[PATCH 00/12] power: add generic power sequence framework

Hi Peter,

On 17.06.2016 12:09, Peter Chen wrote:

Hi all,

We have an well-known problem that the device needs to do some power
sequence before it can be recognized by related host, the typical
example like hard-wired mmc devices and usb devices. This power
sequence is hard to be described at device tree and handled by
related host driver, so we have created a common power sequence
framework to handle this requirement. The generic code is supplied
some common helpers from host driver, and individual power sequence
driver handles kinds of power sequence for devices.

Since the MMC has already done the similar things, and this power
sequence handling can be generic, we use mmc power sequence code
as base to create this framework.

This patch set is based on Krzysztof Kozlowski's RFC patch set (v4.7-rc1)
[1], and making some changes which can let it be generic. After that,
we create a generic power sequence driver for USB devices which handles
below things, it includes all input signals for devices I can consider.

- Clock and its frequencies
- GPIO for reset and the duration time
- GPIO for enable
- Regulator for power

This patch set is tested on i.mx6 sabresx evk using a dts change, I use
two hot-plug devices to simulate this use case. The udoo board changes
were tested using my last power sequence patch set. [2]

@Maciej S. Szmigiero, Oscar, would you please test them on imx6qdl udoo
boards?

Thanks for the patch set, just tested them on my UDOO Quad board and can
confirm that USB and on-board hub work fine.

Tested-by: Maciej S. Szmigiero <redacted>

Maciej