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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/iio/dummy/iio_dummy_evgen.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/iio/dummy/iio_dummy_evgen.c')
-rw-r--r--drivers/iio/dummy/iio_dummy_evgen.c222
1 files changed, 222 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 0000000000..5a0072727b
--- /dev/null
+++ b/drivers/iio/dummy/iio_dummy_evgen.c
@@ -0,0 +1,222 @@
+// 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 10
+
+/**
+ * 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: interrupt simulator
+ * @base: base of irq range
+ * @irq_sim_domain: irq simulator domain
+ */
+struct iio_dummy_eventgen {
+ struct iio_dummy_regs regs[IIO_EVENTGEN_NO];
+ struct mutex lock;
+ bool inuse[IIO_EVENTGEN_NO];
+ struct irq_domain *irq_sim_domain;
+};
+
+/* 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;
+
+ iio_evgen->irq_sim_domain = irq_domain_create_sim(NULL,
+ IIO_EVENTGEN_NO);
+ if (IS_ERR(iio_evgen->irq_sim_domain)) {
+ ret = PTR_ERR(iio_evgen->irq_sim_domain);
+ kfree(iio_evgen);
+ return ret;
+ }
+
+ 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_create_mapping(iio_evgen->irq_sim_domain, 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)
+{
+ struct irq_data *irqd = irq_get_irq_data(irq);
+
+ mutex_lock(&iio_evgen->lock);
+ iio_evgen->inuse[irqd_to_hwirq(irqd)] = false;
+ irq_dispose_mapping(irq);
+ mutex_unlock(&iio_evgen->lock);
+}
+EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq);
+
+struct iio_dummy_regs *iio_dummy_evgen_get_regs(int irq)
+{
+ struct irq_data *irqd = irq_get_irq_data(irq);
+
+ return &iio_evgen->regs[irqd_to_hwirq(irqd)];
+
+}
+EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_regs);
+
+static void iio_dummy_evgen_free(void)
+{
+ irq_domain_remove_sim(iio_evgen->irq_sim_domain);
+ 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, irq;
+
+ 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 = irq_find_mapping(iio_evgen->irq_sim_domain, this_attr->address);
+ ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true);
+ if (ret)
+ return ret;
+
+ 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");
+ ret = device_add(&iio_evgen_dev);
+ if (ret)
+ put_device(&iio_evgen_dev);
+ return ret;
+}
+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");