On 4/19/2012 5:05 PM, Maxime Ripard wrote:
This allows to easily set the frequency for hardware triggers supporting
it.
Other than the missing docs for the new callback this is fine.
I've highlighted some future issues inline but we can tackle them later.
Ultimately from a maintenance point of view I'd like these to look more
similar
to the ones we have in the core (read_raw and write_raw). Those are far more
flexible than we currently need here but that may change.
I'm happy to have this as a stop gap
Signed-off-by: Maxime Ripard<maxime.ripard@xxxxxxxxxxxxxxxxxx>
---
drivers/staging/iio/industrialio-trigger.c | 65 ++++++++++++++++++++++++++-
drivers/staging/iio/trigger.h | 9 ++++
2 files changed, 71 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/iio/industrialio-trigger.c b/drivers/staging/iio/industrialio-trigger.c
index 47ecadd..457ab15 100644
--- a/drivers/staging/iio/industrialio-trigger.c
+++ b/drivers/staging/iio/industrialio-trigger.c
@@ -51,6 +51,42 @@ static ssize_t iio_trigger_read_name(struct device *dev,
static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
+static ssize_t iio_trigger_read_frequency(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_trigger *trig = dev_get_drvdata(dev);
+ return sprintf(buf, "%lu\n", trig->frequency);
Strong assumption of integer value here. I'd not be suprised if we get
fractional values on a few devices over time. Maybe that's something to
fix when we do though!
+}
+
+static ssize_t iio_trigger_write_frequency(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_trigger *trig = dev_get_drvdata(dev);
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul(buf, 10,&val);
+ if (ret)
+ return ret;
+
+ trig->frequency = val;
+
+ if (trig->ops->update_infos) {
+ ret = trig->ops->update_infos(trig, IIO_TRIGGER_INFO_FREQUENCY);
+ if (ret)
+ return ret;
+ }
+
+ return len;
+}
+
+static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR,
+ iio_trigger_read_frequency,
+ iio_trigger_write_frequency);
+
/**
* iio_trigger_register_sysfs() - create a device for this trigger
* @trig_info: the trigger
@@ -59,9 +95,29 @@ static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
**/
static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
{
Doesn't change the fundamental path here, so fine. Note however, that at
somepoint we should ensure these are registered with the device so that we
are sure udev will get notification of their creation...
- return sysfs_add_file_to_group(&trig_info->dev.kobj,
- &dev_attr_name.attr,
- NULL);
+ int ret;
+ ret = sysfs_add_file_to_group(&trig_info->dev.kobj,
+ &dev_attr_name.attr,
+ NULL);
+ if (ret)
+ goto name_error;
+
+ if (trig_info->info_mask& IIO_TRIGGER_INFO_FREQUENCY) {
+ ret = sysfs_add_file_to_group(&trig_info->dev.kobj,
+ &dev_attr_frequency.attr,
+ NULL);
+ if (ret)
+ goto frequency_error;
+ }
+
+ return 0;
+
+frequency_error:
+ sysfs_remove_file_from_group(&trig_info->dev.kobj,
+ &dev_attr_name.attr,
+ NULL);
+name_error:
+ return ret;
}
static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
@@ -69,6 +125,9 @@ static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
sysfs_remove_file_from_group(&trig_info->dev.kobj,
&dev_attr_name.attr,
NULL);
+ sysfs_remove_file_from_group(&trig_info->dev.kobj,
+ &dev_attr_frequency.attr,
+ NULL);
}
int iio_trigger_register(struct iio_trigger *trig_info)
diff --git a/drivers/staging/iio/trigger.h b/drivers/staging/iio/trigger.h
index 1cfca23..a258ef8 100644
--- a/drivers/staging/iio/trigger.h
+++ b/drivers/staging/iio/trigger.h
@@ -16,6 +16,8 @@ struct iio_subirq {
bool enabled;
};
Slight preference for BIT(0)
+#define IIO_TRIGGER_INFO_FREQUENCY (1<< 0)
+
/**
* struct iio_trigger_ops - operations structure for an iio_trigger.
* @owner: used to monitor usage count of the trigger.
Document the new callback please!
@@ -32,6 +34,8 @@ struct iio_trigger_ops {
struct module *owner;
int (*set_trigger_state)(struct iio_trigger *trig, bool state);
int (*try_reenable)(struct iio_trigger *trig);
+ int (*update_infos)(struct iio_trigger *trig,
+ const unsigned long info_mask);
int (*validate_device)(struct iio_trigger *trig,
struct iio_dev *indio_dev);
};
@@ -52,6 +56,9 @@ struct iio_trigger_ops {
* @subirqs: [INTERN] information about the 'child' irqs.
* @pool: [INTERN] bitmap of irqs currently in use.
* @pool_lock: [INTERN] protection of the irq pool.
+ * @frequency: [DRIVER] frequency of the trigger in Hz.
+ * @info_mask: [DRIVER] What informations are to be exported in the
+ * sysfs directory: frequency, etc....
**/
struct iio_trigger {
const struct iio_trigger_ops *ops;
@@ -70,6 +77,8 @@ struct iio_trigger {
struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
struct mutex pool_lock;
+ unsigned long frequency;
+ long info_mask;
};
--
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