Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.4 \(3445.8.2\)) Subject: Re: [PATCH v5 5/7] Bluetooth: Extend btuart driver for join more vendor devices From: Marcel Holtmann In-Reply-To: <1531641134.3955.19.camel@mtkswgap22> Date: Mon, 16 Jul 2018 14:59:58 +0200 Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Johan Hedberg , linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, robh+dt@kernel.org, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org Message-Id: <6476BE78-3FE5-465F-8060-2215387323AA@holtmann.org> References: <85d449cdd34bf47d72935a821915e825c64a2145.1531150733.git.sean.wang@mediatek.com> <70616B99-5A2D-417A-8815-246700EEF4E2@holtmann.org> <1531641134.3955.19.camel@mtkswgap22> To: Sean Wang Sender: linux-kernel-owner@vger.kernel.org List-ID: Hi Sean, >>> Adding an independent btuart.h header allows these essential definitions >>> can be reused in vendor driver. Also, struct btuart_vnd is extended with >>> additional callbacks such as .init initializing vendor data, .shtudown, >>> .recv and .send supporting SoC specific framing for that btuart can >>> simply adapt to various Bluetooth uart-based devices. >>> >>> Signed-off-by: Sean Wang >>> --- >>> drivers/bluetooth/btuart.c | 73 ++++++++++++++++++++++++---------------------- >>> drivers/bluetooth/btuart.h | 30 +++++++++++++++++++ >>> 2 files changed, 68 insertions(+), 35 deletions(-) >>> create mode 100644 drivers/bluetooth/btuart.h >>> >>> diff --git a/drivers/bluetooth/btuart.c b/drivers/bluetooth/btuart.c >>> index a900aac..65d0086 100644 >>> --- a/drivers/bluetooth/btuart.c >>> +++ b/drivers/bluetooth/btuart.c >>> @@ -33,35 +33,11 @@ >>> #include >>> >>> #include "h4_recv.h" >>> +#include "btuart.h" >>> #include "btbcm.h" >>> >>> #define VERSION "1.0" >>> >>> -struct btuart_vnd { >>> - const struct h4_recv_pkt *recv_pkts; >>> - int recv_pkts_cnt; >>> - unsigned int manufacturer; >>> - int (*open)(struct hci_dev *hdev); >>> - int (*close)(struct hci_dev *hdev); >>> - int (*setup)(struct hci_dev *hdev); >>> -}; >>> - >>> -struct btuart_dev { >>> - struct hci_dev *hdev; >>> - struct serdev_device *serdev; >>> - >>> - struct work_struct tx_work; >>> - unsigned long tx_state; >>> - struct sk_buff_head txq; >>> - >>> - struct sk_buff *rx_skb; >>> - >>> - const struct btuart_vnd *vnd; >>> -}; >> >> I really like to avoid this since it is not clean. Frankly I prefer to keep the btuart.c driver for drivers that really just use H:4 as transport protocol. If the protocol is only H:4 alike and has extra headers, then it should be a separate driver. >> > > thanks for letting me know your concern. I think I'm a little over in reusing these existing methods and break something generic and its beauty. > > I'll make the driver be a separate one based on btuart in the next version. > > >> The common H:4 handling is abstracted in h4_recv.h already anyway and we can add more pieces if needed. However I also wonder since you have extra framing that the complex H:4 state keeping might be not needed at all. So it could be simplified. >> > > okay, I will get rid of h4_recv.h and consider to use more simplified logic to handle the extra framing and its payload. only if it is already framed by your extra header, but I seem to recall that it will frame it. For example the bfusb.c old driver does frame H:4 as well and then no extra state keeping for H:4 is needed. Just pass the frames up into the core via hci_recv_frame (or hci_recv_diag for vendor diagnostic) and move on with it. You can of course use h4_recv.h if you need to, but only do that if you are true H:4 stream and have no idea where a frame ends and starts. Regards Marcel