From: Stephen Warren <swarren@wwwdotorg.org>
To: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: stern@rowland.harvard.edu, gregkh@linuxfoundation.org,
balbi@ti.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: tegra: Removing dependency on PHY instance number
Date: Fri, 21 Dec 2012 14:01:35 -0700 [thread overview]
Message-ID: <50D4CE2F.1090303@wwwdotorg.org> (raw)
In-Reply-To: <1356073105-13043-1-git-send-email-vbyravarasu@nvidia.com>
On 12/20/2012 11:58 PM, Venu Byravarasu wrote:
> Tegra2 has two varieties of USB PHYs:
> Instance 0 - legacy PHY interface and
> Instace 1 & 2 - non-legacy standard PHY interfaces.
>
> PHY driver is using instance numbers to identify the
> interface type.
>
> With this patch Modified PHY driver to make use of
> DT property for handling this.
>
> ULPI PHY is used on USB PHY instance 1 & UTMI is
> used on other two instances. Hence modified PHY type
> detection also from instance number to the parameter
> passed from host driver.
Mostly seems fine to me; just a couple more things I noticed inline
below. For the record, I'd like to take this through the Tegra tree with
all the other Tegra-related USB patches in order to manage any
dependencies, with the USB maintainers' Acks. Thanks.
> diff --git a/drivers/usb/phy/tegra_usb_phy.c b/drivers/usb/phy/tegra_usb_phy.c
> +struct tegra_usb_phy *tegra_usb_phy_open(struct device *dev,
> + bool is_legacy_mode, void __iomem *regs, void *config,
> + enum tegra_usb_phy_mode phy_mode)
> + u8 index = is_legacy_mode ? 0 : 2;
I know this looks slightly icky, but I discussed earlier with Venu that
this will be replaced by reading all the parameters out of device tree,
as soon as this code becomes a true driver. I think the patch for that
is up next, or at most after a few more cleanup patches.
> + phy->is_ulpi_phy = config ? true : false;
>
> if (!phy->config) {
> - if (phy_is_ulpi(phy)) {
> + if (phy->is_ulpi_phy) {
> pr_err("%s: ulpi phy configuration missing", __func__);
> err = -EINVAL;
> goto err0;
That check will never fire now, since phy->is_ulpi_phy is calculated
based on whether phy->config is set. I think it's fine for now to rely
on the EHCI driver correctly passing config or NULL, and hence you could
simply delete some of this error-checking code. I imagine that when the
PHY driver is reworked to be an actual device rather than a utility
module, phy->is_ulpi_phy will be determined by the compatible value of
the PHY node in device tree.
next prev parent reply other threads:[~2012-12-21 21:01 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-21 6:58 [PATCH] usb: tegra: Removing dependency on PHY instance number Venu Byravarasu
2012-12-21 21:01 ` Stephen Warren [this message]
2012-12-24 4:32 ` Venu Byravarasu
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