[PATCH 2/2] usb: host: xhci-plat: Fix clock resource by adding a register clock

[Manu Gautam]

Hi,


On 2/14/2018 9:46 PM, Gregory CLEMENT wrote:
> On Armada 7K/8K we need to explicitly enable the register clock. This
> clock is optional because not all the SoCs using this IP need it but at
> least for Armada 7K/8K it is actually mandatory.
>
> The change was done at xhci-plat level and not at a xhci-mvebu.c because,
> it is expected that other SoC would have this kind of constraint.
>
> The binding documentation is updating accordingly.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement at bootlin.com>
> ---
>  Documentation/devicetree/bindings/usb/usb-xhci.txt |  5 +++-
>  drivers/usb/host/xhci-plat.c                       | 33 ++++++++++++++++++----
>  drivers/usb/host/xhci.h                            |  3 +-
>  3 files changed, 33 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> index e2ea59bbca93..e4b14511f4f8 100644
> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> @@ -27,7 +27,10 @@ Required properties:
>    - interrupts: one XHCI interrupt should be described here.
>  
>  Optional properties:
> -  - clocks: reference to a clock
> +  - clocks: reference to the clocks
> +  - clock-names: mandatory if there is a second clock, in this case
> +    the name must be "core" for the first clock and "reg" for the
> +    second one
>    - usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
>    - usb3-lpm-capable: determines if platform is USB3 LPM capable
>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 79afaac57ef6..fd0c399013a2 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -157,6 +157,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
>  	struct resource         *res;
>  	struct usb_hcd		*hcd;
>  	struct clk              *clk;
> +	struct clk              *reg_clk;
>  	int			ret;
>  	int			irq;
>  
> @@ -226,17 +227,27 @@ static int xhci_plat_probe(struct platform_device *pdev)
>  	hcd->rsrc_len = resource_size(res);
>  
>  	/*
> -	 * Not all platforms have a clk so it is not an error if the
> -	 * clock does not exists.
> +	 * Not all platforms have clks so it is not an error if the
> +	 * clock do not exist.
>  	 */
> +	reg_clk = devm_clk_get(&pdev->dev, "reg");
> +	if (!IS_ERR(reg_clk)) {
> +		ret = clk_prepare_enable(reg_clk);
> +		if (ret)
> +			goto put_hcd;
> +	} else if (PTR_ERR(reg_clk) == -EPROBE_DEFER) {
> +		ret = -EPROBE_DEFER;
> +		goto put_hcd;
> +	}
> +

How about using clk_bulk_ APIs?

>  	clk = devm_clk_get(&pdev->dev, NULL);
>  	if (!IS_ERR(clk)) {
>  		ret = clk_prepare_enable(clk);
>

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