[PATCH v1 4/9] pinctrl: tegra-xusb: Add USB PHY support
From: Felipe Balbi <hidden>
Date: 2014-06-27 15:01:38
Also in:
linux-devicetree, linux-tegra, lkml
On Wed, Jun 25, 2014 at 04:30:48PM -0700, Andrew Bresticker wrote:
quoted
quoted
+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; + + value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_USB3_PADX_CTL2(port)); + value &= ~((XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_RX_WANDER_MASK << + XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_RX_WANDER_SHIFT) | + (XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_RX_EQ_MASK << + XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_RX_EQ_SHIFT) | + (XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_CDR_CNTL_MASK << + XUSB_PADCTL_IOPHY_USB3_PAD_CTL2_CDR_CNTL_SHIFT));Hmm. So there is a lot of "PHY" stuff here after all. However, the PHYs implemented here appear to implement very low-level I/O pad code, whereas the PHYs we have for our USB 2.0 controller are somewhat higher-level; they're more USB-oriented than just IO pad oriented. Do you know which level of abstraction a Linux PHY object is supposed to be? I could never get an answer when I asked before.The only other PHY driver I've worked with (Exynos USB2/3 PHYs) also mainly only did low-level pad control stuff, but looking at a couple of other USB PHYs (MSM, MV), there appear to be others that have higher-level USB stuff in the PHY driver. Perhaps Kishon or Felipe could offer us some guidance?
well, if you're adding a new driver, I'd rather see folks moving over to the generic phy framework (drivers/phy) because we're trying really hard to get rid of drivers/usb/phy/. And I think, in your case, it's actually ok to use pinctrl because you actually are muxing pads to the USB3 PHY, you just do it lazyly. my 2 cents -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140627/87a7c7d7/attachment.sig>