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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/iio/industrialio-trigger.c
Initial import
Diffstat (limited to 'drivers/iio/industrialio-trigger.c')
-rw-r--r--drivers/iio/industrialio-trigger.c583
1 files changed, 583 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
new file mode 100644
index 000000000..d31098e0c
--- /dev/null
+++ b/drivers/iio/industrialio-trigger.c
@@ -0,0 +1,583 @@
+/* The industrial I/O core, trigger handling functions
+ *
+ * Copyright (c) 2008 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/idr.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include "iio_core.h"
+#include "iio_core_trigger.h"
+#include <linux/iio/trigger_consumer.h>
+
+/* RFC - Question of approach
+ * Make the common case (single sensor single trigger)
+ * simple by starting trigger capture from when first sensors
+ * is added.
+ *
+ * Complex simultaneous start requires use of 'hold' functionality
+ * of the trigger. (not implemented)
+ *
+ * Any other suggestions?
+ */
+
+static DEFINE_IDA(iio_trigger_ida);
+
+/* Single list of all available triggers */
+static LIST_HEAD(iio_trigger_list);
+static DEFINE_MUTEX(iio_trigger_list_lock);
+
+/**
+ * iio_trigger_read_name() - retrieve useful identifying name
+ **/
+static ssize_t iio_trigger_read_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_trigger *trig = to_iio_trigger(dev);
+ return sprintf(buf, "%s\n", trig->name);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
+
+static struct attribute *iio_trig_dev_attrs[] = {
+ &dev_attr_name.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(iio_trig_dev);
+
+int iio_trigger_register(struct iio_trigger *trig_info)
+{
+ int ret;
+
+ trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
+ if (trig_info->id < 0)
+ return trig_info->id;
+
+ /* Set the name used for the sysfs directory etc */
+ dev_set_name(&trig_info->dev, "trigger%ld",
+ (unsigned long) trig_info->id);
+
+ ret = device_add(&trig_info->dev);
+ if (ret)
+ goto error_unregister_id;
+
+ /* Add to list of available triggers held by the IIO core */
+ mutex_lock(&iio_trigger_list_lock);
+ list_add_tail(&trig_info->list, &iio_trigger_list);
+ mutex_unlock(&iio_trigger_list_lock);
+
+ return 0;
+
+error_unregister_id:
+ ida_simple_remove(&iio_trigger_ida, trig_info->id);
+ return ret;
+}
+EXPORT_SYMBOL(iio_trigger_register);
+
+void iio_trigger_unregister(struct iio_trigger *trig_info)
+{
+ mutex_lock(&iio_trigger_list_lock);
+ list_del(&trig_info->list);
+ mutex_unlock(&iio_trigger_list_lock);
+
+ ida_simple_remove(&iio_trigger_ida, trig_info->id);
+ /* Possible issue in here */
+ device_del(&trig_info->dev);
+}
+EXPORT_SYMBOL(iio_trigger_unregister);
+
+static struct iio_trigger *iio_trigger_find_by_name(const char *name,
+ size_t len)
+{
+ struct iio_trigger *trig = NULL, *iter;
+
+ mutex_lock(&iio_trigger_list_lock);
+ list_for_each_entry(iter, &iio_trigger_list, list)
+ if (sysfs_streq(iter->name, name)) {
+ trig = iter;
+ break;
+ }
+ mutex_unlock(&iio_trigger_list_lock);
+
+ return trig;
+}
+
+void iio_trigger_poll(struct iio_trigger *trig)
+{
+ int i;
+
+ if (!atomic_read(&trig->use_count)) {
+ atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ if (trig->subirqs[i].enabled)
+ generic_handle_irq(trig->subirq_base + i);
+ else
+ iio_trigger_notify_done(trig);
+ }
+ }
+}
+EXPORT_SYMBOL(iio_trigger_poll);
+
+irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
+{
+ iio_trigger_poll(private);
+ return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
+
+void iio_trigger_poll_chained(struct iio_trigger *trig)
+{
+ int i;
+
+ if (!atomic_read(&trig->use_count)) {
+ atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ if (trig->subirqs[i].enabled)
+ handle_nested_irq(trig->subirq_base + i);
+ else
+ iio_trigger_notify_done(trig);
+ }
+ }
+}
+EXPORT_SYMBOL(iio_trigger_poll_chained);
+
+void iio_trigger_notify_done(struct iio_trigger *trig)
+{
+ if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
+ trig->ops->try_reenable)
+ if (trig->ops->try_reenable(trig))
+ /* Missed an interrupt so launch new poll now */
+ iio_trigger_poll(trig);
+}
+EXPORT_SYMBOL(iio_trigger_notify_done);
+
+/* Trigger Consumer related functions */
+static int iio_trigger_get_irq(struct iio_trigger *trig)
+{
+ int ret;
+ mutex_lock(&trig->pool_lock);
+ ret = bitmap_find_free_region(trig->pool,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER,
+ ilog2(1));
+ mutex_unlock(&trig->pool_lock);
+ if (ret >= 0)
+ ret += trig->subirq_base;
+
+ return ret;
+}
+
+static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
+{
+ mutex_lock(&trig->pool_lock);
+ clear_bit(irq - trig->subirq_base, trig->pool);
+ mutex_unlock(&trig->pool_lock);
+}
+
+/* Complexity in here. With certain triggers (datardy) an acknowledgement
+ * may be needed if the pollfuncs do not include the data read for the
+ * triggering device.
+ * This is not currently handled. Alternative of not enabling trigger unless
+ * the relevant function is in there may be the best option.
+ */
+/* Worth protecting against double additions? */
+static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
+ struct iio_poll_func *pf)
+{
+ int ret = 0;
+ bool notinuse
+ = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+
+ /* Prevent the module from being removed whilst attached to a trigger */
+ __module_get(pf->indio_dev->info->driver_module);
+ pf->irq = iio_trigger_get_irq(trig);
+ ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
+ pf->type, pf->name,
+ pf);
+ if (ret < 0) {
+ module_put(pf->indio_dev->info->driver_module);
+ return ret;
+ }
+
+ if (trig->ops && trig->ops->set_trigger_state && notinuse) {
+ ret = trig->ops->set_trigger_state(trig, true);
+ if (ret < 0)
+ module_put(pf->indio_dev->info->driver_module);
+ }
+
+ return ret;
+}
+
+static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
+ struct iio_poll_func *pf)
+{
+ int ret = 0;
+ bool no_other_users
+ = (bitmap_weight(trig->pool,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER)
+ == 1);
+ if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
+ ret = trig->ops->set_trigger_state(trig, false);
+ if (ret)
+ return ret;
+ }
+ iio_trigger_put_irq(trig, pf->irq);
+ free_irq(pf->irq, pf);
+ module_put(pf->indio_dev->info->driver_module);
+
+ return ret;
+}
+
+irqreturn_t iio_pollfunc_store_time(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ pf->timestamp = iio_get_time_ns();
+ return IRQ_WAKE_THREAD;
+}
+EXPORT_SYMBOL(iio_pollfunc_store_time);
+
+struct iio_poll_func
+*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
+ irqreturn_t (*thread)(int irq, void *p),
+ int type,
+ struct iio_dev *indio_dev,
+ const char *fmt,
+ ...)
+{
+ va_list vargs;
+ struct iio_poll_func *pf;
+
+ pf = kmalloc(sizeof *pf, GFP_KERNEL);
+ if (pf == NULL)
+ return NULL;
+ va_start(vargs, fmt);
+ pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
+ va_end(vargs);
+ if (pf->name == NULL) {
+ kfree(pf);
+ return NULL;
+ }
+ pf->h = h;
+ pf->thread = thread;
+ pf->type = type;
+ pf->indio_dev = indio_dev;
+
+ return pf;
+}
+EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
+
+void iio_dealloc_pollfunc(struct iio_poll_func *pf)
+{
+ kfree(pf->name);
+ kfree(pf);
+}
+EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
+
+/**
+ * iio_trigger_read_current() - trigger consumer sysfs query current trigger
+ *
+ * For trigger consumers the current_trigger interface allows the trigger
+ * used by the device to be queried.
+ **/
+static ssize_t iio_trigger_read_current(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+
+ if (indio_dev->trig)
+ return sprintf(buf, "%s\n", indio_dev->trig->name);
+ return 0;
+}
+
+/**
+ * iio_trigger_write_current() - trigger consumer sysfs set current trigger
+ *
+ * For trigger consumers the current_trigger interface allows the trigger
+ * used for this device to be specified at run time based on the trigger's
+ * name.
+ **/
+static ssize_t iio_trigger_write_current(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_trigger *oldtrig = indio_dev->trig;
+ struct iio_trigger *trig;
+ int ret;
+
+ mutex_lock(&indio_dev->mlock);
+ if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+ mutex_unlock(&indio_dev->mlock);
+ return -EBUSY;
+ }
+ mutex_unlock(&indio_dev->mlock);
+
+ trig = iio_trigger_find_by_name(buf, len);
+ if (oldtrig == trig)
+ return len;
+
+ if (trig && indio_dev->info->validate_trigger) {
+ ret = indio_dev->info->validate_trigger(indio_dev, trig);
+ if (ret)
+ return ret;
+ }
+
+ if (trig && trig->ops && trig->ops->validate_device) {
+ ret = trig->ops->validate_device(trig, indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ indio_dev->trig = trig;
+
+ if (oldtrig)
+ iio_trigger_put(oldtrig);
+ if (indio_dev->trig)
+ iio_trigger_get(indio_dev->trig);
+
+ return len;
+}
+
+static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
+ iio_trigger_read_current,
+ iio_trigger_write_current);
+
+static struct attribute *iio_trigger_consumer_attrs[] = {
+ &dev_attr_current_trigger.attr,
+ NULL,
+};
+
+static const struct attribute_group iio_trigger_consumer_attr_group = {
+ .name = "trigger",
+ .attrs = iio_trigger_consumer_attrs,
+};
+
+static void iio_trig_release(struct device *device)
+{
+ struct iio_trigger *trig = to_iio_trigger(device);
+ int i;
+
+ if (trig->subirq_base) {
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ irq_modify_status(trig->subirq_base + i,
+ IRQ_NOAUTOEN,
+ IRQ_NOREQUEST | IRQ_NOPROBE);
+ irq_set_chip(trig->subirq_base + i,
+ NULL);
+ irq_set_handler(trig->subirq_base + i,
+ NULL);
+ }
+
+ irq_free_descs(trig->subirq_base,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+ }
+ kfree(trig->name);
+ kfree(trig);
+}
+
+static struct device_type iio_trig_type = {
+ .release = iio_trig_release,
+ .groups = iio_trig_dev_groups,
+};
+
+static void iio_trig_subirqmask(struct irq_data *d)
+{
+ struct irq_chip *chip = irq_data_get_irq_chip(d);
+ struct iio_trigger *trig
+ = container_of(chip,
+ struct iio_trigger, subirq_chip);
+ trig->subirqs[d->irq - trig->subirq_base].enabled = false;
+}
+
+static void iio_trig_subirqunmask(struct irq_data *d)
+{
+ struct irq_chip *chip = irq_data_get_irq_chip(d);
+ struct iio_trigger *trig
+ = container_of(chip,
+ struct iio_trigger, subirq_chip);
+ trig->subirqs[d->irq - trig->subirq_base].enabled = true;
+}
+
+static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
+{
+ struct iio_trigger *trig;
+ trig = kzalloc(sizeof *trig, GFP_KERNEL);
+ if (trig) {
+ int i;
+ trig->dev.type = &iio_trig_type;
+ trig->dev.bus = &iio_bus_type;
+ device_initialize(&trig->dev);
+
+ mutex_init(&trig->pool_lock);
+ trig->subirq_base
+ = irq_alloc_descs(-1, 0,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER,
+ 0);
+ if (trig->subirq_base < 0) {
+ kfree(trig);
+ return NULL;
+ }
+
+ trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
+ if (trig->name == NULL) {
+ irq_free_descs(trig->subirq_base,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+ kfree(trig);
+ return NULL;
+ }
+ trig->subirq_chip.name = trig->name;
+ trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
+ trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ irq_set_chip(trig->subirq_base + i,
+ &trig->subirq_chip);
+ irq_set_handler(trig->subirq_base + i,
+ &handle_simple_irq);
+ irq_modify_status(trig->subirq_base + i,
+ IRQ_NOREQUEST | IRQ_NOAUTOEN,
+ IRQ_NOPROBE);
+ }
+ get_device(&trig->dev);
+ }
+
+ return trig;
+}
+
+struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
+{
+ struct iio_trigger *trig;
+ va_list vargs;
+
+ va_start(vargs, fmt);
+ trig = viio_trigger_alloc(fmt, vargs);
+ va_end(vargs);
+
+ return trig;
+}
+EXPORT_SYMBOL(iio_trigger_alloc);
+
+void iio_trigger_free(struct iio_trigger *trig)
+{
+ if (trig)
+ put_device(&trig->dev);
+}
+EXPORT_SYMBOL(iio_trigger_free);
+
+static void devm_iio_trigger_release(struct device *dev, void *res)
+{
+ iio_trigger_free(*(struct iio_trigger **)res);
+}
+
+static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
+{
+ struct iio_trigger **r = res;
+
+ if (!r || !*r) {
+ WARN_ON(!r || !*r);
+ return 0;
+ }
+
+ return *r == data;
+}
+
+/**
+ * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
+ * @dev: Device to allocate iio_trigger for
+ * @fmt: trigger name format. If it includes format
+ * specifiers, the additional arguments following
+ * format are formatted and inserted in the resulting
+ * string replacing their respective specifiers.
+ *
+ * Managed iio_trigger_alloc. iio_trigger allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * If an iio_trigger allocated with this function needs to be freed separately,
+ * devm_iio_trigger_free() must be used.
+ *
+ * RETURNS:
+ * Pointer to allocated iio_trigger on success, NULL on failure.
+ */
+struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
+ const char *fmt, ...)
+{
+ struct iio_trigger **ptr, *trig;
+ va_list vargs;
+
+ ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ /* use raw alloc_dr for kmalloc caller tracing */
+ va_start(vargs, fmt);
+ trig = viio_trigger_alloc(fmt, vargs);
+ va_end(vargs);
+ if (trig) {
+ *ptr = trig;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return trig;
+}
+EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
+
+/**
+ * devm_iio_trigger_free - Resource-managed iio_trigger_free()
+ * @dev: Device this iio_dev belongs to
+ * @iio_trig: the iio_trigger associated with the device
+ *
+ * Free iio_trigger allocated with devm_iio_trigger_alloc().
+ */
+void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
+{
+ int rc;
+
+ rc = devres_release(dev, devm_iio_trigger_release,
+ devm_iio_trigger_match, iio_trig);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
+
+void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
+{
+ indio_dev->groups[indio_dev->groupcounter++] =
+ &iio_trigger_consumer_attr_group;
+}
+
+void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
+{
+ /* Clean up an associated but not attached trigger reference */
+ if (indio_dev->trig)
+ iio_trigger_put(indio_dev->trig);
+}
+
+int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
+{
+ return iio_trigger_attach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc);
+}
+EXPORT_SYMBOL(iio_triggered_buffer_postenable);
+
+int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
+{
+ return iio_trigger_detach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc);
+}
+EXPORT_SYMBOL(iio_triggered_buffer_predisable);