On Fri, Feb 26, 2016 at 11:36 AM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
> With the recently introduced hrtimer based trigger we have a fully
> functional replacement for the RTC timer trigger that is more flexible and
> has a better interface to instantiate and manage the trigger instances. The
> RTC trigger timer could only be instantiated using platform devices which
> makes it unsuitable for modern devicetree based platforms, while the
> hrtimer trigger has a configfs based interface that allows creating and
> deletion of triggers at runtime.
>
> In addition since a few years the periodic RTC timer is internally always
> emulated using a hrtimer using the hrtimer interface directly will yield
> the same timing precision. So using the RTC timer won't have any advantages
> on this front either.
>
> There is also no evidence that the periodic RTC trigger is currently
> actually being used on any system. So considering all this remove the
> driver. Also remove the related item from the TODO list.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Acked-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> ---
> drivers/staging/iio/TODO | 8 -
> drivers/staging/iio/trigger/Kconfig | 10 -
> drivers/staging/iio/trigger/Makefile | 1 -
> .../staging/iio/trigger/iio-trig-periodic-rtc.c | 216 ---------------------
> 4 files changed, 235 deletions(-)
> delete mode 100644 drivers/staging/iio/trigger/iio-trig-periodic-rtc.c
>
> diff --git a/drivers/staging/iio/TODO b/drivers/staging/iio/TODO
> index c22a0ed..93a8968 100644
> --- a/drivers/staging/iio/TODO
> +++ b/drivers/staging/iio/TODO
> @@ -58,14 +58,6 @@ different requirements. This one suits mid range
> frequencies (100Hz - 4kHz).
> 2) Lots of testing
>
> -Periodic Timer trigger
> -1) Move to a more general hardware periodic timer request
> -subsystem. Current approach is abusing purpose of RTC.
> -Initial discussions have taken place, but no actual code
> -is in place as yet. This topic will be reopened on lkml
> -shortly. I don't really envision this patch being merged
> -in anything like its current form.
> -
> GPIO trigger
> 1) Add control over the type of interrupt etc. This will
> necessitate a header that is also visible from arch board
> diff --git a/drivers/staging/iio/trigger/Kconfig b/drivers/staging/iio/trigger/Kconfig
> index 710a2f3..0b01d24 100644
> --- a/drivers/staging/iio/trigger/Kconfig
> +++ b/drivers/staging/iio/trigger/Kconfig
> @@ -5,16 +5,6 @@ comment "Triggers - standalone"
>
> if IIO_TRIGGER
>
> -config IIO_PERIODIC_RTC_TRIGGER
> - tristate "Periodic RTC triggers"
> - depends on RTC_CLASS
> - help
> - Provides support for using periodic capable real time
> - clocks as IIO triggers.
> -
> - To compile this driver as a module, choose M here: the
> - module will be called iio-trig-periodic-rtc.
> -
> config IIO_BFIN_TMR_TRIGGER
> tristate "Blackfin TIMER trigger"
> depends on BLACKFIN
> diff --git a/drivers/staging/iio/trigger/Makefile b/drivers/staging/iio/trigger/Makefile
> index 238481b..1300a21 100644
> --- a/drivers/staging/iio/trigger/Makefile
> +++ b/drivers/staging/iio/trigger/Makefile
> @@ -2,5 +2,4 @@
> # Makefile for triggers not associated with iio-devices
> #
>
> -obj-$(CONFIG_IIO_PERIODIC_RTC_TRIGGER) += iio-trig-periodic-rtc.o
> obj-$(CONFIG_IIO_BFIN_TMR_TRIGGER) += iio-trig-bfin-timer.o
> diff --git a/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c b/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c
> deleted file mode 100644
> index 00d1393..0000000
> --- a/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c
> +++ /dev/null
> @@ -1,216 +0,0 @@
> -/* The industrial I/O periodic RTC trigger driver
> - *
> - * Copyright (c) 2008 Jonathan Cameron
> - *
> - * This program is free software; you can redistribute it and/or modify it
> - * under the terms of the GNU General Public License version 2 as published by
> - * the Free Software Foundation.
> - *
> - * This is a heavily rewritten version of the periodic timer system in
> - * earlier version of industrialio. It supplies the same functionality
> - * but via a trigger rather than a specific periodic timer system.
> - */
> -
> -#include <linux/platform_device.h>
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/slab.h>
> -#include <linux/rtc.h>
> -#include <linux/iio/iio.h>
> -#include <linux/iio/trigger.h>
> -
> -static LIST_HEAD(iio_prtc_trigger_list);
> -static DEFINE_MUTEX(iio_prtc_trigger_list_lock);
> -
> -struct iio_prtc_trigger_info {
> - struct rtc_device *rtc;
> - unsigned int frequency;
> - struct rtc_task task;
> - bool state;
> -};
> -
> -static int iio_trig_periodic_rtc_set_state(struct iio_trigger *trig, bool state)
> -{
> - struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
> - int ret;
> -
> - if (trig_info->frequency == 0 && state)
> - return -EINVAL;
> - dev_dbg(&trig_info->rtc->dev, "trigger frequency is %u\n",
> - trig_info->frequency);
> - ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, state);
> - if (!ret)
> - trig_info->state = state;
> -
> - return ret;
> -}
> -
> -static ssize_t iio_trig_periodic_read_freq(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> -{
> - struct iio_trigger *trig = to_iio_trigger(dev);
> - struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
> -
> - return sprintf(buf, "%u\n", trig_info->frequency);
> -}
> -
> -static ssize_t iio_trig_periodic_write_freq(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf,
> - size_t len)
> -{
> - struct iio_trigger *trig = to_iio_trigger(dev);
> - struct iio_prtc_trigger_info *trig_info = iio_trigger_get_drvdata(trig);
> - unsigned int val;
> - int ret;
> -
> - ret = kstrtouint(buf, 10, &val);
> - if (ret)
> - goto error_ret;
> -
> - if (val > 0) {
> - ret = rtc_irq_set_freq(trig_info->rtc, &trig_info->task, val);
> - if (ret == 0 && trig_info->state && trig_info->frequency == 0)
> - ret = rtc_irq_set_state(trig_info->rtc,
> - &trig_info->task, 1);
> - } else {
> - ret = rtc_irq_set_state(trig_info->rtc, &trig_info->task, 0);
> - }
> - if (ret)
> - goto error_ret;
> -
> - trig_info->frequency = val;
> -
> - return len;
> -
> -error_ret:
> - return ret;
> -}
> -
> -static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
> - iio_trig_periodic_read_freq,
> - iio_trig_periodic_write_freq);
> -
> -static struct attribute *iio_trig_prtc_attrs[] = {
> - &dev_attr_frequency.attr,
> - NULL,
> -};
> -
> -static const struct attribute_group iio_trig_prtc_attr_group = {
> - .attrs = iio_trig_prtc_attrs,
> -};
> -
> -static const struct attribute_group *iio_trig_prtc_attr_groups[] = {
> - &iio_trig_prtc_attr_group,
> - NULL
> -};
> -
> -static void iio_prtc_trigger_poll(void *private_data)
> -{
> - iio_trigger_poll(private_data);
> -}
> -
> -static const struct iio_trigger_ops iio_prtc_trigger_ops = {
> - .owner = THIS_MODULE,
> - .set_trigger_state = &iio_trig_periodic_rtc_set_state,
> -};
> -
> -static int iio_trig_periodic_rtc_probe(struct platform_device *dev)
> -{
> - char **pdata = dev->dev.platform_data;
> - struct iio_prtc_trigger_info *trig_info;
> - struct iio_trigger *trig, *trig2;
> -
> - int i, ret;
> -
> - for (i = 0;; i++) {
> - if (!pdata[i])
> - break;
> - trig = iio_trigger_alloc("periodic%s", pdata[i]);
> - if (!trig) {
> - ret = -ENOMEM;
> - goto error_free_completed_registrations;
> - }
> - list_add(&trig->alloc_list, &iio_prtc_trigger_list);
> -
> - trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
> - if (!trig_info) {
> - ret = -ENOMEM;
> - goto error_put_trigger_and_remove_from_list;
> - }
> - iio_trigger_set_drvdata(trig, trig_info);
> - trig->ops = &iio_prtc_trigger_ops;
> - /* RTC access */
> - trig_info->rtc = rtc_class_open(pdata[i]);
> - if (!trig_info->rtc) {
> - ret = -EINVAL;
> - goto error_free_trig_info;
> - }
> - trig_info->task.func = iio_prtc_trigger_poll;
> - trig_info->task.private_data = trig;
> - ret = rtc_irq_register(trig_info->rtc, &trig_info->task);
> - if (ret)
> - goto error_close_rtc;
> - trig->dev.groups = iio_trig_prtc_attr_groups;
> - ret = iio_trigger_register(trig);
> - if (ret)
> - goto error_unregister_rtc_irq;
> - }
> - return 0;
> -error_unregister_rtc_irq:
> - rtc_irq_unregister(trig_info->rtc, &trig_info->task);
> -error_close_rtc:
> - rtc_class_close(trig_info->rtc);
> -error_free_trig_info:
> - kfree(trig_info);
> -error_put_trigger_and_remove_from_list:
> - list_del(&trig->alloc_list);
> - iio_trigger_put(trig);
> -error_free_completed_registrations:
> - list_for_each_entry_safe(trig,
> - trig2,
> - &iio_prtc_trigger_list,
> - alloc_list) {
> - trig_info = iio_trigger_get_drvdata(trig);
> - rtc_irq_unregister(trig_info->rtc, &trig_info->task);
> - rtc_class_close(trig_info->rtc);
> - kfree(trig_info);
> - iio_trigger_unregister(trig);
> - }
> - return ret;
> -}
> -
> -static int iio_trig_periodic_rtc_remove(struct platform_device *dev)
> -{
> - struct iio_trigger *trig, *trig2;
> - struct iio_prtc_trigger_info *trig_info;
> -
> - mutex_lock(&iio_prtc_trigger_list_lock);
> - list_for_each_entry_safe(trig,
> - trig2,
> - &iio_prtc_trigger_list,
> - alloc_list) {
> - trig_info = iio_trigger_get_drvdata(trig);
> - rtc_irq_unregister(trig_info->rtc, &trig_info->task);
> - rtc_class_close(trig_info->rtc);
> - kfree(trig_info);
> - iio_trigger_unregister(trig);
> - }
> - mutex_unlock(&iio_prtc_trigger_list_lock);
> - return 0;
> -}
> -
> -static struct platform_driver iio_trig_periodic_rtc_driver = {
> - .probe = iio_trig_periodic_rtc_probe,
> - .remove = iio_trig_periodic_rtc_remove,
> - .driver = {
> - .name = "iio_prtc_trigger",
> - },
> -};
> -
> -module_platform_driver(iio_trig_periodic_rtc_driver);
> -
> -MODULE_AUTHOR("Jonathan Cameron <jic23@xxxxxxxxxx>");
> -MODULE_DESCRIPTION("Periodic realtime clock trigger for the iio subsystem");
> -MODULE_LICENSE("GPL v2");
> --
> 2.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
