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: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>tirimbino
Jonathan Cameron
13 years ago
committed by
Greg Kroah-Hartman
parent
3a84331db2
commit
e6477000fc
@ -0,0 +1,217 @@ |
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/**
|
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* Copyright (c) 2011 Jonathan Cameron |
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* |
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* This program is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 as published by |
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* the Free Software Foundation. |
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* |
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* Companion module to the iio simple dummy example driver. |
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* The purpose of this is to generate 'fake' event interrupts thus |
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* allowing that driver's code to be as close as possible to that of |
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* a normal driver talking to hardware. The approach used here |
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* is not intended to be general and just happens to work for this |
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* particular use case. |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/interrupt.h> |
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#include <linux/irq.h> |
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#include <linux/mutex.h> |
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#include <linux/module.h> |
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#include <linux/sysfs.h> |
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#include "iio_dummy_evgen.h" |
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#include "iio.h" |
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#include "sysfs.h" |
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/* Fiddly bit of faking and irq without hardware */ |
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#define IIO_EVENTGEN_NO 10 |
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/**
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* struct iio_dummy_evgen - evgen state |
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* @chip: irq chip we are faking |
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* @base: base of irq range |
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* @enabled: mask of which irqs are enabled |
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* @inuse: mask of which irqs actually have anyone connected |
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* @lock: protect the evgen state |
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*/ |
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struct iio_dummy_eventgen { |
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struct irq_chip chip; |
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int base; |
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bool enabled[IIO_EVENTGEN_NO]; |
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bool inuse[IIO_EVENTGEN_NO]; |
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struct mutex lock; |
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}; |
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/* We can only ever have one instance of this 'device' */ |
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static struct iio_dummy_eventgen *iio_evgen; |
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static const char *iio_evgen_name = "iio_dummy_evgen"; |
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static void iio_dummy_event_irqmask(struct irq_data *d) |
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{ |
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struct irq_chip *chip = irq_data_get_irq_chip(d); |
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struct iio_dummy_eventgen *evgen = |
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container_of(chip, struct iio_dummy_eventgen, chip); |
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evgen->enabled[d->irq - evgen->base] = false; |
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} |
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static void iio_dummy_event_irqunmask(struct irq_data *d) |
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{ |
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struct irq_chip *chip = irq_data_get_irq_chip(d); |
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struct iio_dummy_eventgen *evgen = |
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container_of(chip, struct iio_dummy_eventgen, chip); |
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evgen->enabled[d->irq - evgen->base] = true; |
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} |
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static int iio_dummy_evgen_create(void) |
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{ |
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int ret, i; |
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iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL); |
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if (iio_evgen == NULL) |
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return -ENOMEM; |
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iio_evgen->base = irq_alloc_descs(-1, 0, IIO_EVENTGEN_NO, 0); |
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if (iio_evgen->base < 0) { |
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ret = iio_evgen->base; |
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kfree(iio_evgen); |
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return ret; |
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} |
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iio_evgen->chip.name = iio_evgen_name; |
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iio_evgen->chip.irq_mask = &iio_dummy_event_irqmask; |
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iio_evgen->chip.irq_unmask = &iio_dummy_event_irqunmask; |
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for (i = 0; i < IIO_EVENTGEN_NO; i++) { |
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irq_set_chip(iio_evgen->base + i, &iio_evgen->chip); |
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irq_set_handler(iio_evgen->base + i, &handle_simple_irq); |
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irq_modify_status(iio_evgen->base + i, |
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IRQ_NOREQUEST | IRQ_NOAUTOEN, |
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IRQ_NOPROBE); |
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} |
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mutex_init(&iio_evgen->lock); |
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return 0; |
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} |
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/**
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* iio_dummy_evgen_get_irq() - get an evgen provided irq for a device |
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* |
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* This function will give a free allocated irq to a client device. |
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* That irq can then be caused to 'fire' by using the associated sysfs file. |
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*/ |
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int iio_dummy_evgen_get_irq(void) |
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{ |
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int i, ret = 0; |
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mutex_lock(&iio_evgen->lock); |
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for (i = 0; i < IIO_EVENTGEN_NO; i++) |
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if (iio_evgen->inuse[i] == false) { |
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ret = iio_evgen->base + i; |
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iio_evgen->inuse[i] = true; |
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break; |
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} |
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mutex_unlock(&iio_evgen->lock); |
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if (i == IIO_EVENTGEN_NO) |
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return -ENOMEM; |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_irq); |
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/**
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* iio_dummy_evgen_release_irq() - give the irq back. |
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* @irq: irq being returned to the pool |
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* |
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* Used by client driver instances to give the irqs back when they disconnect |
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*/ |
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int iio_dummy_evgen_release_irq(int irq) |
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{ |
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mutex_lock(&iio_evgen->lock); |
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iio_evgen->inuse[irq - iio_evgen->base] = false; |
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mutex_unlock(&iio_evgen->lock); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq); |
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static void iio_dummy_evgen_free(void) |
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{ |
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irq_free_descs(iio_evgen->base, IIO_EVENTGEN_NO); |
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kfree(iio_evgen); |
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} |
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static void iio_evgen_release(struct device *dev) |
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{ |
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iio_dummy_evgen_free(); |
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} |
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static ssize_t iio_evgen_poke(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, |
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size_t len) |
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{ |
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
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if (iio_evgen->enabled[this_attr->address]) |
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handle_nested_irq(iio_evgen->base + this_attr->address); |
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return len; |
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} |
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static IIO_DEVICE_ATTR(poke_ev0, S_IWUSR, NULL, &iio_evgen_poke, 0); |
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static IIO_DEVICE_ATTR(poke_ev1, S_IWUSR, NULL, &iio_evgen_poke, 1); |
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static IIO_DEVICE_ATTR(poke_ev2, S_IWUSR, NULL, &iio_evgen_poke, 2); |
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static IIO_DEVICE_ATTR(poke_ev3, S_IWUSR, NULL, &iio_evgen_poke, 3); |
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static IIO_DEVICE_ATTR(poke_ev4, S_IWUSR, NULL, &iio_evgen_poke, 4); |
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static IIO_DEVICE_ATTR(poke_ev5, S_IWUSR, NULL, &iio_evgen_poke, 5); |
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static IIO_DEVICE_ATTR(poke_ev6, S_IWUSR, NULL, &iio_evgen_poke, 6); |
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static IIO_DEVICE_ATTR(poke_ev7, S_IWUSR, NULL, &iio_evgen_poke, 7); |
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static IIO_DEVICE_ATTR(poke_ev8, S_IWUSR, NULL, &iio_evgen_poke, 8); |
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static IIO_DEVICE_ATTR(poke_ev9, S_IWUSR, NULL, &iio_evgen_poke, 9); |
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static struct attribute *iio_evgen_attrs[] = { |
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&iio_dev_attr_poke_ev0.dev_attr.attr, |
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&iio_dev_attr_poke_ev1.dev_attr.attr, |
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&iio_dev_attr_poke_ev2.dev_attr.attr, |
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&iio_dev_attr_poke_ev3.dev_attr.attr, |
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&iio_dev_attr_poke_ev4.dev_attr.attr, |
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&iio_dev_attr_poke_ev5.dev_attr.attr, |
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&iio_dev_attr_poke_ev6.dev_attr.attr, |
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&iio_dev_attr_poke_ev7.dev_attr.attr, |
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&iio_dev_attr_poke_ev8.dev_attr.attr, |
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&iio_dev_attr_poke_ev9.dev_attr.attr, |
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NULL, |
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}; |
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static const struct attribute_group iio_evgen_group = { |
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.attrs = iio_evgen_attrs, |
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}; |
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static const struct attribute_group *iio_evgen_groups[] = { |
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&iio_evgen_group, |
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NULL |
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}; |
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static struct device iio_evgen_dev = { |
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.bus = &iio_bus_type, |
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.groups = iio_evgen_groups, |
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.release = &iio_evgen_release, |
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}; |
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static __init int iio_dummy_evgen_init(void) |
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{ |
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int ret = iio_dummy_evgen_create(); |
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if (ret < 0) |
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return ret; |
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device_initialize(&iio_evgen_dev); |
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dev_set_name(&iio_evgen_dev, "iio_evgen"); |
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return device_add(&iio_evgen_dev); |
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} |
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module_init(iio_dummy_evgen_init); |
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static __exit void iio_dummy_evgen_exit(void) |
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{ |
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device_unregister(&iio_evgen_dev); |
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} |
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module_exit(iio_dummy_evgen_exit); |
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MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>"); |
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MODULE_DESCRIPTION("IIO dummy driver"); |
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MODULE_LICENSE("GPL v2"); |
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@ -0,0 +1,2 @@ |
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int iio_dummy_evgen_get_irq(void); |
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int iio_dummy_evgen_release_irq(int irq); |
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@ -0,0 +1,81 @@ |
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/**
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* Copyright (c) 2011 Jonathan Cameron |
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* |
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* This program is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 as published by |
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* the Free Software Foundation. |
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* |
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* Join together the various functionality of iio_simple_dummy driver |
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*/ |
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#include <linux/kernel.h> |
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struct iio_dummy_accel_calibscale; |
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/**
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* struct iio_dummy_state - device instance specific state. |
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* @dac_val: cache for dac value |
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* @single_ended_adc_val: cache for single ended adc value |
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* @differential_adc_val: cache for differential adc value |
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* @accel_val: cache for acceleration value |
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* @accel_calibbias: cache for acceleration calibbias |
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* @accel_calibscale: cache for acceleration calibscale |
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* @lock: lock to ensure state is consistent |
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* @event_irq: irq number for event line (faked) |
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* @event_val: cache for event theshold value |
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* @event_en: cache of whether event is enabled |
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*/ |
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struct iio_dummy_state { |
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int dac_val; |
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int single_ended_adc_val; |
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int differential_adc_val[2]; |
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int accel_val; |
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int accel_calibbias; |
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const struct iio_dummy_accel_calibscale *accel_calibscale; |
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struct mutex lock; |
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#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
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int event_irq; |
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int event_val; |
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bool event_en; |
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#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ |
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}; |
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#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS |
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struct iio_dev; |
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int iio_simple_dummy_read_event_config(struct iio_dev *indio_dev, |
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u64 event_code); |
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int iio_simple_dummy_write_event_config(struct iio_dev *indio_dev, |
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u64 event_code, |
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int state); |
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int iio_simple_dummy_read_event_value(struct iio_dev *indio_dev, |
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u64 event_code, |
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int *val); |
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int iio_simple_dummy_write_event_value(struct iio_dev *indio_dev, |
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u64 event_code, |
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int val); |
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int iio_simple_dummy_events_register(struct iio_dev *indio_dev); |
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int iio_simple_dummy_events_unregister(struct iio_dev *indio_dev); |
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#else /* Stubs for when events are disabled at compile time */ |
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static inline int |
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iio_simple_dummy_events_register(struct iio_dev *indio_dev) |
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{ |
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return 0; |
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}; |
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static inline int |
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iio_simple_dummy_events_unregister(struct iio_dev *indio_dev) |
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{ |
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return 0; |
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}; |
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#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS*/ |
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@ -0,0 +1,190 @@ |
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/**
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* Copyright (c) 2011 Jonathan Cameron |
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* |
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* This program is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 as published by |
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* the Free Software Foundation. |
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* |
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* Event handling elements of industrial I/O reference driver. |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/interrupt.h> |
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#include <linux/irq.h> |
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#include "iio.h" |
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#include "sysfs.h" |
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#include "iio_simple_dummy.h" |
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/* Evgen 'fakes' interrupt events for this example */ |
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#include "iio_dummy_evgen.h" |
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|
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/**
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* iio_simple_dummy_read_event_config() - is event enabled? |
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* @indio_dev: the device instance data |
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* @event_code: event code of the event being queried |
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* |
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* This function would normally query the relevant registers or a cache to |
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* discover if the event generation is enabled on the device. |
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*/ |
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int iio_simple_dummy_read_event_config(struct iio_dev *indio_dev, |
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u64 event_code) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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|
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return st->event_en; |
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} |
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|
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/**
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* iio_simple_dummy_write_event_config() - set whether event is enabled |
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* @indio_dev: the device instance data |
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* @event_code: event code of event being enabled/disabled |
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* @state: whether to enable or disable the device. |
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* |
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* This function would normally set the relevant registers on the devices |
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* so that it generates the specified event. Here it just sets up a cached |
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* value. |
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*/ |
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int iio_simple_dummy_write_event_config(struct iio_dev *indio_dev, |
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u64 event_code, |
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int state) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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|
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/*
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* Deliberately over the top code splitting to illustrate |
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* how this is done when multiple events exist. |
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*/ |
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switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { |
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case IIO_VOLTAGE: |
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switch (IIO_EVENT_CODE_EXTRACT_TYPE(event_code)) { |
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case IIO_EV_TYPE_THRESH: |
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if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) == |
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IIO_EV_DIR_RISING) |
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st->event_en = state; |
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else |
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return -EINVAL; |
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break; |
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default: |
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return -EINVAL; |
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} |
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default: |
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return -EINVAL; |
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} |
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|
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return 0; |
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} |
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|
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/**
|
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* iio_simple_dummy_read_event_value() - get value associated with event |
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* @indio_dev: device instance specific data |
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* @event_code: event code for the event whose value is being queried |
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* @val: value for the event code. |
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* |
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* Many devices provide a large set of events of which only a subset may |
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* be enabled at a time, with value registers whose meaning changes depending |
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* on the event enabled. This often means that the driver must cache the values |
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* associated with each possible events so that the right value is in place when |
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* the enabled event is changed. |
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*/ |
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int iio_simple_dummy_read_event_value(struct iio_dev *indio_dev, |
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u64 event_code, |
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int *val) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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|
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*val = st->event_val; |
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|
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return 0; |
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} |
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|
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/**
|
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* iio_simple_dummy_write_event_value() - set value associate with event |
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* @indio_dev: device instance specific data |
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* @event_code: event code for the event whose value is being set |
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* @val: the value to be set. |
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*/ |
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int iio_simple_dummy_write_event_value(struct iio_dev *indio_dev, |
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u64 event_code, |
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int val) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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|
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st->event_val = val; |
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|
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return 0; |
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} |
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|
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/**
|
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* iio_simple_dummy_event_handler() - identify and pass on event |
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* @irq: irq of event line |
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* @private: pointer to device instance state. |
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* |
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* This handler is responsible for querying the device to find out what |
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* event occured and for then pushing that event towards userspace. |
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* Here only one event occurs so we push that directly on with locally |
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* grabbed timestamp. |
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*/ |
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static irqreturn_t iio_simple_dummy_event_handler(int irq, void *private) |
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{ |
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struct iio_dev *indio_dev = private; |
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iio_push_event(indio_dev, |
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IIO_EVENT_CODE(IIO_VOLTAGE, 0, 0, |
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IIO_EV_DIR_RISING, |
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IIO_EV_TYPE_THRESH, 0, 0, 0), |
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iio_get_time_ns()); |
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return IRQ_HANDLED; |
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} |
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|
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/**
|
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* iio_simple_dummy_events_register() - setup interrupt handling for events |
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* @indio_dev: device instance data |
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* |
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* This function requests the threaded interrupt to handle the events. |
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* Normally the irq is a hardware interrupt and the number comes |
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* from board configuration files. Here we get it from a companion |
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* module that fakes the interrupt for us. Note that module in |
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* no way forms part of this example. Just assume that events magically |
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* appear via the provided interrupt. |
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*/ |
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int iio_simple_dummy_events_register(struct iio_dev *indio_dev) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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int ret; |
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|
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/* Fire up event source - normally not present */ |
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st->event_irq = iio_dummy_evgen_get_irq(); |
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if (st->event_irq < 0) { |
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ret = st->event_irq; |
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goto error_ret; |
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} |
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ret = request_threaded_irq(st->event_irq, |
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NULL, |
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&iio_simple_dummy_event_handler, |
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IRQF_ONESHOT, |
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"iio_simple_event", |
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indio_dev); |
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if (ret < 0) |
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goto error_free_evgen; |
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return 0; |
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|
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error_free_evgen: |
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iio_dummy_evgen_release_irq(st->event_irq); |
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error_ret: |
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return ret; |
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} |
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|
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/**
|
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* iio_simple_dummy_events_unregister() - tidy up interrupt handling on remove |
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* @indio_dev: device instance data |
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*/ |
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int iio_simple_dummy_events_unregister(struct iio_dev *indio_dev) |
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{ |
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struct iio_dummy_state *st = iio_priv(indio_dev); |
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|
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free_irq(st->event_irq, indio_dev); |
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/* Not part of normal driver */ |
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iio_dummy_evgen_release_irq(st->event_irq); |
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|
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return 0; |
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} |
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Loading…
Reference in new issue