On 4/17/20 12:10 PM, Jeff Kirsher wrote:
From: Dave Ertman <david.m.ertman@xxxxxxxxx>
This is the initial implementation of the Virtual Bus,
virtbus_device and virtbus_driver. The virtual bus is
a software based bus intended to support registering
virtbus_devices and virtbus_drivers and provide matching
between them and probing of the registered drivers.
The bus will support probe/remove shutdown and
suspend/resume callbacks.
Kconfig and Makefile alterations are included
Signed-off-by: Dave Ertman <david.m.ertman@xxxxxxxxx>
Signed-off-by: Kiran Patil <kiran.patil@xxxxxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
FWIW we are planning to use this Virtual Bus to support multiple clients
for the Sound Open Firmware driver, instead of using platform devices as
suggested by GregKH.
Minor nit-picks below, please feel free to add my tag for patch 1/9:
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
+config VIRTUAL_BUS
+ tristate "Software based Virtual Bus"
+ help
+ Provides a software bus for virtbus_devices to be added to it
+ and virtbus_drivers to be registered on it. It matches driver
+ and device based on id and calls the driver's pobe routine.
typo: probe
[...]
diff --git a/drivers/bus/virtual_bus.c b/drivers/bus/virtual_bus.c
new file mode 100644
index 000000000000..fb14cca40eea
--- /dev/null
+++ b/drivers/bus/virtual_bus.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
did you mean GPL-2.0-only, as done for virtual-bus.h?
+/*
+ * virtual_bus.c - lightweight software based bus for virtual devices
+ *
+ * Copyright (c) 2019-20 Intel Corporation
I think the recommendation is to use 2019-2020 explicitly.
+ *
+ * Please see Documentation/driver-api/virtual_bus.rst for
+ * more information
+ */
+
+#include <linux/string.h>
+#include <linux/virtual_bus.h>
+#include <linux/of_irq.h>
is of_irq.h required?
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/acpi.h>
is there any ACPI dependency?
+#include <linux/device.h>
alphabetical order for the headers maybe?
[...]
+int virtbus_register_device(struct virtbus_device *vdev)
+{
+ int ret;
+
+ /* Do this first so that all error paths perform a put_device */
+ device_initialize(&vdev->dev);
+
+ if (!vdev->release) {
+ ret = -EINVAL;
+ dev_err(&vdev->dev, "virtbus_device MUST have a .release callback that does something.\n");
+ goto device_pre_err;
+ }
+
+ /* All device IDs are automatically allocated */
+ ret = ida_simple_get(&virtbus_dev_ida, 0, 0, GFP_KERNEL);
+ if (ret < 0) {
+ dev_err(&vdev->dev, "get IDA idx for virtbus device failed!\n");
+ goto device_pre_err;
+ }
+
+
extra line
+ vdev->dev.bus = &virtual_bus_type;
+ vdev->dev.release = virtbus_release_device;
+
+ vdev->id = ret;
+ dev_set_name(&vdev->dev, "%s.%d", vdev->name, vdev->id);
+
+ dev_dbg(&vdev->dev, "Registering virtbus device '%s'\n",
+ dev_name(&vdev->dev));
+
+ ret = device_add(&vdev->dev);
+ if (ret)
+ goto device_add_err;
+
+ return 0;
+
+device_add_err:
+ ida_simple_remove(&virtbus_dev_ida, vdev->id);
+
+device_pre_err:
+ dev_err(&vdev->dev, "Add device to virtbus failed!: %d\n", ret);
+ put_device(&vdev->dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtbus_register_device);
+
+/**
+ * virtbus_unregister_device - remove a virtual bus device
+ * @vdev: virtual bus device we are removing
+ */
+void virtbus_unregister_device(struct virtbus_device *vdev)
+{
+ device_del(&vdev->dev);
+ put_device(&vdev->dev);
looks like device_unregister(&vdev->dev) ?
+}
+EXPORT_SYMBOL_GPL(virtbus_unregister_device);
+
+static int virtbus_probe_driver(struct device *_dev)
+{
+ struct virtbus_driver *vdrv = to_virtbus_drv(_dev->driver);
+ struct virtbus_device *vdev = to_virtbus_dev(_dev);
+ int ret;
+
+ ret = dev_pm_domain_attach(_dev, true);
+ if (ret) {
+ dev_warn(_dev, "Failed to attatch to PM Domain : %d\n", ret);
typo: attach
[...]
diff --git a/include/linux/virtual_bus.h b/include/linux/virtual_bus.h
new file mode 100644
index 000000000000..4df06178e72f
--- /dev/null
+++ b/include/linux/virtual_bus.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * virtual_bus.h - lightweight software bus
+ *
+ * Copyright (c) 2019-20 Intel Corporation
2019-2020?
