[RFC v2 00/13] usb/mmc/power: Fix USB/LAN when TFTP booting

Krzysztof Kozlowski
2016-05-05T12:34:13Z

Hi,

This is a different, second try to fix usb3503+lan on Odroid U3 board
if it was initialized by bootloader (e.g. for TFTP boot).

First version:
http://www.spinics.net/lists/linux-usb/msg140042.html

Problem
=======
When Odroid U3 (usb3503 + smsc95xx + max77686) boots from network (TFTP),
the usb3503 and LAN smsc95xx do not show up in "lsusb". Hard-reset
is required, e.g. by suspend to RAM. The actual TFTP boot does
not have to happen. Just "usb start" from U-Boot is sufficient.

>From the schematics, the regulator is a supply only to LAN, however
without toggling it off/on, the usb3503 hub won appear neither.

Solution
========
This is very similar to the MMC pwrseq behavior so the idea is to:
1. Move MMC pwrseq drivers to generic place,
2. Extend the pwrseq-simple with regulator toggling,
3. Add support to USB hub and port core for pwrseq,
4. Toggle the regulator when needed.

Issues
======
I am not familiar with USB subsystem, so please kindly guide me
where USB related code should be placed.

In the code there are still some issues to solve (FIXME/TODO notes).
If the approach is okay, I will improve the patchset. However at this
point - IT WORKS, which is nice. :)

Best regards,
Krzysztof

Krzysztof Kozlowski (13):
usb: misc: usb3503: Clean up on driver unbind
power/mmc: Move pwrseq drivers to power/pwrseq
MAINTAINERS: Retain Ulf Hansson as the same maintainer of pwrseq
power: pwrseq: Enable COMPILE_TEST for drivers
power: pwrseq: Remove mmc prefix from mmc_pwrseq
power: pwrseq: Generalize mmc_pwrseq operations by removing mmc prefix
power: pwrseq: simple: Add support for toggling regulator
usb: hub: Handle deferred probe
power: pwrseq: Add support for USB hubs with external power
usb: hub: Power sequence the ports on activation
usb: port: Parse pwrseq phandle from Device Tree
ARM: dts: exynos: Switch the buck8 to GPIO mode on Odroid U3
ARM: dts: exynos: Fix LAN and HUB after bootloader initialization on
Odroid U3

.../devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 2 +
MAINTAINERS | 8 +++
arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 +-
arch/arm/boot/dts/exynos4412-odroidu3.dts | 7 ++
drivers/mmc/Kconfig | 2 -
drivers/mmc/core/Makefile | 3 -
drivers/mmc/core/core.c | 8 +--
drivers/mmc/core/host.c | 2 +-
drivers/mmc/core/pwrseq.h | 52 --------------
drivers/power/Kconfig | 1 +
drivers/power/Makefile | 1 +
drivers/{mmc/core => power/pwrseq}/Kconfig | 21 ++++--
drivers/power/pwrseq/Makefile | 3 +
drivers/{mmc/core => power/pwrseq}/pwrseq.c | 80 +++++++++++++++++-----
drivers/{mmc/core => power/pwrseq}/pwrseq_emmc.c | 15 ++--
drivers/{mmc/core => power/pwrseq}/pwrseq_simple.c | 73 ++++++++++++++++----
drivers/usb/core/hub.c | 17 ++++-
drivers/usb/core/hub.h | 3 +
drivers/usb/core/port.c | 15 ++++
drivers/usb/misc/usb3503.c | 28 ++++++++
include/linux/mmc/host.h | 4 +-
include/linux/pwrseq.h | 60 ++++++++++++++++
22 files changed, 294 insertions(+), 113 deletions(-)
delete mode 100644 drivers/mmc/core/pwrseq.h
rename drivers/{mmc/core => power/pwrseq}/Kconfig (65%)
create mode 100644 drivers/power/pwrseq/Makefile
rename drivers/{mmc/core => power/pwrseq}/pwrseq.c (50%)
rename drivers/{mmc/core => power/pwrseq}/pwrseq_emmc.c (89%)
rename drivers/{mmc/core => power/pwrseq}/pwrseq_simple.c (64%)
create mode 100644 include/linux/pwrseq.h

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1.9.1