RE: [PATCH] usb: tegra: moving phy driver into drivers directory

[Venu Byravarasu <vbyravarasu@nvidia.com>]

> -----Original Message-----
> From: Stephen Warren [mailto:swarren@wwwdotorg.org]
> Sent: Tuesday, August 28, 2012 7:37 PM
> To: Venu Byravarasu
> Cc: ccross@android.com; olof@lixom.net; linux@arm.linux.org.uk;
> stern@rowland.harvard.edu; gregkh@linuxfoundation.org; balbi@ti.com;
> linux-kernel@vger.kernel.org; linux-tegra@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-usb@vger.kernel.org
> Subject: Re: [PATCH] usb: tegra: moving phy driver into drivers directory
> 
> On 08/28/2012 02:32 AM, Venu Byravarasu wrote:
> > In order to keep up with the USB driver files organization,
> > moving USB phy driver from mach-tegra to drivers/USB directory.
> >
> > Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
> 
> > diff --git a/arch/arm/mach-tegra/devices.c b/arch/arm/mach-
> tegra/devices.c
> 
> > -struct tegra_ulpi_config tegra_ehci2_ulpi_phy_config = {
> > -	.reset_gpio = -1,
> > -	.clk = "cdev2",
> > -};
> > -
> >  struct tegra_ehci_platform_data tegra_ehci1_pdata = {
> >  	.operating_mode = TEGRA_USB_OTG,
> >  	.power_down_on_bus_suspend = 1,
> > @@ -450,7 +444,7 @@ struct tegra_ehci_platform_data tegra_ehci1_pdata
> = {
> >  };
> >
> >  struct tegra_ehci_platform_data tegra_ehci2_pdata = {
> > -	.phy_config = &tegra_ehci2_ulpi_phy_config,
> > +	.phy_config = NULL,
> 
> The PHY driver checks that field isn't NULL, and fails if it is:
> 
> > struct tegra_usb_phy *tegra_usb_phy_open(struct device *dev, int
> instance,
> >         void __iomem *regs, void *config, enum tegra_usb_phy_mode
> phy_mode)
> > {
> ...
> >         phy->config = config;
> >         phy->mode = phy_mode;
> >
> >         if (!phy->config) {
> >                 if (phy_is_ulpi(phy)) {
> >                         pr_err("%s: ulpi phy configuration missing", __func__);
> >                         err = -EINVAL;
> >                         goto err0;
> 
> So, this change will completely break ULPI support, which currently
> works fine. So, NAK.

My initial plan was to add support for phy interfaces one by one.
As part of that thought of UTMI only support at first and then add
ULPI and HSIC in next patches.
However as you were mentioning that it is not correct way, will
push ULPI & UTMI support at once in next patches.

> 
> I also plan on deleting devices.[ch] in kernel 3.7, and moving the USB
> platform data into board-dt-tegra20.c, since that's the only place it's
> used right now. So, this patch would conflict with that rather badly. I
> just posted the patches for that to the linux-tegra mailing list last
> night. Do you have better proposals for that? Perhaps usb_phy.c should
> set phy->config to &ulpi_default in a similar fashion to how it works
> for UTMI; that would remove some of the coupling between the changes.
> 
> BTW, in your response to Felipe, you said...
> 
> > Thanks Felipe for your comments.
> > Created a patch to separate out phy related stuff to phy.h with you as a
> reviewer.
> > Plz let me know your comments.
> 
> ... where is that patch?

Plz see https://lkml.org/lkml/2012/8/28/58