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

From: Stephen Warren <swarren@wwwdotorg.org>
To: Venu Byravarasu <vbyravarasu@nvidia.com>
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
Date: Tue, 28 Aug 2012 07:07:28 -0700	[thread overview]
Message-ID: <503CD0A0.7080300@wwwdotorg.org> (raw)
In-Reply-To: <1346146338-4996-1-git-send-email-vbyravarasu@nvidia.com>

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.

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?