEVICE_ATTR_RO(name); -static ssize_t pps_show_path(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t path_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct pps_device *pps = dev_get_drvdata(dev); return sprintf(buf, "%s\n", pps->info.path); } +static DEVICE_ATTR_RO(path); + +static struct attribute *pps_attrs[] = { + &dev_attr_assert.attr, + &dev_attr_clear.attr, + &dev_attr_mode.attr, + &dev_attr_echo.attr, + &dev_attr_name.attr, + &dev_attr_path.attr, + NULL, +}; + +static const struct attribute_group pps_group = { + .attrs = pps_attrs, +}; -struct device_attribute pps_attrs[] = { - __ATTR(assert, S_IRUGO, pps_show_assert, NULL), - __ATTR(clear, S_IRUGO, pps_show_clear, NULL), - __ATTR(mode, S_IRUGO, pps_show_mode, NULL), - __ATTR(echo, S_IRUGO, pps_show_echo, NULL), - __ATTR(name, S_IRUGO, pps_show_name, NULL), - __ATTR(path, S_IRUGO, pps_show_path, NULL), - __ATTR_NULL, +const struct attribute_group *pps_groups[] = { + &pps_group, + NULL, }; |