Re: [PATCH v3 12/12] ARM: dts: exynos: Fix LAN and HUB after bootloader initialization on Odroid U3

From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
To: Peter Chen <hzpeterchen@gmail.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Sebastian Reichel <sre@kernel.org>,
	Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Javier Martinez Canillas <javier@osg.samsung.com>,
	linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org,
	linux-pm@vger.kernel.or, Alan Stern <stern@rowland.harvard.edu>,
	linux-usb@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>, Kukjin Kim <kgene@kernel.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH v3 12/12] ARM: dts: exynos: Fix LAN and HUB after bootloader initialization on Odroid U3
Date: Thu, 02 Jun 2016 09:26:57 +0200	[thread overview]
Message-ID: <574FDFC1.5050209@samsung.com> (raw)
In-Reply-To: <20160601115929.GA16740@shlinux2>

On 06/01/2016 01:59 PM, Peter Chen wrote:
> On Wed, Jun 01, 2016 at 10:02:21AM +0200, Krzysztof Kozlowski wrote:
>> On Odroid U3 (Exynos4412-based) board if USB was initialized by
>> bootloader (in U-Boot "usb start" before tftpboot), the HUB (usb3503)
>> and LAN (smsc95xx) after after successful probing were not visible in the
>> system ("lsusb").
>>
>> In such case the devices had to be fully reset before configuring.
>> Reset by GPIO (called RESET_N pin) and by RESET field in STCD register
>> in usb3503 HUB are not sufficient. Instead full reset has to be done by
>> disabling and enabling regulator.
>>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>> ---
>>  arch/arm/boot/dts/exynos4412-odroidu3.dts | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/exynos4412-odroidu3.dts b/arch/arm/boot/dts/exynos4412-odroidu3.dts
>> index 31cdc036fda4..23e30e4609df 100644
>> --- a/arch/arm/boot/dts/exynos4412-odroidu3.dts
>> +++ b/arch/arm/boot/dts/exynos4412-odroidu3.dts
>> @@ -99,11 +99,15 @@
>>  	clock-names = "refclk";
>>  	clocks = <&pmu_system_controller 0>;
>>  	refclk-frequency = <24000000>;
>> +
>> +	power-sequence;
>> +	ext-supply = <&buck8_reg>;
>>  };
>>  
>>  &ehci {
>>  	port@1 {
>>  		status = "okay";
>> +		usb-pwrseq = <&usb3503>;
>>  	};
>>  	port@2 {
>>  		status = "okay";
>> -- 
>> 1.9.1
>>
> 
> The hub is under the port1, you may need to describe it
> under the port@1, see below:
> Documentation/devicetree/bindings/usb/usb-device.txt

My configuration is a little bit different than yours.

In my case I have a USB hub (usb3503) which is also a a i2c device
because it has to be configured through I2C.

I can add the power-sequence properties to the I2C node or as you
pointed under port using the vendor-product-id compatible. In the first
option: not many USB changes are needed. It works for me, at least as a
proof of concept.

The second solution: currently it does not work because the USB device
does not get enumerated before the power sequence begins. It would be
great if you could implement this on USB side.

> 
> If I get Rob's comments correctly, you may need to consider 
> below MMC and USB device tree description together, it seems
> hard for USB to use pwrseq driver, sorry for confusing you.
> 
> If rob can accept below USB device description, we have to
> do it under USB. In future, if there is some suitable framework,
> we can move it.
> 
> 1. MMC device:
> 	usdhc3_pwrseq: usdhc3_pwrseq {
> 		compatible = "mmc-pwrseq-simple";
> 		reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>, 	/* WL_REG_ON */
> 			      <&gpio4 7 GPIO_ACTIVE_LOW>, 	/* WL_HOSTWAKE */
> 			      <&gpio3 25 GPIO_ACTIVE_LOW>, 	/* BT_REG_ON */
> 			      <&gpio3 27 GPIO_ACTIVE_LOW>,	/* BT_HOSTWAKE */
> 			      <&gpio4 4 GPIO_ACTIVE_LOW>, 	/* BT_WAKE */
> 			      <&gpio4 6 GPIO_ACTIVE_LOW>; 	/* BT_RST_N */
> 	};
> 
> &usdhc3 {
> 	pinctrl-names = "default", "state_100mhz", "state_200mhz";
> 	pinctrl-0 = <&pinctrl_usdhc3>;
> 	pinctrl-1 = <&pinctrl_usdhc3_100mhz>;
> 	pinctrl-2 = <&pinctrl_usdhc3_200mhz>;
> 	bus-width = <4>;
> 	non-removable;
> 	keep-power-in-suspend;
> 	wakeup-source;
> 	mmc-pwrseq = <&usdhc3_pwrseq>;
> 	status = "okay";
> };
> 
> 2. USB device 
> 
> &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>;
> 		reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */
> 		reset-duration-us = <10>;
> 		clocks = <&clks IMX6SX_CLK_CKO>;
> 	};

Yes, that looks like what Rob wanted... Do you plan to work on it? The
power sequence is needed before device is enumerated.

BTW, if you would like to play with the patchset, it is here:
repo:   https://github.com/krzk/linux
branch: for-next/odroid-u3-usb3503-lan-boot-fixes-v3

Best regards,
Krzysztof