Re: [PATCH 2/2] usb: chipidea: imx: Fix ULPI on imx53

[Sebastian Reichel <sebastian.reichel@collabora.co.uk>]

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Hi Peter,

On Mon, Jan 29, 2018 at 11:33:15AM +0800, Peter Chen wrote:
> On Wed, Jan 24, 2018 at 06:14:39PM +0100, Sebastian Reichel wrote:
> > Traditionally, PORTSC should be set before initializing ULPI phys. But
> > setting PORTSC before powering on the phy results in a kernel freeze
> > on imx53 based GE PPD. As a workaround this initializes the phy early
> > in the imx platform code and disables phy power management from the
> > core.
> > 
> > Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
> > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
> > ---
> >  drivers/usb/chipidea/ci_hdrc_imx.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> > index de155c80eb70..e431c5aafe35 100644
> > --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> > +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> > @@ -83,6 +83,7 @@ struct ci_hdrc_imx_data {
> >  	struct clk *clk;
> >  	struct imx_usbmisc_data *usbmisc_data;
> >  	bool supports_runtime_pm;
> > +	bool override_phy_control;
> >  	bool in_lpm;
> >  	/* SoC before i.mx6 (except imx23/imx28) needs three clks */
> >  	bool need_three_clks;
> > @@ -254,6 +255,7 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
> >  	int ret;
> >  	const struct of_device_id *of_id;
> >  	const struct ci_hdrc_imx_platform_flag *imx_platform_flag;
> > +	struct device_node *np = pdev->dev.of_node;
> >  
> >  	of_id = of_match_device(ci_hdrc_imx_dt_ids, &pdev->dev);
> >  	if (!of_id)
> > @@ -288,6 +290,14 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
> >  	}
> >  
> >  	pdata.usb_phy = data->phy;
> > +
> > +	if (of_device_is_compatible(np, "fsl,imx53-usb") && pdata.usb_phy &&
> > +	    of_usb_get_phy_mode(np) == USBPHY_INTERFACE_MODE_ULPI) {
> > +		pdata.flags |= CI_HDRC_OVERRIDE_PHY_CONTROL;
> > +		data->override_phy_control = true;
> > +		usb_phy_init(pdata.usb_phy);
> > +	}
> > +
> >  	pdata.flags |= imx_platform_flag->flags;
> >  	if (pdata.flags & CI_HDRC_SUPPORTS_RUNTIME_PM)
> >  		data->supports_runtime_pm = true;
> > @@ -341,6 +351,8 @@ static int ci_hdrc_imx_remove(struct platform_device *pdev)
> >  		pm_runtime_put_noidle(&pdev->dev);
> >  	}
> >  	ci_hdrc_remove_device(data->ci_pdev);
> > +	if (data->override_phy_control)
> > +		usb_phy_shutdown(data->phy);
> >  	imx_disable_unprepare_clks(&pdev->dev);
> >  
> 
> Sebastian, I have a question, do you have any USB or generic PHY drivers
> for ULPI bus, any power controls are needed for your ULPI peripheral?

The devicetree for GE PPD is available in the mainline kernel:

$ grep -A9 "usbphy[23] {" arch/arm/boot/dts/imx53-ppd.dts
	usbphy2: usbphy2 {
		compatible = "usb-nop-xceiv";
		reset-gpios = <&gpio4 4 GPIO_ACTIVE_LOW>;
		clock-names = "main_clk";
		clock-frequency = <24000000>;
		clocks = <&clks IMX5_CLK_CKO2>;
		assigned-clocks = <&clks IMX5_CLK_CKO2_SEL>, <&clks IMX5_CLK_OSC>;
		assigned-clock-parents = <&clks IMX5_CLK_OSC>;
	};

	usbphy3: usbphy3 {
		compatible = "usb-nop-xceiv";
		reset-gpios = <&gpio2 19 GPIO_ACTIVE_LOW>;
		clock-names = "main_clk";

		clock-frequency = <24000000>;
		clocks = <&clks IMX5_CLK_CKO2>;
		assigned-clocks = <&clks IMX5_CLK_CKO2_SEL>, <&clks IMX5_CLK_OSC>;
		assigned-clock-parents = <&clks IMX5_CLK_OSC>;
	};

So currently the machine only uses drivers/usb/phy/phy-generic.c. Both
USB phys are actually SMSC USB3315, which is also detected by the kernel:

root@csmon :~# cat /sys/bus/ulpi/devices/ci_hdrc.*.ulpi/uevent 
DEVTYPE=ulpi_device
MODALIAS=ulpi:v0424p0006
DEVTYPE=ulpi_device
MODALIAS=ulpi:v0424p0006

So maybe drivers/usb/phy/phy-ulpi.c should be used, but I don't see
a simple way to do so and using the generic PHY works.

-- Sebastian

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