[PATCH v6 4/6] usb: dwc3: core: Don't touch resets and clocks

Bjorn Andersson posted 6 patches 10 months ago
There is a newer version of this series
[PATCH v6 4/6] usb: dwc3: core: Don't touch resets and clocks
Posted by Bjorn Andersson 10 months ago
When the core is integrated with glue, it's reasonable to assume that
the glue driver will have to touch the IP before/after the core takes
the hardware out and into reset. As such the glue must own these
resources and be allowed to turn them on/off outside the core's
handling.

Allow the platform or glue layer to indicate if the core logic for
clocks and resets should be skipped to deal with this.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
---
 drivers/usb/dwc3/core.c | 20 +++++++++++---------
 drivers/usb/dwc3/glue.h |  3 +++
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index b428b6fc3d0a55811e2f75d33d79df4b0c67dcac..77a9848a0ac70fbe563988cecbe489130989aadc 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2198,15 +2198,17 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
 	if (IS_ERR(dwc->usb_psy))
 		return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n");
 
-	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
-	if (IS_ERR(dwc->reset)) {
-		ret = PTR_ERR(dwc->reset);
-		goto err_put_psy;
-	}
+	if (!data->ignore_clocks_and_resets) {
+		dwc->reset = devm_reset_control_array_get_optional_shared(dev);
+		if (IS_ERR(dwc->reset)) {
+			ret = PTR_ERR(dwc->reset);
+			goto err_put_psy;
+		}
 
-	ret = dwc3_get_clocks(dwc);
-	if (ret)
-		goto err_put_psy;
+		ret = dwc3_get_clocks(dwc);
+		if (ret)
+			goto err_put_psy;
+	}
 
 	ret = reset_control_deassert(dwc->reset);
 	if (ret)
@@ -2321,7 +2323,7 @@ EXPORT_SYMBOL_GPL(dwc3_core_probe);
 
 static int dwc3_probe(struct platform_device *pdev)
 {
-	struct dwc3_probe_data probe_data;
+	struct dwc3_probe_data probe_data = {};
 	struct resource *res;
 	struct dwc3 *dwc;
 
diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
index e73cfc466012f07214291abe56454934ab014013..703d40c189565b1e28ae28afb8728b78f4cd2fca 100644
--- a/drivers/usb/dwc3/glue.h
+++ b/drivers/usb/dwc3/glue.h
@@ -13,10 +13,13 @@
  * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
  * @dwc: Reference to dwc3 context structure
  * @res: resource for the DWC3 core mmio region
+ * @ignore_clocks_and_resets: clocks and resets defined for the device should
+ *		be ignored by the DWC3 core, as they are managed by the glue
  */
 struct dwc3_probe_data {
 	struct dwc3 *dwc;
 	struct resource *res;
+	bool ignore_clocks_and_resets;
 };
 
 int dwc3_core_probe(const struct dwc3_probe_data *data);

-- 
2.49.0