Best Regards Jerry Huang -----Original Message----- From: Michael Walle <michael@xxxxxxxx> Sent: 2022年4月21日 17:44 To: krzysztof.kozlowski@xxxxxxxxxx Cc: broonie@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Jerry Huang <jerry.huang@xxxxxxx>; krzysztof.kozlowski+dt@xxxxxxxxxx; Leo Li <leoyang.li@xxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; shawnguo@xxxxxxxxxx; Vladimir Oltean <olteanv@xxxxxxxxx>; Michael Walle <michael@xxxxxxxx> Subject: Re: [EXT] Re: [PATCH 1/2 v4] dt-bindings: dspi: added for semtech sx1301 Caution: EXT Email On 21/04/2022 11:11, Jerry Huang wrote: >> Please also answer Michael's comments. >> >> [Jerry Huang] I double checked the MikroBus devices, we used two MikcroBus devices: >> BLE P click: >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww >> .mikroe.com%2Fble-p-click&data=05%7C01%7Cjerry.huang%40nxp.com%7C >> 39106c035c374b5ec60608da237b883f%7C686ea1d3bc2b4c6fa92cd99c5c301635%7 >> C0%7C1%7C637861310738684479%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM >> DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C& >> ;sdata=rsETzlFhfe2hyRAiQOL4KHAQ4vwh%2FFrYzroZ%2B0ccSMw%3D&reserve >> d=0 BEE click: >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww >> .mikroe.com%2Fbee-click&data=05%7C01%7Cjerry.huang%40nxp.com%7C39 >> 106c035c374b5ec60608da237b883f%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0 >> %7C1%7C637861310738684479%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDA >> iLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&s >> data=LEmwF46B9GYD%2BcpGoxpiGTnMgvTbLHP4IUirGR78A5U%3D&reserved=0 >> Both of them are SPI interface connect to ls1028ardb through MiKcroBus interface. >> So the name "semtech sx1301" is not correct for this node. > > I asked to remove the words "Devicetree bindings" and this was not finished. > > Now you mention that entire name of device is wrong... It's confusing. > I don't know what device you are describing here. I expect you know. > :) > > What is this binding about exactly? I *think* it's just exposing the mikrobus connector as an spidev device. There was a former attempt by Vladimir here [1]. Now as it the nature of such a connector that you can connect a myriad of devices there, it doesn't really make sense to have a just particular one described. What happens if that one will switch from spidev to a real driver in the kernel? So using "spidev" for the compatible would be the first reflex. But as described in the spidev driver this is plain wrong (and also causes a warning/info message it) because it should describe the actual hardware. Thus I proposed to use DT overlays which are loaded according to what is actually attached to the header, so a real driver could be loaded. But there *could* be a sane default which then could be replaced in an DT overlay. Like "mirkobus-socket" or similar, which might expose spidev. Actually it is more than just SPI, there is GPIO and resets and I2C. Maybe it should be an MFD? I don't know. But that is something for the DT maintainers to decide if they'll allow such "generic" devices. -michael [Jerry Huang] Thank a lot, Michael. Yes, there are I2C, Uart (or GPIO) and SPI interface in MikcroBus socket. Krzysztof, How about compatible = "mikcroe,mikcroe-socket"? or how about Vladimir's patch? [1] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flinux-devicetree%2F20200318001603.9650-13-olteanv%40gmail.com%2F&data=05%7C01%7Cjerry.huang%40nxp.com%7C39106c035c374b5ec60608da237b883f%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637861310738684479%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&sdata=Y166YDGSpEX0wtUQE8V7ql8atkb79BmG9Y5mXb8KWJM%3D&reserved=0
