[PATCH v2 1/2] usb: phy: add a new driver for usb3 phy
Russell King - ARM Linux
linux at arm.linux.org.uk
Fri Sep 28 00:18:38 EST 2012
On Thu, Sep 27, 2012 at 07:34:07PM +0530, Kishon Vijay Abraham I wrote:
> +static int omap5_usb_phy_power(struct omap_usb *phy, bool on)
> +{
> + u32 val;
> + unsigned long rate;
> + struct clk *sys_clk;
> +
> + sys_clk = clk_get(NULL, "sys_clkin");
> + if (IS_ERR(sys_clk)) {
> + pr_err("%s: unable to get sys_clkin\n", __func__);
> + return -EINVAL;
> + }
> +
> + rate = clk_get_rate(sys_clk);
> + rate = rate/1000000;
> + clk_put(sys_clk);
Actually, you're supposed to hold on to the struct clk all the time your
driver is making use of that - you're not supposed to drop it.
That has several advantages: if clk_get() fails, then you're failing
earlier on (when the driver is being probed) and when some event occurs.
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