On Mon, Jun 20, 2016 at 08:29:55PM +0800, Chen-Yu Tsai wrote:

Hi,

On Mon, Jun 20, 2016 at 7:26 PM, Peter Chen [off-list ref] wrote:

quoted

On Fri, Jun 17, 2016 at 12:16:48PM -0500, Rob Herring wrote:

quoted

On Fri, Jun 17, 2016 at 5:09 AM, Peter Chen [off-list ref] wrote:

quoted

Add binding doc for generic usb power sequence driver, and update
generic usb device binding-doc accordingly.

Signed-off-by: Peter Chen <redacted>
---
 .../bindings/power/pwrseq/pwrseq-usb-generic.txt   | 31 ++++++++++++++++++++++
 .../devicetree/bindings/usb/usb-device.txt         |  2 ++
 2 files changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-usb-generic.txt

diff --git a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-usb-generic.txt b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-usb-generic.txt
new file mode 100644
index 0000000..8ad98382
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-usb-generic.txt

@@ -0,0 +1,31 @@
+The power sequence for generic USB Devices
+
+Some hard-wired USB devices need to do power sequence to let the
+device work normally, the typical power sequence like: enable USB
+PHY clock, toggle reset pin, etc. But current Linux USB driver
+lacks of such code to do it, it may cause some hard-wired USB devices
+works abnormal or can't be recognized by controller at all. The
+power sequence will be done before this device can be found at USB
+bus.
+
+Required properties:
+- compatible : contains "usb-pwrseq-generic".

In case I have not been clear, no.

I am not going to accept anything along the lines of the current mmc
pwrseq. I am basically okay with Krzysztof's proposal as it is *only*
an added property and not a duplication of information. I'd suggest
you figure out how to make the kernel work with that rather than
trying to work-around whatever kernel limitations there are.

I see.

Would you agree with below:

&usbotg1 {
        vbus-supply = <&reg_usb_otg1_vbus>;
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_usb_otg1_id>;
        status = "okay";

        #address-cells = <1>;
        #size-cells = <0>;
        hub: genesys@1 {
                compatible = "usb5e3,608";
                reg = <1>;

                power-sequence;
                reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
                reset-duration-us = <10>;
                clocks = <&clks IMX6SX_CLK_CKO>;

                #address-cells = <1>;
                #size-cells = <0>;
                ethernet: asix@1 {
                        compatible = "usbb95,1708";
                        reg = <1>;

                        power-sequence;
                        reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */
                        reset-duration-us = <15>;
                        clocks = <&clks IMX6SX_CLK_IPG>;
                };
        };
};

If the node has property "power-sequence", the pwrseq core will create
related platform device, and the driver under pwrseq driver will handle
power sequence stuffs. The property below "power-sequence" will be
handled at pwrseq driver.

Isn't this binding what Krzysztof proposed? His series also provides example
code for enabling USB device power sequencing. Does it not work for you?

In this series, I just change RFC to formal patch, and finished his
example code. USB power sequence should be described on USB bus, not
platform bus.

-- 

Best Regards,
Peter Chen