Hi Martin, On Thu, 5 Aug 2021 at 23:48, Anand Moon <linux.amoon@xxxxxxxxx> wrote: > > Hi Martin, > > On Thu, 5 Aug 2021 at 03:28, Martin Blumenstingl > <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > > > > On Sun, Jul 18, 2021 at 9:09 PM Martin Blumenstingl > > <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > > > > > > Hi Anand, > > > > > > On Sun, Jul 18, 2021 at 4:01 PM Martin Blumenstingl > > > <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > > > [...] > > > > > From the schematics [1] > > > > > https://dn.odroid.com/S805/Schematics/odroid-c1+_rev0.4_20160226.pdf > > > > > > > > > > You could find references to PWREN <--- GPIOAO.BIT5 > > > > > The second reference is USB HOST Power Switch > > > > > The third reference is USB HOST POWER. > > > > > > > > > > Hope I am clean in my thought process now. > > > > Can you please point out the page numbers for me? > > > > > > > > What I am seeing on page 1 is: > > > > GPIOAO_5 (called GPIOAO.BIT5) is connected as an INPUT to the USB_OTG > > > > PWREN signal (that's the green box with the label "USB_OTG.SchDoc" > > > > above it). > > > I unfortunately missed your question on IRC on this topic: > > > <armoon> xdarklight: just want to understand the confusion on PWREN, > > > either is INPUT / OTPUT to usb hub am I correct > > > My understanding of the INPUT/OUTPUT direction in the Odroid-C1 > > > schematics (which you linked) above is that the arrow direction shows > > > whether it's an input or output. > > > For example (all on page one): > > > - HDMI_HPD is an input to the Meson8b SoC, arrow direction is: HDMI => S805 > > > - IR_IN is an input to the Meson8b SoC, arrow direction is: S805 <= > > > GPIOAO.BIT7 IR_IN > > > - PWM is an output, arrow direction is: S805 => PWM.C VCCK_PWM > > > - 3.3V/1.8V switch for the SD card is an output, arrow direction is: > > > S805 => GPIOAO.BIT3 TF_3V3N_1V8_EN > > > > > > That tells me: the arrow direction shows which connections are inputs > > > or outputs. > > > Some pins can be input and output at the same time (HDMI_CEC). But > > > let's keep it simple for now any only look at inputs/output. > > > > > > Based on this information I am looking at the arrow direction for > > > USB_OTG: GPIOAO.BIT5 PWREN <= S805 > > > So this confirms that GPIOAO_5 is an output to the SoC. > > > Please note though that this part is not linked with any USB host > > > connector, it's only linked to the USB OTG path. > > > > > > For the next part the S805 SoC is not involved: > > > USB1 USB_HOST_PWR_SW PWREN <= PWREN USB_HUB_GL852G > > > USB2 USB_HOST_PWR_SW PWREN <= PWREN USB_HUB_GL852G > > > This tells me that the PWREN signal for the two USB_HOST_PWR_SW (USB > > > host power switches / current limiters) is driven by the GL852G USB > > > hub. > > Hardkernel team responded on the Odroid forums to the request from Anand: > > "Power-Enable signal to the USB load switch ICs is connected to the > > USB hub controller. > > It is not connected the CPU GPIO." > > > > The regulator from Anand's patch is therefore connected to the micro USB port. > > This means that the patch needs updating in case Anand wants to have > > it included. > > > > Yes, I will send a corrected version of the patches soon. I have a small query regarding GPIO polarity As per the datasheet of *MP62551DGT-LF-Z* [0] https://www.mouser.in/datasheet/2/277/MP62550-1384050.pdf USB power enables EN signal need to be Active High. PIN Fucntion > Enable input. Active Low: (MP62550), Active High: (MP62551). So the correct option in dts + /* + * signal name from schematics: PWREN - GPIOAO.BIT5 + */ + gpios = <&gpio_ao GPIOAO_5 GPIO_ACTIVE_HIGH>; + enable-active-high; which gives me the below output. $ sudo cat /sys/kernel/debug/gpio | grep USB gpio-1953 (USB_HUB_RST_N |usb-hub-reset ) out hi gpio-1954 (USB_OTG_PWREN |regulator-usb-pwr-en) out hi Please clear this small query so that I can send the update patch. Thanks -Anand > > > > > Best regards, > > Martin > > > > > > [0] https://forum.odroid.com/viewtopic.php?p=332217#p332217 > > Thanks > -Anand
