diff options
author | Jonathan Cameron <jic23@cam.ac.uk> | 2009-08-18 18:06:26 +0100 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-09-15 12:02:25 -0700 |
commit | 1637db44413e32a0f100dd4bd164644e641842f7 (patch) | |
tree | 112d2671204259195dff3b8f021fe33ed8ca6afe /drivers/staging/iio/trigger.h | |
parent | 574fb258d63658e4564c32c1940068a3bad666a0 (diff) | |
download | linux-1637db44413e32a0f100dd4bd164644e641842f7.tar.bz2 |
Staging: IIO: Trigger support added to core.
Add general registration support for IIO triggers. These
are currently only used to initialize a 'poll' of a given
device. Examples include the lis3l02dq's data ready signal
being used to initialize a read and gpio triggers being
used to allow externally synchronized sensor reading.
Each trigger can cause any number of 'consumer' devices
to be polled with each storing data into a related ring
buffer.
Two stage triggering is supported with 'fast' and 'slow'
paths. The first is used for things like pulling a data
hold line high and the second for actual read which
may take far longer.
Changes since V2:
* As with IIO triggers now use a registration approach
much closer to that of input leading to cleaner code.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/iio/trigger.h')
-rw-r--r-- | drivers/staging/iio/trigger.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/staging/iio/trigger.h b/drivers/staging/iio/trigger.h new file mode 100644 index 000000000000..8284098c9589 --- /dev/null +++ b/drivers/staging/iio/trigger.h @@ -0,0 +1,151 @@ +/* The industrial I/O core, trigger handling functions + * + * 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. + */ +#ifndef _IIO_TRIGGER_H_ +#define _IIO_TRIGGER_H_ +#define IIO_TRIGGER_NAME_LENGTH 20 +#define IIO_TRIGGER_ID_PREFIX "iio:trigger" +#define IIO_TRIGGER_ID_FORMAT IIO_TRIGGER_ID_PREFIX "%d" + + +/** + * struct iio_trigger - industrial I/O trigger device + * + * @id: [INTERN] unique id number + * @name: [DRIVER] unique name + * @dev: [DRIVER] associated device (if relevant) + * @sysfs_dev: [INTERN] sysfs relevant device + * @private_data: [DRIVER] device specific data + * @list: [INTERN] used in maintenance of global trigger list + * @alloc_list: [DRIVER] used for driver specific trigger list + * @poll_func_list_lock:[INTERN] protection of the polling function list + * @pollfunc_list: [INTERN] list of functions to run on trigger. + * @control_attrs: [DRIVER] sysfs attributes relevant to trigger type + * @set_trigger_state: [DRIVER] switch on/off the trigger on demand + * @timestamp: [INTERN] timestamp usesd by some trigs (e.g. datardy) + * @owner: [DRIVER] used to monitor usage count of the trigger. + **/ +struct iio_trigger { + int id; + const char *name; + struct device dev; + + void *private_data; + struct list_head list; + struct list_head alloc_list; + spinlock_t pollfunc_list_lock; + struct list_head pollfunc_list; + const struct attribute_group *control_attrs; + s64 timestamp; + struct module *owner; + int use_count; + + int (*set_trigger_state)(struct iio_trigger *trig, bool state); + int (*try_reenable)(struct iio_trigger *trig); +}; + +static inline struct iio_trigger *to_iio_trigger(struct device *d) +{ + return container_of(d, struct iio_trigger, dev); +}; + +static inline void iio_put_trigger(struct iio_trigger *trig) +{ + put_device(&trig->dev); + module_put(trig->owner); +}; + +static inline void iio_get_trigger(struct iio_trigger *trig) +{ + __module_get(trig->owner); + get_device(&trig->dev); +}; + +/** + * iio_trigger_read_name() - sysfs access function to get the trigger name + **/ +ssize_t iio_trigger_read_name(struct device *dev, + struct device_attribute *attr, + char *buf); + +#define IIO_TRIGGER_NAME_ATTR DEVICE_ATTR(name, S_IRUGO, \ + iio_trigger_read_name, \ + NULL); + +/** + * iio_trigger_find_by_name() - search global trigger list + **/ +struct iio_trigger *iio_trigger_find_by_name(const char *name, size_t len); + +/** + * iio_trigger_register() - register a trigger with the IIO core + * @trig_info: trigger to be registered + **/ +int iio_trigger_register(struct iio_trigger *trig_info); + +/** + * iio_trigger_unregister() - unregister a trigger from the core + **/ +void iio_trigger_unregister(struct iio_trigger *trig_info); + +/** + * iio_trigger_attach_poll_func() - add a function pair to be run on trigger + * @trig: trigger to which the function pair are being added + * @pf: poll function pair + **/ +int iio_trigger_attach_poll_func(struct iio_trigger *trig, + struct iio_poll_func *pf); + +/** + * iio_trigger_dettach_poll_func() - remove function pair from those to be + * run on trigger. + * @trig: trigger from which the function is being removed. + * @pf: poll function pair + **/ +int iio_trigger_dettach_poll_func(struct iio_trigger *trig, + struct iio_poll_func *pf); + +/** + * iio_trigger_poll() - called on a trigger occuring + * Typically called in relevant hardware interrupt handler. + **/ +void iio_trigger_poll(struct iio_trigger *); +void iio_trigger_notify_done(struct iio_trigger *); + +/** + * struct iio_poll_func - poll function pair + * + * @list: associate this with a triggers pollfunc_list + * @private_data: data specific to device (passed into poll func) + * @poll_func_immediate: function in here is run first. They should be + * extremely lightweight. Typically used for latch + * control on sensor supporting it. + * @poll_func_main: function in here is run after all immediates. + * Reading from sensor etc typically involves + * scheduling + * from here. + * + * The two stage approach used here only important when multiple sensors are + * being triggered by a single trigger. This really comes into it's own with + * simultaneous sampling devices where a simple latch command can be used to + * make the device store the values on all inputs. + **/ +struct iio_poll_func { + struct list_head list; + void *private_data; + void (*poll_func_immediate)(struct iio_dev *indio_dev); + void (*poll_func_main)(struct iio_dev *private_data); + +}; + +struct iio_trigger *iio_allocate_trigger(void); + +void iio_free_trigger(struct iio_trigger *trig); + + +#endif /* _IIO_TRIGGER_H_ */ |