[V8 PATCH 01/16] usb: phy: mv_usb2: add PHY driver for marvell usb2 controller

Felipe Balbi balbi at ti.com
Wed Mar 6 03:53:13 EST 2013


On Wed, Mar 06, 2013 at 04:24:58PM +0800, Chao Xie wrote:
> On Wed, Mar 6, 2013 at 4:10 PM, Felipe Balbi <balbi at ti.com> wrote:
> > Hi,
> >
> > On Wed, Mar 06, 2013 at 10:11:41AM +0800, Chao Xie wrote:
> >> 3. For the revison register. It exists in some SOCes(pxa168), but for
> >> some SOCes, the register dispears(pxa910, armada610). These SOCes are
> >> developed by different desgin teams, and it need to be enhanced, but
> >> for current products i have to use the device_id to detect the PHY
> >> controller.
> >
> > fair enough, make sure to add a comment to the driver about this so
> > grumpy maintainers stop complaining ;-)
> >
> >> 4. For the mutex and refcount. The "USB controller" includes two
> >> blocks - the udc and ehci. In fact they will not be used at same time,
> >> but for some SOCes it duplicates the ehci block. It means that the
> >> SOCes have two or more ehci blocks. The added ehci blocks depend on
> >> the PHY to be initialized, and they can be used at same time as the
> >> "USB controller". That is the reason i add mutex and refcount for phy
> >> driver.
> >
> > alright, let's add refcounting to the generic PHY layer then.
> >
> >> 5. For the clock name. Can you describe it in details? For clkdev, if
> >> it want to find the clock, it still depends on the dev_name and
> >> con_id.
> >
> > right, the idea of clkdev is that you associate a clock provider with
> > its consumer by means of dev_name. Then you can fetch the clock from
> > driver with any name you want. Which means if you do you clkdev properly
> > you could:
> >
> > clk_get(dev, "clk1");
> > clk_get(dev, "clk2");
> > ...
> >
> > and so on.
> >
> 
> It is same as what i think.
> The clock numbers and names are depent of SOCes, i do not want to fix

no, they're not dependent on anything, not if you use clkdev correctly.

> it in ther driver. So i use pdata to pass the clknum and clk names
> "clk1", "clk2" and so on.
> in the driver, i use
> devm_clk_get(&pdev->dev, pdata->clkname[i]);
> Do you think it is acceptable?

no

> When device tree for clock framework are supported, the things get
> easier, and it is my next step.

not strong enough argument to accept passing clock names via
platform_data.

-- 
balbi
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20130306/826acfb5/attachment.sig>


More information about the linux-arm-kernel mailing list