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>
Acked-by: Felipe Balbi <balbi@xxxxxx>
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
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 f5351af4b2c5..8108e58c9e02 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 d280e9213d08..003dc094ca37 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;
--
1.8.1.2
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