From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4520DF9C6 for ; Mon, 3 Jul 2023 13:29:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C280C433C8; Mon, 3 Jul 2023 13:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1688390952; bh=RepaxfoshajN3K+86IX/ZsnlByloWQVwfP5afn9bAIo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=a01/bBaTvRO7151qPYjGovg7X61pYNS8WuLngBl/R/ygEsWml/MFCD8ti68mDbRfR /gqr12qZAVTOQnBot19XMqUwR5iE6Rg75i6WTree65eTIT6H43SHHWztQYTEMxsU4u 2pWe7hivCrxhExrQAW0S3fMWl+1MWjjGjSrym8g4= Date: Mon, 3 Jul 2023 15:28:34 +0200 From: Greg KH To: Umang Jain Cc: linux-staging@lists.linux.dev, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, stefan.wahren@i2se.com, f.fainelli@gmail.com, athierry@redhat.com, error27@gmail.com, dave.stevenson@raspberrypi.com, kieran.bingham@ideasonboard.com, laurent.pinchart@ideasonboard.com Subject: Re: [PATCH v8 1/5] staging: vc04_services: vchiq_arm: Add new bus type and device type Message-ID: <2023070302-gallon-unison-2b9c@gregkh> References: <20230627201628.207483-1-umang.jain@ideasonboard.com> <20230627201628.207483-2-umang.jain@ideasonboard.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230627201628.207483-2-umang.jain@ideasonboard.com> On Tue, Jun 27, 2023 at 10:16:24PM +0200, Umang Jain wrote: > The devices that the vchiq interface registers (bcm2835-audio, > bcm2835-camera) are implemented and exposed by the VC04 firmware. > The device tree describes the VC04 itself with the resources required > to communicate with it through a mailbox interface. However, the > vchiq interface registers these devices as platform devices. This > also means the specific drivers for these devices are getting > registered as platform drivers. This is not correct and a blatant > abuse of platform device/driver. > > Add a new bus type, vchiq_bus_type and device type (struct vchiq_device) > which will be used to migrate child devices that the vchiq interfaces > creates/registers from the platform device/driver. > > Signed-off-by: Umang Jain > --- > drivers/staging/vc04_services/Makefile | 1 + > .../interface/vchiq_arm/vchiq_device.c | 78 +++++++++++++++++++ > .../interface/vchiq_arm/vchiq_device.h | 43 ++++++++++ > 3 files changed, 122 insertions(+) > create mode 100644 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c > create mode 100644 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.h > > diff --git a/drivers/staging/vc04_services/Makefile b/drivers/staging/vc04_services/Makefile > index 44794bdf6173..2d071e55e175 100644 > --- a/drivers/staging/vc04_services/Makefile > +++ b/drivers/staging/vc04_services/Makefile > @@ -5,6 +5,7 @@ vchiq-objs := \ > interface/vchiq_arm/vchiq_core.o \ > interface/vchiq_arm/vchiq_arm.o \ > interface/vchiq_arm/vchiq_debugfs.o \ > + interface/vchiq_arm/vchiq_device.o \ > interface/vchiq_arm/vchiq_connected.o \ > > ifdef CONFIG_VCHIQ_CDEV > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c > new file mode 100644 > index 000000000000..dff312e9735c > --- /dev/null > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_device.c > @@ -0,0 +1,78 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * vchiq_device.c - VCHIQ generic device and bus-type > + * > + * Copyright (c) 2023 Ideas On Board Oy > + */ > + > +#include > +#include > +#include > + > +#include "vchiq_device.h" > + > +static int vchiq_bus_type_match(struct device *dev, struct device_driver *drv); > + > +struct bus_type vchiq_bus_type = { > + .name = "vchiq-bus", > + .match = vchiq_bus_type_match, > +}; > + > +static int vchiq_bus_type_match(struct device *dev, struct device_driver *drv) > +{ > + if (dev->bus == &vchiq_bus_type && > + strcmp(dev_name(dev), drv->name) == 0) > + return 1; > + return 0; > +} > + > +static void vchiq_device_release(struct device *dev) > +{ > + struct vchiq_device *device; > + > + device = container_of(dev, struct vchiq_device, dev); > + kfree(device); > +} > + > +int vchiq_device_register(struct device *parent, const char *name) > +{ > + struct vchiq_device *device = NULL; No need to set this to NULL. > + int ret; > + > + device = kzalloc(sizeof(*device), GFP_KERNEL); > + if (!device) > + return -ENOMEM; > + > + device->dev.init_name = name; > + device->dev.parent = parent; > + device->dev.bus = &vchiq_bus_type; > + device->dev.release = vchiq_device_release; > + > + ret = device_register(&device->dev); > + if (ret) { > + put_device(&device->dev); > + return -EINVAL; Why not return the error given to you? > + } > + > + return 0; You create a new device, shouldn't you return it? How is it going to be looked up again? > +} > + > +int vchiq_device_unregister(struct device *dev, void *data) You should be passing in a sruct vchiq_device *device here, right? And why the void pointer you do nothing with? > +{ > + device_unregister(dev); > + return 0; > +} No need to export this? thanks, greg k-h