diff options
Diffstat (limited to 'drivers/iio/dummy/iio_simple_dummy_events.c')
| -rw-r--r-- | drivers/iio/dummy/iio_simple_dummy_events.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/drivers/iio/dummy/iio_simple_dummy_events.c b/drivers/iio/dummy/iio_simple_dummy_events.c new file mode 100644 index 000000000..7ec2a0bb0 --- /dev/null +++ b/drivers/iio/dummy/iio_simple_dummy_events.c @@ -0,0 +1,277 @@ +/** + * Copyright (c) 2011 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. + * + * Event handling elements of industrial I/O reference driver. + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/events.h> +#include "iio_simple_dummy.h" + +/* Evgen 'fakes' interrupt events for this example */ +#include "iio_dummy_evgen.h" + +/** + * iio_simple_dummy_read_event_config() - is event enabled? + * @indio_dev: the device instance data + * @chan: channel for the event whose state is being queried + * @type: type of the event whose state is being queried + * @dir: direction of the vent whose state is being queried + * + * This function would normally query the relevant registers or a cache to + * discover if the event generation is enabled on the device. + */ +int iio_simple_dummy_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + + return st->event_en; +} + +/** + * iio_simple_dummy_write_event_config() - set whether event is enabled + * @indio_dev: the device instance data + * @chan: channel for the event whose state is being set + * @type: type of the event whose state is being set + * @dir: direction of the vent whose state is being set + * @state: whether to enable or disable the device. + * + * This function would normally set the relevant registers on the devices + * so that it generates the specified event. Here it just sets up a cached + * value. + */ +int iio_simple_dummy_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + int state) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + + /* + * Deliberately over the top code splitting to illustrate + * how this is done when multiple events exist. + */ + switch (chan->type) { + case IIO_VOLTAGE: + switch (type) { + case IIO_EV_TYPE_THRESH: + if (dir == IIO_EV_DIR_RISING) + st->event_en = state; + else + return -EINVAL; + break; + default: + return -EINVAL; + } + break; + case IIO_ACTIVITY: + switch (type) { + case IIO_EV_TYPE_THRESH: + st->event_en = state; + break; + default: + return -EINVAL; + } + break; + case IIO_STEPS: + switch (type) { + case IIO_EV_TYPE_CHANGE: + st->event_en = state; + break; + default: + return -EINVAL; + } + break; + default: + return -EINVAL; + } + + return 0; +} + +/** + * iio_simple_dummy_read_event_value() - get value associated with event + * @indio_dev: device instance specific data + * @chan: channel for the event whose value is being read + * @type: type of the event whose value is being read + * @dir: direction of the vent whose value is being read + * @info: info type of the event whose value is being read + * @val: value for the event code. + * + * Many devices provide a large set of events of which only a subset may + * be enabled at a time, with value registers whose meaning changes depending + * on the event enabled. This often means that the driver must cache the values + * associated with each possible events so that the right value is in place when + * the enabled event is changed. + */ +int iio_simple_dummy_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int *val, int *val2) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + + *val = st->event_val; + + return IIO_VAL_INT; +} + +/** + * iio_simple_dummy_write_event_value() - set value associate with event + * @indio_dev: device instance specific data + * @chan: channel for the event whose value is being set + * @type: type of the event whose value is being set + * @dir: direction of the vent whose value is being set + * @info: info type of the event whose value is being set + * @val: the value to be set. + */ +int iio_simple_dummy_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int val, int val2) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + + st->event_val = val; + + return 0; +} + +static irqreturn_t iio_simple_dummy_get_timestamp(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct iio_dummy_state *st = iio_priv(indio_dev); + + st->event_timestamp = iio_get_time_ns(indio_dev); + return IRQ_WAKE_THREAD; +} + +/** + * iio_simple_dummy_event_handler() - identify and pass on event + * @irq: irq of event line + * @private: pointer to device instance state. + * + * This handler is responsible for querying the device to find out what + * event occurred and for then pushing that event towards userspace. + * Here only one event occurs so we push that directly on with locally + * grabbed timestamp. + */ +static irqreturn_t iio_simple_dummy_event_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct iio_dummy_state *st = iio_priv(indio_dev); + + dev_dbg(&indio_dev->dev, "id %x event %x\n", + st->regs->reg_id, st->regs->reg_data); + + switch (st->regs->reg_data) { + case 0: + iio_push_event(indio_dev, + IIO_EVENT_CODE(IIO_VOLTAGE, 0, 0, + IIO_EV_DIR_RISING, + IIO_EV_TYPE_THRESH, 0, 0, 0), + st->event_timestamp); + break; + case 1: + if (st->activity_running > st->event_val) + iio_push_event(indio_dev, + IIO_EVENT_CODE(IIO_ACTIVITY, 0, + IIO_MOD_RUNNING, + IIO_EV_DIR_RISING, + IIO_EV_TYPE_THRESH, + 0, 0, 0), + st->event_timestamp); + break; + case 2: + if (st->activity_walking < st->event_val) + iio_push_event(indio_dev, + IIO_EVENT_CODE(IIO_ACTIVITY, 0, + IIO_MOD_WALKING, + IIO_EV_DIR_FALLING, + IIO_EV_TYPE_THRESH, + 0, 0, 0), + st->event_timestamp); + break; + case 3: + iio_push_event(indio_dev, + IIO_EVENT_CODE(IIO_STEPS, 0, IIO_NO_MOD, + IIO_EV_DIR_NONE, + IIO_EV_TYPE_CHANGE, 0, 0, 0), + st->event_timestamp); + break; + default: + break; + } + + return IRQ_HANDLED; +} + +/** + * iio_simple_dummy_events_register() - setup interrupt handling for events + * @indio_dev: device instance data + * + * This function requests the threaded interrupt to handle the events. + * Normally the irq is a hardware interrupt and the number comes + * from board configuration files. Here we get it from a companion + * module that fakes the interrupt for us. Note that module in + * no way forms part of this example. Just assume that events magically + * appear via the provided interrupt. + */ +int iio_simple_dummy_events_register(struct iio_dev *indio_dev) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + int ret; + + /* Fire up event source - normally not present */ + st->event_irq = iio_dummy_evgen_get_irq(); + if (st->event_irq < 0) { + ret = st->event_irq; + goto error_ret; + } + st->regs = iio_dummy_evgen_get_regs(st->event_irq); + + ret = request_threaded_irq(st->event_irq, + &iio_simple_dummy_get_timestamp, + &iio_simple_dummy_event_handler, + IRQF_ONESHOT, + "iio_simple_event", + indio_dev); + if (ret < 0) + goto error_free_evgen; + return 0; + +error_free_evgen: + iio_dummy_evgen_release_irq(st->event_irq); +error_ret: + return ret; +} + +/** + * iio_simple_dummy_events_unregister() - tidy up interrupt handling on remove + * @indio_dev: device instance data + */ +void iio_simple_dummy_events_unregister(struct iio_dev *indio_dev) +{ + struct iio_dummy_state *st = iio_priv(indio_dev); + + free_irq(st->event_irq, indio_dev); + /* Not part of normal driver */ + iio_dummy_evgen_release_irq(st->event_irq); +} |