Thank you for your answer. Yes reg = <1>; selects the chip select. I'm going to send an email at http://vger.kernel.org/vger-lists.html#linux-spi because I think is spi-related and not just the conf. This is handled by hardware, the spi of MT7628 supports two slaves. And yes, as far as I can see on dmesg, I only read 0. Thanks, Baptiste 2015-06-01 9:28 GMT+02:00 Alexander Aring <alex.aring@xxxxxxxxx>: > On Mon, Jun 01, 2015 at 09:00:30AM +0200, Baptiste Clenet wrote: >> Sorry, it was Ralink MT7628. >> I boot via device tree yes and the dts is configured to use AT86RF212B >> with chip select 1 : >> >> palmbus@10000000 { >> spi@b00 { >> status = "okay"; >> >> m25p80@0 { >> #address-cells = <1>; >> #size-cells = <1>; >> compatible = "en25q64"; >> reg = <0 0>; >> ... >> }; >> >> at86rf212@0 { >> compatible = "atmel,at86rf212"; >> reg = <1>; > > this normally represents the chip select, I don't know if this is just > eye candy or it's _really_ evaluated. > >> interrupts = <15 4>; >> interrupt-parent = <&intc>; >> reset-gpio = <&gpio0 16 1>; >> sleep-gpio = <&gpio0 17 1>; >> spi-max-frequency = <1000000>; >> }; >> }; >> }; >> >> >> This didn't work so I had a look a the spi driver spi-mt7621.c and I >> saw that the driver wasn't implemented FOR two chip selects. This is >> why I change the function "static void mt7621_spi_set_cs();" (last >> message) >> >> Does it make sense? >> > > I think it could make sense, depends what the hardware designer for Ralink > MT7628 did there. > > First you need to figure out "who" make your chip select. I mean with > this question, if your SPI controller do the chip select or is it > software triggered by GPIO. > > I don't know the spi subsystem much if the lastest one is ever supported > or you need to implement yourself (if possible). I think the spi subsystem > supports that, but I never setup such configuration. > > If it's triggered by GPIO (this smells like the spi-mt7621.c function), > you need to care that the cs is handled by software correctly and now I > think that this can have 100 issues why it's not working currently in > your setup. > > I think this is more a spi specific question and you should ask on: > > http://vger.kernel.org/vger-lists.html#linux-spi > > or get commercial support. Sorry, but I can't really help your with a > generic spi question and your issue smells like "reading zeros" on the > bus only. > > - Alex -- To unsubscribe from this list: send the line "unsubscribe linux-wpan" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
