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    SubjectRe: [LinuxPPS] [PATCH 2/2] pps: new client driver using IRQs
    Hi James,

    В Wed, 27 Apr 2011 14:14:14 -0400
    James Nuss <jamesnuss@nanometrics.ca> пишет:

    > This client driver allows you to use raw IRQs as a source for PPS
    > signals.
    >
    > This driver is based on the work by Ricardo Martins <rasm@fe.up.pt> who
    > submitted an initial implementation [1] of a PPS IRQ client driver to
    > the linuxpps mailing-list on Dec 3 2010.
    >
    > [1] http://ml.enneenne.com/pipermail/linuxpps/2010-December/004155.html
    >
    > Signed-off-by: James Nuss <jamesnuss@nanometrics.ca>
    > Reviewed-by: Ben Gardiner <bengardiner@nanometrics.ca>
    > CC: Ricardo Martins <rasm@fe.up.pt>
    > ---
    > NOTE: drivers/pps/clients/Kconfig does not have the obligatory statements
    > regarding building the drivers as modules, even though they are all tristates.
    > This was purposefully omitted from the new config item for consistency.
    > This could be addressed in a separate patch.
    >
    > drivers/pps/clients/Kconfig | 8 ++
    > drivers/pps/clients/Makefile | 1 +
    > drivers/pps/clients/pps-irq.c | 169 +++++++++++++++++++++++++++++++++++++++++
    > 3 files changed, 178 insertions(+), 0 deletions(-)
    > create mode 100644 drivers/pps/clients/pps-irq.c
    >
    > diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
    > index 8520a7f..94b2cc6 100644
    > --- a/drivers/pps/clients/Kconfig
    > +++ b/drivers/pps/clients/Kconfig
    > @@ -29,4 +29,12 @@ config PPS_CLIENT_PARPORT
    > If you say yes here you get support for a PPS source connected
    > with the interrupt pin of your parallel port.
    >
    > +config PPS_CLIENT_IRQ
    > + tristate "PPS client based on raw IRQs"
    > + depends on PPS
    > + help
    > + If you say yes here you get support for a PPS source based
    > + on raw IRQs. To be useful, you must also register a platform
    > + device with an IRQ resource, usually in your board setup.
    > +
    > endif
    > diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
    > index 42517da..609a332 100644
    > --- a/drivers/pps/clients/Makefile
    > +++ b/drivers/pps/clients/Makefile
    > @@ -5,6 +5,7 @@
    > obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o
    > obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o
    > obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o
    > +obj-$(CONFIG_PPS_CLIENT_IRQ) += pps-irq.o
    >
    > ifeq ($(CONFIG_PPS_DEBUG),y)
    > EXTRA_CFLAGS += -DDEBUG
    > diff --git a/drivers/pps/clients/pps-irq.c b/drivers/pps/clients/pps-irq.c
    > new file mode 100644
    > index 0000000..33c1bf4
    > --- /dev/null
    > +++ b/drivers/pps/clients/pps-irq.c
    > @@ -0,0 +1,169 @@
    > +/*
    > + * pps-irq.c -- PPS IRQ client
    > + *
    > + *
    > + * Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt>
    > + * Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca>
    > + *
    > + * 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/init.h>
    > +#include <linux/kernel.h>
    > +#include <linux/interrupt.h>
    > +#include <linux/module.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/slab.h>
    > +#include <linux/pps_kernel.h>
    > +#include <linux/gpio.h>
    > +#include <linux/list.h>
    > +
    > +#define PPS_IRQ_NAME "pps-irq"
    > +#define PPS_IRQ_VERSION "1.1.0"
    > +
    > +/* Info for each registered platform device */
    > +struct pps_irq_data {
    > + int irq; /* IRQ used as PPS source */
    > + struct pps_device *pps; /* PPS source device */
    > + struct pps_source_info info; /* PPS source information */
    > +};
    > +
    > +/*
    > + * Report the PPS event
    > + */
    > +
    > +static irqreturn_t pps_irq_irq_handler(int irq, void *data)
    > +{
    > + struct pps_irq_data *info;
    > + struct pps_event_time ts;
    > +
    > + /* Get the time stamp first */
    > + pps_get_ts(&ts);
    > +
    > + info = (struct pps_irq_data *)data;
    > + pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL);
    > +
    > + return IRQ_HANDLED;
    > +}
    > +
    > +static int pps_irq_probe(struct platform_device *pdev)
    > +{
    > + struct pps_irq_data *data;
    > + struct resource *res;
    > + int irq;
    > + int ret;
    > +
    > + /* Validate resource. */
    > + if (pdev->num_resources != 1) {
    > + pr_err(PPS_IRQ_NAME ": this driver handles only one IRQ resource");

    Shouldn't the format string in pr_*/dev_* call be ended with a '\n' or I
    missed something?
    Also I suggest you what I was once suggested: to define pr_fmt() macro
    with a module name as in drivers/pps/clients/pps_parport.c to omit
    it's use in every pr_* call. :)

    > + return -EINVAL;
    > + }
    > +
    > + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
    > + if (res == NULL) {
    > + pr_err(PPS_IRQ_NAME ": no IRQ resource was given");
    > + return -EINVAL;
    > + }
    > +
    > + if (!(res->flags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) {
    > + pr_err(PPS_IRQ_NAME ": given IRQ resource must be edge triggered");
    > + return -EINVAL;
    > + }

    I think it doesn't actually expect that both flags are set because it
    always treats it as assert in the irq handler. What does your signal
    look like?

    > + /* Allocate space for device info */
    > + data = kzalloc(sizeof(struct pps_irq_data), GFP_KERNEL);
    > + if (data == NULL)
    > + return -ENOMEM;
    > +
    > + /* Initialize PPS specific parts of the bookkeeping data structure. */
    > + data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
    > + PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC;
    > + data->info.owner = THIS_MODULE;
    > + snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d",
    > + pdev->name, pdev->id);
    > +
    > + /* Register PPS source. */
    > + irq = platform_get_irq(pdev, 0);
    > + pr_info(PPS_IRQ_NAME ": registering IRQ %d as PPS source", irq);
    > + data->pps = pps_register_source(&data->info, PPS_CAPTUREASSERT
    > + | PPS_OFFSETASSERT);
    > + if (data->pps == NULL) {
    > + kfree(data);
    > + pr_err(PPS_IRQ_NAME ": failed to register IRQ %d as PPS source",
    > + irq);
    > + return -1;
    > + }
    > +
    > + /* Request IRQ. */
    > + pr_info(PPS_IRQ_NAME ": requesting IRQ %d", irq);
    > + ret = request_irq(irq, pps_irq_irq_handler,
    > + res->flags & IRQF_TRIGGER_MASK,
    > + data->info.name, data);
    > + if (ret) {
    > + pps_unregister_source(data->pps);
    > + kfree(data);
    > + pr_err(PPS_IRQ_NAME ": failed to acquire IRQ %d\n", irq);
    > + return ret;
    > + }
    > + data->irq = irq;
    > +
    > + platform_set_drvdata(pdev, data);
    > + dev_info(data->pps->dev, "Registered IRQ %d as PPS source", data->irq);
    > +
    > + return 0;
    > +}
    > +
    > +static int pps_irq_remove(struct platform_device *pdev)
    > +{
    > + struct pps_irq_data *data = platform_get_drvdata(pdev);
    > + platform_set_drvdata(pdev, NULL);
    > + free_irq(data->irq, data);
    > + pps_unregister_source(data->pps);
    > + pr_info(PPS_IRQ_NAME ": removed IRQ %d as PPS source", data->irq);
    > + kfree(data);
    > + return 0;
    > +}
    > +
    > +static struct platform_driver pps_irq_driver = {
    > + .probe = pps_irq_probe,
    > + .remove = __devexit_p(pps_irq_remove),
    > + .driver = {
    > + .name = PPS_IRQ_NAME,
    > + .owner = THIS_MODULE
    > + },
    > +};
    > +
    > +static int __init pps_irq_init(void)
    > +{
    > + int ret = platform_driver_register(&pps_irq_driver);
    > + if (ret < 0)
    > + pr_err(PPS_IRQ_NAME ": failed to register platform driver");
    > + return ret;
    > +}
    > +
    > +static void __exit pps_irq_exit(void)
    > +{
    > + platform_driver_unregister(&pps_irq_driver);
    > + pr_debug(PPS_IRQ_NAME ": unregistered platform driver");
    > +}
    > +
    > +module_init(pps_irq_init);
    > +module_exit(pps_irq_exit);
    > +
    > +MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>");
    > +MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>");
    > +MODULE_DESCRIPTION("Use raw IRQs as PPS source");
    > +MODULE_LICENSE("GPL");
    > +MODULE_VERSION(PPS_IRQ_VERSION);


    --
    Alexander
    [unhandled content-type:application/pgp-signature]
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