5 files changed, 313 insertions, 60 deletions

diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
index 4e801bd7254f..8520a7f4dd62 100644
--- a/drivers/pps/clients/Kconfig
+++ b/drivers/pps/clients/Kconfig
@@ -22,4 +22,11 @@ config PPS_CLIENT_LDISC
           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
index 812c9b19b430..4feb7e9e71ee 100644
--- a/drivers/pps/clients/Makefile
+++ b/drivers/pps/clients/Makefile
@@ -4,7 +4,6 @@
 
 obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o
 obj-$(CONFIG_PPS_CLIENT_LDISC)  += pps-ldisc.o
+obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o
 
-ifeq ($(CONFIG_PPS_DEBUG),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c
index e7ef5b8186d0..82583b0ff82d 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;
 
 /*
@@ -40,19 +41,12 @@ 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);
 }
@@ -61,12 +55,11 @@ static void pps_ktimer_event(unsigned long ptr)
  * The echo function
  */
 
-static void pps_ktimer_echo(int source, int event, void *data)
+static void pps_ktimer_echo(struct pps_device *pps, int event, void *data)
 {
-        pr_info("echo %s %s for source %d\n",
+        dev_info(pps->dev, "echo %s %s\n",
                 event & PPS_CAPTUREASSERT ? "assert" : "",
-                event & PPS_CAPTURECLEAR ? "clear" : "",
-                source);
+                event & PPS_CAPTURECLEAR ? "clear" : "");
 }
 
 /*
@@ -89,30 +82,27 @@ 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 8e1932d29fd4..79451f2dea6a 100644
--- a/drivers/pps/clients/pps-ldisc.c
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -19,6 +19,8 @@
  *   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>
@@ -27,30 +29,18 @@
 #define PPS_TTY_MAGIC           0x0001
 
 static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,
-                                struct timespec *ts)
+                                struct pps_event_time *ts)
 {
-        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_device *)tty->disc_data;
+
+        BUG_ON(pps == NULL);
 
         /* 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 +50,7 @@ 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 +61,42 @@ 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;
+        tty->disc_data = pps;
 
         /* Should open N_TTY ldisc too */
         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:
+        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)
 {
-        int id = (long)tty->disc_data;
+        struct pps_device *pps = (struct pps_device *)tty->disc_data;
 
-        pps_unregister_source(id);
         alias_n_tty_close(tty);
 
-        pr_info("PPS source #%d removed\n", id);
+        tty->disc_data = NULL;
+        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 000000000000..c571d6dd8f61
--- /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");