This patchset adds several PPS functionalities.
All patches have a specific comment but I prefer say something more:
* Patches 01-02 are just documentation about PPS support.
* Patch 03 adds PPS client support skeleton.
* Patches 04-06 add generic PPS serial support (with specific
modifications requested by Alan Cox).
* Patches 07-08 add PPS serial support for specific hardware.
Changelog:
V3 -> V2
* On patch 01:
- client name moved to pps-ktimer.
- not needed continuation characters removed.
- typos fix up.
V2 -> V1
* Old patches 01-02 removed due related to userland code and then
managed elsewhere.
* char: n_tty.c: documentation in kerneldoc form added.
* pps: pps-ldisc: avoid using global functions over in n_tty.c
Ciao,
Rodolfo
--
b/Documentation/serial/tty.txt | 4
b/drivers/char/n_tty.c | 17 ++++
b/drivers/pps/Kconfig | 2
b/drivers/pps/Makefile | 1
b/drivers/pps/clients/Kconfig | 18 ++++
b/drivers/pps/clients/Makefile | 9 ++
b/drivers/pps/clients/pps-ktimer.c | 123 +++++++++++++++++++++++++++++
b/drivers/pps/clients/pps-ldisc.c | 154 +++++++++++++++++++++++++++++++++++++
b/drivers/serial/8250.c | 16 +++
b/drivers/serial/amba-pl010.c | 15 +++
b/include/linux/serial_core.h | 11 ++
b/include/linux/tty.h | 1
b/include/linux/tty_ldisc.h | 8 +
drivers/pps/clients/Kconfig | 7 +
drivers/pps/clients/Makefile | 1
15 files changed, 386 insertions(+), 1 deletion(-)
Adds support, by using the PPS line discipline, for the PPS sources
connected with the CD (Carrier Detect) pin of a serial port.
Signed-off-by: Rodolfo Giometti <[email protected]>
---
drivers/pps/clients/Kconfig | 7 ++
drivers/pps/clients/Makefile | 1 +
drivers/pps/clients/pps-ldisc.c | 154 +++++++++++++++++++++++++++++++++++++++
include/linux/serial_core.h | 11 +++-
4 files changed, 172 insertions(+), 1 deletions(-)
create mode 100644 drivers/pps/clients/pps-ldisc.c
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
index 43ccd3b..4e801bd 100644
--- a/drivers/pps/clients/Kconfig
+++ b/drivers/pps/clients/Kconfig
@@ -15,4 +15,11 @@ config PPS_CLIENT_KTIMER
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.
+
endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
index 115572a..812c9b1 100644
--- a/drivers/pps/clients/Makefile
+++ b/drivers/pps/clients/Makefile
@@ -3,6 +3,7 @@
#
obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o
+obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o
ifeq ($(CONFIG_PPS_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
new file mode 100644
index 0000000..2607d0b
--- /dev/null
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -0,0 +1,154 @@
+/*
+ * pps-ldisc.c -- PPS line discipline
+ *
+ *
+ * Copyright (C) 2008 Rodolfo Giometti <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <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 timespec *ts)
+{
+ int id = (int) 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;
+ }
+
+ /* Now do the PPS event report */
+ pps_event(id, &pps_ts, status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR,
+ NULL);
+
+ pr_debug("PPS %s at %lu on source #%d\n",
+ status ? "assert" : "clear", jiffies, id);
+}
+
+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;
+ 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;
+
+ ret = pps_register_source(&info, PPS_CAPTUREBOTH | \
+ PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
+ if (ret < 0) {
+ pr_err("cannot register PPS source \"%s\"\n", info.path);
+ return ret;
+ }
+ tty->disc_data = (void *) ret;
+
+ /* Should open N_TTY ldisc too */
+ ret = alias_n_tty_open(tty);
+ if (ret < 0)
+ pps_unregister_source((int) tty->disc_data);
+
+ pr_info("PPS source #%d \"%s\" added\n", ret, info.path);
+
+ return 0;
+}
+
+static void (*alias_n_tty_close)(struct tty_struct *tty);
+
+static void pps_tty_close(struct tty_struct *tty)
+{
+ int id = (int) tty->disc_data;
+
+ pps_unregister_source(id);
+ alias_n_tty_close(tty);
+
+ pr_info("PPS source #%d removed\n", id);
+}
+
+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 <[email protected]>");
+MODULE_DESCRIPTION("PPS TTY device driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 8c3dd36..78dd1e7 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -491,9 +491,13 @@ uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
{
struct uart_state *state = uport->state;
struct tty_port *port = &state->port;
+ struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
+ struct timespec ts;
- uport->icount.dcd++;
+ if (ld && ld->ops->dcd_change)
+ getnstimeofday(&ts);
+ uport->icount.dcd++;
#ifdef CONFIG_HARD_PPS
if ((uport->flags & UPF_HARDPPS_CD) && status)
hardpps();
@@ -505,6 +509,11 @@ uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
else if (port->tty)
tty_hangup(port->tty);
}
+
+ if (ld && ld->ops->dcd_change)
+ ld->ops->dcd_change(port->tty, status, &ts);
+ if (ld)
+ tty_ldisc_deref(ld);
}
/**
--
1.6.3.3
This new method can be used to init a new struct tty_ldisc_ops as the
default tty_ldisc_N_TTY struct.
Signed-off-by: Rodolfo Giometti <[email protected]>
---
drivers/char/n_tty.c | 17 +++++++++++++++++
include/linux/tty.h | 1 +
2 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 2e50f4d..bdae832 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -48,6 +48,7 @@
#include <linux/audit.h>
#include <linux/file.h>
#include <linux/uaccess.h>
+#include <linux/module.h>
#include <asm/system.h>
@@ -2091,3 +2092,19 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
.receive_buf = n_tty_receive_buf,
.write_wakeup = n_tty_write_wakeup
};
+
+/**
+ * n_tty_inherit_ops - inherit N_TTY methods
+ * @ops: struct tty_ldisc_ops where to save N_TTY methods
+ *
+ * Used by a generic struct tty_ldisc_ops to easily inherit N_TTY
+ * methods.
+ */
+
+void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
+{
+ *ops = tty_ldisc_N_TTY;
+ ops->owner = NULL;
+ ops->refcount = ops->flags = 0;
+}
+EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 6abfcf5..d6cc652 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -504,6 +504,7 @@ extern void tty_ldisc_enable(struct tty_struct *tty);
/* n_tty.c */
extern struct tty_ldisc_ops tty_ldisc_N_TTY;
+extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
/* tty_audit.c */
#ifdef CONFIG_AUDIT
--
1.6.3.3
Signed-off-by: Rodolfo Giometti <[email protected]>
---
Documentation/serial/tty.txt | 4 ++++
include/linux/tty_ldisc.h | 8 ++++++++
2 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt
index 5e5349a..7c90050 100644
--- a/Documentation/serial/tty.txt
+++ b/Documentation/serial/tty.txt
@@ -105,6 +105,10 @@ write_wakeup() - May be called at any point between open and close.
is permitted to call the driver write method from
this function. In such a situation defer it.
+dcd_change() - Report to the tty line the current DCD pin status
+ changes and the relative timestamp. The timestamp
+ can be NULL.
+
Driver Access
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 0c4ee9b..526d66f 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -99,6 +99,12 @@
* cease I/O to the tty driver. Can sleep. The driver should
* seek to perform this action quickly but should wait until
* any pending driver I/O is completed.
+ *
+ * void (*dcd_change)(struct tty_struct *tty, unsigned int status,
+ * struct timespec *ts)
+ *
+ * Tells the discipline that the DCD pin has changed its status and
+ * the relative timestamp. Pointer ts can be NULL.
*/
#include <linux/fs.h>
@@ -136,6 +142,8 @@ struct tty_ldisc_ops {
void (*receive_buf)(struct tty_struct *, const unsigned char *cp,
char *fp, int count);
void (*write_wakeup)(struct tty_struct *);
+ void (*dcd_change)(struct tty_struct *, unsigned int,
+ struct timespec *);
struct module *owner;
--
1.6.3.3
Automagically function serial8250_enable_ms() is called when PPS ldisc
is selected.
Signed-off-by: Rodolfo Giometti <[email protected]>
---
drivers/serial/8250.c | 16 ++++++++++++++++
1 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c3e37c8..48aa0b4 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2413,6 +2413,21 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
}
static void
+serial8250_set_ldisc(struct uart_port *port)
+{
+ int line = port->line;
+
+ if (line >= port->state->port.tty->driver->num)
+ return;
+
+ if (port->state->port.tty->ldisc->ops->num == N_PPS) {
+ port->flags |= UPF_HARDPPS_CD;
+ serial8250_enable_ms(port);
+ } else
+ port->flags &= ~UPF_HARDPPS_CD;
+}
+
+static void
serial8250_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
@@ -2626,6 +2641,7 @@ static struct uart_ops serial8250_pops = {
.startup = serial8250_startup,
.shutdown = serial8250_shutdown,
.set_termios = serial8250_set_termios,
+ .set_ldisc = serial8250_set_ldisc,
.pm = serial8250_pm,
.type = serial8250_type,
.release_port = serial8250_release_port,
--
1.6.3.3
Function pl010_enable_ms() is automagically called when PPS ldisc
is selected.
Signed-off-by: Rodolfo Giometti <[email protected]>
---
drivers/serial/amba-pl010.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c
index 429a8ae..e4b3c2c 100644
--- a/drivers/serial/amba-pl010.c
+++ b/drivers/serial/amba-pl010.c
@@ -471,6 +471,20 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
spin_unlock_irqrestore(&uap->port.lock, flags);
}
+static void pl010_set_ldisc(struct uart_port *port)
+{
+ int line = port->line;
+
+ if (line >= port->state->port.tty->driver->num)
+ return;
+
+ if (port->state->port.tty->ldisc->ops->num == N_PPS) {
+ port->flags |= UPF_HARDPPS_CD;
+ pl010_enable_ms(port);
+ } else
+ port->flags &= ~UPF_HARDPPS_CD;
+}
+
static const char *pl010_type(struct uart_port *port)
{
return port->type == PORT_AMBA ? "AMBA" : NULL;
@@ -531,6 +545,7 @@ static struct uart_ops amba_pl010_pops = {
.startup = pl010_startup,
.shutdown = pl010_shutdown,
.set_termios = pl010_set_termios,
+ .set_ldisc = pl010_set_ldisc,
.type = pl010_type,
.release_port = pl010_release_port,
.request_port = pl010_request_port,
--
1.6.3.3
Each PPS source can be registered/deregistered into the system by
using special modules called "clients". They simply define the PPS
sources' attributes and implement the time signal registartion
mechanism.
This patch adds a special directory for such clients and adds a dummy
client that can be useful to test system integrity on real systems.
Signed-off-by: Rodolfo Giometti <[email protected]>
---
drivers/pps/Kconfig | 2 +
drivers/pps/Makefile | 1 +
drivers/pps/clients/Kconfig | 18 ++++++
drivers/pps/clients/Makefile | 9 +++
drivers/pps/clients/pps-ktimer.c | 123 ++++++++++++++++++++++++++++++++++++++
5 files changed, 153 insertions(+), 0 deletions(-)
create mode 100644 drivers/pps/clients/Kconfig
create mode 100644 drivers/pps/clients/Makefile
create mode 100644 drivers/pps/clients/pps-ktimer.c
diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig
index cc2eb8e..1afe4e0 100644
--- a/drivers/pps/Kconfig
+++ b/drivers/pps/Kconfig
@@ -30,4 +30,6 @@ config PPS_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.
+source drivers/pps/clients/Kconfig
+
endmenu
diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile
index 19ea582..98960dd 100644
--- a/drivers/pps/Makefile
+++ b/drivers/pps/Makefile
@@ -4,5 +4,6 @@
pps_core-y := pps.o kapi.o sysfs.o
obj-$(CONFIG_PPS) := pps_core.o
+obj-y += clients/
ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
new file mode 100644
index 0000000..43ccd3b
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,18 @@
+#
+# PPS clients configuration
+#
+
+if PPS
+
+comment "PPS clients support"
+
+config PPS_CLIENT_KTIMER
+ tristate "Kernel timer client (Testing client, use for debug)"
+ help
+ If you say yes here you get support for a PPS debugging client
+ which uses a kernel timer to generate the PPS signal.
+
+ This driver can also be built as a module. If so, the module
+ will be called pps-ktimer.
+
+endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
new file mode 100644
index 0000000..115572a
--- /dev/null
+++ b/drivers/pps/clients/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for PPS clients.
+#
+
+obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o
+
+ifeq ($(CONFIG_PPS_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c
new file mode 100644
index 0000000..bd09253
--- /dev/null
+++ b/drivers/pps/clients/pps-ktimer.c
@@ -0,0 +1,123 @@
+/*
+ * pps-ktimer.c -- kernel timer test client
+ *
+ *
+ * Copyright (C) 2005-2006 Rodolfo Giometti <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <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 int source;
+static struct timer_list ktimer;
+
+/*
+ * The kernel timer
+ */
+
+static void pps_ktimer_event(unsigned long ptr)
+{
+ struct timespec __ts;
+ struct pps_ktime ts;
+
+ /* First of all we get the time stamp... */
+ getnstimeofday(&__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);
+
+ 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
+ */
+
+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)
+{
+ del_timer_sync(&ktimer);
+ pps_unregister_source(source);
+
+ pr_info("ktimer PPS source unregistered\n");
+}
+
+static int __init pps_ktimer_init(void)
+{
+ int ret;
+
+ ret = pps_register_source(&pps_ktimer_info,
+ PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
+ if (ret < 0) {
+ printk(KERN_ERR "cannot register ktimer source\n");
+ return ret;
+ }
+ source = ret;
+
+ setup_timer(&ktimer, pps_ktimer_event, 0);
+ mod_timer(&ktimer, jiffies + HZ);
+
+ pr_info("ktimer PPS source registered at %d\n", source);
+
+ return 0;
+}
+
+module_init(pps_ktimer_init);
+module_exit(pps_ktimer_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <[email protected]>");
+MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
+MODULE_LICENSE("GPL");
--
1.6.3.3