[PATCH v8] usb: dwc3: of-simple: Add support to get resets for the device

From: Philipp Zabel
Date: Thu Oct 19 2017 - 07:47:57 EST


From: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
[p.zabel@xxxxxxxxxxxxxx: switch to hidden reset control array]
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
v7: Rebased onto git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
---
drivers/usb/dwc3/dwc3-of-simple.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index e129c32780818..ceea1619f8aa3 100644
--- 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);

--
2.11.0