On Sun, May 11, 2014 at 08:17:55PM +0200, Thomas Petazzoni wrote:
> From: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
>
> Some platforms (such as the Armada 38x ones) can gate the clock of
> their USB controller. This patch adds the support for one clock in
> xhci-plat, by enabling it during probe and disabling it on remove.
>
> To achieve this, it adds a 'struct clk *' member in xhci_hcd. While
> only used for now in xhci-plat, it might be used by other drivers in
> the future. Moreover, the xhci_hcd structure already holds other
> members such as msix_count and msix_entries, which are MSI-X specific,
> and therefore only used by xhci-pci.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
FWIW
Acked-by: Felipe Balbi <balbi@xxxxxx>
> ---
> drivers/usb/host/xhci-plat.c | 24 +++++++++++++++++++++++-
> drivers/usb/host/xhci.h | 2 ++
> 2 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index f5351af..8108e58 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>
> @@ -91,6 +92,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
> struct xhci_hcd *xhci;
> struct resource *res;
> struct usb_hcd *hcd;
> + struct clk *clk;
> int ret;
> int irq;
>
> @@ -137,14 +139,27 @@ static int xhci_plat_probe(struct platform_device *pdev)
> goto release_mem_region;
> }
>
> + /*
> + * Not all platforms have a clk so it is not an error if the
> + * clock does not exists.
> + */
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(clk)) {
> + ret = clk_prepare_enable(clk);
> + if (ret)
> + goto unmap_registers;
> + }
> +
> ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
> if (ret)
> - goto unmap_registers;
> + goto disable_clk;
> +
> device_wakeup_enable(hcd->self.controller);
>
> /* USB 2.0 roothub is stored in the platform_device now. */
> hcd = platform_get_drvdata(pdev);
> xhci = hcd_to_xhci(hcd);
> + xhci->clk = clk;
> xhci->shared_hcd = usb_create_shared_hcd(driver, &pdev->dev,
> dev_name(&pdev->dev), hcd);
> if (!xhci->shared_hcd) {
> @@ -173,6 +188,10 @@ put_usb3_hcd:
> dealloc_usb2_hcd:
> usb_remove_hcd(hcd);
>
> +disable_clk:
> + if (!IS_ERR(clk))
> + clk_disable_unprepare(clk);
> +
> unmap_registers:
> iounmap(hcd->regs);
>
> @@ -189,11 +208,14 @@ 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;
>
> usb_remove_hcd(xhci->shared_hcd);
> usb_put_hcd(xhci->shared_hcd);
>
> usb_remove_hcd(hcd);
> + if (!IS_ERR(clk))
> + clk_disable_unprepare(clk);
> iounmap(hcd->regs);
> release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
> usb_put_hcd(hcd);
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index d280e92..003dc09 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1478,6 +1478,8 @@ struct xhci_hcd {
> /* msi-x vectors */
> int msix_count;
> struct msix_entry *msix_entries;
> + /* optional clock */
> + struct clk *clk;
> /* data structures */
> struct xhci_device_context_array *dcbaa;
> struct xhci_ring *cmd_ring;
> --
> 1.9.2
>
--
balbi
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