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.

Cc: Felipe Balbi <ba...@kernel.org>
Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org>
---

Based on torvald's master branch.

 drivers/usb/dwc3/dwc3-of-simple.c | 49 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c 
b/drivers/usb/dwc3/dwc3-of-simple.c
index fe414e7a9c78..025de7342d28 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -29,13 +29,52 @@
 #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;
+       int                     num_resets;
 };
 
+static int dwc3_of_simple_reset_init(struct dwc3_of_simple *simple, int count)
+{
+       struct device           *dev = simple->dev;
+       int                     i;
+
+       simple->num_resets = count;
+
+       if (!count)
+               return 0;
+
+       simple->resets = devm_kcalloc(dev, simple->num_resets,
+                               sizeof(struct reset_control *), GFP_KERNEL);
+       if (!simple->resets)
+               return -ENOMEM;
+
+       for (i = 0; i < simple->num_resets; i++) {
+               struct reset_control *reset;
+               int ret;
+
+               reset = devm_reset_control_get_by_index(dev, i);
+               if (IS_ERR(reset))
+                       return PTR_ERR(reset);
+
+               simple->resets[i] = reset;
+
+               ret = reset_control_deassert(reset);
+               if (ret) {
+                       while (--i >= 0)
+                               reset_control_assert(reset);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
 static int dwc3_of_simple_clk_init(struct dwc3_of_simple *simple, int count)
 {
        struct device           *dev = simple->dev;
@@ -100,6 +139,10 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
        if (ret)
                return ret;
 
+       ret = dwc3_of_simple_reset_init(simple, of_reset_control_get_count(np));
+       if (ret)
+               return ret;
+
        ret = of_platform_populate(np, NULL, NULL, dev);
        if (ret) {
                for (i = 0; i < simple->num_clocks; i++) {
@@ -107,6 +150,9 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
                        clk_put(simple->clks[i]);
                }
 
+               for (i = 0; i < simple->num_resets; i++)
+                       reset_control_assert(simple->resets[i]);
+
                return ret;
        }
 
@@ -128,6 +174,9 @@ static int dwc3_of_simple_remove(struct platform_device 
*pdev)
                clk_put(simple->clks[i]);
        }
 
+       for (i = 0; i < simple->num_resets; i++)
+               reset_control_assert(simple->resets[i]);
+
        of_platform_depopulate(dev);
 
        pm_runtime_put_sync(dev);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

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