[RFC][PATCH v3 05/11] usb: dwc3: Rework clock initialization to be more flexible

[John Stultz]

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

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 reccomended by Rob Herring <Rob.Herring@xxxxxxx>
as an alternative to creating multiple bindings for each variant
of hardware when the only unique bits were clocks and resets.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
CC: ShuFan Lee <shufan_lee@xxxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Cc: Yu Chen <chenyu56@xxxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Jun Li <lijun.kernel@xxxxxxxxx>
Cc: Valentin Schneider <valentin.schneider@xxxxxxx>
Cc: Jack Pham <jackp@xxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Suggested-by: Rob Herring <Rob.Herring@xxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
v3: Rework dwc3 core rather then adding another dwc-of-simple
    binding.
---
 drivers/usb/dwc3/core.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a039e35ec7ad..4d4f1836b62c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -305,12 +305,6 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
 	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
@@ -1418,11 +1412,6 @@ 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);
@@ -1458,17 +1447,18 @@ 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);
-- 
2.17.1