On Tue, May 06, 2014 at 02:14:00AM +0200, Gregory CLEMENT wrote:
> Some platform (such as the Armada 38x ones) can gate the clock of
> their USB controller. This patch add the support for the clock, by
> enabling them during probe and disabling them on remove.
>
> As not all platforms have clock support then enabling and disabling
> the clocks have been placed in separate functions. Then if the clocks
> are not supported we still can use the same calls, and there is no
... ?
thx,
Jason.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-plat.c | 57 +++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 54 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index f5351af4b2c5..bb37b941c8ec 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -11,6 +11,7 @@
> * version 2 as published by the Free Software Foundation.
> */
>
> +#include <linux/clk.h>
> #include <linux/dma-mapping.h>
> #include <linux/module.h>
> #include <linux/of.h>
> @@ -19,6 +20,10 @@
>
> #include "xhci.h"
>
> +struct xhci_plat_priv {
> + struct clk *clk;
> +};
> +
> static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
> {
> /*
> @@ -38,7 +43,8 @@ static int xhci_plat_setup(struct usb_hcd *hcd)
> static const struct hc_driver xhci_plat_xhci_driver = {
> .description = "xhci-hcd",
> .product_desc = "xHCI Host Controller",
> - .hcd_priv_size = sizeof(struct xhci_hcd *),
> + .hcd_priv_size = sizeof(struct xhci_hcd *) +
> + sizeof(struct xhci_plat_priv),
>
> /*
> * generic hardware linkage
> @@ -85,6 +91,40 @@ static const struct hc_driver xhci_plat_xhci_driver = {
> .bus_resume = xhci_bus_resume,
> };
>
> +static int xhci_plat_enable_clk(struct platform_device *pdev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> + struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> + struct xhci_plat_priv *priv = (struct xhci_plat_priv *) xhci->priv;
> +
> + priv->clk = devm_clk_get(&pdev->dev, NULL);
> +
> + /*
> + * Not all platforms have a clk so it is not an error if the
> + * clock does not exists.
> + */
> + if (IS_ERR(priv->clk))
> + return 0;
> +
> + return clk_prepare_enable(priv->clk);
> +}
> +
> +static void xhci_plat_disable_clk(struct platform_device *pdev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> + struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> + struct xhci_plat_priv *priv = (struct xhci_plat_priv *) xhci->priv;
> +
> + /*
> + * Not all platforms have a clk so it is not an error if the
> + * clock does not exists.
> + */
> + if (IS_ERR(priv->clk))
> + return;
> +
> + clk_disable_unprepare(priv->clk);
> +}
> +
> static int xhci_plat_probe(struct platform_device *pdev)
> {
> const struct hc_driver *driver;
> @@ -118,7 +158,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
>
> hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
> if (!hcd)
> - return -ENOMEM;
> + ret = -ENOMEM;
>
> hcd->rsrc_start = res->start;
> hcd->rsrc_len = resource_size(res);
> @@ -140,6 +180,13 @@ static int xhci_plat_probe(struct platform_device *pdev)
> ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
> if (ret)
> goto unmap_registers;
> +
> + ret = xhci_plat_enable_clk(pdev);
> + if (ret) {
> + dev_dbg(&pdev->dev, "error enabling clocks\n");
> + goto dealloc_usb2_hcd;
> + }
> +
> device_wakeup_enable(hcd->self.controller);
>
> /* USB 2.0 roothub is stored in the platform_device now. */
> @@ -149,7 +196,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
> dev_name(&pdev->dev), hcd);
> if (!xhci->shared_hcd) {
> ret = -ENOMEM;
> - goto dealloc_usb2_hcd;
> + goto disable_clk;
> }
>
> /*
> @@ -170,6 +217,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
> put_usb3_hcd:
> usb_put_hcd(xhci->shared_hcd);
>
> +disable_clk:
> + xhci_plat_disable_clk(pdev);
> +
> dealloc_usb2_hcd:
> usb_remove_hcd(hcd);
>
> @@ -193,6 +243,7 @@ static int xhci_plat_remove(struct platform_device *dev)
> usb_remove_hcd(xhci->shared_hcd);
> usb_put_hcd(xhci->shared_hcd);
>
> + xhci_plat_disable_clk(dev);
> usb_remove_hcd(hcd);
> iounmap(hcd->regs);
> release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
> --
> 1.8.1.2
>
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