Commit e6477000 authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Greg Kroah-Hartman

staging:iio:dummy Add event support + fake event generator

The event generator is not very pretty but does the job and
allows this driver to look a lot more like a normal driver
than it otherwise would.
Signed-off-by: default avatarJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3a84331d
......@@ -70,12 +70,26 @@ source "drivers/staging/iio/meter/Kconfig"
source "drivers/staging/iio/resolver/Kconfig"
source "drivers/staging/iio/trigger/Kconfig"
config IIO_DUMMY_EVGEN
tristate
config IIO_SIMPLE_DUMMY
tristate "An example driver with no hardware requirements"
select IIO_SIMPLE_DUMMY_EVGEN if IIO_SIMPLE_DUMMY_EVENTS
help
Driver intended mainly as documentation for how to write
a driver. May also be useful for testing userspace code
without hardward.
Driver intended mainly as documentation for how to write
a driver. May also be useful for testing userspace code
without hardward.
if IIO_SIMPLE_DUMMY
config IIO_SIMPLE_DUMMY_EVENTS
boolean "Event generation support"
select IIO_DUMMY_EVGEN
help
Add some dummy events to the simple dummy driver.
endif # IIO_SIMPLE_DUMMY
endif # IIO
......@@ -10,7 +10,11 @@ industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
obj-$(CONFIG_IIO_SW_RING) += ring_sw.o
obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
obj-$(CONFIG_IIO_SIMPLE_DUMMY) += iio_simple_dummy.o
obj-$(CONFIG_IIO_SIMPLE_DUMMY) += iio_dummy.o
iio_dummy-y := iio_simple_dummy.o
iio_dummy-$(CONFIG_IIO_SIMPLE_DUMMY_EVENTS) += iio_simple_dummy_events.o
obj-$(CONFIG_IIO_DUMMY_EVGEN) += iio_dummy_evgen.o
obj-y += accel/
obj-y += adc/
......
/**
* 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.
*
* Companion module to the iio simple dummy example driver.
* The purpose of this is to generate 'fake' event interrupts thus
* allowing that driver's code to be as close as possible to that of
* a normal driver talking to hardware. The approach used here
* is not intended to be general and just happens to work for this
* particular use case.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/sysfs.h>
#include "iio_dummy_evgen.h"
#include "iio.h"
#include "sysfs.h"
/* Fiddly bit of faking and irq without hardware */
#define IIO_EVENTGEN_NO 10
/**
* struct iio_dummy_evgen - evgen state
* @chip: irq chip we are faking
* @base: base of irq range
* @enabled: mask of which irqs are enabled
* @inuse: mask of which irqs actually have anyone connected
* @lock: protect the evgen state
*/
struct iio_dummy_eventgen {
struct irq_chip chip;
int base;
bool enabled[IIO_EVENTGEN_NO];
bool inuse[IIO_EVENTGEN_NO];
struct mutex lock;
};
/* We can only ever have one instance of this 'device' */
static struct iio_dummy_eventgen *iio_evgen;
static const char *iio_evgen_name = "iio_dummy_evgen";
static void iio_dummy_event_irqmask(struct irq_data *d)
{
struct irq_chip *chip = irq_data_get_irq_chip(d);
struct iio_dummy_eventgen *evgen =
container_of(chip, struct iio_dummy_eventgen, chip);
evgen->enabled[d->irq - evgen->base] = false;
}
static void iio_dummy_event_irqunmask(struct irq_data *d)
{
struct irq_chip *chip = irq_data_get_irq_chip(d);
struct iio_dummy_eventgen *evgen =
container_of(chip, struct iio_dummy_eventgen, chip);
evgen->enabled[d->irq - evgen->base] = true;
}
static int iio_dummy_evgen_create(void)
{
int ret, i;
iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL);
if (iio_evgen == NULL)
return -ENOMEM;
iio_evgen->base = irq_alloc_descs(-1, 0, IIO_EVENTGEN_NO, 0);
if (iio_evgen->base < 0) {
ret = iio_evgen->base;
kfree(iio_evgen);
return ret;
}
iio_evgen->chip.name = iio_evgen_name;
iio_evgen->chip.irq_mask = &iio_dummy_event_irqmask;
iio_evgen->chip.irq_unmask = &iio_dummy_event_irqunmask;
for (i = 0; i < IIO_EVENTGEN_NO; i++) {
irq_set_chip(iio_evgen->base + i, &iio_evgen->chip);
irq_set_handler(iio_evgen->base + i, &handle_simple_irq);
irq_modify_status(iio_evgen->base + i,
IRQ_NOREQUEST | IRQ_NOAUTOEN,
IRQ_NOPROBE);
}
mutex_init(&iio_evgen->lock);
return 0;
}
/**
* iio_dummy_evgen_get_irq() - get an evgen provided irq for a device
*
* This function will give a free allocated irq to a client device.
* That irq can then be caused to 'fire' by using the associated sysfs file.
*/
int iio_dummy_evgen_get_irq(void)
{
int i, ret = 0;
mutex_lock(&iio_evgen->lock);
for (i = 0; i < IIO_EVENTGEN_NO; i++)
if (iio_evgen->inuse[i] == false) {
ret = iio_evgen->base + i;
iio_evgen->inuse[i] = true;
break;
}
mutex_unlock(&iio_evgen->lock);
if (i == IIO_EVENTGEN_NO)
return -ENOMEM;
return ret;
}
EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_irq);
/**
* iio_dummy_evgen_release_irq() - give the irq back.
* @irq: irq being returned to the pool
*
* Used by client driver instances to give the irqs back when they disconnect
*/
int iio_dummy_evgen_release_irq(int irq)
{
mutex_lock(&iio_evgen->lock);
iio_evgen->inuse[irq - iio_evgen->base] = false;
mutex_unlock(&iio_evgen->lock);
return 0;
}
EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq);
static void iio_dummy_evgen_free(void)
{
irq_free_descs(iio_evgen->base, IIO_EVENTGEN_NO);
kfree(iio_evgen);
}
static void iio_evgen_release(struct device *dev)
{
iio_dummy_evgen_free();
}
static ssize_t iio_evgen_poke(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
if (iio_evgen->enabled[this_attr->address])
handle_nested_irq(iio_evgen->base + this_attr->address);
return len;
}
static IIO_DEVICE_ATTR(poke_ev0, S_IWUSR, NULL, &iio_evgen_poke, 0);
static IIO_DEVICE_ATTR(poke_ev1, S_IWUSR, NULL, &iio_evgen_poke, 1);
static IIO_DEVICE_ATTR(poke_ev2, S_IWUSR, NULL, &iio_evgen_poke, 2);
static IIO_DEVICE_ATTR(poke_ev3, S_IWUSR, NULL, &iio_evgen_poke, 3);
static IIO_DEVICE_ATTR(poke_ev4, S_IWUSR, NULL, &iio_evgen_poke, 4);
static IIO_DEVICE_ATTR(poke_ev5, S_IWUSR, NULL, &iio_evgen_poke, 5);
static IIO_DEVICE_ATTR(poke_ev6, S_IWUSR, NULL, &iio_evgen_poke, 6);
static IIO_DEVICE_ATTR(poke_ev7, S_IWUSR, NULL, &iio_evgen_poke, 7);
static IIO_DEVICE_ATTR(poke_ev8, S_IWUSR, NULL, &iio_evgen_poke, 8);
static IIO_DEVICE_ATTR(poke_ev9, S_IWUSR, NULL, &iio_evgen_poke, 9);
static struct attribute *iio_evgen_attrs[] = {
&iio_dev_attr_poke_ev0.dev_attr.attr,
&iio_dev_attr_poke_ev1.dev_attr.attr,
&iio_dev_attr_poke_ev2.dev_attr.attr,
&iio_dev_attr_poke_ev3.dev_attr.attr,
&iio_dev_attr_poke_ev4.dev_attr.attr,
&iio_dev_attr_poke_ev5.dev_attr.attr,
&iio_dev_attr_poke_ev6.dev_attr.attr,
&iio_dev_attr_poke_ev7.dev_attr.attr,
&iio_dev_attr_poke_ev8.dev_attr.attr,
&iio_dev_attr_poke_ev9.dev_attr.attr,
NULL,
};
static const struct attribute_group iio_evgen_group = {
.attrs = iio_evgen_attrs,
};
static const struct attribute_group *iio_evgen_groups[] = {
&iio_evgen_group,
NULL
};
static struct device iio_evgen_dev = {
.bus = &iio_bus_type,
.groups = iio_evgen_groups,
.release = &iio_evgen_release,
};
static __init int iio_dummy_evgen_init(void)
{
int ret = iio_dummy_evgen_create();
if (ret < 0)
return ret;
device_initialize(&iio_evgen_dev);
dev_set_name(&iio_evgen_dev, "iio_evgen");
return device_add(&iio_evgen_dev);
}
module_init(iio_dummy_evgen_init);
static __exit void iio_dummy_evgen_exit(void)
{
device_unregister(&iio_evgen_dev);
}
module_exit(iio_dummy_evgen_exit);
MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
MODULE_DESCRIPTION("IIO dummy driver");
MODULE_LICENSE("GPL v2");
int iio_dummy_evgen_get_irq(void);
int iio_dummy_evgen_release_irq(int irq);
......@@ -20,6 +20,8 @@
#include <linux/moduleparam.h>
#include "iio.h"
#include "sysfs.h"
#include "iio_simple_dummy.h"
/*
* A few elements needed to fake a bus for this driver
......@@ -53,26 +55,6 @@ static const struct iio_dummy_accel_calibscale dummy_scales[] = {
{ 733, 13, 0x9 }, /* 733.00013 */
};
/**
* struct iio_dummy_state - device instance specific state.
* @dac_val: cache for dac value
* @single_ended_adc_val: cache for single ended adc value
* @differential_adc_val: cache for differential adc value
* @accel_val: cache for acceleration value
* @accel_calibbias: cache for acceleration calibbias
* @accel_calibscale: cache for acceleration calibscale
* @lock: lock to ensure state is consistent
*/
struct iio_dummy_state {
int dac_val;
int single_ended_adc_val;
int differential_adc_val[2];
int accel_val;
int accel_calibbias;
const struct iio_dummy_accel_calibscale *accel_calibscale;
struct mutex lock;
};
/*
* iio_dummy_channels - Description of available channels
*
......@@ -101,6 +83,14 @@ static struct iio_chan_spec iio_dummy_channels[] = {
*/
(1 << IIO_CHAN_INFO_SCALE_SEPARATE),
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
/*
* simple event - triggered when value rises above
* a threshold
*/
.event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH,
IIO_EV_DIR_RISING),
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
},
/* Differential ADC channel in_voltage1-voltage2_raw etc*/
{
......@@ -296,6 +286,12 @@ static const struct iio_info iio_dummy_info = {
.driver_module = THIS_MODULE,
.read_raw = &iio_dummy_read_raw,
.write_raw = &iio_dummy_write_raw,
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
.read_event_config = &iio_simple_dummy_read_event_config,
.write_event_config = &iio_simple_dummy_write_event_config,
.read_event_value = &iio_simple_dummy_read_event_value,
.write_event_value = &iio_simple_dummy_write_event_value,
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
};
/**
......@@ -392,11 +388,16 @@ static int __devinit iio_dummy_probe(int index)
/* Specify that device provides sysfs type interfaces */
indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_device_register(indio_dev);
ret = iio_simple_dummy_events_register(indio_dev);
if (ret < 0)
goto error_free_device;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto error_unregister_events;
return 0;
error_unregister_events:
iio_simple_dummy_events_unregister(indio_dev);
error_free_device:
/* Note free device should only be called, before registration
* has succeeded. */
......@@ -413,6 +414,7 @@ static int __devinit iio_dummy_probe(int index)
*/
static int iio_dummy_remove(int index)
{
int ret;
/*
* Get a pointer to the device instance iio_dev structure
* from the bus subsystem. E.g.
......@@ -421,15 +423,22 @@ static int iio_dummy_remove(int index)
*/
struct iio_dev *indio_dev = iio_dummy_devs[index];
/* Unregister the device */
iio_device_unregister(indio_dev);
/* Device specific code to power down etc */
ret = iio_simple_dummy_events_unregister(indio_dev);
if (ret)
goto error_ret;
/* Free all structures */
iio_free_device(indio_dev);
return 0;
error_ret:
return ret;
}
/**
......
/**
* 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.
*
* Join together the various functionality of iio_simple_dummy driver
*/
#include <linux/kernel.h>
struct iio_dummy_accel_calibscale;
/**
* struct iio_dummy_state - device instance specific state.
* @dac_val: cache for dac value
* @single_ended_adc_val: cache for single ended adc value
* @differential_adc_val: cache for differential adc value
* @accel_val: cache for acceleration value
* @accel_calibbias: cache for acceleration calibbias
* @accel_calibscale: cache for acceleration calibscale
* @lock: lock to ensure state is consistent
* @event_irq: irq number for event line (faked)
* @event_val: cache for event theshold value
* @event_en: cache of whether event is enabled
*/
struct iio_dummy_state {
int dac_val;
int single_ended_adc_val;
int differential_adc_val[2];
int accel_val;
int accel_calibbias;
const struct iio_dummy_accel_calibscale *accel_calibscale;
struct mutex lock;
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
int event_irq;
int event_val;
bool event_en;
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
};
#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
struct iio_dev;
int iio_simple_dummy_read_event_config(struct iio_dev *indio_dev,
u64 event_code);
int iio_simple_dummy_write_event_config(struct iio_dev *indio_dev,
u64 event_code,
int state);
int iio_simple_dummy_read_event_value(struct iio_dev *indio_dev,
u64 event_code,
int *val);
int iio_simple_dummy_write_event_value(struct iio_dev *indio_dev,
u64 event_code,
int val);
int iio_simple_dummy_events_register(struct iio_dev *indio_dev);
int iio_simple_dummy_events_unregister(struct iio_dev *indio_dev);
#else /* Stubs for when events are disabled at compile time */
static inline int
iio_simple_dummy_events_register(struct iio_dev *indio_dev)
{
return 0;
};
static inline int
iio_simple_dummy_events_unregister(struct iio_dev *indio_dev)
{
return 0;
};
#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS*/
/**
* 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 "iio.h"
#include "sysfs.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
* @event_code: event code of the event 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,
u64 event_code)
{
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
* @event_code: event code of event being enabled/disabled
* @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,
u64 event_code,
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 (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) {
case IIO_VOLTAGE:
switch (IIO_EVENT_CODE_EXTRACT_TYPE(event_code)) {
case IIO_EV_TYPE_THRESH:
if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==
IIO_EV_DIR_RISING)
st->event_en = state;
else
return -EINVAL;
break;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
return 0;
}
/**
* iio_simple_dummy_read_event_value() - get value associated with event
* @indio_dev: device instance specific data
* @event_code: event code for the event whose value is being queried
* @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,
u64 event_code,
int *val)
{
struct iio_dummy_state *st = iio_priv(indio_dev);
*val = st->event_val;
return 0;
}
/**
* iio_simple_dummy_write_event_value() - set value associate with event
* @indio_dev: device instance specific data
* @event_code: event code for 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,
u64 event_code,
int val)
{
struct iio_dummy_state *st = iio_priv(indio_dev);
st->event_val = val;
return 0;
}
/**
* 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 occured 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;
iio_push_event(indio_dev,
IIO_EVENT_CODE(IIO_VOLTAGE, 0, 0,
IIO_EV_DIR_RISING,
IIO_EV_TYPE_THRESH, 0, 0, 0),
iio_get_time_ns());
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;
}
ret = request_threaded_irq(st->event_irq,
NULL,
&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
*/
int 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);
return 0;
}
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