usb: ohci-platform: Enable optional use of reset controller

The OHCI controllers used in the Allwinner A31 are asserted in reset using a
global reset controller.

Add optional support for such a controller in the OHCI platform driver.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 24 insertions, 3 deletions

diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index b6002c951c5c..4369299064c7 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <linux/usb/ohci_pdriver.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
@@ -36,6 +37,7 @@
 
 struct ohci_platform_priv {
         struct clk *clks[OHCI_MAX_CLKS];
+        struct reset_control *rst;
         struct phy *phy;
 };
 
@@ -191,6 +193,19 @@ static int ohci_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;
         }
 
         if (pdata->big_endian_desc)
@@ -203,7 +218,7 @@ static int ohci_platform_probe(struct platform_device *dev)
                 dev_err(&dev->dev,
                         "Error: CONFIG_USB_OHCI_BIG_ENDIAN_MMIO not set\n");
                 err = -EINVAL;
-                goto err_put_clks;
+                goto err_reset;
         }
 #endif
 #ifndef CONFIG_USB_OHCI_BIG_ENDIAN_DESC
@@ -211,14 +226,14 @@ static int ohci_platform_probe(struct platform_device *dev)
                 dev_err(&dev->dev,
                         "Error: CONFIG_USB_OHCI_BIG_ENDIAN_DESC not set\n");
                 err = -EINVAL;
-                goto err_put_clks;
+                goto err_reset;
         }
 #endif
 
         if (pdata->power_on) {
                 err = pdata->power_on(dev);
                 if (err < 0)
-                        goto err_put_clks;
+                        goto err_reset;
         }
 
         hcd->rsrc_start = res_mem->start;
@@ -242,6 +257,9 @@ static int ohci_platform_probe(struct platform_device *dev)
 err_power:
         if (pdata->power_off)
                 pdata->power_off(dev);
+err_reset:
+        if (priv->rst)
+                reset_control_assert(priv->rst);
 err_put_clks:
         while (--clk >= 0)
                 clk_put(priv->clks[clk]);
@@ -266,6 +284,9 @@ static int ohci_platform_remove(struct platform_device *dev)
         if (pdata->power_off)
                 pdata->power_off(dev);
 
+        if (priv->rst)
+                reset_control_assert(priv->rst);
+
         for (clk = 0; clk < OHCI_MAX_CLKS && priv->clks[clk]; clk++)
                 clk_put(priv->clks[clk]);