[PATCH v4 1/2] ehci-platform: Add support for controllers with multiple reset lines

[Hans de Goede]

From: Reinder de Haan <patchesrdh at mveas.com>

At least the EHCI/OHCI found on the Allwinnner H3 SoC needs multiple
reset lines, the controller will not initialize while the reset for
its companion is still asserted, which means we need to de-assert
2 resets for the controller to work.

Signed-off-by: Reinder de Haan <patchesrdh at mveas.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Acked-by: Alan Stern <stern at rowland.harvard.edu>
---
Changes in v2:
-Use the new reset_control_[de]assert_shared reset-controller functions
Changes in v3:
-Adjust for changes to shared-reset reset-controller functions
Changes in v4:
-Fix Ugly continuation line
---
 Documentation/devicetree/bindings/usb/usb-ehci.txt |  2 +-
 drivers/usb/host/ehci-platform.c                   | 41 ++++++++++++----------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
index a12d601..0701812 100644
--- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
@@ -18,7 +18,7 @@ Optional properties:
  - clocks : a list of phandle + clock specifier pairs
  - phys : phandle + phy specifier pair
  - phy-names : "usb"
- - resets : phandle + reset specifier pair
+ - resets : a list of phandle + reset specifier pairs
 
 Example (Sequoia 440EPx):
     ehci at e0000300 {
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index bd7082f2..5ca749c 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -39,11 +39,12 @@
 
 #define DRIVER_DESC "EHCI generic platform driver"
 #define EHCI_MAX_CLKS 3
+#define EHCI_MAX_RESETS 2
 #define hcd_to_ehci_priv(h) ((struct ehci_platform_priv *)hcd_to_ehci(h)->priv)
 
 struct ehci_platform_priv {
 	struct clk *clks[EHCI_MAX_CLKS];
-	struct reset_control *rst;
+	struct reset_control *resets[EHCI_MAX_RESETS];
 	struct phy **phys;
 	int num_phys;
 	bool reset_on_resume;
@@ -149,7 +150,7 @@ static int ehci_platform_probe(struct platform_device *dev)
 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
 	struct ehci_platform_priv *priv;
 	struct ehci_hcd *ehci;
-	int err, irq, phy_num, clk = 0;
+	int err, irq, phy_num, clk = 0, rst = 0;
 
 	if (usb_disabled())
 		return -ENODEV;
@@ -232,18 +233,22 @@ static int ehci_platform_probe(struct platform_device *dev)
 				break;
 			}
 		}
-	}
 
-	priv->rst = devm_reset_control_get_optional(&dev->dev, NULL);
-	if (IS_ERR(priv->rst)) {
-		err = PTR_ERR(priv->rst);
-		if (err == -EPROBE_DEFER)
-			goto err_put_clks;
-		priv->rst = NULL;
-	} else {
-		err = reset_control_deassert(priv->rst);
-		if (err)
-			goto err_put_clks;
+		for (rst = 0; rst < EHCI_MAX_RESETS; rst++) {
+			priv->resets[rst] =
+				devm_reset_control_get_shared_by_index(
+						&dev->dev, rst);
+			if (IS_ERR(priv->resets[rst])) {
+				err = PTR_ERR(priv->resets[rst]);
+				if (err == -EPROBE_DEFER)
+					goto err_reset;
+				priv->resets[rst] = NULL;
+				break;
+			}
+			err = reset_control_deassert(priv->resets[rst]);
+			if (err)
+				goto err_reset;
+		}
 	}
 
 	if (pdata->big_endian_desc)
@@ -300,8 +305,8 @@ err_power:
 	if (pdata->power_off)
 		pdata->power_off(dev);
 err_reset:
-	if (priv->rst)
-		reset_control_assert(priv->rst);
+	while (--rst >= 0)
+		reset_control_assert(priv->resets[rst]);
 err_put_clks:
 	while (--clk >= 0)
 		clk_put(priv->clks[clk]);
@@ -319,15 +324,15 @@ static int ehci_platform_remove(struct platform_device *dev)
 	struct usb_hcd *hcd = platform_get_drvdata(dev);
 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
 	struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
-	int clk;
+	int clk, rst;
 
 	usb_remove_hcd(hcd);
 
 	if (pdata->power_off)
 		pdata->power_off(dev);
 
-	if (priv->rst)
-		reset_control_assert(priv->rst);
+	for (rst = 0; rst < EHCI_MAX_RESETS && priv->resets[rst]; rst++)
+		reset_control_assert(priv->resets[rst]);
 
 	for (clk = 0; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++)
 		clk_put(priv->clks[clk]);
-- 
2.7.1