Re: [PATCH v2 4/9] pinctrl: tegra-xusb: Add USB PHY support

From: Mikko Perttunen
Date: Tue Aug 26 2014 - 03:29:45 EST


On 25/08/14 22:22, Stephen Warren wrote:
On 08/18/2014 11:08 AM, Andrew Bresticker wrote:
In addition to the PCIe and SATA PHYs, the XUSB pad controller also
supports 3 UTMI, 2 HSIC, and 2 USB3 PHYs. Each USB3 PHY uses a single
PCIe or SATA lane and is mapped to one of the three UTMI ports.

The xHCI controller will also send messages intended for the PHY driver,
so request and listen for messages on the mailbox's PHY channel.

I'd like a review from Thierry here as the HW expert.

I need an ack from LinusW in order to take this pinctrl patch through
the Tegra tree.

diff --git a/drivers/pinctrl/pinctrl-tegra-xusb.c
b/drivers/pinctrl/pinctrl-tegra-xusb.c

+static int usb3_phy_power_on(struct phy *phy)
+{
+ struct tegra_xusb_padctl *padctl = phy_get_drvdata(phy);
+ int port = usb3_phy_to_port(phy);
+ int lane = padctl->usb3_ports[port].lane;
+ u32 value, offset;
+
+ if (!is_pcie_or_sata_lane(lane)) {
+ dev_err(padctl->dev, "USB3 PHY %d mapped to invalid lane: %d\n",
+ port, lane);
+ return -EINVAL;
+ }

An aside: This implies that the SATA driver should be talking to this
pinctrl driver and explicitly powering on the XUSB pins. However, the
SATA driver doesn't depend on this series. I'm a bit confused how that
works. Perhaps it's just by accident? Mikko, can you comment?

The SATA driver does depend on the pinctrl-tegra-xusb driver to power on the SATA lane. It looks like what this patch does is it adds support for using the SATA pad for USB3, in which case the SATA lane also needs to be powered on. At least that's the understanding I got from a quick read.

Mikko
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