Re: [RESEND PATCH v6, 3/5] usb: xhci-mtk: make IPPC register optional

[Matthias Brugger]

On 09/21/2016 07:54 AM, Chunfeng Yun wrote:
> Make IPPC register optional to support host side of dual-role mode,
> due to it is moved into common glue layer for simplification.
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> ---
>  drivers/usb/host/xhci-mtk.c |   36 +++++++++++++++++++++++++++++-------
>  1 file changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
> index 79959f1..4bf99b9 100644
> --- a/drivers/usb/host/xhci-mtk.c
> +++ b/drivers/usb/host/xhci-mtk.c
> @@ -94,6 +94,9 @@ static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
>  	int ret;
>  	int i;
>
> +	if (ippc == NULL)
> +		return 0;
> +
>  	/* power on host ip */
>  	value = readl(&ippc->ip_pw_ctr1);
>  	value &= ~CTRL1_IP_HOST_PDN;
> @@ -139,6 +142,9 @@ static int xhci_mtk_host_disable(struct xhci_hcd_mtk *mtk)
>  	int ret;
>  	int i;
>
> +	if (ippc == NULL)
> +		return 0;
> +
>  	/* power down all u3 ports */
>  	for (i = 0; i < mtk->num_u3_ports; i++) {
>  		value = readl(&ippc->u3_ctrl_p[i]);
> @@ -173,6 +179,9 @@ static int xhci_mtk_ssusb_config(struct xhci_hcd_mtk *mtk)
>  	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
>  	u32 value;
>
> +	if (ippc == NULL)
> +		return 0;
> +

I would prefer to add a flag/bool in xhci_hcd_mtk to signal the absence 
of the ippc. Or at least use a macro which checks the presence before 
calling any of this three functions.

Regards,
Matthias
>  	/* reset whole ip */
>  	value = readl(&ippc->ip_pw_ctr0);
>  	value |= CTRL0_IP_SW_RST;
> @@ -475,6 +484,7 @@ static void xhci_mtk_quirks(struct device *dev, struct xhci_hcd *xhci)
>  /* called during probe() after chip reset completes */
>  static int xhci_mtk_setup(struct usb_hcd *hcd)
>  {
> +	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>  	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
>  	int ret;
>
> @@ -482,12 +492,21 @@ static int xhci_mtk_setup(struct usb_hcd *hcd)
>  		ret = xhci_mtk_ssusb_config(mtk);
>  		if (ret)
>  			return ret;
> +	}
> +
> +	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
> +	if (ret)
> +		return ret;
> +
> +	if (usb_hcd_is_primary_hcd(hcd)) {
> +		mtk->num_u3_ports = xhci->num_usb3_ports;
> +		mtk->num_u2_ports = xhci->num_usb2_ports;
>  		ret = xhci_mtk_sch_init(mtk);
>  		if (ret)
>  			return ret;
>  	}
>
> -	return xhci_gen_setup(hcd, xhci_mtk_quirks);
> +	return ret;
>  }
>
>  static int xhci_mtk_probe(struct platform_device *pdev)
> @@ -586,7 +605,7 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>  	mtk->hcd = platform_get_drvdata(pdev);
>  	platform_set_drvdata(pdev, mtk);
>
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mac");
>  	hcd->regs = devm_ioremap_resource(dev, res);
>  	if (IS_ERR(hcd->regs)) {
>  		ret = PTR_ERR(hcd->regs);
> @@ -595,11 +614,14 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>  	hcd->rsrc_start = res->start;
>  	hcd->rsrc_len = resource_size(res);
>
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -	mtk->ippc_regs = devm_ioremap_resource(dev, res);
> -	if (IS_ERR(mtk->ippc_regs)) {
> -		ret = PTR_ERR(mtk->ippc_regs);
> -		goto put_usb2_hcd;
> +	mtk->ippc_regs = NULL;
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ippc");
> +	if (res) {	/* ippc register is optional */
> +		mtk->ippc_regs = devm_ioremap_resource(dev, res);
> +		if (IS_ERR(mtk->ippc_regs)) {
> +			ret = PTR_ERR(mtk->ippc_regs);
> +			goto put_usb2_hcd;
> +		}
>  	}
>
>  	for (phy_num = 0; phy_num < mtk->num_phys; phy_num++) {