Subject: Re: [PATCH 3/8] dt-bindings: net: bluetooth: Add rtl8723bs-bluetooth
To:     Rob Herring <robh@kernel.org>,
        Vasily Khoruzhick <anarsoul@gmail.com>
Cc:     Stefan Wahren <stefan.wahren@i2se.com>,
        Mark Rutland <mark.rutland@arm.com>,
        devicetree <devicetree@vger.kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        netdev <netdev@vger.kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        "open list:BLUETOOTH DRIVERS" <linux-bluetooth@vger.kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        "David S. Miller" <davem@davemloft.net>,
        arm-linux <linux-arm-kernel@lists.infradead.org>
References: <20190118170232.16142-1-anarsoul@gmail.com>
 <20190118170232.16142-4-anarsoul@gmail.com> <20190218211035.GA28145@bogus>
 <CA+E=qVdq5GORg-t-vVXM3zBxy3Aq93iCE+zmcGgLFBMcnTDgfw@mail.gmail.com>
 <1245842044.588056.1550527701604@email.ionos.de>
 <CA+E=qVdMNmVkytCzXqYgJtV196-G=c_bWx+aLvs=Y0iuRpjdRg@mail.gmail.com>
 <CAL_JsqLROpJMoEPLXaAL_JG1SNufstMDmB4xy_V_p4=duHKPSA@mail.gmail.com>
From:   David Summers <beagleboard@davidjohnsummers.uk>
Message-ID: <6a26ff97-0b9c-cfdd-9428-74580694220a@davidjohnsummers.uk>
Date:   Tue, 19 Feb 2019 21:09:21 +0000
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On 19/02/2019 14:17, Rob Herring wrote:
> On Mon, Feb 18, 2019 at 4:28 PM Vasily Khoruzhick <anarsoul@gmail.com> wrote:
>> On Mon, Feb 18, 2019 at 2:08 PM Stefan Wahren <stefan.wahren@i2se.com> wrote:
>>> Hi Vasily,
>> Hi Stefan,
>>
>>>> Vasily Khoruzhick <anarsoul@gmail.com> hat am 18. Februar 2019 um 22:24 geschrieben:
>>>>
>>>>
>>>> On Mon, Feb 18, 2019 at 1:10 PM Rob Herring <robh@kernel.org> wrote:
>>>>> On Fri, Jan 18, 2019 at 09:02:27AM -0800, Vasily Khoruzhick wrote:
>>>>>> Add binding document for bluetooth part of RTL8723BS/RTL8723CS
>>>>>>
>>>>>> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
>>>>>> ---
>>>>>>   .../bindings/net/rtl8723bs-bluetooth.txt      | 35 +++++++++++++++++++
>>>>>>   1 file changed, 35 insertions(+)
>>>>>>   create mode 100644 Documentation/devicetree/bindings/net/rtl8723bs-bluetooth.txt
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/net/rtl8723bs-bluetooth.txt b/Documentation/devicetree/bindings/net/rtl8723bs-bluetooth.txt
>>>>>> new file mode 100644
>>>>>> index 000000000000..8357f242ae4c
>>>>>> --- /dev/null
>>>>>> +++ b/Documentation/devicetree/bindings/net/rtl8723bs-bluetooth.txt
>>>>>> @@ -0,0 +1,35 @@
>>>>>> +RTL8723BS/RTL8723CS Bluetooth
>>>>>> +---------------------
>>>>>> +
>>>>>> +RTL8723CS/RTL8723CS is WiFi + BT chip. WiFi part is connected over SDIO, while
>>>>>> +BT is connected over serial. It speaks H5 protocol with few extra commands
>>>>>> +to upload firmware and change module speed.
>>>>>> +
>>>>>> +Required properties:
>>>>>> +
>>>>>> + - compatible: should be one of the following:
>>>>>> +   * "realtek,rtl8723bs-bt"
>>>>>> +   * "realtek,rtl8723cs-bt"
>>>>>> +Optional properties:
>>>>>> +
>>>>>> + - device-wake-gpios: GPIO specifier, used to wakeup the BT module (active high)
>>>>>> + - enable-gpios: GPIO specifier, used to enable the BT module (active high)
>>>>>> + - host-wake-gpios: GPIO specifier, used to wakeup the host processor (active high)
>>>>>> + - firmware-postfix: firmware postfix to be used for firmware config
>>> sorry, i didn't noticed your great series before. David and i working at the same stuff but for the Asus Tinker Board.
>>>
>>> I created a similiar yet untested patch version for hci_h5 [1]. Maybe it's useful.
>> Looks good to me, but you may need to add firmware-postfix.
>>
>>> Just a comment about the binding. It's really necessary to add the reset-gpio? Can't we use the enable-gpio with inverse polarity for this?
>> Yes, we can use enable-gpio instead of reset-gpio on pine64 and pinebook.
> Then why do we have both? Reset and enable are distinct. The inverse
> of enable-gpios is typically powerdown-gpios, not reset-gpios.
>
> Rob

Both data sheets that I know:

http://cit.odessa.ua/media/pdf/Intel-Compute-Stick/FN-Link_F23BDSM25-W1.pdf
http://files.pine64.org/doc/datasheet/pine64/RTL8723BS.pdf

BT_RST_N BT Reset IN / BT_DIS# General Purpose I/O Pin

So from the datasheet there is only one pin. And from its name it sounds 
like reset.

This said though the datasheets of these Realtek devices are a bit thin ....