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Diffstat (limited to 'drivers/staging/iio/iio.h')
-rw-r--r-- | drivers/staging/iio/iio.h | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h new file mode 100644 index 00000000000..25ccb809221 --- /dev/null +++ b/drivers/staging/iio/iio.h @@ -0,0 +1,411 @@ +/* The industrial I/O core + * + * 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 _INDUSTRIAL_IO_H_ +#define _INDUSTRIAL_IO_H_ + +#include <linux/device.h> +#include <linux/cdev.h> +#include "sysfs.h" +#include "chrdev.h" + +/* IIO TODO LIST */ +/* Static device specific elements (conversion factors etc) + * should be exported via sysfs + * + * Provide means of adjusting timer accuracy. + * Currently assumes nano seconds. + */ + +/* Event interface flags */ +#define IIO_BUSY_BIT_POS 1 + +struct iio_dev; + +/** + * iio_get_time_ns() - utility function to get a time stamp for events etc + **/ +static inline s64 iio_get_time_ns(void) +{ + struct timespec ts; + /* + * calls getnstimeofday. + * If hrtimers then up to ns accurate, if not microsecond. + */ + ktime_get_real_ts(&ts); + + return timespec_to_ns(&ts); +} + +/** + * iio_add_event_to_list() - Wraps adding to event lists + * @el: the list element of the event to be handled. + * @head: the list associated with the event handler being used. + * + * Does reference counting to allow shared handlers. + **/ +void iio_add_event_to_list(struct iio_event_handler_list *el, + struct list_head *head); + +/** + * iio_remove_event_from_list() - Wraps removing from event list + * @el: element to be removed + * @head: associate list head for the interrupt handler. + * + * Does reference counting to allow shared handlers. + **/ +void iio_remove_event_from_list(struct iio_event_handler_list *el, + struct list_head *head); + +/* Device operating modes */ +#define INDIO_DIRECT_MODE 0x01 +#define INDIO_RING_TRIGGERED 0x02 +#define INDIO_RING_HARDWARE_BUFFER 0x08 + +#define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER) + +/* Vast majority of this is set by the industrialio subsystem on a + * call to iio_device_register. */ + +/** + * struct iio_dev - industrial I/O device + * @id: [INTERN] used to identify device internally + * @dev_data: [DRIVER] device specific data + * @modes: [DRIVER] operating modes supported by device + * @currentmode: [DRIVER] current operating mode + * @dev: [DRIVER] device structure, should be assigned a parent + * and owner + * @attrs: [DRIVER] general purpose device attributes + * @driver_module: [DRIVER] module structure used to ensure correct + * ownership of chrdevs etc + * @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device + * @interrupts: [INTERN] interrupt line specific event lists etc + * @event_attrs: [DRIVER] event control attributes + * @event_conf_attrs: [DRIVER] event configuration attributes + * @event_interfaces: [INTERN] event chrdevs associated with interrupt lines + * @ring: [DRIVER] any ring buffer present + * @mlock: [INTERN] lock used to prevent simultaneous device state + * changes + * @scan_el_attrs: [DRIVER] control of scan elements if that scan mode + * control method is used + * @scan_count: [INTERN] the number of elements in the current scan mode + * @scan_mask: [INTERN] bitmask used in masking scan mode elements + * @scan_timestamp: [INTERN] does the scan mode include a timestamp + * @trig: [INTERN] current device trigger (ring buffer modes) + * @pollfunc: [DRIVER] function run on trigger being recieved + **/ +struct iio_dev { + int id; + void *dev_data; + int modes; + int currentmode; + struct device dev; + const struct attribute_group *attrs; + struct module *driver_module; + + int num_interrupt_lines; + struct iio_interrupt **interrupts; + struct attribute_group *event_attrs; + struct attribute_group *event_conf_attrs; + + struct iio_event_interface *event_interfaces; + + struct iio_ring_buffer *ring; + struct mutex mlock; + + struct attribute_group *scan_el_attrs; + int scan_count; + + u16 scan_mask; + bool scan_timestamp; + struct iio_trigger *trig; + struct iio_poll_func *pollfunc; +}; + +/* + * These are mainly provided to allow for a change of implementation if a device + * has a large number of scan elements + */ +#define IIO_MAX_SCAN_LENGTH 15 + +static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit) +{ + if (bit > IIO_MAX_SCAN_LENGTH) + return -EINVAL; + else + return !!(dev_info->scan_mask & (1 << bit)); +}; + +static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit) +{ + if (bit > IIO_MAX_SCAN_LENGTH) + return -EINVAL; + dev_info->scan_mask |= (1 << bit); + dev_info->scan_count++; + return 0; +}; + +static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit) +{ + if (bit > IIO_MAX_SCAN_LENGTH) + return -EINVAL; + dev_info->scan_mask &= ~(1 << bit); + dev_info->scan_count--; + return 0; +}; + +/** + * iio_scan_mask_count_to_right() - how many scan elements occur before here + * @dev_info: the iio_device whose scan mode we are querying + * @bit: which number scan element is this + **/ +static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info, +int bit) +{ + int count = 0; + int mask = (1 << bit); + if (bit > IIO_MAX_SCAN_LENGTH) + return -EINVAL; + while (mask) { + mask >>= 1; + if (mask & dev_info->scan_mask) + count++; + } + + return count; +} + +/** + * iio_device_register() - register a device with the IIO subsystem + * @dev_info: Device structure filled by the device driver + **/ +int iio_device_register(struct iio_dev *dev_info); + +/** + * iio_device_unregister() - unregister a device from the IIO subsystem + * @dev_info: Device structure representing the device. + **/ +void iio_device_unregister(struct iio_dev *dev_info); + +/** + * struct iio_interrupt - wrapper used to allow easy handling of multiple + * physical interrupt lines + * @dev_info: the iio device for which the is an interrupt line + * @line_number: associated line number + * @id: idr allocated unique id number + * @irq: associate interrupt number + * @ev_list: event handler list for associated events + * @ev_list_lock: ensure only one access to list at a time + **/ +struct iio_interrupt { + struct iio_dev *dev_info; + int line_number; + int id; + int irq; + struct list_head ev_list; + spinlock_t ev_list_lock; +}; + +#define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list) + +/** + * iio_register_interrupt_line() - Tell IIO about interrupt lines + * + * @irq: Typically provided via platform data + * @dev_info: IIO device info structure for device + * @line_number: Which interrupt line of the device is this? + * @type: Interrupt type (e.g. edge triggered etc) + * @name: Identifying name. + **/ +int iio_register_interrupt_line(unsigned int irq, + struct iio_dev *dev_info, + int line_number, + unsigned long type, + const char *name); + +void iio_unregister_interrupt_line(struct iio_dev *dev_info, + int line_number); + + + +/** + * iio_push_event() - try to add event to the list for userspace reading + * @dev_info: IIO device structure + * @ev_line: Which event line (hardware interrupt) + * @ev_code: What event + * @timestamp: When the event occured + **/ +int iio_push_event(struct iio_dev *dev_info, + int ev_line, + int ev_code, + s64 timestamp); + +/** + * struct iio_work_cont - container for when singleton handler case matters + * @ws: [DEVICE]work_struct when not only possible event + * @ws_nocheck: [DEVICE]work_struct when only possible event + * @address: [DEVICE]associated register address + * @mask: [DEVICE]associated mask for identifying event source + * @st: [DEVICE]device specific state information + **/ +struct iio_work_cont { + struct work_struct ws; + struct work_struct ws_nocheck; + int address; + int mask; + void *st; +}; + +#define to_iio_work_cont_check(_ws) \ + container_of(_ws, struct iio_work_cont, ws) + +#define to_iio_work_cont_no_check(_ws) \ + container_of(_ws, struct iio_work_cont, ws_nocheck) + +/** + * iio_init_work_cont() - intiialize the elements of a work container + * @cont: the work container + * @_checkfunc: function called when there are multiple possible int sources + * @_nocheckfunc: function for when there is only one int source + * @_add: driver dependant, typically a register address + * @_mask: driver dependant, typically a bit mask for a register + * @_st: driver dependant, typically pointer to a device state structure + **/ +static inline void +iio_init_work_cont(struct iio_work_cont *cont, + void (*_checkfunc)(struct work_struct *), + void (*_nocheckfunc)(struct work_struct *), + int _add, int _mask, void *_st) +{ + INIT_WORK(&(cont)->ws, _checkfunc); + INIT_WORK(&(cont)->ws_nocheck, _nocheckfunc); + cont->address = _add; + cont->mask = _mask; + cont->st = _st; +} +/** + * __iio_push_event() tries to add an event to the list associated with a chrdev + * @ev_int: the event interface to which we are pushing the event + * @ev_code: the outgoing event code + * @timestamp: timestamp of the event + * @shared_pointer_p: the shared event pointer + **/ +int __iio_push_event(struct iio_event_interface *ev_int, + int ev_code, + s64 timestamp, + struct iio_shared_ev_pointer* + shared_pointer_p); +/** + * __iio_change_event() change an event code in case of event escallation + * @ev: the evnet to be changed + * @ev_code: new event code + * @timestamp: new timestamp + **/ +void __iio_change_event(struct iio_detected_event_list *ev, + int ev_code, + s64 timestamp); + +/** + * iio_setup_ev_int() Configure an event interface (chrdev) + * @name: name used for resulting sysfs directory etc. + * @ev_int: interface we are configuring + * @owner: module that is responsible for registering this ev_int + * @dev: device whose ev_int this is + **/ +int iio_setup_ev_int(struct iio_event_interface *ev_int, + const char *name, + struct module *owner, + struct device *dev); + +void iio_free_ev_int(struct iio_event_interface *ev_int); + +/** + * iio_allocate_chrdev() - Allocate a chrdev + * @handler: struct that contains relevant file handling for chrdev + * @dev_info: iio_dev for which chrdev is being created + **/ +int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info); +void iio_deallocate_chrdev(struct iio_handler *handler); + +/* Used to distinguish between bipolar and unipolar scan elemenents. + * Whilst this may seem obvious, we may well want to change the representation + * in the future!*/ +#define IIO_SIGNED(a) -(a) +#define IIO_UNSIGNED(a) (a) + +extern dev_t iio_devt; +extern struct class iio_class; + +/** + * iio_put_device() - reference counted deallocated of struct device + * @dev: the iio_device containing the device + **/ +static inline void iio_put_device(struct iio_dev *dev) +{ + if (dev) + put_device(&dev->dev); +}; + +/** + * to_iio_dev() - get iio_dev for which we have have the struct device + * @d: the struct device + **/ +static inline struct iio_dev *to_iio_dev(struct device *d) +{ + return container_of(d, struct iio_dev, dev); +}; + +/** + * iio_dev_get_devdata() - helper function gets device specific data + * @d: the iio_dev associated with the device + **/ +static inline void *iio_dev_get_devdata(struct iio_dev *d) +{ + return d->dev_data; +} + +/** + * iio_allocate_device() - allocate an iio_dev from a driver + **/ +struct iio_dev *iio_allocate_device(void); + +/** + * iio_free_device() - free an iio_dev from a driver + **/ +void iio_free_device(struct iio_dev *dev); + +/** + * iio_put() - internal module reference count reduce + **/ +void iio_put(void); + +/** + * iio_get() - internal module reference count increase + **/ +void iio_get(void); + +/* Ring buffer related */ +int iio_device_get_chrdev_minor(void); +void iio_device_free_chrdev_minor(int val); + +/** + * iio_ring_enabled() helper function to test if any form of ring enabled + **/ +static inline bool iio_ring_enabled(struct iio_dev *dev_info) +{ + return dev_info->currentmode + & (INDIO_RING_TRIGGERED + | INDIO_RING_HARDWARE_BUFFER); +}; + +struct idr; + +int iio_get_new_idr_val(struct idr *this_idr); +void iio_free_idr_val(struct idr *this_idr, int id); +#endif /* _INDUSTRIAL_IO_H_ */ |