Am Sonntag, 14. August 2016, 20:38:59 schrieb ayaka: > On 08/14/2016 08:30 PM, Heiko Stuebner wrote: > > Am Sonntag, 14. August 2016, 19:27:23 CEST schrieb Randy Li: > >> Because of a bug in hardware design, the sdcard at firefly > >> rk3288 reload board can't switch the io voltage level to 1.8v. > >> > >> Signed-off-by: Randy Li <ayaka@xxxxxxxxxxx> > >> --- > >> > >> arch/arm/boot/dts/rk3288-firefly-reload.dts | 7 +------ > >> 1 file changed, 1 insertion(+), 6 deletions(-) > >> > >> diff --git a/arch/arm/boot/dts/rk3288-firefly-reload.dts > >> b/arch/arm/boot/dts/rk3288-firefly-reload.dts index 43145d1..a2b1f14 > >> 100644 > >> --- a/arch/arm/boot/dts/rk3288-firefly-reload.dts > >> +++ b/arch/arm/boot/dts/rk3288-firefly-reload.dts > >> @@ -202,18 +202,13 @@ > >> > >> bus-width = <4>; > >> cap-mmc-highspeed; > >> cap-sd-highspeed; > >> > >> - sd-uhs-sdr12; > >> - sd-uhs-sdr25; > >> - sd-uhs-sdr50; > >> - sd-uhs-sdr104; > >> - sd-uhs-ddr50; > >> > >> card-detect-delay = <200>; > >> disable-wp; > >> num-slots = <1>; > >> pinctrl-names = "default"; > >> pinctrl-0 = <&sdmmc_clk>, <&sdmmc_cmd>, <&sdmmc_cd>, <&sdmmc_bus4>; > >> vmmc-supply = <&vcc_sd>; > >> > >> - vqmmc-supply = <&vccio_sd>; > >> + vqmmc-supply = <&vcc_sd>; > > > > that looks wrong. vccio_sd is still the vqmmc supply in the schematics > > even > > though we don't want to switch to 1.8V . But that regulator should still > > be > > I think the vccio_sd is just the one connected to the io_domains, but > the voltage source for the > pull up register is not vccio_sd but vcc_io. vqmmc-supply is the so called io-voltage according to the code and also the jedec spec (VCCQ). And the sdmmc0_vdd that vccio_sd is connected to is exactly that ... according to the rk3288 datasheet the "SDMMC0 Digital IO Power Supply", so that connection is not only meaningful for the iodomains, but _is_ an actual supply and if you turn off vccio_sd, you probably won't get any sdmmc transfers at all ;-) . So yes, due to the resistor misheap vccio_sd should stay limited to 3.3V, but its connection as vqmmc should stay. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
