On Thu, Apr 16, 2015 at 12:01 PM, Robert Dolca <robert.dolca@xxxxxxxxx> wrote: > This patch adds a new function called iio_trigger_register_with_dev > which is a wrapper for iio_trigger_register. Besides the iio_trigger > struct this function requires iio_dev struct. It adds the trigger in > the device's trigger list and saves a reference to the device in the > trigger's struct. > > When the device is registered, in the trigger folder of the device > (where current_trigger file resides) a symlink is being created for > each trigger that was registered width iio_trigger_register_with_dev. s/width/with > > # ls -l /sys/bus/iio/devices/iio:device0/trigger/ > total 0 > -rw-r--r-- 1 root root 4096 Apr 16 08:33 current_trigger > lrwxrwxrwx 1 root root 0 Apr 16 08:33 trigger0 -> ../../trigg > er0 > > This should be used for device specific triggers. Doing this the user space > applications can figure out what if the trigger registered by a specific device s/what if/what is > and what should they write in the current_trigger file. Currently some > applications rely on the trigger name and this does not always work. > > This implementation assumes that the trigger is registered before the device is > registered. If the order is not this the symlink will not be created but > everything else will work as before. This patch is very useful. Also I think that the userspace ABI is good. We need to work on the in-kernel API because I think we can do better. We should create a separate function that "attaches" a trigger with a device. So, the sequence at probe will be: indio = iio_device_alloc(); trig = iio_trigger_alloc(); iio_trigger_attach(indio, trig); iio_trigger_register(); iio_device_register(); The sequence at remove will be in reverse order, where we would introduce iio_trigger_detach(). We might want document the ABI here: http://lxr.free-electrons.com/source/Documentation/ABI/testing/sysfs-bus-iio > > Signed-off-by: Robert Dolca <robert.dolca@xxxxxxxxx> > --- > drivers/iio/industrialio-core.c | 20 ++++++++++++ > drivers/iio/industrialio-trigger.c | 64 ++++++++++++++++++++++++++++++++++++++ > include/linux/iio/iio.h | 1 + > include/linux/iio/trigger.h | 24 ++++++++++++++ > 4 files changed, 109 insertions(+) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index 69feb91..94bcd54 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -26,6 +26,7 @@ > #include <linux/anon_inodes.h> > #include <linux/debugfs.h> > #include <linux/iio/iio.h> > +#include <linux/iio/trigger.h> > #include "iio_core.h" > #include "iio_core_trigger.h" > #include <linux/iio/sysfs.h> > @@ -988,6 +989,7 @@ struct iio_dev *iio_device_alloc(int sizeof_priv) > } > dev_set_name(&dev->dev, "iio:device%d", dev->id); > INIT_LIST_HEAD(&dev->buffer_list); > + INIT_LIST_HEAD(&dev->triggers); > } > > return dev; > @@ -1166,6 +1168,8 @@ static const struct iio_buffer_setup_ops noop_ring_setup_ops; > int iio_device_register(struct iio_dev *indio_dev) > { > int ret; > + struct iio_trigger *trig_info; > + struct list_head *pos; > > /* If the calling driver did not initialize of_node, do it here */ > if (!indio_dev->dev.of_node && indio_dev->dev.parent) > @@ -1222,6 +1226,13 @@ int iio_device_register(struct iio_dev *indio_dev) > if (ret < 0) > goto error_cdev_del; > > + list_for_each(pos, &indio_dev->triggers) { > + trig_info = list_entry(pos, struct iio_trigger, indio_dev_list); > + ret = iio_trigger_link(trig_info); > + if (ret < 0) > + goto error_cdev_del; > + } > + > return 0; > error_cdev_del: > cdev_del(&indio_dev->chrdev); > @@ -1243,8 +1254,17 @@ EXPORT_SYMBOL(iio_device_register); > **/ > void iio_device_unregister(struct iio_dev *indio_dev) > { > + struct list_head *pos, *safe; > + struct iio_trigger *trig_info; > + > mutex_lock(&indio_dev->info_exist_lock); > > + list_for_each_safe(pos, safe, &indio_dev->triggers) { > + trig_info = list_entry(pos, struct iio_trigger, indio_dev_list); > + list_del(pos); > + iio_trigger_unlink(trig_info); > + } > + > device_del(&indio_dev->dev); > > if (indio_dev->chrdev.dev) > diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c > index d31098e..cebdd10 100644 > --- a/drivers/iio/industrialio-trigger.c > +++ b/drivers/iio/industrialio-trigger.c > @@ -57,6 +57,24 @@ static struct attribute *iio_trig_dev_attrs[] = { > }; > ATTRIBUTE_GROUPS(iio_trig_dev); > > +int iio_trigger_register_with_dev(struct iio_dev *indio_dev, > + struct iio_trigger *trig_info) > +{ > + int ret; > + > + ret = iio_trigger_register(trig_info); > + if (ret < 0) > + goto error; > + > + trig_info->indio_dev = indio_dev; > + list_add(&trig_info->indio_dev_list, &indio_dev->triggers); > + > + return 0; > +error: > + return ret; > +} > +EXPORT_SYMBOL(iio_trigger_register_with_dev); > + > int iio_trigger_register(struct iio_trigger *trig_info) > { > int ret; > @@ -88,6 +106,11 @@ EXPORT_SYMBOL(iio_trigger_register); > > void iio_trigger_unregister(struct iio_trigger *trig_info) > { > + if (trig_info->indio_dev) { > + iio_trigger_unlink(trig_info); > + list_del(&trig_info->indio_dev_list); > + } > + > mutex_lock(&iio_trigger_list_lock); > list_del(&trig_info->list); > mutex_unlock(&iio_trigger_list_lock); > @@ -98,6 +121,47 @@ void iio_trigger_unregister(struct iio_trigger *trig_info) > } > EXPORT_SYMBOL(iio_trigger_unregister); > > +int iio_trigger_link(struct iio_trigger *trig_info) > +{ > + int ret; > + char *name; > + struct iio_dev *indio_dev; > + > + indio_dev = trig_info->indio_dev; > + if (!indio_dev) > + return -EINVAL; > + > + name = kasprintf(GFP_KERNEL, "trigger%d", trig_info->id); > + if (!name) > + return -ENOMEM; > + > + ret = sysfs_add_link_to_group(&indio_dev->dev.kobj, "trigger", > + &trig_info->dev.kobj, name); > + kfree(name); > + return ret; > +} > +EXPORT_SYMBOL(iio_trigger_link); > + > +int iio_trigger_unlink(struct iio_trigger *trig_info) > +{ > + char *name; > + struct iio_dev *indio_dev; > + > + indio_dev = trig_info->indio_dev; > + if (!trig_info->indio_dev) > + return -EINVAL; > + > + name = kasprintf(GFP_KERNEL, "trigger%d", trig_info->id); > + if (!name) > + return -ENOMEM; > + > + sysfs_remove_link_from_group(&indio_dev->dev.kobj, "trigger", name); > + kfree(name); > + trig_info->indio_dev = NULL; > + return 0; > +} > +EXPORT_SYMBOL(iio_trigger_unlink); > + > static struct iio_trigger *iio_trigger_find_by_name(const char *name, > size_t len) > { > diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h > index 878d861..9ff54ef 100644 > --- a/include/linux/iio/iio.h > +++ b/include/linux/iio/iio.h > @@ -495,6 +495,7 @@ struct iio_dev { > struct dentry *debugfs_dentry; > unsigned cached_reg_addr; > #endif > + struct list_head triggers; Better name for this would be trigger_list (see buffer_list or chan_attr_list in the same structure). Also, please update the doc string above. > }; > > const struct iio_chan_spec > diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h > index fa76c79..4001e44 100644 > --- a/include/linux/iio/trigger.h > +++ b/include/linux/iio/trigger.h > @@ -70,6 +70,9 @@ 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; > + > + struct iio_dev *indio_dev; > + struct list_head indio_dev_list; > }; The same observation about the doc string. > > > @@ -117,6 +120,15 @@ static inline void *iio_trigger_get_drvdata(struct iio_trigger *trig) > } > > /** > + * iio_trigger_register_width_dev() - register a trigger with the IIO core > + * and associate it with a device > + * @iio_dev: device to associate the trigger with > + * @trig_info: trigger to be registered > + **/ > +int iio_trigger_register_with_dev(struct iio_dev *indio_dev, > + struct iio_trigger *trig_info); > + > +/** > * iio_trigger_register() - register a trigger with the IIO core > * @trig_info: trigger to be registered > **/ > @@ -129,6 +141,18 @@ int iio_trigger_register(struct iio_trigger *trig_info); > void iio_trigger_unregister(struct iio_trigger *trig_info); > > /** > + * Add a symlink to the trigger in the devices' trigger folder > + * @trig_info: symlink destination trigger > + */ > +int iio_trigger_link(struct iio_trigger *trig_info); > + > +/** > + * Remove the trigger's symlink from the device's trigger folder > + * @trig_info: symlink destination trigger > + */ > +int iio_trigger_unlink(struct iio_trigger *trig_info); > + > +/** > * iio_trigger_poll() - called on a trigger occurring > * @trig: trigger which occurred > * > -- > 1.9.1 > > -- > 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
