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From: balbi@ti.com (Felipe Balbi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/2] usb: phy: Add keystone usb phy driver
Date: Mon, 9 Dec 2013 22:47:28 -0600	[thread overview]
Message-ID: <20131210044728.GB28252@saruman.home> (raw)
In-Reply-To: <1386627424-373-3-git-send-email-w-kwok2@ti.com>

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
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  parent reply	other threads:[~2013-12-10  4:47 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-09 22:17 [PATCH v3 0/2] Kesytone II USB host and PHY drivers WingMan Kwok
2013-12-09 22:17 ` [PATCH v3 1/2] usb: dwc3: Add Keystone specific glue layer WingMan Kwok
2013-12-10  2:51   ` Felipe Balbi
2013-12-10 15:11     ` Santosh Shilimkar
2013-12-12 17:48       ` Felipe Balbi
2013-12-12 19:36         ` Santosh Shilimkar
2013-12-12 19:41           ` Felipe Balbi
2013-12-12 19:52             ` Santosh Shilimkar
2013-12-09 22:17 ` [PATCH v3 2/2] usb: phy: Add keystone usb phy driver WingMan Kwok
2013-12-10  2:54   ` Felipe Balbi
2013-12-10 15:14     ` Santosh Shilimkar
2013-12-12 17:20       ` Kwok, WingMan
2013-12-12 17:47         ` Felipe Balbi
2013-12-10  3:09   ` Roger Quadros
2013-12-12 17:24     ` Kwok, WingMan
2013-12-10  4:47   ` Felipe Balbi [this message]
2013-12-10 15:17     ` Santosh Shilimkar

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