Re: [PATCH v3 6/7] USB: ohci-at91: add usb_clk for transition tocommon clk framework

From: Alan Stern
Date: Tue Jul 16 2013 - 12:49:01 EST


On Tue, 16 Jul 2013, Boris BREZILLON wrote:

> The AT91 PMC (Power Management Controller) provides an USB clock used by
> USB Full Speed host (ohci) and USB Full Speed device (udc).
> The usb drivers (ohci and udc) must configure this clock to 48Mhz.
> This configuration was formely done in mach-at91/clock.c, but this
> implementation will be removed when moving to common clk framework.
>
> This patch add support for usb clock retrieval and configuration, and is
> backward compatible with the current at91 clk implementation (if usb clk
> is not found, it does not configure/enable the usb clk).

But it does print a warning in the system log, right?

> @@ -144,6 +150,11 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver,
> goto err2;
> }
>
> + uclk = clk_get(&pdev->dev, "usb_clk");
> + if (IS_ERR(uclk)) {
> + uclk = NULL;
> + dev_warn(&pdev->dev, "failed to get usb_clk\n");
> + }

Is this really what you want for backward compatibility?

Alan Stern

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