Hi Rob, Appreciate your insights.
-----Original Message----- From: Rob Herring [mailto:[email protected]] Sent: Monday, June 01, 2015 8:19 PM To: Ilya Faenson Cc: Marcel Holtmann; [email protected]; [email protected]; [email protected] Subject: Re: [RFC v4 1/4] Broadcom Bluetooth UART Device Tree bindings On Fri, May 22, 2015 at 3:10 PM, Ilya Faenson <[email protected]> wrote: > Device Tree bindings to configure the Broadcom Bluetooth UART device. > > Signed-off-by: Ilya Faenson <[email protected]> > --- > .../devicetree/bindings/net/bluetooth/btbcm.txt | 82 > ++++++++++++++++++++++ > 1 file changed, 82 insertions(+) > create mode 100644 Documentation/devicetree/bindings/net/bluetooth/btbcm.txt > > diff --git a/Documentation/devicetree/bindings/net/bluetooth/btbcm.txt > b/Documentation/devicetree/bindings/net/bluetooth/btbcm.txt > new file mode 100644 > index 0000000..968421b > --- /dev/null > +++ b/Documentation/devicetree/bindings/net/bluetooth/btbcm.txt > @@ -0,0 +1,82 @@ > +btbcm > +------ > + > +Required properties: > + > + - compatible : must be "brcm,brcm-bt-uart". > + - tty : tty device connected to this Bluetooth device. Neil Brown has been working on generic bindings for tty/UART slaves which should be used here. IF: I certainly like what is being developed for the UART child devices in the DeviceTree. It will finally catch up with what's been available in the ACPI for years. However, to the best of my understanding, that effort is currently not in the bluetooth-next git repo. As Marcel told me earlier this year, "if it is not in the bluetooth-next, it does not exist". I'm afraid I can't use it therefore. Also, we need to ship this driver sooner rather than later. The integration with the UART slave devices sounds like a worthwhile future enhancement to me. > + > +Optional properties: > + > + - bt-host-wake-gpios : bt-host-wake input GPIO to be used as an interrupt. > + > + - bt-wake-gpios : bt-wake output GPIO to be used to suspend / resume > device. > + > + - bt-reg-on-gpios : reg-on output GPIO to be used to power device on/off. > + > + - baud-rate-before-config-download : initial Bluetooth device baud rate. > + Default: 3000000. What's the baudrate after download? Why not just use standard "baud-rate" if you only specify one rate? IF: You're right: this doc used to list two rates. :-) To be compatible with what Intel is doing in the same area, I will call it "oper-speed" if you don't mind. > + > + - manual-fc : flow control UART in suspend / resume scenarios. > + Default: 0. > + > + - configure-sleep : configure suspend / resume flag. > + Default: false. > + > + - configure-audio : configure platform PCM SCO flag. > + Default: false. > + > + - PCMClockMode : PCM clock mode. 0-slave, 1-master. > + Default: 0. > + > + - PCMFillMethod : PCM fill method. 0 to 3. > + Default: 2. > + > + - PCMFillNum : PCM number of fill bits. 0 to 3. > + Default: 0. > + > + - PCMFillValue : PCM fill value. 0 to 7. > + Default: 3. > + > + - PCMInCallBitclock : PCM interface rate. 0-128Kbps, 1-256Kbps, 2-512Kbps, > + 3-1024Kbps, 4-2048Kbps. > + Default: 0. > + > + - PCMLSBFirst : PCM LSB first. 0 or 1. > + Default: 0. > + > + - PCMRightJustify : PCM Justify. 0-left, 1-right. > + Default: 0. > + > + - PCMRouting : PCM routing. 0-PCM, 1-SCO over HCI. > + Default: 0. > + > + - PCMShortFrameSync : PCM sync. 0-short, 1-long. > + Default: 0. > + > + - PCMSyncMode : PCM sync mode. 0-slave, 1-master. Please no CamelCase. These need better descriptions. IF: I am certainly aware that the CamelCase is generally not used on Linux. The Broadcom however have a spec describing what needs to be done to integrate these kinds of chips on hardware platforms (for Windows). Anybody who wishes to use SCO PCM audio will need to read that spec. These parameter names are from that spec. A lot of additional technical info Is there, along with various diagrams. It can't be all placed in this help file. Of course, I can change these parameter names but it would make things harder for those wishing to use the hardware as they would not match the spec. Could you make an exception? > + Default: 0. > + > + > +Example: > + > + brcm4354_bt_uart: brcm4354-bt-uart { > + compatible = "brcm,brcm-bt-uart"; > + bt-wake-gpios = <&gpio4 30 GPIO_ACTIVE_HIGH>; > + bt-host-wake-gpios = <&gpio4 31 GPIO_ACTIVE_HIGH>; > + tty = "ttyS0"; > + baud-rate-before-config-download = <3000000>; > + configure-sleep; > + configure-audio; > + PCMClockMode = <0>; > + PCMFillMethod = <2>; > + PCMFillNum = <0>; > + PCMFillValue = <3>; > + PCMInCallBitclock = <0>; > + PCMLSBFirst = <0>; > + PCMRightJustify = <0>; > + PCMRouting = <0>; > + PCMShortFrameSync = <0>; > + PCMSyncMode = <0>; > + }; > + > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree-spec" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html
