[LinuxPPS] [pre-PATCH v3] PPS line discipline support
Rodolfo Giometti
giometti at enneenne.com
Tue Jun 17 23:02:44 CEST 2008
Hello,
here my last patch for PPS ldisc support. I rewrote the ldisc code
following Alan's suggestions. :)
Please, let me know if something changes (no hardware to test).
Ciao,
Rodolfo
--
GNU/Linux Solutions e-mail: giometti at enneenne.com
Linux Device Driver giometti at linux.it
Embedded Systems phone: +39 349 2432127
UNIX programming skype: rodolfo.giometti
-------------- next part --------------
diff --git a/Documentation/ABI/testing/sysfs-pps b/Documentation/ABI/testing/sysfs-pps
index 881b331..8cba1d9 100644
--- a/Documentation/ABI/testing/sysfs-pps
+++ b/Documentation/ABI/testing/sysfs-pps
@@ -3,8 +3,8 @@ Date: February 2008
Contact: Rodolfo Giometti <giometti at linux.it>
Description:
The /sys/class/pps/ directory will contain files and
- directories that will provide a unified interface to
- the PPS sources.
+ directories that will provide a unified interface to
+ the PPS sources.
What: /sys/class/pps/ppsX/
Date: February 2008
@@ -31,7 +31,7 @@ Date: February 2008
Contact: Rodolfo Giometti <giometti at linux.it>
Description:
The /sys/class/pps/ppsX/clear file reports the clear events
- and the clear sequence number of the X-th source in the form:
+ and the clear sequence number of the X-th source in the form:
<secs>.<nsec>#<sequence>
diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt
index c608aa8..c558ec3 100644
--- a/Documentation/pps/pps.txt
+++ b/Documentation/pps/pps.txt
@@ -73,13 +73,13 @@ To register a PPS source into the kernel you should define a struct
pps_source_info_s as follow:
static struct pps_source_info pps_ktimer_info = {
- .name = "ktimer",
- .path = "",
- .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
+ .name = "ktimer",
+ .path = "",
+ .mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
PPS_ECHOASSERT | \
- PPS_CANWAIT | PPS_TSFMT_TSPEC,
- .echo = pps_ktimer_echo,
- .owner = THIS_MODULE,
+ PPS_CANWAIT | PPS_TSFMT_TSPEC,
+ .echo = pps_ktimer_echo,
+ .owner = THIS_MODULE,
};
and then calling the function pps_register_source() in your
@@ -102,7 +102,9 @@ Once you have registered a new PPS source into the system you can
signal an assert event (for example in the interrupt handler routine)
just using:
- pps_event(source, PPS_CAPTUREASSERT, ptr);
+ pps_event(source, &ts, PPS_CAPTUREASSERT, ptr)
+
+where "ts" is the event's timestamp.
The same function may also run the defined echo function
(pps_ktimer_echo(), passing to it the "ptr" pointer) if the user
diff --git a/Documentation/tty.txt b/Documentation/tty.txt
index 8e65c44..3fc812a 100644
--- a/Documentation/tty.txt
+++ b/Documentation/tty.txt
@@ -100,6 +100,10 @@ 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/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 596c717..ac30f1e 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -26,7 +26,7 @@
*
* 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
* waiting writing processes-Sapan Bhatia <sapan at corewars.org>.
- * Also fixed a bug in BLOCKING mode where write_chan returns
+ * Also fixed a bug in BLOCKING mode where n_tty_write returns
* EAGAIN
*/
@@ -43,10 +43,10 @@
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/slab.h>
-#include <linux/poll.h>
#include <linux/bitops.h>
#include <linux/audit.h>
#include <linux/file.h>
+#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -187,7 +187,7 @@ static void reset_buffer_flags(struct tty_struct *tty)
* lock_kernel() still.
*/
-static void n_tty_flush_buffer(struct tty_struct * tty)
+void n_tty_flush_buffer(struct tty_struct * tty)
{
/* clear everything and unthrottle the driver */
reset_buffer_flags(tty);
@@ -200,6 +200,7 @@ static void n_tty_flush_buffer(struct tty_struct * tty)
wake_up_interruptible(&tty->link->read_wait);
}
}
+EXPORT_SYMBOL(n_tty_flush_buffer);
/**
* n_tty_chars_in_buffer - report available bytes
@@ -209,7 +210,7 @@ static void n_tty_flush_buffer(struct tty_struct * tty)
* at this instant in time.
*/
-static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
+ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
{
unsigned long flags;
ssize_t n = 0;
@@ -225,6 +226,7 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
spin_unlock_irqrestore(&tty->read_lock, flags);
return n;
}
+EXPORT_SYMBOL(n_tty_chars_in_buffer);
/**
* is_utf8_continuation - utf8 multibyte check
@@ -337,7 +339,7 @@ static int opost(unsigned char c, struct tty_struct *tty)
* the simple cases normally found and helps to generate blocks of
* symbols for the console driver and thus improve performance.
*
- * Called from write_chan under the tty layer write lock.
+ * Called from n_tty_write under the tty layer write lock.
*/
static ssize_t opost_block(struct tty_struct * tty,
@@ -883,7 +885,7 @@ send_signal:
* IO must be woken up
*/
-static void n_tty_write_wakeup(struct tty_struct *tty)
+void n_tty_write_wakeup(struct tty_struct *tty)
{
if (tty->fasync)
{
@@ -892,6 +894,7 @@ static void n_tty_write_wakeup(struct tty_struct *tty)
}
return;
}
+EXPORT_SYMBOL(n_tty_write_wakeup);
/**
* n_tty_receive_buf - data receive
@@ -906,7 +909,7 @@ static void n_tty_write_wakeup(struct tty_struct *tty)
* calls one at a time and in order (or using flush_to_ldisc)
*/
-static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
char *fp, int count)
{
const unsigned char *p;
@@ -984,6 +987,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
tty->driver->throttle(tty);
}
}
+EXPORT_SYMBOL(n_tty_receive_buf);
int is_ignored(int sig)
{
@@ -1003,7 +1007,7 @@ int is_ignored(int sig)
* when the ldisc is closed.
*/
-static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
+void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
{
if (!tty)
return;
@@ -1067,6 +1071,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
}
n_tty_set_room(tty);
}
+EXPORT_SYMBOL(n_tty_set_termios);
/**
* n_tty_close - close the ldisc for this tty
@@ -1078,7 +1083,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
* ldisc methods are in progress.
*/
-static void n_tty_close(struct tty_struct *tty)
+void n_tty_close(struct tty_struct *tty)
{
n_tty_flush_buffer(tty);
if (tty->read_buf) {
@@ -1086,6 +1091,7 @@ static void n_tty_close(struct tty_struct *tty)
tty->read_buf = NULL;
}
}
+EXPORT_SYMBOL(n_tty_close);
/**
* n_tty_open - open an ldisc
@@ -1097,7 +1103,7 @@ static void n_tty_close(struct tty_struct *tty)
* until a close.
*/
-static int n_tty_open(struct tty_struct *tty)
+int n_tty_open(struct tty_struct *tty)
{
if (!tty)
return -EINVAL;
@@ -1116,6 +1122,7 @@ static int n_tty_open(struct tty_struct *tty)
tty->closing = 0;
return 0;
}
+EXPORT_SYMBOL(n_tty_open);
static inline int input_available_p(struct tty_struct *tty, int amt)
{
@@ -1134,7 +1141,7 @@ static inline int input_available_p(struct tty_struct *tty, int amt)
* @b: user data
* @nr: size of data
*
- * Helper function to speed up read_chan. It is only called when
+ * Helper function to speed up n_tty_read. It is only called when
* ICANON is off; it copies characters straight from the tty queue to
* user space directly. It can be profitably called twice; once to
* drain the space from the tail pointer to the (physical) end of the
@@ -1195,7 +1202,7 @@ static int job_control(struct tty_struct *tty, struct file *file)
if (file->f_op->write != redirected_tty_write &&
current->signal->tty == tty) {
if (!tty->pgrp)
- printk("read_chan: no tty->pgrp!\n");
+ printk("n_tty_read: no tty->pgrp!\n");
else if (task_pgrp(current) != tty->pgrp) {
if (is_ignored(SIGTTIN) ||
is_current_pgrp_orphaned())
@@ -1210,7 +1217,7 @@ static int job_control(struct tty_struct *tty, struct file *file)
/**
- * read_chan - read function for tty
+ * n_tty_read - read function for tty
* @tty: tty device
* @file: file object
* @buf: userspace buffer pointer
@@ -1224,7 +1231,7 @@ static int job_control(struct tty_struct *tty, struct file *file)
* This code must be sure never to sleep through a hangup.
*/
-static ssize_t read_chan(struct tty_struct *tty, struct file *file,
+ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr)
{
unsigned char __user *b = buf;
@@ -1239,7 +1246,7 @@ static ssize_t read_chan(struct tty_struct *tty, struct file *file,
do_it_again:
if (!tty->read_buf) {
- printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
+ printk("n_tty_read: called with read_buf == NULL?!?\n");
return -EIO;
}
@@ -1422,9 +1429,10 @@ do_it_again:
return retval;
}
+EXPORT_SYMBOL(n_tty_read);
/**
- * write_chan - write function for tty
+ * n_tty_write - write function for tty
* @tty: tty device
* @file: file object
* @buf: userspace buffer pointer
@@ -1438,7 +1446,7 @@ do_it_again:
* This code must be sure never to sleep through a hangup.
*/
-static ssize_t write_chan(struct tty_struct * tty, struct file * file,
+ssize_t n_tty_write(struct tty_struct * tty, struct file * file,
const unsigned char * buf, size_t nr)
{
const unsigned char *b = buf;
@@ -1510,9 +1518,10 @@ break_out:
remove_wait_queue(&tty->write_wait, &wait);
return (b - buf) ? b - buf : retval;
}
+EXPORT_SYMBOL(n_tty_write);
/**
- * normal_poll - poll method for N_TTY
+ * n_tty_poll - poll method for N_TTY
* @tty: terminal device
* @file: file accessing it
* @wait: poll table
@@ -1530,7 +1539,7 @@ break_out:
* a read wakeup to fix this bug.
*/
-static unsigned int normal_poll(struct tty_struct * tty, struct file * file, poll_table *wait)
+unsigned int n_tty_poll(struct tty_struct * tty, struct file * file, poll_table *wait)
{
unsigned int mask = 0;
@@ -1556,6 +1565,7 @@ static unsigned int normal_poll(struct tty_struct * tty, struct file * file, pol
mask |= POLLOUT | POLLWRNORM;
return mask;
}
+EXPORT_SYMBOL(n_tty_poll);
struct tty_ldisc tty_ldisc_N_TTY = {
.magic = TTY_LDISC_MAGIC,
@@ -1564,11 +1574,11 @@ struct tty_ldisc tty_ldisc_N_TTY = {
.close = n_tty_close,
.flush_buffer = n_tty_flush_buffer,
.chars_in_buffer = n_tty_chars_in_buffer,
- .read = read_chan,
- .write = write_chan,
+ .read = n_tty_read,
+ .write = n_tty_write,
.ioctl = n_tty_ioctl,
.set_termios = n_tty_set_termios,
- .poll = normal_poll,
+ .poll = n_tty_poll,
.receive_buf = n_tty_receive_buf,
.write_wakeup = n_tty_write_wakeup
};
diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig
index cf04837..7c0b094 100644
--- a/drivers/pps/Kconfig
+++ b/drivers/pps/Kconfig
@@ -36,7 +36,7 @@ config PPS_IRQ_EVENTS
config PPS_DEBUG
bool "PPS debugging messages"
- depends on PPS
+ 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
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
index 09ba5c3..b4054cd 100644
--- a/drivers/pps/clients/Kconfig
+++ b/drivers/pps/clients/Kconfig
@@ -15,12 +15,9 @@ config PPS_CLIENT_KTIMER
This driver can also be built as a module. If so, the module
will be called ktimer.ko.
-comment "UART serial support (forced off)"
- depends on ! (SERIAL_CORE != n && !(PPS = m && SERIAL_CORE = y))
-
-config PPS_CLIENT_UART
- bool "UART serial support"
- depends on SERIAL_CORE != n && !(PPS = m && SERIAL_CORE = y)
+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.
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
index f3c1e39..9f5b988 100644
--- a/drivers/pps/clients/Makefile
+++ b/drivers/pps/clients/Makefile
@@ -3,6 +3,7 @@
#
obj-$(CONFIG_PPS_CLIENT_KTIMER) += ktimer.o
+obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o
ifeq ($(CONFIG_PPS_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 4368a13..7e73c45 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -33,7 +33,6 @@
#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
#include <linux/delay.h>
#include <linux/mutex.h>
-#include <linux/pps.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
@@ -634,63 +633,6 @@ static int uart_get_info(struct uart_state *state,
return 0;
}
-#ifdef CONFIG_PPS_CLIENT_UART
-
-static int
-uart_register_pps_port(struct uart_state *state, struct uart_port *port)
-{
- struct tty_driver *drv = port->info->tty->driver;
- int ret;
-
- state->pps_info.owner = THIS_MODULE;
- state->pps_info.dev = port->dev;
- snprintf(state->pps_info.name, PPS_MAX_NAME_LEN, "%s%d",
- drv->driver_name, port->line);
- snprintf(state->pps_info.path, PPS_MAX_NAME_LEN, "/dev/%s%d",
- drv->name, port->line);
-
- state->pps_info.mode = PPS_CAPTUREBOTH | \
- PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
- PPS_CANWAIT | PPS_TSFMT_TSPEC;
-
- ret = pps_register_source(&state->pps_info, PPS_CAPTUREBOTH | \
- PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
- if (ret < 0) {
- dev_err(port->dev, "cannot register PPS source \"%s\"\n",
- state->pps_info.path);
- return ret;
- }
- port->pps_source = ret;
- dev_dbg(port->dev, "PPS source #%d \"%s\" added\n",
- port->pps_source, state->pps_info.path);
-
- return 0;
-}
-
-static void
-uart_unregister_pps_port(struct uart_state *state, struct uart_port *port)
-{
- pps_unregister_source(port->pps_source);
- dev_dbg(port->dev, "PPS source #%d \"%s\" removed\n",
- port->pps_source, state->pps_info.path);
-}
-
-#else
-
-static inline int
-uart_register_pps_port(struct uart_state *state, struct uart_port *port)
-{
- return 0;
-}
-
-static inline void
-uart_unregister_pps_port(struct uart_state *state, struct uart_port *port)
-{
- /* Nop */
-}
-
-#endif /* CONFIG_PPS_CLIENT_UART */
-
static int uart_set_info(struct uart_state *state,
struct serial_struct __user *newinfo)
{
@@ -865,14 +807,6 @@ static int uart_set_info(struct uart_state *state,
(port->flags & UPF_LOW_LATENCY) ? 1 : 0;
check_and_exit:
- /* PPS support enabled/disabled? */
- if ((old_flags & UPF_HARDPPS_CD) != (new_flags & UPF_HARDPPS_CD)) {
- if (new_flags & UPF_HARDPPS_CD)
- uart_register_pps_port(state, port);
- else
- uart_unregister_pps_port(state, port);
- }
-
retval = 0;
if (port->type == PORT_UNKNOWN)
goto exit;
@@ -2206,12 +2140,6 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
port->ops->config_port(port, flags);
}
- /*
- * Add the PPS support for the current port.
- */
- if (port->flags & UPF_HARDPPS_CD)
- uart_register_pps_port(state, port);
-
if (port->type != PORT_UNKNOWN) {
unsigned long flags;
@@ -2468,12 +2396,6 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
mutex_unlock(&state->mutex);
/*
- * Remove PPS support from the current port.
- */
- if (port->flags & UPF_HARDPPS_CD)
- uart_unregister_pps_port(state, port);
-
- /*
* Remove the devices from the tty layer
*/
tty_unregister_device(drv->tty_driver, port->line);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index a80d1ea..80f85fc 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -240,9 +240,6 @@ struct uart_port {
unsigned char regshift; /* reg offset shift */
unsigned char iotype; /* io access style */
unsigned char unused1;
-#ifdef CONFIG_PPS_CLIENT_UART
- int pps_source; /* PPS source ID */
-#endif
#define UPIO_PORT (0)
#define UPIO_HUB6 (1)
@@ -321,10 +318,6 @@ struct uart_state {
struct uart_info *info;
struct uart_port *port;
-#ifdef CONFIG_PPS_CLIENT_UART
- struct pps_source_info pps_info;
-#endif
-
struct mutex mutex;
};
@@ -488,31 +481,11 @@ static inline void
uart_handle_dcd_change(struct uart_port *port, unsigned int status)
{
struct uart_info *info = port->info;
+ struct tty_ldisc *ld = tty_ldisc_ref(info->tty);
+ struct timespec ts;
-#ifdef CONFIG_PPS_CLIENT_UART
- struct timespec __ts;
- struct pps_ktime ts;
-
- /* First of all we get the time stamp... */
- getnstimeofday(&__ts);
-
- /* ... and translate it to PPS time data struct */
- ts.sec = __ts.tv_sec;
- ts.nsec = __ts.tv_nsec;
-
- if (port->flags & UPF_HARDPPS_CD) {
- pps_event(port->pps_source,
-#ifdef CONFIG_PPS_IRQ_EVENTS
- &pps_irq_ts[port->irq],
-#else
- &ts,
-#endif
- status ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR,
- port);
- dev_dbg(port->dev, "PPS %s at %lu on source #%d\n",
- status ? "assert" : "clear", jiffies, port->pps_source);
- }
-#endif
+ if (ld->dcd_change)
+ getnstimeofday(&ts);
port->icount.dcd++;
@@ -522,6 +495,10 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status)
else if (info->tty)
tty_hangup(info->tty);
}
+
+ if (ld->dcd_change)
+ ld->dcd_change(port, status, &ts);
+ tty_ldisc_deref(ld);
}
/**
diff --git a/include/linux/tty.h b/include/linux/tty.h
index defd2ab..50656a0 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -13,6 +13,7 @@
#include <linux/tty_driver.h>
#include <linux/tty_ldisc.h>
#include <linux/mutex.h>
+#include <linux/poll.h>
#include <asm/system.h>
@@ -23,7 +24,7 @@
*/
#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
-#define NR_LDISCS 17
+#define NR_LDISCS 18
/* line disciplines */
#define N_TTY 0
@@ -44,6 +45,7 @@
#define N_SYNC_PPP 14 /* synchronous PPP */
#define N_HCI 15 /* Bluetooth HCI UART */
#define N_GIGASET_M101 16 /* Siemens Gigaset M101 serial DECT adapter */
+#define N_PPS 17 /* Pulse per Second */
/*
* This character is the same as _POSIX_VDISABLE: it cannot be used as
@@ -383,7 +385,21 @@ static inline void tty_audit_opening(void)
#endif
/* tty_ioctl.c */
-extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
+extern void n_tty_flush_buffer(struct tty_struct * tty);
+extern ssize_t n_tty_chars_in_buffer(struct tty_struct *tty);
+extern void n_tty_write_wakeup(struct tty_struct *tty);
+extern void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count);
+extern void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old);
+extern void n_tty_close(struct tty_struct *tty);
+extern int n_tty_open(struct tty_struct *tty);
+extern ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
+ unsigned char __user *buf, size_t nr);
+extern ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr);
+extern unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
+ poll_table *wait);
+extern int n_tty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg);
/* serial.c */
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 6226504..a135d6c 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -99,11 +99,19 @@
* 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 uart_port *port, 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>
#include <linux/wait.h>
+struct uart_port;
+
struct tty_ldisc {
int magic;
char *name;
@@ -136,6 +144,8 @@ struct tty_ldisc {
void (*receive_buf)(struct tty_struct *, const unsigned char *cp,
char *fp, int count);
void (*write_wakeup)(struct tty_struct *);
+ void (*dcd_change)(struct uart_port *, unsigned int,
+ struct timespec *);
struct module *owner;
More information about the LinuxPPS
mailing list