Commit 4718c177 authored by Gregory CLEMENT's avatar Gregory CLEMENT Committed by Greg Kroah-Hartman
Browse files

usb: host: xhci-plat: add clock support 



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: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: default avatarFelipe Balbi <balbi@ti.com>
Acked-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 48157bb9

drivers/usb/host/xhci-plat.c

+23 −1
Original line number Diff line number Diff line
@@ -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;

	}



	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);

	/*

	 * 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 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);

drivers/usb/host/xhci.h

+2 −0
Original line number Diff line number Diff line
@@ -1472,6 +1472,8 @@ 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;

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