From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Mon, 9 Dec 2013 22:47:28 -0600 Subject: [PATCH v3 2/2] usb: phy: Add keystone usb phy driver In-Reply-To: <1386627424-373-3-git-send-email-w-kwok2@ti.com> References: <1386627424-373-1-git-send-email-w-kwok2@ti.com> <1386627424-373-3-git-send-email-w-kwok2@ti.com> Message-ID: <20131210044728.GB28252@saruman.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi again, On Mon, Dec 09, 2013 at 05:17:04PM -0500, WingMan Kwok wrote: > +static int keystone_usbphy_init(struct usb_phy *phy) > +{ > + struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev); > + u32 val; > + > + val = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK); > + keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK, > + val | PHY_REF_SSP_EN); you need to enable this device's clock to access its registers right ? > + udelay(20); why the magic 20 usecs ? Where does that come from ? Empirically found or is there a documentation reference ? At least add a comment there. -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: