staging:iio:trigger sysfs userspace trigger rework.

Awaiting comments on using the nested_irq_trick so that may change.
Moves away from platform device to sysfs controlled creation and
removal of these triggers.

Fix double free of name on trigger allocation failure thanks
to Michael Hennerich.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Reviewed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/industrialio-trigger.c

@@ -181,6 +181,19 @@ irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
 }
 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--;

drivers/staging/iio/trigger.h

@@ -121,6 +121,7 @@ int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
  * Typically called in relevant hardware interrupt handler.
  **/
 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
+void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 void iio_trigger_notify_done(struct iio_trigger *trig);
 
 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);

drivers/staging/iio/trigger/iio-trig-sysfs.c

@@ -9,15 +9,84 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/list.h>
 
 #include "../iio.h"
 #include "../trigger.h"
 
+struct iio_sysfs_trig {
+	struct iio_trigger *trig;
+	int id;
+	struct list_head l;
+};
+
+static LIST_HEAD(iio_sysfs_trig_list);
+static DEFINE_MUTEX(iio_syfs_trig_list_mut);
+
+static int iio_sysfs_trigger_probe(int id);
+static ssize_t iio_sysfs_trig_add(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf,
+				  size_t len)
+{
+	int ret;
+	unsigned long input;
+
+	ret = strict_strtoul(buf, 10, &input);
+	if (ret)
+		return ret;
+	ret = iio_sysfs_trigger_probe(input);
+	if (ret)
+		return ret;
+	return len;
+}
+static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_trig_add);
+
+static int iio_sysfs_trigger_remove(int id);
+static ssize_t iio_sysfs_trig_remove(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf,
+				     size_t len)
+{
+	int ret;
+	unsigned long input;
+
+	ret = strict_strtoul(buf, 10, &input);
+	if (ret)
+		return ret;
+	ret = iio_sysfs_trigger_remove(input);
+	if (ret)
+		return ret;
+	return len;
+}
+
+static DEVICE_ATTR(remove_trigger, S_IWUSR, NULL, &iio_sysfs_trig_remove);
+
+static struct attribute *iio_sysfs_trig_attrs[] = {
+	&dev_attr_add_trigger.attr,
+	&dev_attr_remove_trigger.attr,
+	NULL,
+};
+
+static const struct attribute_group iio_sysfs_trig_group = {
+	.attrs = iio_sysfs_trig_attrs,
+};
+
+static const struct attribute_group *iio_sysfs_trig_groups[] = {
+	&iio_sysfs_trig_group,
+	NULL
+};
+
+static struct device iio_sysfs_trig_dev = {
+	.bus = &iio_bus_type,
+	.groups = iio_sysfs_trig_groups,
+};
+
 static ssize_t iio_sysfs_trigger_poll(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct iio_trigger *trig = dev_get_drvdata(dev);
-	iio_trigger_poll(trig, 0);
+	iio_trigger_poll_chained(trig, 0);
 
 	return count;
 }
@@ -35,70 +104,101 @@ static const struct attribute_group iio_sysfs_trigger_attr_group = {
 	.attrs = iio_sysfs_trigger_attrs,
 };
 
-static int __devinit iio_sysfs_trigger_probe(struct platform_device *pdev)
+static int iio_sysfs_trigger_probe(int id)
 {
-	struct iio_trigger *trig;
+	struct iio_sysfs_trig *t;
 	int ret;
+	char *name;
+	bool foundit = false;
+	mutex_lock(&iio_syfs_trig_list_mut);
+	list_for_each_entry(t, &iio_sysfs_trig_list, l)
+		if (id == t->id) {
+			foundit = true;
+			break;
+		}
+	if (foundit) {
+		ret = -EINVAL;
+		goto out1;
+	}
 
-	trig = iio_allocate_trigger();
-	if (!trig) {
+	name = kasprintf(GFP_KERNEL, "sysfstrig%d", id);
+	if (name == NULL) {
 		ret = -ENOMEM;
 		goto out1;
 	}
-
-	trig->control_attrs = &iio_sysfs_trigger_attr_group;
-	trig->owner = THIS_MODULE;
-	trig->name = kasprintf(GFP_KERNEL, "sysfstrig%d", pdev->id);
-	if (trig->name == NULL) {
+	t = kmalloc(sizeof(*t), GFP_KERNEL);
+	if (t == NULL) {
 		ret = -ENOMEM;
-		goto out2;
+		goto free_name;
+	}
+	t->id = id;
+	t->trig = iio_allocate_trigger_named(name);
+	if (!t->trig) {
+		ret = -ENOMEM;
+		goto free_t;
 	}
 
-	ret = iio_trigger_register(trig);
-	if (ret)
-		goto out3;
-
-	platform_set_drvdata(pdev, trig);
+	t->trig->control_attrs = &iio_sysfs_trigger_attr_group;
+	t->trig->owner = THIS_MODULE;
+	t->trig->dev.parent = &iio_sysfs_trig_dev;
 
+	ret = iio_trigger_register(t->trig);
+	if (ret)
+		goto out2;
+	list_add(&t->l, &iio_sysfs_trig_list);
+	__module_get(THIS_MODULE);
+	mutex_unlock(&iio_syfs_trig_list_mut);
 	return 0;
-out3:
-	kfree(trig->name);
+
 out2:
-	iio_put_trigger(trig);
+	iio_put_trigger(t->trig);
+free_t:
+	kfree(t);
+free_name:
+	kfree(name);
 out1:
-
+	mutex_unlock(&iio_syfs_trig_list_mut);
 	return ret;
 }
 
-static int __devexit iio_sysfs_trigger_remove(struct platform_device *pdev)
+static int iio_sysfs_trigger_remove(int id)
 {
-	struct iio_trigger *trig = platform_get_drvdata(pdev);
+	bool foundit = false;
+	struct iio_sysfs_trig *t;
+	mutex_lock(&iio_syfs_trig_list_mut);
+	list_for_each_entry(t, &iio_sysfs_trig_list, l)
+		if (id == t->id) {
+			foundit = true;
+			break;
+		}
+	if (!foundit) {
+		mutex_unlock(&iio_syfs_trig_list_mut);
+		return -EINVAL;
+	}
 
-	iio_trigger_unregister(trig);
-	kfree(trig->name);
-	iio_put_trigger(trig);
+	iio_trigger_unregister(t->trig);
+	kfree(t->trig->name);
+	iio_free_trigger(t->trig);
 
+	list_del(&t->l);
+	kfree(t);
+	module_put(THIS_MODULE);
+	mutex_unlock(&iio_syfs_trig_list_mut);
 	return 0;
 }
 
-static struct platform_driver iio_sysfs_trigger_driver = {
-	.driver = {
-		.name = "iio_sysfs_trigger",
-		.owner = THIS_MODULE,
-	},
-	.probe = iio_sysfs_trigger_probe,
-	.remove = __devexit_p(iio_sysfs_trigger_remove),
-};
 
 static int __init iio_sysfs_trig_init(void)
 {
-	return platform_driver_register(&iio_sysfs_trigger_driver);
+	device_initialize(&iio_sysfs_trig_dev);
+	dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger");
+	return device_add(&iio_sysfs_trig_dev);
 }
 module_init(iio_sysfs_trig_init);
 
 static void __exit iio_sysfs_trig_exit(void)
 {
-	platform_driver_unregister(&iio_sysfs_trigger_driver);
+	device_unregister(&iio_sysfs_trig_dev);
 }
 module_exit(iio_sysfs_trig_exit);