Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/drivers/iio/dummy/iio_dummy_evgen.c b/drivers/iio/dummy/iio_dummy_evgen.c
new file mode 100644
index 000000000..efd0005f5
--- /dev/null
+++ b/drivers/iio/dummy/iio_dummy_evgen.c
@@ -0,0 +1,211 @@
+/**
+ * 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 <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 10
+
+/**
+ * @regs: irq regs we are faking
+ * @lock: protect the evgen state
+ * @inuse: mask of which irqs are connected
+ * @irq_sim: interrupt simulator
+ * @base: base of irq range
+ */
+struct iio_dummy_eventgen {
+	struct iio_dummy_regs regs[IIO_EVENTGEN_NO];
+	struct mutex lock;
+	bool inuse[IIO_EVENTGEN_NO];
+	struct irq_sim irq_sim;
+	int base;
+};
+
+/* We can only ever have one instance of this 'device' */
+static struct iio_dummy_eventgen *iio_evgen;
+
+static int iio_dummy_evgen_create(void)
+{
+	int ret;
+
+	iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL);
+	if (!iio_evgen)
+		return -ENOMEM;
+
+	ret = irq_sim_init(&iio_evgen->irq_sim, IIO_EVENTGEN_NO);
+	if (ret < 0) {
+		kfree(iio_evgen);
+		return ret;
+	}
+
+	iio_evgen->base = irq_sim_irqnum(&iio_evgen->irq_sim, 0);
+	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;
+
+	if (!iio_evgen)
+		return -ENODEV;
+
+	mutex_lock(&iio_evgen->lock);
+	for (i = 0; i < IIO_EVENTGEN_NO; i++) {
+		if (!iio_evgen->inuse[i]) {
+			ret = irq_sim_irqnum(&iio_evgen->irq_sim, 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
+ */
+void 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);
+}
+EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq);
+
+struct iio_dummy_regs *iio_dummy_evgen_get_regs(int irq)
+{
+	return &iio_evgen->regs[irq - iio_evgen->base];
+}
+EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_regs);
+
+static void iio_dummy_evgen_free(void)
+{
+	irq_sim_fini(&iio_evgen->irq_sim);
+	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);
+	unsigned long event;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &event);
+	if (ret)
+		return ret;
+
+	iio_evgen->regs[this_attr->address].reg_id   = this_attr->address;
+	iio_evgen->regs[this_attr->address].reg_data = event;
+
+	irq_sim_fire(&iio_evgen->irq_sim, 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@kernel.org>");
+MODULE_DESCRIPTION("IIO dummy driver");
+MODULE_LICENSE("GPL v2");