Re: [Patch v7 1/3] usb: dwc3: Add Qualcomm DWC3 glue layer driver

From: Felipe Balbi
Date: Mon Jun 30 2014 - 12:53:36 EST


Hi,

On Mon, Jun 30, 2014 at 11:03:51AM -0500, Andy Gross wrote:
> +static int dwc3_qcom_probe(struct platform_device *pdev)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + struct dwc3_qcom *qdwc;
> + int ret = 0;
> +
> + qdwc = devm_kzalloc(&pdev->dev, sizeof(*qdwc), GFP_KERNEL);
> + if (!qdwc)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, qdwc);
> +
> + qdwc->dev = &pdev->dev;
> +
> + qdwc->gdsc = devm_regulator_get(qdwc->dev, "gdsc");
> +
> + qdwc->core_clk = devm_clk_get(qdwc->dev, "core");
> + if (IS_ERR(qdwc->core_clk)) {
> + dev_dbg(qdwc->dev, "failed to get core clock\n");
> + return PTR_ERR(qdwc->core_clk);
> + }
> +
> + qdwc->iface_clk = devm_clk_get(qdwc->dev, "iface");
> + if (IS_ERR(qdwc->iface_clk)) {
> + dev_dbg(qdwc->dev, "failed to get iface clock, skipping\n");
> + qdwc->iface_clk = NULL;

so this clock and sleep_clk are optional, that's fine...

> + }
> +
> + qdwc->sleep_clk = devm_clk_get(qdwc->dev, "sleep");
> + if (IS_ERR(qdwc->sleep_clk)) {
> + dev_dbg(qdwc->dev, "failed to get sleep clock, skipping\n");
> + qdwc->sleep_clk = NULL;
> + }
> +
> + if (!IS_ERR(qdwc->gdsc)) {
> + ret = regulator_enable(qdwc->gdsc);
> + if (ret)
> + dev_err(qdwc->dev, "cannot enable gdsc\n");
> + }
> +
> + clk_prepare_enable(qdwc->core_clk);
> +
> + if (qdwc->iface_clk)
> + clk_prepare_enable(qdwc->iface_clk);

... right here you can drop the NULL check because clk_prepare_enable()
is safe against NULL pointers.

--
balbi

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