usb: dwc3: of-simple: Add support to get resets for the device

Add support to get a list of resets available for the device.
These resets must be kept de-asserted until the device is
in use.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
[p.zabel@pengutronix.de: switch to hidden reset control array]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index e129c32..ceea161 100644 (file)
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -28,11 +28,13 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 
 struct dwc3_of_simple {
        struct device           *dev;
        struct clk              **clks;
        int                     num_clocks;
+       struct reset_control    *resets;
 };
 
 static int dwc3_of_simple_clk_init(struct dwc3_of_simple *simple, int count)
@@ -95,10 +97,21 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, simple);
        simple->dev = dev;
 
+       simple->resets = of_reset_control_array_get_optional_exclusive(np);
+       if (IS_ERR(simple->resets)) {
+               ret = PTR_ERR(simple->resets);
+               dev_err(dev, "failed to get device resets, err=%d\n", ret);
+               return ret;
+       }
+
+       ret = reset_control_deassert(simple->resets);
+       if (ret)
+               goto err_resetc_put;
+
        ret = dwc3_of_simple_clk_init(simple, of_count_phandle_with_args(np,
                                                "clocks", "#clock-cells"));
        if (ret)
-               return ret;
+               goto err_resetc_assert;
 
        ret = of_platform_populate(np, NULL, NULL, dev);
        if (ret) {
@@ -107,7 +120,7 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
                        clk_put(simple->clks[i]);
                }
 
-               return ret;
+               goto err_resetc_assert;
        }
 
        pm_runtime_set_active(dev);
@@ -115,6 +128,13 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
        pm_runtime_get_sync(dev);
 
        return 0;
+
+err_resetc_assert:
+       reset_control_assert(simple->resets);
+
+err_resetc_put:
+       reset_control_put(simple->resets);
+       return ret;
 }
 
 static int dwc3_of_simple_remove(struct platform_device *pdev)
@@ -130,6 +150,9 @@ static int dwc3_of_simple_remove(struct platform_device *pdev)
                clk_put(simple->clks[i]);
        }
 
+       reset_control_assert(simple->resets);
+       reset_control_put(simple->resets);
+
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);