On 09/19/2012 04:42 PM, Felipe Balbi wrote:
> On Wed, Sep 19, 2012 at 04:45:01PM +0200, Marc Kleine-Budde wrote:
>> On 09/19/2012 01:56 PM, Felipe Balbi wrote:
>>> On Wed, Sep 19, 2012 at 05:00:29PM +0530, Kishon Vijay Abraham I wrote:
>>>> "usb_otg_ss_refclk960m" is needed by usb2 phy present in omap5. For
>>>> omap4, the clk_get of this clock will fail since it does not have this
>>>> clock.
>>>>
>>>> Signed-off-by: Kishon Vijay Abraham I <kis...@ti.com>
>>>> ---
>>>> Documentation/devicetree/bindings/usb/usb-phy.txt | 3 +++
>>>> drivers/usb/phy/omap-usb2.c | 28
>>>> ++++++++++++++++++++-
>>>> 2 files changed, 30 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/usb/usb-phy.txt
>>>> b/Documentation/devicetree/bindings/usb/usb-phy.txt
>>>> index 7c5fd89..d5626de 100644
>>>> --- a/Documentation/devicetree/bindings/usb/usb-phy.txt
>>>> +++ b/Documentation/devicetree/bindings/usb/usb-phy.txt
>>>> @@ -24,6 +24,9 @@ Required properties:
>>>> add the address of control module phy power register until a driver for
>>>> control module is added
>>>>
>>>> +Optional properties:
>>>> + - has960mhzclk: should be added if the phy needs 960mhz clock
>>>> +
>>>> This is usually a subnode of ocp2scp to which it is connected.
>>>>
>>>> usb3phy@4a084400 {
>>>> diff --git a/drivers/usb/phy/omap-usb2.c b/drivers/usb/phy/omap-usb2.c
>>>> index d36c282..d6612ba 100644
>>>> --- a/drivers/usb/phy/omap-usb2.c
>>>> +++ b/drivers/usb/phy/omap-usb2.c
>>>> @@ -146,6 +146,7 @@ static int __devinit omap_usb2_probe(struct
>>>> platform_device *pdev)
>>>> struct omap_usb *phy;
>>>> struct usb_otg *otg;
>>>> struct resource *res;
>>>> + struct device_node *np = pdev->dev.of_node;
>>>>
>>>> phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
>>>> if (!phy) {
>>>> @@ -190,6 +191,15 @@ static int __devinit omap_usb2_probe(struct
>>>> platform_device *pdev)
>>>> }
>>>> clk_prepare(phy->wkupclk);
>>>>
>>>> + if (of_property_read_bool(np, "has960mhzclk")) {
>>>> + phy->optclk = devm_clk_get(phy->dev, "usb_otg_ss_refclk960m");
>>>> + if (IS_ERR(phy->optclk)) {
>>>> + dev_err(&pdev->dev, "unable to get refclk960m\n");
>>>> + return PTR_ERR(phy->optclk);
>>>> + }
>>>> + clk_prepare(phy->optclk);
>>>> + }
>>>
>>> instead, can't you just always try to get the clock but ignore the error
>>> if it fails ?
>>
>> On imx we add no-op dummy clocks, so that the drivers will always find
>> all needed clocks. If a clk_get fails it's an error.
>
> It's an error from a clk API point of view, it doesn't mean device can't
> work without that optional clock. Drivers are free to treat errors
> however they like, even by ignoring it and defaulting to some other
> behavior.Sure. > Adding dummy clocks just bloats the kernel with useless data IMHO. Just wanted to point out there's more than one way to do it. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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