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Subject[PATCH v2 2/2] usb: host: xhci-plat: Fix clock resource by adding a register clock
Date
On Armada 7K/8K we need to explicitly enable the register clock. This
clock is optional because not all the SoCs using this IP need it but at
least for Armada 7K/8K it is actually mandatory.

The change was done at xhci-plat level and not at a xhci-mvebu.c because,
it is expected that other SoC would have this kind of constraint.

The binding documentation is updating accordingly.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
Documentation/devicetree/bindings/usb/usb-xhci.txt | 5 ++++-
drivers/usb/host/xhci-plat.c | 25 ++++++++++++++++++----
drivers/usb/host/xhci.h | 3 ++-
3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index c4c00dff4b56..bd1dd316fb23 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -28,7 +28,10 @@ Required properties:
- interrupts: one XHCI interrupt should be described here.

Optional properties:
- - clocks: reference to a clock
+ - clocks: reference to the clocks
+ - clock-names: mandatory if there is a second clock, in this case
+ the name must be "core" for the first clock and "reg" for the
+ second one
- usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
- usb3-lpm-capable: determines if platform is USB3 LPM capable
- quirk-broken-port-ped: set if the controller has broken port disable mechanism
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index f0231fea524e..596e7a71b666 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -157,6 +157,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
struct resource *res;
struct usb_hcd *hcd;
struct clk *clk;
+ struct clk *reg_clk;
int ret;
int irq;

@@ -226,17 +227,27 @@ static int xhci_plat_probe(struct platform_device *pdev)
hcd->rsrc_len = resource_size(res);

/*
- * Not all platforms have a clk so it is not an error if the
- * clock does not exists.
+ * Not all platforms have clks so it is not an error if the
+ * clock do not exist.
*/
+ reg_clk = devm_clk_get(&pdev->dev, "reg");
+ if (!IS_ERR(reg_clk)) {
+ ret = clk_prepare_enable(reg_clk);
+ if (ret)
+ goto put_hcd;
+ } else if (PTR_ERR(reg_clk) == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto put_hcd;
+ }
+
clk = devm_clk_get(&pdev->dev, NULL);
if (!IS_ERR(clk)) {
ret = clk_prepare_enable(clk);
if (ret)
- goto put_hcd;
+ goto disable_reg_clk;
} else if (PTR_ERR(clk) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
- goto put_hcd;
+ goto disable_reg_clk;
}

xhci = hcd_to_xhci(hcd);
@@ -252,6 +263,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
device_wakeup_enable(hcd->self.controller);

xhci->clk = clk;
+ xhci->reg_clk = reg_clk;
xhci->main_hcd = hcd;
xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
dev_name(&pdev->dev), hcd);
@@ -322,6 +334,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
disable_clk:
clk_disable_unprepare(clk);

+disable_reg_clk:
+ clk_disable_unprepare(reg_clk);
+
put_hcd:
usb_put_hcd(hcd);

@@ -337,6 +352,7 @@ 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;
+ struct clk *reg_clk = xhci->reg_clk;

xhci->xhc_state |= XHCI_STATE_REMOVING;

@@ -347,6 +363,7 @@ static int xhci_plat_remove(struct platform_device *dev)
usb_put_hcd(xhci->shared_hcd);

clk_disable_unprepare(clk);
+ clk_disable_unprepare(reg_clk);
usb_put_hcd(hcd);

pm_runtime_set_suspended(&dev->dev);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 05c909b04f14..6dfc4867dbcf 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1729,8 +1729,9 @@ struct xhci_hcd {
int page_shift;
/* msi-x vectors */
int msix_count;
- /* optional clock */
+ /* optional clocks */
struct clk *clk;
+ struct clk *reg_clk;
/* data structures */
struct xhci_device_context_array *dcbaa;
struct xhci_ring *cmd_ring;
--
2.16.3
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