[PATCH v3 2/2] usb: phy: Add keystone usb phy driver

Santosh Shilimkar santosh.shilimkar at ti.com
Tue Dec 10 10:17:07 EST 2013


On Monday 09 December 2013 11:47 PM, Felipe Balbi wrote:
> 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 ?
> 
Nope.. This clock is always running for CFG block where the phy control
is residing.

>> +	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.
> 
Above probably isn't needed either but good to check why was this added.
In refreshed patch, this can be either removed or a comment can be
added accordingly.

Thanks for spotting that.

Regards,
Santosh



More information about the linux-arm-kernel mailing list