usb: dwc3: Rework clock initialization to be more flexible

The dwc3 core binding specifies three clocks:
  ref, bus_early, and suspend

which are all controlled in the driver together.

However some variants of the hardware my not have all three
clks, or some may have more. Usually this was handled by using
the dwc3-of-simple glue driver, but that resulted in a
proliferation of bindings for for every variant, when the only
difference was the clocks and resets lists.

So this patch reworks the reading of the clks from the dts to
use devm_clk_bulk_get_all() will will fetch all the clocks
specified in the dts together.

This patch was recommended by Rob Herring <[email protected]>
as an alternative to creating multiple bindings for each variant
of hardware.

Cc: Greg Kroah-Hartman <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Mark Rutland <[email protected]>
CC: ShuFan Lee <[email protected]>
Cc: Heikki Krogerus <[email protected]>
Cc: Suzuki K Poulose <[email protected]>
Cc: Chunfeng Yun <[email protected]>
Cc: Yu Chen <[email protected]>
Cc: Felipe Balbi <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Jun Li <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Guillaume Gardet <[email protected]>
Cc: Jack Pham <[email protected]>
Cc: [email protected]
Cc: [email protected]
Suggested-by: Rob Herring <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>

1 files changed, 5 insertions, 15 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 43bd5b1ea9e2..874bc49d417f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -289,12 +289,6 @@ done:
 	return 0;
 }
 
-static const struct clk_bulk_data dwc3_core_clks[] = {
-	{ .id = "ref" },
-	{ .id = "bus_early" },
-	{ .id = "suspend" },
-};
-
 /*
  * dwc3_frame_length_adjustment - Adjusts frame length if required
  * @dwc3: Pointer to our controller context structure
@@ -1446,11 +1440,6 @@ static int dwc3_probe(struct platform_device *pdev)
 	if (!dwc)
 		return -ENOMEM;
 
-	dwc->clks = devm_kmemdup(dev, dwc3_core_clks, sizeof(dwc3_core_clks),
-				 GFP_KERNEL);
-	if (!dwc->clks)
-		return -ENOMEM;
-
 	dwc->dev = dev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1486,17 +1475,18 @@ static int dwc3_probe(struct platform_device *pdev)
 		return PTR_ERR(dwc->reset);
 
 	if (dev->of_node) {
-		dwc->num_clks = ARRAY_SIZE(dwc3_core_clks);
-
-		ret = devm_clk_bulk_get(dev, dwc->num_clks, dwc->clks);
+		ret = devm_clk_bulk_get_all(dev, &dwc->clks);
 		if (ret == -EPROBE_DEFER)
 			return ret;
 		/*
 		 * Clocks are optional, but new DT platforms should support all
 		 * clocks as required by the DT-binding.
 		 */
-		if (ret)
+		if (ret < 0)
 			dwc->num_clks = 0;
+		else
+			dwc->num_clks = ret;
+
 	}
 
 	ret = reset_control_deassert(dwc->reset);