[patch 20/32] greybus: vibrator driver

[Greg KH <gregkh@linuxfoundation.org>]

This driver implements the Greybus vibrator class protocol.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/greybus/vibrator.c |  249 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 249 insertions(+)

--- /dev/null
+++ b/drivers/greybus/vibrator.c
@@ -0,0 +1,249 @@
+/*
+ * Greybus Vibrator protocol driver.
+ *
+ * Copyright 2014 Google Inc.
+ * Copyright 2014 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/kdev_t.h>
+#include <linux/idr.h>
+#include <linux/pm_runtime.h>
+
+#include "greybus.h"
+
+struct gb_vibrator_device {
+	struct gb_connection	*connection;
+	struct device		*dev;
+	int			minor;		/* vibrator minor number */
+	struct delayed_work     delayed_work;
+};
+
+/* Greybus Vibrator operation types */
+#define	GB_VIBRATOR_TYPE_ON			0x02
+#define	GB_VIBRATOR_TYPE_OFF			0x03
+
+static int turn_off(struct gb_vibrator_device *vib)
+{
+	struct gb_bundle *bundle = vib->connection->bundle;
+	int ret;
+
+	ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_OFF,
+			NULL, 0, NULL, 0);
+
+	gb_pm_runtime_put_autosuspend(bundle);
+
+	return ret;
+}
+
+static int turn_on(struct gb_vibrator_device *vib, u16 timeout_ms)
+{
+	struct gb_bundle *bundle = vib->connection->bundle;
+	int ret;
+
+	ret = gb_pm_runtime_get_sync(bundle);
+	if (ret)
+		return ret;
+
+	/* Vibrator was switched ON earlier */
+	if (cancel_delayed_work_sync(&vib->delayed_work))
+		turn_off(vib);
+
+	ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_ON,
+			NULL, 0, NULL, 0);
+	if (ret) {
+		gb_pm_runtime_put_autosuspend(bundle);
+		return ret;
+	}
+
+	schedule_delayed_work(&vib->delayed_work, msecs_to_jiffies(timeout_ms));
+
+	return 0;
+}
+
+static void gb_vibrator_worker(struct work_struct *work)
+{
+	struct delayed_work *delayed_work = to_delayed_work(work);
+	struct gb_vibrator_device *vib =
+		container_of(delayed_work, struct gb_vibrator_device, delayed_work);
+
+	turn_off(vib);
+}
+
+static ssize_t timeout_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct gb_vibrator_device *vib = dev_get_drvdata(dev);
+	unsigned long val;
+	int retval;
+
+	retval = kstrtoul(buf, 10, &val);
+	if (retval < 0) {
+		dev_err(dev, "could not parse timeout value %d\n", retval);
+		return retval;
+	}
+
+	if (val)
+		retval = turn_on(vib, (u16)val);
+	else
+		retval = turn_off(vib);
+	if (retval)
+		return retval;
+
+	return count;
+}
+static DEVICE_ATTR_WO(timeout);
+
+static struct attribute *vibrator_attrs[] = {
+	&dev_attr_timeout.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(vibrator);
+
+static struct class vibrator_class = {
+	.name		= "vibrator",
+	.owner		= THIS_MODULE,
+	.dev_groups	= vibrator_groups,
+};
+
+static DEFINE_IDA(minors);
+
+static int gb_vibrator_probe(struct gb_bundle *bundle,
+					const struct greybus_bundle_id *id)
+{
+	struct greybus_descriptor_cport *cport_desc;
+	struct gb_connection *connection;
+	struct gb_vibrator_device *vib;
+	struct device *dev;
+	int retval;
+
+	if (bundle->num_cports != 1)
+		return -ENODEV;
+
+	cport_desc = &bundle->cport_desc[0];
+	if (cport_desc->protocol_id != GREYBUS_PROTOCOL_VIBRATOR)
+		return -ENODEV;
+
+	vib = kzalloc(sizeof(*vib), GFP_KERNEL);
+	if (!vib)
+		return -ENOMEM;
+
+	connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
+						NULL);
+	if (IS_ERR(connection)) {
+		retval = PTR_ERR(connection);
+		goto err_free_vib;
+	}
+	gb_connection_set_data(connection, vib);
+
+	vib->connection = connection;
+
+	greybus_set_drvdata(bundle, vib);
+
+	retval = gb_connection_enable(connection);
+	if (retval)
+		goto err_connection_destroy;
+
+	/*
+	 * For now we create a device in sysfs for the vibrator, but odds are
+	 * there is a "real" device somewhere in the kernel for this, but I
+	 * can't find it at the moment...
+	 */
+	vib->minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
+	if (vib->minor < 0) {
+		retval = vib->minor;
+		goto err_connection_disable;
+	}
+	dev = device_create(&vibrator_class, &bundle->dev,
+			    MKDEV(0, 0), vib, "vibrator%d", vib->minor);
+	if (IS_ERR(dev)) {
+		retval = -EINVAL;
+		goto err_ida_remove;
+	}
+	vib->dev = dev;
+
+	INIT_DELAYED_WORK(&vib->delayed_work, gb_vibrator_worker);
+
+	gb_pm_runtime_put_autosuspend(bundle);
+
+	return 0;
+
+err_ida_remove:
+	ida_simple_remove(&minors, vib->minor);
+err_connection_disable:
+	gb_connection_disable(connection);
+err_connection_destroy:
+	gb_connection_destroy(connection);
+err_free_vib:
+	kfree(vib);
+
+	return retval;
+}
+
+static void gb_vibrator_disconnect(struct gb_bundle *bundle)
+{
+	struct gb_vibrator_device *vib = greybus_get_drvdata(bundle);
+	int ret;
+
+	ret = gb_pm_runtime_get_sync(bundle);
+	if (ret)
+		gb_pm_runtime_get_noresume(bundle);
+
+	if (cancel_delayed_work_sync(&vib->delayed_work))
+		turn_off(vib);
+
+	device_unregister(vib->dev);
+	ida_simple_remove(&minors, vib->minor);
+	gb_connection_disable(vib->connection);
+	gb_connection_destroy(vib->connection);
+	kfree(vib);
+}
+
+static const struct greybus_bundle_id gb_vibrator_id_table[] = {
+	{ GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_VIBRATOR) },
+	{ }
+};
+MODULE_DEVICE_TABLE(greybus, gb_vibrator_id_table);
+
+static struct greybus_driver gb_vibrator_driver = {
+	.name		= "vibrator",
+	.probe		= gb_vibrator_probe,
+	.disconnect	= gb_vibrator_disconnect,
+	.id_table	= gb_vibrator_id_table,
+};
+
+static __init int gb_vibrator_init(void)
+{
+	int retval;
+
+	retval = class_register(&vibrator_class);
+	if (retval)
+		return retval;
+
+	retval = greybus_register(&gb_vibrator_driver);
+	if (retval)
+		goto err_class_unregister;
+
+	return 0;
+
+err_class_unregister:
+	class_unregister(&vibrator_class);
+
+	return retval;
+}
+module_init(gb_vibrator_init);
+
+static __exit void gb_vibrator_exit(void)
+{
+	greybus_deregister(&gb_vibrator_driver);
+	class_unregister(&vibrator_class);
+	ida_destroy(&minors);
+}
+module_exit(gb_vibrator_exit);
+
+MODULE_LICENSE("GPL v2");