[PATCH 2/2] usb; dwc3: of-simple: Add support to get resets for the device
From: Vivek Gautam
Date: Wed Feb 22 2017 - 00:24:34 EST
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 <balbi@xxxxxxxxxx>
Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
---
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);
--
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