Re: [PATCH v4 2/5] phy: tegra: xusb: Add Tegra194 support

From: Thierry Reding
Date: Mon Oct 14 2019 - 09:12:34 EST


On Wed, Oct 09, 2019 at 10:43:40AM +0800, JC Kuo wrote:
> Add support for the XUSB pad controller found on Tegra194 SoCs. It is
> mostly similar to the same IP found on Tegra186, but the number of
> pads exposed differs, as do the programming sequences. Because most of
> the Tegra194 XUSB PADCTL registers definition and programming sequence
> are the same as Tegra186, Tegra194 XUSB PADCTL can share the same
> driver, xusb-tegra186.c, with Tegra186 XUSB PADCTL.
>
> Tegra194 XUSB PADCTL supports up to USB 3.1 Gen 2 speed, however, it
> is possible for some platforms have long signal trace that could not
> provide sufficient electrical environment for Gen 2 speed. This patch
> introduce a new device node property "nvidia,disable-gen2" that can
> be used to specifically disable Gen 2 speed for a particular USB 3.0
> port so that the port can be limited to Gen 1 speed and avoid the
> instability.
>
> Signed-off-by: JC Kuo <jckuo@xxxxxxxxxx>
> ---
> Changes in v4: none
> Changes in v3: none
> Changes in v2:
> - removed unnecessary #if/#endif pairs
> - introduce new soc->supports_gen2 flag which indicate whether or not
> a soc supports USB 3.1 Gen 2 speed
>
> drivers/phy/tegra/Makefile | 1 +
> drivers/phy/tegra/xusb-tegra186.c | 74 +++++++++++++++++++++++++++++++
> drivers/phy/tegra/xusb.c | 7 +++
> drivers/phy/tegra/xusb.h | 6 +++
> 4 files changed, 88 insertions(+)

Acked-by: Thierry Reding <treding@xxxxxxxxxx>

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