Vivek, On 09/02/17 08:42, Vivek Gautam wrote: > Hi Roger, > > On Mon, Jan 23, 2017 at 4:49 PM, Roger Quadros <rogerq@xxxxxx> wrote: >> Hi, >> >> We rely on the OTG controller block to provide us with >> VBUS and ID line status via an interrupt. >> >> This is then used to switch the controller between host, peripheral >> and idle roles based on the following table. >> >> ID VBUS dual-role state >> -- ---- --------------- >> 0 x A_HOST - Host controller active >> 1 0 B_IDLE - Both Host and Gadget controllers inactive >> 1 1 B_PERIPHERAL - Gadget controller active >> > > Thanks for this series. > Sorry, i was held up with something else so couldn't take a look at it. > I will integrate this with my work, and add some basic extcon > support to enable passing vbus and id events to dwc3 layer to test > this out on msm platforms. I already have this done for one of our platforms to workaround a limitation with the OTG IP block on it. I can post it today and you can give your comments. cheers, -roger > > > Regards > Vivek > >> Couple of things to clarify: >> - There is a small window where we can potentially miss an >> event related to OTG. I've added a comment in the code where this >> could happen. How can we prevent this? Is it better to just leave >> the OTG events unmasked (but keep otg_irq on ARM GIC disabled) >> so that any new events can be captured by the OTG event register >> and interrupt re-triggered if it has not been serviced by the >> previous interrupt. >> - I'm running the entire dual-role state change logic inside >> the threaded interrupt handler with dwc->lock (spinlock) held >> but IRQs enabled. OTG events are very rare i.e. manual intervention >> so I don't see this as a problem. Just wanted to double check. >> - Some SoC's (e.g. Qualcomm MSM) do not have the OTG controller block >> but do have both host and peripheral controllers and so can operate >> in dual role mode. Current series does not address this case. >> We can get dual-role to work with such SoCs if core.c can get >> information about ID and VBUS somehow (private interface >> from parent or directly read extcon?). >> >> cheers, >> -roger >> >> Roger Quadros (8): >> usb: otg-fsm: Prevent build warning "VDBG" redefined >> usb: dwc3-omap: Fix missing break in dwc3_omap_set_mailbox() >> usb: dwc3: use BIT() macro where possible >> usb: dwc3: core.h: add some register definitions >> usb: dwc3: add dual-role support >> ARM: dts: dra7x-evm: Enable dual-role mode for USB1 >> ARM: dts: am43xx: Enable dual-role mode for USB1 >> ARM: dts: am57xx-idk: Enable dual-role mode for USB2 >> >> arch/arm/boot/dts/am437x-gp-evm.dts | 2 +- >> arch/arm/boot/dts/am437x-sk-evm.dts | 2 +- >> arch/arm/boot/dts/am43x-epos-evm.dts | 2 +- >> arch/arm/boot/dts/am57xx-idk-common.dtsi | 2 +- >> arch/arm/boot/dts/dra7-evm.dts | 2 +- >> arch/arm/boot/dts/dra72-evm-common.dtsi | 2 +- >> drivers/usb/common/usb-otg-fsm.c | 7 + >> drivers/usb/dwc3/core.c | 583 ++++++++++++++++++++++++++++++- >> drivers/usb/dwc3/core.h | 312 ++++++++++++----- >> drivers/usb/dwc3/dwc3-omap.c | 49 +-- >> drivers/usb/dwc3/gadget.c | 18 +- >> drivers/usb/dwc3/gadget.h | 20 +- >> drivers/usb/phy/phy-fsl-usb.c | 7 + >> include/linux/usb/otg-fsm.h | 15 - >> 14 files changed, 848 insertions(+), 175 deletions(-) >> >> -- >> 2.7.4 >> > -- cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
