d1d8abdb05
These should be static. Cc: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
199 lines
4.6 KiB
C
199 lines
4.6 KiB
C
/*
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* Industrial I/O - gpio based trigger support
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*
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* Copyright (c) 2008 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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* Currently this is more of a functioning proof of concept that a fully
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* fledged trigger driver.
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*
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* TODO:
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*
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* Add board config elements to allow specification of startup settings.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/gpio.h>
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#include <linux/slab.h>
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#include "../iio.h"
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#include "../trigger.h"
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static LIST_HEAD(iio_gpio_trigger_list);
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static DEFINE_MUTEX(iio_gpio_trigger_list_lock);
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struct iio_gpio_trigger_info {
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struct mutex in_use;
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unsigned int irq;
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};
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/*
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* Need to reference count these triggers and only enable gpio interrupts
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* as appropriate.
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*/
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/* So what functionality do we want in here?... */
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/* set high / low as interrupt type? */
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static irqreturn_t iio_gpio_trigger_poll(int irq, void *private)
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{
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iio_trigger_poll(private);
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return IRQ_HANDLED;
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}
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static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
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static struct attribute *iio_gpio_trigger_attrs[] = {
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&dev_attr_name.attr,
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NULL,
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};
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static const struct attribute_group iio_gpio_trigger_attr_group = {
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.attrs = iio_gpio_trigger_attrs,
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};
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static int iio_gpio_trigger_probe(struct platform_device *pdev)
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{
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struct iio_gpio_trigger_info *trig_info;
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struct iio_trigger *trig, *trig2;
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unsigned long irqflags;
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struct resource *irq_res;
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int irq, ret = 0, irq_res_cnt = 0;
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do {
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irq_res = platform_get_resource(pdev,
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IORESOURCE_IRQ, irq_res_cnt);
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if (irq_res == NULL) {
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if (irq_res_cnt == 0)
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dev_err(&pdev->dev, "No GPIO IRQs specified");
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break;
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}
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irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
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for (irq = irq_res->start; irq <= irq_res->end; irq++) {
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trig = iio_allocate_trigger();
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if (!trig) {
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ret = -ENOMEM;
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goto error_free_completed_registrations;
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}
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trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
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if (!trig_info) {
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ret = -ENOMEM;
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goto error_put_trigger;
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}
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trig->control_attrs = &iio_gpio_trigger_attr_group;
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trig->private_data = trig_info;
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trig_info->irq = irq;
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trig->owner = THIS_MODULE;
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trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH,
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GFP_KERNEL);
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if (!trig->name) {
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ret = -ENOMEM;
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goto error_free_trig_info;
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}
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snprintf((char *)trig->name,
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IIO_TRIGGER_NAME_LENGTH,
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"irqtrig%d", irq);
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ret = request_irq(irq, iio_gpio_trigger_poll,
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irqflags, trig->name, trig);
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if (ret) {
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dev_err(&pdev->dev,
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"request IRQ-%d failed", irq);
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goto error_free_name;
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}
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ret = iio_trigger_register(trig);
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if (ret)
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goto error_release_irq;
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list_add_tail(&trig->alloc_list,
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&iio_gpio_trigger_list);
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}
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irq_res_cnt++;
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} while (irq_res != NULL);
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return 0;
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/* First clean up the partly allocated trigger */
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error_release_irq:
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free_irq(irq, trig);
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error_free_name:
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kfree(trig->name);
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error_free_trig_info:
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kfree(trig_info);
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error_put_trigger:
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iio_put_trigger(trig);
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error_free_completed_registrations:
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/* The rest should have been added to the iio_gpio_trigger_list */
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list_for_each_entry_safe(trig,
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trig2,
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&iio_gpio_trigger_list,
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alloc_list) {
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trig_info = trig->private_data;
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free_irq(gpio_to_irq(trig_info->irq), trig);
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kfree(trig->name);
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kfree(trig_info);
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iio_trigger_unregister(trig);
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}
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return ret;
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}
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static int iio_gpio_trigger_remove(struct platform_device *pdev)
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{
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struct iio_trigger *trig, *trig2;
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struct iio_gpio_trigger_info *trig_info;
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mutex_lock(&iio_gpio_trigger_list_lock);
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list_for_each_entry_safe(trig,
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trig2,
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&iio_gpio_trigger_list,
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alloc_list) {
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trig_info = trig->private_data;
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iio_trigger_unregister(trig);
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free_irq(trig_info->irq, trig);
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kfree(trig->name);
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kfree(trig_info);
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iio_put_trigger(trig);
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}
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mutex_unlock(&iio_gpio_trigger_list_lock);
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return 0;
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}
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static struct platform_driver iio_gpio_trigger_driver = {
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.probe = iio_gpio_trigger_probe,
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.remove = iio_gpio_trigger_remove,
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.driver = {
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.name = "iio_gpio_trigger",
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.owner = THIS_MODULE,
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},
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};
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static int __init iio_gpio_trig_init(void)
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{
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return platform_driver_register(&iio_gpio_trigger_driver);
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}
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module_init(iio_gpio_trig_init);
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static void __exit iio_gpio_trig_exit(void)
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{
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platform_driver_unregister(&iio_gpio_trigger_driver);
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}
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module_exit(iio_gpio_trig_exit);
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MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
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MODULE_DESCRIPTION("Example gpio trigger for the iio subsystem");
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MODULE_LICENSE("GPL v2");
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