On Mon 11 Feb 2019 at 14:17, Loys Ollivier <lollivier@xxxxxxxxxxxx> wrote: > On Mon 11 Feb 2019 at 08:33, Johan Hovold <johan@xxxxxxxxxx> wrote: > >> On Mon, Jan 28, 2019 at 04:46:53PM +0100, Loys Ollivier wrote: >>> >>> On Fri 25 Jan 2019 at 09:07, Johan Hovold wrote: >>> >>> > On Thu, Jan 17, 2019 at 05:54:32PM +0100, Loys Ollivier wrote: >>> >> Add binding for Mediatek-based GNSS receivers. >>> >> >>> >> Signed-off-by: Loys Ollivier <lollivier@xxxxxxxxxxxx> >>> >> --- >>> >> >>> >> v2: >>> >> Renamed bindings from Globaltop/gtop to Mediatek/mtk. >>> >> Moved current-speed as an optional propertie. >>> >> Removed the status line in the example. >>> >> Added "mediatek,mt3339" compatible. >> >>> >> +++ b/Documentation/devicetree/bindings/gnss/mediatek.txt >>> >> @@ -0,0 +1,39 @@ >>> >> +Mediatek-based GNSS Receiver DT binding >>> >> + >>> >> +Mediatek chipsets are used in GNSS-receiver modules produced by several >>> >> +vendors and can use UART, SPI or I2C interfaces. >>> >> + >>> >> +Please see Documentation/devicetree/bindings/gnss/gnss.txt for generic >>> >> +properties. >>> >> + >>> >> +Required properties: >>> >> + >>> >> +- compatible : Must be one of >>> >> + >>> >> + "globaltop,pa6h" >>> >> + "mediatek,mt3339" >>> > >>> > I'm not sure it makes sense to add the GPS chip itself as it cannot be >>> > used stand-alone AFAIU, and either not way would require a lot more >>> > resources to be defined than what you add to this binding. >>> >>> OK, I find it a bit confusing to have Mediatek bindings but no >>> compatible Mediatek SoCs. >>> But it is true that it can't be used stand-alone. I will remove this >>> reference and also remove it from the mtk.c driver code from this patch >>> serie. >> >>> >> +Required properties (I2C): >>> >> +- reg : I2C slave address >>> >> + >>> >> +Required properties (SPI): >>> >> +- reg : SPI chip select address >>> > >>> > While the mt3339 appears to support these interfaces, the globaltop one >>> > does not. >>> > >>> > Have you looked around for a small sample of mt3339-based receivers, to >>> > see whether anyone actually provides these? >>> >>> Again I'm confused by the fact that it is the Mediatek bindings. >>> Hence why I have added it and why it was not present in the v1 that was >>> only for Globaltop. >> >> This is no different from the sirfstar driver for receivers based on >> those chipsets but manufactured by various other vendors. >> > Indeed. > >>> I find it odd mentionning the chipset but not all its interfaces. >>> I will remove these sections and only list supported interfaces (i.e. >>> UART). Other interfaces can be added afterward if one finds a board that >>> provides them. >> >> Right, but please do look around for other receivers using this chipset >> so that we can make the binding generic enough to cover those as well >> (e.g. by choosing representative resource names). >> > OK will have a look. The only mt3339-based receivers I have found are: - [0] Globaltop - [1] Locosys / Pololu They both only provide the UART interface and do not list the I2C/SPI interfaces. [0] https://cdn-shop.adafruit.com/datasheets/GlobalTop-FGPMMOPA6H-Datasheet-V0A.pdf [1] https://www.pololu.com/file/0J641/LS20030~3_datasheet_v1.3.pdf > >> Johan -- -L
