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authorJonathan Cameron <jic23@kernel.org>2012-04-25 15:54:59 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-04-25 11:11:38 -0700
commita980e046098b0a40eaff5e4e7fcde6cf035b7c06 (patch)
tree23375fc2bba39f088974cf621f7abf006d43d087 /drivers/iio/industrialio-trigger.c
parent06458e277eac2b8761b0a04d3c808d57be281a2e (diff)
downloadlinux-a980e046098b0a40eaff5e4e7fcde6cf035b7c06.tar.gz
IIO: Move the core files to drivers/iio
Take the core support + the kfifo buffer implentation out of staging. Whilst we are far from done in improving this subsystem it is now at a stage where the userspae interfaces (provided by the core) can be considered stable. Drivers will follow over a longer time scale. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio/industrialio-trigger.c')
-rw-r--r--drivers/iio/industrialio-trigger.c509
1 files changed, 509 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
new file mode 100644
index 000000000000..03fee2e097ca
--- /dev/null
+++ b/drivers/iio/industrialio-trigger.c
@@ -0,0 +1,509 @@
+/* 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 = dev_get_drvdata(dev);
+ return sprintf(buf, "%s\n", trig->name);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
+
+/**
+ * iio_trigger_register_sysfs() - create a device for this trigger
+ * @trig_info: the trigger
+ *
+ * Also adds any control attribute registered by the trigger driver
+ **/
+static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
+{
+ return sysfs_add_file_to_group(&trig_info->dev.kobj,
+ &dev_attr_name.attr,
+ NULL);
+}
+
+static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
+{
+ sysfs_remove_file_from_group(&trig_info->dev.kobj,
+ &dev_attr_name.attr,
+ NULL);
+}
+
+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) {
+ ret = trig_info->id;
+ goto error_ret;
+ }
+ /* 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;
+
+ ret = iio_trigger_register_sysfs(trig_info);
+ if (ret)
+ goto error_device_del;
+
+ /* 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_device_del:
+ device_del(&trig_info->dev);
+error_unregister_id:
+ ida_simple_remove(&iio_trigger_ida, trig_info->id);
+error_ret:
+ 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);
+
+ iio_trigger_unregister_sysfs(trig_info);
+ ida_simple_remove(&iio_trigger_ida, trig_info->id);
+ /* Possible issue in here */
+ device_unregister(&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, s64 time)
+{
+ int i;
+ if (!trig->use_count)
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
+ if (trig->subirqs[i].enabled) {
+ trig->use_count++;
+ generic_handle_irq(trig->subirq_base + i);
+ }
+}
+EXPORT_SYMBOL(iio_trigger_poll);
+
+irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
+{
+ iio_trigger_poll(private, iio_get_time_ns());
+ return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
+
+void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
+{
+ int i;
+ if (!trig->use_count)
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
+ if (trig->subirqs[i].enabled) {
+ trig->use_count++;
+ handle_nested_irq(trig->subirq_base + i);
+ }
+}
+EXPORT_SYMBOL(iio_trigger_poll_chained);
+
+void iio_trigger_notify_done(struct iio_trigger *trig)
+{
+ trig->use_count--;
+ if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
+ if (trig->ops->try_reenable(trig))
+ /* Missed and interrupt so launch new poll now */
+ iio_trigger_poll(trig, 0);
+}
+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 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_dettach_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)
+ goto error_ret;
+ }
+ iio_trigger_put_irq(trig, pf->irq);
+ free_irq(pf->irq, pf);
+ module_put(pf->indio_dev->info->driver_module);
+
+error_ret:
+ 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 which 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_get_drvdata(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 triggers
+ * 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_get_drvdata(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 && indio_dev->trig != oldtrig)
+ iio_put_trigger(oldtrig);
+ if (indio_dev->trig)
+ iio_get_trigger(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,
+};
+
+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;
+}
+
+struct iio_trigger *iio_allocate_trigger(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);
+ dev_set_drvdata(&trig->dev, (void *)trig);
+
+ 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;
+ }
+ va_start(vargs, fmt);
+ trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
+ va_end(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;
+}
+EXPORT_SYMBOL(iio_allocate_trigger);
+
+void iio_free_trigger(struct iio_trigger *trig)
+{
+ if (trig)
+ put_device(&trig->dev);
+}
+EXPORT_SYMBOL(iio_free_trigger);
+
+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 and associated but not attached triggers references */
+ if (indio_dev->trig)
+ iio_put_trigger(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_dettach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc);
+}
+EXPORT_SYMBOL(iio_triggered_buffer_predisable);