initial_commit

5 files changed, 565 insertions, 0 deletions

diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
new file mode 100644
index 00000000..8520a7f4
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,32 @@
+#
+# PPS clients configuration
+#
+
+if PPS
+
+comment "PPS clients support"
+
+config PPS_CLIENT_KTIMER
+	tristate "Kernel timer client (Testing client, use for debug)"
+	help
+	  If you say yes here you get support for a PPS debugging client
+	  which uses a kernel timer to generate the PPS signal.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called pps-ktimer.
+
+config PPS_CLIENT_LDISC
+	tristate "PPS line discipline"
+	depends on PPS
+	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.
+
+endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
new file mode 100644
index 00000000..4feb7e9e
--- /dev/null
+++ b/drivers/pps/clients/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for PPS clients.
+#
+
+obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= pps-ktimer.o
+obj-$(CONFIG_PPS_CLIENT_LDISC)	+= pps-ldisc.o
+obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o
+
+ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c
new file mode 100644
index 00000000..82583b0f
--- /dev/null
+++ b/drivers/pps/clients/pps-ktimer.c
@@ -0,0 +1,113 @@
+/*
+ * pps-ktimer.c -- kernel timer test client
+ *
+ *
+ * Copyright (C) 2005-2006   Rodolfo Giometti <giometti@linux.it>
+ *
+ *   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/init.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+#include <linux/pps_kernel.h>
+
+/*
+ * Global variables
+ */
+
+static struct pps_device *pps;
+static struct timer_list ktimer;
+
+/*
+ * The kernel timer
+ */
+
+static void pps_ktimer_event(unsigned long ptr)
+{
+	struct pps_event_time ts;
+
+	/* First of all we get the time stamp... */
+	pps_get_ts(&ts);
+
+	pps_event(pps, &ts, PPS_CAPTUREASSERT, NULL);
+
+	mod_timer(&ktimer, jiffies + HZ);
+}
+
+/*
+ * The echo function
+ */
+
+static void pps_ktimer_echo(struct pps_device *pps, int event, void *data)
+{
+	dev_info(pps->dev, "echo %s %s\n",
+		event & PPS_CAPTUREASSERT ? "assert" : "",
+		event & PPS_CAPTURECLEAR ? "clear" : "");
+}
+
+/*
+ * The PPS info struct
+ */
+
+static struct pps_source_info pps_ktimer_info = {
+	.name		= "ktimer",
+	.path		= "",
+	.mode		= PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
+			  PPS_ECHOASSERT |
+			  PPS_CANWAIT | PPS_TSFMT_TSPEC,
+	.echo		= pps_ktimer_echo,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_ktimer_exit(void)
+{
+	dev_info(pps->dev, "ktimer PPS source unregistered\n");
+
+	del_timer_sync(&ktimer);
+	pps_unregister_source(pps);
+}
+
+static int __init pps_ktimer_init(void)
+{
+	pps = pps_register_source(&pps_ktimer_info,
+				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
+	if (pps == NULL) {
+		pr_err("cannot register PPS source\n");
+		return -ENOMEM;
+	}
+
+	setup_timer(&ktimer, pps_ktimer_event, 0);
+	mod_timer(&ktimer, jiffies + HZ);
+
+	dev_info(pps->dev, "ktimer PPS source registered\n");
+
+	return 0;
+}
+
+module_init(pps_ktimer_init);
+module_exit(pps_ktimer_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
new file mode 100644
index 00000000..79451f2d
--- /dev/null
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -0,0 +1,153 @@
+/*
+ * pps-ldisc.c -- PPS line discipline
+ *
+ *
+ * Copyright (C) 2008	Rodolfo Giometti <giometti@linux.it>
+ *
+ *   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/module.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/pps_kernel.h>
+
+#define PPS_TTY_MAGIC		0x0001
+
+static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,
+				struct pps_event_time *ts)
+{
+	struct pps_device *pps = (struct pps_device *)tty->disc_data;
+
+	BUG_ON(pps == NULL);
+
+	/* Now do the PPS event report */
+	pps_event(pps, ts, status ? PPS_CAPTUREASSERT :
+			PPS_CAPTURECLEAR, NULL);
+
+	dev_dbg(pps->dev, "PPS %s at %lu\n",
+			status ? "assert" : "clear", jiffies);
+}
+
+static int (*alias_n_tty_open)(struct tty_struct *tty);
+
+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;
+	info.dev = NULL;
+	snprintf(info.name, PPS_MAX_NAME_LEN, "%s%d", drv->driver_name, index);
+	snprintf(info.path, PPS_MAX_NAME_LEN, "/dev/%s%d", drv->name, index);
+	info.mode = PPS_CAPTUREBOTH | \
+			PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
+			PPS_CANWAIT | PPS_TSFMT_TSPEC;
+
+	pps = pps_register_source(&info, PPS_CAPTUREBOTH | \
+				PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
+	if (pps == NULL) {
+		pr_err("cannot register PPS source \"%s\"\n", info.path);
+		return -ENOMEM;
+	}
+	tty->disc_data = pps;
+
+	/* Should open N_TTY ldisc too */
+	ret = alias_n_tty_open(tty);
+	if (ret < 0) {
+		pr_err("cannot open tty ldisc \"%s\"\n", info.path);
+		goto err_unregister;
+	}
+
+	dev_info(pps->dev, "source \"%s\" added\n", info.path);
+
+	return 0;
+
+err_unregister:
+	tty->disc_data = NULL;
+	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)
+{
+	struct pps_device *pps = (struct pps_device *)tty->disc_data;
+
+	alias_n_tty_close(tty);
+
+	tty->disc_data = NULL;
+	dev_info(pps->dev, "removed\n");
+	pps_unregister_source(pps);
+}
+
+static struct tty_ldisc_ops pps_ldisc_ops;
+
+/*
+ * Module stuff
+ */
+
+static int __init pps_tty_init(void)
+{
+	int err;
+
+	/* Inherit the N_TTY's ops */
+	n_tty_inherit_ops(&pps_ldisc_ops);
+
+	/* Save N_TTY's open()/close() methods */
+	alias_n_tty_open = pps_ldisc_ops.open;
+	alias_n_tty_close = pps_ldisc_ops.close;
+
+	/* Init PPS_TTY data */
+	pps_ldisc_ops.owner = THIS_MODULE;
+	pps_ldisc_ops.magic = PPS_TTY_MAGIC;
+	pps_ldisc_ops.name = "pps_tty";
+	pps_ldisc_ops.dcd_change = pps_tty_dcd_change;
+	pps_ldisc_ops.open = pps_tty_open;
+	pps_ldisc_ops.close = pps_tty_close;
+
+	err = tty_register_ldisc(N_PPS, &pps_ldisc_ops);
+	if (err)
+		pr_err("can't register PPS line discipline\n");
+	else
+		pr_info("PPS line discipline registered\n");
+
+	return err;
+}
+
+static void __exit pps_tty_cleanup(void)
+{
+	int err;
+
+	err = tty_unregister_ldisc(N_PPS);
+	if (err)
+		pr_err("can't unregister PPS line discipline\n");
+	else
+		pr_info("PPS line discipline removed\n");
+}
+
+module_init(pps_tty_init);
+module_exit(pps_tty_cleanup);
+
+MODULE_ALIAS_LDISC(N_PPS);
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("PPS TTY device driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c
new file mode 100644
index 00000000..c571d6dd
--- /dev/null
+++ b/drivers/pps/clients/pps_parport.c
@@ -0,0 +1,258 @@
+/*
+ * 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/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;
+}
+
+/* the PPS echo function */
+static void pps_echo(struct pps_device *pps, int event, void *data)
+{
+	dev_info(pps->dev, "echo %s %s\n",
+		event & PPS_CAPTUREASSERT ? "assert" : "",
+		event & PPS_CAPTURECLEAR ? "clear" : "");
+}
+
+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,
+		.echo		= pps_echo,
+		.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");