[RFC v4 00/14] usb/mmc/power: Generic power sequence (and fix USB/LAN when TFTP booting)

Krzysztof Kozlowski
2016-06-09T09:44:17Z

Hi,

Another version for solving a problem of power sequence on USB
hubs and devices. Apparently I am not the only one experiencing it.

The patchset tries to provide a framework for generic power sequence
of USB devices but the USB part is left to Peter Chen.

Patchset is also available here:
repo: https://github.com/krzk/linux
branch: for-next/odroid-u3-usb3503-lan-boot-fixes-v4

Changes since v3
================
1. Address Rob's comments. All regulator supplies are parsed and
toggled during power sequence. This comes with two new patches:
a. regulator,
b. simplefb.
2. Minor fixes in pwrseq-simple driver - proper module removal path.
3. Minor fixes in example USB code (pointed out by Stephen Boyd).

Changes since v2
================
1. Add Javier's reviewed-by tags. Address some comments.
2. Re-use existing properties for GPIOs etc by pwrseq-simple
driver. New property is still added: "power-sequence".
I tried to address and do according to Rob's comments.

Please look at patch 6/12 ("power: pwrseq: simple: Add support
for regulator and generic property") for bindings and the
new code around matching "power-sequence" property.

3. I marked the usb code as "EXAMPLE" because that part
is left to Peter Chen.

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.

Best regards,
Krzysztof

Krzysztof Kozlowski (14):
regulator: of: Add helper for getting all supplies
simplefb: Use new devm_of_regulator_all_get helper and bulk API
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 regulators and generic property
power: pwrseq: Add support for USB hubs with external power
usb: hub: Handle deferred probe
EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree
EXAMPLE CODE: usb: hub: Power sequence the ports on activation
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

.../pwrseq/pwrseq-emmc.txt} | 0
.../pwrseq/pwrseq-simple.txt} | 30 ++-
MAINTAINERS | 9 +
arch/arm/boot/dts/exynos4412-odroidu3.dts | 5 +
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.c | 110 ---------
drivers/mmc/core/pwrseq.h | 52 -----
drivers/mmc/core/pwrseq_simple.c | 141 ------------
drivers/power/Kconfig | 1 +
drivers/power/Makefile | 1 +
drivers/{mmc/core => power/pwrseq}/Kconfig | 22 +-
drivers/power/pwrseq/Makefile | 3 +
drivers/power/pwrseq/pwrseq.c | 153 +++++++++++++
drivers/{mmc/core => power/pwrseq}/pwrseq_emmc.c | 17 +-
drivers/power/pwrseq/pwrseq_simple.c | 245 +++++++++++++++++++++
drivers/regulator/of_regulator.c | 86 ++++++++
drivers/usb/core/hub.c | 16 +-
drivers/usb/core/hub.h | 3 +
drivers/usb/core/port.c | 15 ++
drivers/video/fbdev/simplefb.c | 71 ++----
include/linux/mmc/host.h | 4 +-
include/linux/pwrseq.h | 63 ++++++
include/linux/regulator/of_regulator.h | 13 ++
26 files changed, 680 insertions(+), 395 deletions(-)
rename Documentation/devicetree/bindings/{mmc/mmc-pwrseq-emmc.txt => power/pwrseq/pwrseq-emmc.txt} (100%)
rename Documentation/devicetree/bindings/{mmc/mmc-pwrseq-simple.txt => power/pwrseq/pwrseq-simple.txt} (50%)
delete mode 100644 drivers/mmc/core/pwrseq.c
delete mode 100644 drivers/mmc/core/pwrseq.h
delete mode 100644 drivers/mmc/core/pwrseq_simple.c
rename drivers/{mmc/core => power/pwrseq}/Kconfig (60%)
create mode 100644 drivers/power/pwrseq/Makefile
create mode 100644 drivers/power/pwrseq/pwrseq.c
rename drivers/{mmc/core => power/pwrseq}/pwrseq_emmc.c (88%)
create mode 100644 drivers/power/pwrseq/pwrseq_simple.c
create mode 100644 include/linux/pwrseq.h

--
1.9.1

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