Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
>From: Marten Svanfeldt <marten@xxxxxxxxxxxxxxxxxxx>
>
>This patch adds a IIO trigger driver which uses a highres timer to
>provide a
>frequency based trigger.
Fine as it stands but same issue arises as we had with userspace trigger still. What are we doing registering a pure software element not associated to any specific hardware via a platform device. Why not do it on userspace asking for one as we do with the sysfs file based trigger?
>
>Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
>---
>This patch is based on the version sent by Marten Svanfeldt about a
>year ago.
>
>Changes since v2:
> * Use iio_trigger_free to free the trigger
> * Set device data in probe
>Changes since the inital version:
> * Set new timeout in the trigger handler
> * Register one trigger device per platform device
> * Codestyle cleanups
>
>Marten can I get your Signed-off-by for this new version?
>---
> drivers/staging/iio/trigger/Kconfig | 8 ++
> drivers/staging/iio/trigger/Makefile | 1 +
>drivers/staging/iio/trigger/iio-trig-hrtimer.c | 179
>++++++++++++++++++++++++
> 3 files changed, 188 insertions(+)
> create mode 100644 drivers/staging/iio/trigger/iio-trig-hrtimer.c
>
>diff --git a/drivers/staging/iio/trigger/Kconfig
>b/drivers/staging/iio/trigger/Kconfig
>index b8abf54..7393584 100644
>--- a/drivers/staging/iio/trigger/Kconfig
>+++ b/drivers/staging/iio/trigger/Kconfig
>@@ -39,4 +39,12 @@ config IIO_BFIN_TMR_TRIGGER
> To compile this driver as a module, choose M here: the
> module will be called iio-trig-bfin-timer.
>
>+config IIO_TRIGGER_HRTIMER
>+ tristate "Highres timer trigger"
>+ help
>+ Provides a frequency based IIO trigger using hrtimers.
>+
>+ To compile this driver as a module, choose M here: the
>+ module will be called iio-trig-hrtimer.
>+
> endif # IIO_TRIGGER
>diff --git a/drivers/staging/iio/trigger/Makefile
>b/drivers/staging/iio/trigger/Makefile
>index b088b57..f6f99c2 100644
>--- a/drivers/staging/iio/trigger/Makefile
>+++ b/drivers/staging/iio/trigger/Makefile
>@@ -6,3 +6,4 @@ obj-$(CONFIG_IIO_PERIODIC_RTC_TRIGGER) +=
>iio-trig-periodic-rtc.o
> obj-$(CONFIG_IIO_GPIO_TRIGGER) += iio-trig-gpio.o
> obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o
> obj-$(CONFIG_IIO_BFIN_TMR_TRIGGER) += iio-trig-bfin-timer.o
>+obj-$(CONFIG_IIO_TRIGGER_HRTIMER) += iio-trig-hrtimer.o
>diff --git a/drivers/staging/iio/trigger/iio-trig-hrtimer.c
>b/drivers/staging/iio/trigger/iio-trig-hrtimer.c
>new file mode 100644
>index 0000000..54167fd
>--- /dev/null
>+++ b/drivers/staging/iio/trigger/iio-trig-hrtimer.c
>@@ -0,0 +1,179 @@
>+/**
>+ * The industrial I/O periodic hrtimer trigger driver
>+ *
>+ * Copyright (C) Intuitive Aerial AB
>+ * Written by Marten Svanfeldt, marten@xxxxxxxxxxxxxxxxxxx
>+ * Copyright (C) 2012, Analog Device Inc.
>+ * Author: Lars-Peter Clausen <lars@xxxxxxxxxx>
>+ *
>+ * 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.
>+ *
>+ */
>+
>+#include <linux/platform_device.h>
>+#include <linux/kernel.h>
>+#include <linux/slab.h>
>+#include <linux/hrtimer.h>
>+#include "../iio.h"
>+#include "../trigger.h"
>+
>+struct iio_hrtimer_trig_info {
>+ struct iio_trigger *trigger;
>+ unsigned int frequency;
>+ struct hrtimer timer;
>+ ktime_t period;
>+};
>+
>+static enum hrtimer_restart iio_trig_hrtimer_trig(struct hrtimer
>*timer)
>+{
>+ struct iio_hrtimer_trig_info *trig_info;
>+ trig_info = container_of(timer, struct iio_hrtimer_trig_info, timer);
>+
>+ hrtimer_forward_now(timer, trig_info->period);
>+ iio_trigger_poll(trig_info->trigger, 0);
>+
>+ return HRTIMER_RESTART;
>+}
>+
>+static int iio_trig_hrtimer_set_state(struct iio_trigger *trig, bool
>state)
>+{
>+ struct iio_hrtimer_trig_info *trig_info = trig->private_data;
>+
>+ if (trig_info->frequency == 0)
>+ return -EINVAL;
>+
>+ if (state) {
>+ hrtimer_start(&trig_info->timer, trig_info->period,
>+ HRTIMER_MODE_REL);
>+ } else {
>+ hrtimer_cancel(&trig_info->timer);
>+ }
>+
>+ return 0;
>+}
>+
>+static ssize_t iio_trig_hrtimer_read_freq(struct device *dev,
>+ struct device_attribute *attr, char *buf)
>+{
>+ struct iio_trigger *trig = dev_get_drvdata(dev);
>+ struct iio_hrtimer_trig_info *trig_info = trig->private_data;
>+
>+ return sprintf(buf, "%u\n", trig_info->frequency);
>+}
>+
>+static ssize_t iio_trig_hrtimer_write_freq(struct device *dev,
>+ struct device_attribute *attr, const char *buf, size_t len)
>+{
>+ struct iio_trigger *trig = dev_get_drvdata(dev);
>+ struct iio_hrtimer_trig_info *trig_info = trig->private_data;
>+ unsigned long val;
>+ int ret;
>+
>+ ret = kstrtoul(buf, 10, &val);
>+ if (ret)
>+ return ret;
>+
>+ if (val > NSEC_PER_SEC)
>+ return -EINVAL;
>+
>+ trig_info->frequency = val;
>+ if (trig_info->frequency != 0)
>+ trig_info->period = ktime_set(0, NSEC_PER_SEC /
>trig_info->frequency);
>+
>+ return len;
>+}
>+
>+static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
>+ iio_trig_hrtimer_read_freq,
>+ iio_trig_hrtimer_write_freq);
>+
>+static struct attribute *iio_trig_hrtimer_attrs[] = {
>+ &dev_attr_frequency.attr,
>+ NULL,
>+};
>+
>+static const struct attribute_group iio_trig_hrtimer_attr_group = {
>+ .attrs = iio_trig_hrtimer_attrs,
>+};
>+
>+static const struct attribute_group *iio_trig_hrtimer_attr_groups[] =
>{
>+ &iio_trig_hrtimer_attr_group,
>+ NULL
>+};
>+
>+static const struct iio_trigger_ops iio_hrtimer_trigger_ops = {
>+ .owner = THIS_MODULE,
>+ .set_trigger_state = iio_trig_hrtimer_set_state,
>+};
>+
>+static int __devinit iio_trig_hrtimer_probe(struct platform_device
>*pdev)
>+{
>+ struct iio_hrtimer_trig_info *trig_info;
>+ struct iio_trigger *trig;
>+ const char *name;
>+ int ret;
>+
>+ trig_info = devm_kzalloc(&pdev->dev, sizeof(*trig_info), GFP_KERNEL);
>+ if (!trig_info)
>+ return -ENOMEM;
>+
>+ name = pdev->dev.platform_data;
>+
>+ if (name != NULL)
>+ trig = iio_allocate_trigger("hrtimer%s", name);
>+ else
>+ trig = iio_allocate_trigger("hrtimer%d", pdev->id);
>+
>+ if (!trig)
>+ return -ENOMEM;
>+
>+ trig_info->trigger = trig;
>+ trig->private_data = trig_info;
>+ trig->ops = &iio_hrtimer_trigger_ops;
>+ trig->dev.groups = iio_trig_hrtimer_attr_groups;
>+ trig->dev.parent = &pdev->dev;
>+
>+ hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>+ trig_info->timer.function = iio_trig_hrtimer_trig;
>+
>+ ret = iio_trigger_register(trig);
>+ if (ret)
>+ goto err_free_trigger;
>+
>+ platform_set_drvdata(pdev, trig_info);
>+
>+ return 0;
>+err_free_trigger:
>+ iio_free_trigger(trig);
>+
>+ return ret;
>+}
>+
>+static int __devexit iio_trig_hrtimer_remove(struct platform_device
>*pdev)
>+{
>+ struct iio_hrtimer_trig_info *trig_info = platform_get_drvdata(pdev);
>+ struct iio_trigger *trig = trig_info->trigger;
>+
>+ iio_trigger_unregister(trig);
>+ hrtimer_cancel(&trig_info->timer);
>+ iio_free_trigger(trig);
>+
>+ return 0;
>+}
>+
>+static struct platform_driver iio_trig_hrtimer_driver = {
>+ .driver = {
>+ .name = "iio-trigger-hrtimer",
>+ .owner = THIS_MODULE
>+ },
>+ .probe = iio_trig_hrtimer_probe,
>+ .remove = __devexit_p(iio_trig_hrtimer_remove),
>+};
>+module_platform_driver(iio_trig_hrtimer_driver);
>+
>+MODULE_AUTHOR("Marten Svanfeldt <marten@xxxxxxxxxxxxxxxxxxx>");
>+MODULE_DESCRIPTION("Periodic hrtimer trigger for the IIO subsystem");
>+MODULE_LICENSE("GPL v2");
>+MODULE_ALIAS("platform:iio-trigger-hrtimer");
>--
>1.7.9.5
>
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