Hi,
On 03/15/2017 04:15 PM, Philipp Zabel wrote:
On Wed, 2017-02-22 at 10:54 +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 <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);
Please use devm_reset_control_get_exclusive_by_index instead. See
include/linux/reset.h for details.
Sure, will make use of *exclusive version of the api.
+ 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;
+}
This looks rather generic. Should we have a
reset_control_get/assert/deassert_array functionality at the reset API
level?
Yes, i think we should. Something on the lines of 'regulator_bulk_*'
interface?
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;
+
Not a blocker, but it seems a bit inconsistent to count the reset
controls via the device node (of_...), but then get them via the device
(devm_reset_control_get_... instead of of_reset_control_get_...).
You are right, it looks inconsistent. I thought of using a resource
managed API. But now i think it doesn't make much sense.
Best Regards
Vivek
regards
Philipp
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