On Wed, Feb 28, 2018 at 07:50:57PM -0800, Tony Lindgren wrote: > Let's add support for the GPIO controlled USB PHY on the MDM6600 modem. > It is used on some Motorola Mapphone series of phones and tablets such > as Droid 4. > > The MDM6600 is hardwired to the first OHCI port in the Droid 4 case, and > is controlled by several GPIOs. The USB PHY is integrated into the MDM6600 > device it seems. We know this as we get L3 errors from omap-usb-host if > trying to use the PHY before MDM6600 is configured. > > The GPIOs controlling MDM6600 are used to power device on and off, to > configure the USB start-up mode (normal mode versus USB flashing), and > they also tell the state of the MDM6600 device. > > The two start-up mode GPIOs are dual-purposed and used for out of band > (OOB) wake-up for USB and TS 27.010 serial mux. But we need to configure > the USB start-up mode first to get MDM6600 booted in the right mode to > be usable in the first place. > > Note that the Motorola Mapphone Linux kernel tree has a "radio-ctrl" > driver for modems. But it really does not control the radio at all, it > just controls the modem power and start-up mode for USB. So I came to > the conclusion that we're better off having this done in the USB PHY > driver. For adding support for USB flashing mode, we can later on add > a kernel module option for flash_mode=1 or something similar. > > Also note that currently there is no PM runtime support for the OHCI > on omap variant SoCs. So for low(er) power idle states, currenty both > ohci-platform and phy-mapphone-mdm6600 must be unloaded or unbound. > > For reference here is what I measured for total power consumption on > an idle Droid 4 with and without USB related MDM6600 modules: > > idle lcd off phy-mapphone-mdm6600 ohci-platform > 153mW 284mW 344mW > > So it seems that MDM6600 is currently not yet idling even with it's > radio turned off, but that's something that is beyond the control of > this USB PHY driver. This patch does get us to the point where modem > data and GPS are usable with libqmi and ModemManager for example. > Voice calls need more audio driver work. > > Cc: devicetree@xxxxxxxxxxxxxxx > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Marcel Partap <mpartap@xxxxxxx> > Cc: Michael Scott <michael.scott@xxxxxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Sebastian Reichel <sre@xxxxxxxxxx> > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > --- > > Changes since v1: > - Fixed up issues noticed by Rob and Sebastian > - Implemented wake irq handler (for debug use only for now) > - Improved error handling based on more testing > > --- > .../bindings/phy/phy-mapphone-mdm6600.txt | 30 ++ Reviewed-by: Rob Herring <robh@xxxxxxxxxx> > drivers/phy/motorola/Kconfig | 9 + > drivers/phy/motorola/Makefile | 1 + > drivers/phy/motorola/phy-mapphone-mdm6600.c | 556 +++++++++++++++++++++ > 4 files changed, 596 insertions(+) > create mode 100644 Documentation/devicetree/bindings/phy/phy-mapphone-mdm6600.txt > create mode 100644 drivers/phy/motorola/phy-mapphone-mdm6600.c -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
