Re: [PATCH V3 3/4] usb: dwc3: of-simple: Add support to get resets for the device

2017-04-19 Thread Vivek Gautam 



On 04/19/2017 04:02 PM, Philipp Zabel wrote:

On Tue, 2017-04-18 at 16:51 +0530, Vivek Gautam wrote:

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 
Cc: Philipp Zabel 
Signed-off-by: Vivek Gautam 
---
  drivers/usb/dwc3/dwc3-of-simple.c | 36 
  1 file changed, 36 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c 
b/drivers/usb/dwc3/dwc3-of-simple.c
index fe414e7a9c78..9116df649f0b 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -29,13 +29,39 @@
  #include 
  #include 
  #include 
+#include 
  
  struct dwc3_of_simple {

struct device   *dev;
struct clk  **clks;
int num_clocks;
+   struct reset_control_array *resets;
  };
  
+static int dwc3_of_simple_reset_init(struct dwc3_of_simple *simple)

+{
+   struct device   *dev = simple->dev;
+   int ret;
+
+   simple->resets = of_reset_control_array_get_exclusive(dev->of_node);
+   if (IS_ERR(simple->resets)) {
+   ret = PTR_ERR(simple->resets);
+   if (ret == -ENOENT)
+   /* not all controllers required resets */
+   return 0;

If you use the of_reset_control_array_get_optional_exclusive variant,
you can remove the three lines directly above.


No, it's a little tricky here.
of_reset_control_get_count() returns an error code, that we then return from
of_reset_control_array_get().

This is something that tegra/pmc driver required (return errorno in case 
count

of reset controls is zero.

So we handle that error separately here.




+   dev_err(dev, "failed to get device resets\n");

It would be nice to print the error code here.


Sure.




+   return ret;
+   }
+
+   ret = reset_control_array_deassert(simple->resets);
+   if (ret) {
+   reset_control_array_put(simple->resets);
+   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 +126,10 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
if (ret)
return ret;
  
+	ret = dwc3_of_simple_reset_init(simple);

+   if (ret)
+   return ret;
+

I would just move the contents of dwc3_of_simple_reset_init here and add
a goto error path at the end of dwc3_of_simple_clk_init to handle the
reset control cleanup as needed.


Okay, i can restructure it.




ret = of_platform_populate(np, NULL, NULL, dev);
if (ret) {
for (i = 0; i < simple->num_clocks; i++) {
@@ -107,6 +137,9 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
clk_put(simple->clks[i]);
}
  
+		reset_control_array_assert(simple->resets);

+   reset_control_array_put(simple->resets);
+
return ret;
}
  
@@ -128,6 +161,9 @@ static int dwc3_of_simple_remove(struct platform_device *pdev)

clk_put(simple->clks[i]);
}
  
+	reset_control_array_assert(simple->resets);

+   reset_control_array_put(simple->resets);
+

Must the reset be asserted before of_platform_depopulate?


Right, the order must be taken care of here. Will change this.




of_platform_depopulate(dev);

Given the order above, I'd expect the reset cleanup here.


Sure.




pm_runtime_put_sync(dev);

regards
Philipp


Thanks for reviewing.

Best Regards
Vivek

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Re: [PATCH V3 3/4] usb: dwc3: of-simple: Add support to get resets for the device

2017-04-19 Thread Philipp Zabel 
On Tue, 2017-04-18 at 16:51 +0530, Vivek Gautam wrote:
> 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 
> Cc: Philipp Zabel 
> Signed-off-by: Vivek Gautam 
> ---
>  drivers/usb/dwc3/dwc3-of-simple.c | 36 
>  1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c 
> b/drivers/usb/dwc3/dwc3-of-simple.c
> index fe414e7a9c78..9116df649f0b 100644
> --- a/drivers/usb/dwc3/dwc3-of-simple.c
> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
> @@ -29,13 +29,39 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  struct dwc3_of_simple {
>   struct device   *dev;
>   struct clk  **clks;
>   int num_clocks;
> + struct reset_control_array *resets;
>  };
>  
> +static int dwc3_of_simple_reset_init(struct dwc3_of_simple *simple)
> +{
> + struct device   *dev = simple->dev;
> + int ret;
> +
> + simple->resets = of_reset_control_array_get_exclusive(dev->of_node);
> + if (IS_ERR(simple->resets)) {
> + ret = PTR_ERR(simple->resets);
> + if (ret == -ENOENT)
> + /* not all controllers required resets */
> + return 0;

If you use the of_reset_control_array_get_optional_exclusive variant,
you can remove the three lines directly above.

> + dev_err(dev, "failed to get device resets\n");

It would be nice to print the error code here.

> + return ret;
> + }
> +
> + ret = reset_control_array_deassert(simple->resets);
> + if (ret) {
> + reset_control_array_put(simple->resets);
> + 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 +126,10 @@ static int dwc3_of_simple_probe(struct platform_device 
> *pdev)
>   if (ret)
>   return ret;
>  
> + ret = dwc3_of_simple_reset_init(simple);
> + if (ret)
> + return ret;
> +

I would just move the contents of dwc3_of_simple_reset_init here and add
a goto error path at the end of dwc3_of_simple_clk_init to handle the
reset control cleanup as needed.

>   ret = of_platform_populate(np, NULL, NULL, dev);
>   if (ret) {
>   for (i = 0; i < simple->num_clocks; i++) {
> @@ -107,6 +137,9 @@ static int dwc3_of_simple_probe(struct platform_device 
> *pdev)
>   clk_put(simple->clks[i]);
>   }
>  
> + reset_control_array_assert(simple->resets);
> + reset_control_array_put(simple->resets);
> +
>   return ret;
>   }
>  
> @@ -128,6 +161,9 @@ static int dwc3_of_simple_remove(struct platform_device 
> *pdev)
>   clk_put(simple->clks[i]);
>   }
>  
> + reset_control_array_assert(simple->resets);
> + reset_control_array_put(simple->resets);
> +

Must the reset be asserted before of_platform_depopulate?

>   of_platform_depopulate(dev);

Given the order above, I'd expect the reset cleanup here.

>   pm_runtime_put_sync(dev);

regards
Philipp

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[PATCH V3 3/4] usb: dwc3: of-simple: Add support to get resets for the device

2017-04-18 Thread Vivek Gautam 
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 
Cc: Philipp Zabel 
Signed-off-by: Vivek Gautam 
---
 drivers/usb/dwc3/dwc3-of-simple.c | 36 
 1 file changed, 36 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c 
b/drivers/usb/dwc3/dwc3-of-simple.c
index fe414e7a9c78..9116df649f0b 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -29,13 +29,39 @@
 #include 
 #include 
 #include 
+#include 
 
 struct dwc3_of_simple {
struct device   *dev;
struct clk  **clks;
int num_clocks;
+   struct reset_control_array *resets;
 };
 
+static int dwc3_of_simple_reset_init(struct dwc3_of_simple *simple)
+{
+   struct device   *dev = simple->dev;
+   int ret;
+
+   simple->resets = of_reset_control_array_get_exclusive(dev->of_node);
+   if (IS_ERR(simple->resets)) {
+   ret = PTR_ERR(simple->resets);
+   if (ret == -ENOENT)
+   /* not all controllers required resets */
+   return 0;
+   dev_err(dev, "failed to get device resets\n");
+   return ret;
+   }
+
+   ret = reset_control_array_deassert(simple->resets);
+   if (ret) {
+   reset_control_array_put(simple->resets);
+   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 +126,10 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
if (ret)
return ret;
 
+   ret = dwc3_of_simple_reset_init(simple);
+   if (ret)
+   return ret;
+
ret = of_platform_populate(np, NULL, NULL, dev);
if (ret) {
for (i = 0; i < simple->num_clocks; i++) {
@@ -107,6 +137,9 @@ static int dwc3_of_simple_probe(struct platform_device 
*pdev)
clk_put(simple->clks[i]);
}
 
+   reset_control_array_assert(simple->resets);
+   reset_control_array_put(simple->resets);
+
return ret;
}
 
@@ -128,6 +161,9 @@ static int dwc3_of_simple_remove(struct platform_device 
*pdev)
clk_put(simple->clks[i]);
}
 
+   reset_control_array_assert(simple->resets);
+   reset_control_array_put(simple->resets);
+
of_platform_depopulate(dev);
 
pm_runtime_put_sync(dev);
-- 
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a Linux Foundation Collaborative Project

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