![David Howells](/assets/img/avatar_default.png)
Include missing linux/slab.h inclusions where the source file is currently expecting to get kmalloc() and co. through linux/proc_fs.h. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: linux-s390@vger.kernel.org cc: sparclinux@vger.kernel.org cc: linux-efi@vger.kernel.org cc: linux-mtd@lists.infradead.org cc: devel@driverdev.osuosl.org cc: x86@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
251 lines
6.1 KiB
C
251 lines
6.1 KiB
C
/*
|
|
* 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");
|