linux/drivers/iio/dummy/iio_dummy_evgen.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011 Jonathan Cameron
 *
 * 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 <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/irq_sim.h>

/* Fiddly bit of faking and irq without hardware */
#define IIO_EVENTGEN_NO …

/**
 * struct iio_dummy_eventgen - event generator specific state
 * @regs: irq regs we are faking
 * @lock: protect the evgen state
 * @inuse: mask of which irqs are connected
 * @irq_sim_domain: irq simulator domain
 */
struct iio_dummy_eventgen { … };

/* We can only ever have one instance of this 'device' */
static struct iio_dummy_eventgen *iio_evgen;

static int iio_dummy_evgen_create(void)
{ … }

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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
 */
void iio_dummy_evgen_release_irq(int irq)
{ … }
EXPORT_SYMBOL_GPL(…);

struct iio_dummy_regs *iio_dummy_evgen_get_regs(int irq)
{ … }
EXPORT_SYMBOL_GPL(…);

static void iio_dummy_evgen_free(void)
{ … }

static void iio_evgen_release(struct device *dev)
{ … }

static ssize_t iio_evgen_poke(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf,
			      size_t 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[] = …;

static const struct attribute_group iio_evgen_group = …;

static const struct attribute_group *iio_evgen_groups[] = …;

static struct device iio_evgen_dev = …;

static __init int iio_dummy_evgen_init(void)
{ … }
module_init(…) …;

static __exit void iio_dummy_evgen_exit(void)
{ … }
module_exit(iio_dummy_evgen_exit);

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;