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

[Mathias Nyman]

On 14.02.2018 18:16, 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

Would be good to get a Ack or review by Rob Herring for the above

> 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;
> +	}
> +
>   	clk = devm_clk_get(&pdev->dev, NULL);
>   	if (!IS_ERR(clk)) {
>   		ret = clk_prepare_enable(clk);
>   		if (ret)
> -			goto put_hcd;
> +			goto disable_reg_clk;
>   	} else if (PTR_ERR(clk) == -EPROBE_DEFER) {
>   		ret = -EPROBE_DEFER;
> -		goto put_hcd;
> +		goto disable_reg_clk;
>   	}
>   
>   	xhci = hcd_to_xhci(hcd);
> @@ -252,6 +263,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
>   	device_wakeup_enable(hcd->self.controller);
>   
>   	xhci->clk = clk;
> +	xhci->reg_clk = reg_clk;
>   	xhci->main_hcd = hcd;
>   	xhci->shared_hcd = __usb_create_

hcd(driver, sysdev, &pdev->dev,
>   			dev_name(&pdev->dev), hcd);
> @@ -321,6 +333,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
>   disable_clk:
>   	clk_disable_unprepare(clk);
>   
> +disable_reg_clk:
> +	clk_disable_unprepare(reg_clk);
> +
>   put_hcd:
>   	usb_put_hcd(hcd);
>   
> @@ -336,6 +351,7 @@ static int xhci_plat_remove(struct platform_device *dev)
>   	struct usb_hcd	*hcd = platform_get_drvdata(dev);
>   	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
>   	struct clk *clk = xhci->clk;
> +	struct clk *reg_clk = xhci->reg_clk;
>   
>   	xhci->xhc_state |= XHCI_STATE_REMOVING;
>   
> @@ -346,6 +362,7 @@ static int xhci_plat_remove(struct platform_device *dev)
>   	usb_put_hcd(xhci->shared_hcd);
>   
>   	clk_disable_unprepare(clk);
> +	clk_disable_unprepare(reg_clk);
>   	usb_put_hcd(hcd);
>   
>   	pm_runtime_set_suspended(&dev->dev);
> @@ -370,8 +387,10 @@ static int __maybe_unused xhci_plat_suspend(struct device *dev)
>   	 */
>   	ret = xhci_suspend(xhci, device_may_wakeup(dev));
>   
> -	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk))
> +	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk)) {
>   		clk_disable_unprepare(xhci->clk);
> +		clk_disable_unprepare(xhci->reg_clk);
> +	}
>   
>   	return ret;
>   }
> @@ -382,8 +401,10 @@ static int __maybe_unused xhci_plat_resume(struct device *dev)
>   	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
>   	int ret;
>   
> -	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk))
> +	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk)) {
> +		clk_prepare_enable(xhci->reg_clk);
>   		clk_prepare_enable(xhci->clk);
> +	}
>   
>   	ret = xhci_priv_resume_quirk(hcd);
>   	if (ret)
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 96099a245c69..9884aaba1b40 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1726,8 +1726,9 @@ struct xhci_hcd {
>   	int		page_shift;
>   	/* msi-x vectors */
>   	int		msix_count;
> -	/* optional clock */
> +	/* optional clocks */
>   	struct clk		*clk;
> +	struct clk		*reg_clk;
>   	/* data structures */
>   	struct xhci_device_context_array *dcbaa;
>   	struct xhci_ring	*cmd_ring;
> 

Looks good to me, I'll queue it up if the devicetree bindings looks ok for Rob Herring

-Mathias