Hi Krzysztof, On 30 November 2015 at 11:12, Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> wrote: > On 27.11.2015 15:42, Anand Moon wrote: >> hi Krzysztof, >> >> On 22 October 2015 at 18:34, Anand Moon <linux.amoon@xxxxxxxxx> wrote: >>> hi Krzysztof, >>> >>> On 22 October 2015 at 06:31, Krzysztof Kozlowski >>> <k.kozlowski@xxxxxxxxxxx> wrote: >>>> On 20.10.2015 21:56, Anand Moon wrote: >>>>> Changes need for host controller to detect UHS-I highspeed cards. >>>>> Changes in VDDQ_MMC2 voltage range help scale >>>>> the required voltage to detect and load the microSD cards. >>>> >>>> Thanks for updating description of commit. >>>> >>>>> >>>>> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx> >>>>> --- >>>>> Changes based on git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung.git v4.4-next/dt-samsung branch >>>>> >>>>> Changes: >>>>> Drop the ranp_delay for LDO9. >>>>> >>>>> Thanks to : Krzysztof, Doug Anderson, Jaehoon Chung for helping >>>>> me out figure out the mmc core requirement. >>>>> >>>>> Also drop the previous changes: >>>>> use cd-gpio method to detect sd-card. >>>>> Added UHS-I bus speed support. >>>>> >>>>> [ 4.713553] random: nonblocking pool is initialized >>>>> [ 4.718423] 14530000.hdmi supply hdmi-en not found, using dummy regulator >>>>> [ 4.726206] exynos-drm exynos-drm: bound 14400000.fimd (ops fimd_component_ops) >>>>> [ 4.732555] exynos-drm exynos-drm: bound 14450000.mixer (ops mixer_component_ops) >>>>> [ 4.740180] exynos-drm exynos-drm: bound 14530000.hdmi (ops hdmi_component_ops) >>>>> [ 4.746936] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). >>>>> [ 4.753428] [drm] No driver support for vblank timestamp query. >>>>> [ 4.940794] Console: switching to colour frame buffer device 274x77 >>>>> [ 4.995344] exynos-drm exynos-drm: fb0: frame buffer device >>>>> [ 5.024573] [drm] Initialized exynos 1.0.0 20110530 on minor 0 >>>>> [ 5.031164] exynos-dwc3 usb@12000000: no suspend clk specified >>>>> [ 5.054571] usb 2-1: new full-speed USB device number 2 using exynos-ohci >>>>> [ 5.159527] dwmmc_exynos 12220000.mmc: Busy; trying anyway >>>>> [ 5.163705] mmc_host mmc1: Timeout sending command (cmd 0x202000 arg 0x0 status 0x0) >>>>> --- >>>>> arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi | 7 ++++++- >>>>> 1 file changed, 6 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi >>>>> index 1af5bdc..a4be3e0 100644 >>>>> --- a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi >>>>> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi >>>>> @@ -182,9 +182,10 @@ >>>>> >>>>> ldo13_reg: LDO13 { >>>>> regulator-name = "vdd_ldo13"; >>>>> - regulator-min-microvolt = <2800000>; >>>>> + regulator-min-microvolt = <1800000>; >>>> >>>> You did not convinced me in previous discussion about the change to >>>> 1.8V. I said that: >>>>> On the same diagram few lines below: >>>>> VDDQ_MMC2: 2.8V 250mA >>>> >>>> You responded: >>>>> You are correct. >>>> >>>> So I am confused. Are you sure that this SD card block can/should >>>> operate on 1.8V? Have you actually tried this? >>>> >>> >>> Look like I missed this point. Here is the link I would like to share. >>> >>> http://www.hjreggel.net/cardspeed/cs_sdxc.html >>> Section: Summary of SD modes >>> >>> https://en.wikipedia.org/wiki/Secure_Digital >>> Section: Power consumption >>> >>> Their different requirement for voltage requirement for UHS-I, the max >>> value is around 3.3V >> >> Do you have any comment on this voltage selection for UHS-I card (1.8V). > > I asked whether you tried this, whether setting real 1.8V works fine. > You did not respond. As you can see on Odroid schematics, the VDDQ for > MMC[01] operates under 1.8V. > > The VDDQ for MMC2 - under 2.8V. > > In commit description you mentioned that this voltage "helps scale the > required voltage to detect and load the microSD cards". What does it > mean "help"? I would expect that detecting and loading of microSD cards > either works or does not work. I am not sure how does it help. > > Best regards, > Krzysztof I will fix the commit message. Earlier around v4.2 detection of UHS-I card was not working,but now it seen to work in v4.4 kernel. May be some driver issue which might have been fixed. I am just trying to set the voltage range for LDO13 from 1.8V (min) to 2.8V (max). If setting this is wrong according to datasheet then I will drop this setting. -Anand Moon -- 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