diff mbox series

[v6,3/6] usb: dwc3: core: Expose core driver as library

Message ID 20250410-dwc3-refactor-v6-3-dc0d1b336135@oss.qualcomm.com
State New
Headers show
Series [v6,1/6] usb: dwc3: qcom: Snapshot driver for backwards compatibilty | expand

Commit Message

Bjorn Andersson April 11, 2025, 3:50 a.m. UTC 
The DWC3 IP block is handled by three distinct device drivers: XHCI,
DWC3 core and a platform specific (optional) DWC3 glue driver.

This has resulted in, at least in the case of the Qualcomm glue, the
presence of a number of layering violations, where the glue code either
can't handle, or has to work around, the fact that core might not probe
deterministically.

An example of this is that the suspend path should operate slightly
different depending on the device operating in host or peripheral mode,
and the only way to determine the operating state is to peek into the
core's drvdata.

The Qualcomm glue driver is expected to make updates in the qscratch
register region (the "glue" region) during role switch events, but with
the glue and core split using the driver model, there is no reasonable
way to introduce listeners for mode changes.

Split the dwc3 core platform_driver callbacks and their implementation
and export the implementation, to make it possible to deterministically
instantiate the dwc3 core as part of the dwc3 glue drivers and to
allow flattening of the DeviceTree representation.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
---
 drivers/usb/dwc3/core.c | 142 +++++++++++++++++++++++++++++++++---------------
 drivers/usb/dwc3/glue.h |  32 +++++++++++
 2 files changed, 129 insertions(+), 45 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 66a08b5271653abd458f9ec85ca730afd7779d71..b428b6fc3d0a55811e2f75d33d79df4b0c67dcac 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -36,6 +36,7 @@ 
 
 #include "core.h"
 #include "gadget.h"
+#include "glue.h"
 #include "io.h"
 
 #include "debug.h"
@@ -2148,27 +2149,16 @@  static struct power_supply *dwc3_get_usb_power_supply(struct dwc3 *dwc)
 	return usb_psy;
 }
 
-static int dwc3_probe(struct platform_device *pdev)
+int dwc3_core_probe(const struct dwc3_probe_data *data)
 {
-	struct device		*dev = &pdev->dev;
-	struct resource		*res, dwc_res;
+	struct dwc3		*dwc = data->dwc;
+	struct device		*dev = dwc->dev;
+	struct resource		dwc_res;
 	unsigned int		hw_mode;
 	void __iomem		*regs;
-	struct dwc3		*dwc;
+	struct resource		*res = data->res;
 	int			ret;
 
-	dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
-	if (!dwc)
-		return -ENOMEM;
-
-	dwc->dev = dev;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(dev, "missing memory resource\n");
-		return -ENODEV;
-	}
-
 	dwc->xhci_resources[0].start = res->start;
 	dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
 					DWC3_XHCI_REGS_END;
@@ -2232,7 +2222,7 @@  static int dwc3_probe(struct platform_device *pdev)
 		goto err_disable_clks;
 	}
 
-	platform_set_drvdata(pdev, dwc);
+	dev_set_drvdata(dev, dwc);
 	dwc3_cache_hwparams(dwc);
 
 	if (!dwc->sysdev_is_parent &&
@@ -2327,12 +2317,35 @@  static int dwc3_probe(struct platform_device *pdev)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(dwc3_core_probe);
 
-static void dwc3_remove(struct platform_device *pdev)
+static int dwc3_probe(struct platform_device *pdev)
 {
-	struct dwc3	*dwc = platform_get_drvdata(pdev);
+	struct dwc3_probe_data probe_data;
+	struct resource *res;
+	struct dwc3 *dwc;
 
-	pm_runtime_get_sync(&pdev->dev);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource\n");
+		return -ENODEV;
+	}
+
+	dwc = devm_kzalloc(&pdev->dev, sizeof(*dwc), GFP_KERNEL);
+	if (!dwc)
+		return -ENOMEM;
+
+	dwc->dev = &pdev->dev;
+
+	probe_data.dwc = dwc;
+	probe_data.res = res;
+
+	return dwc3_core_probe(&probe_data);
+}
+
+void dwc3_core_remove(struct dwc3 *dwc)
+{
+	pm_runtime_get_sync(dwc->dev);
 
 	dwc3_core_exit_mode(dwc);
 	dwc3_debugfs_exit(dwc);
@@ -2340,22 +2353,28 @@  static void dwc3_remove(struct platform_device *pdev)
 	dwc3_core_exit(dwc);
 	dwc3_ulpi_exit(dwc);
 
-	pm_runtime_allow(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
-	pm_runtime_dont_use_autosuspend(&pdev->dev);
-	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_allow(dwc->dev);
+	pm_runtime_disable(dwc->dev);
+	pm_runtime_dont_use_autosuspend(dwc->dev);
+	pm_runtime_put_noidle(dwc->dev);
 	/*
 	 * HACK: Clear the driver data, which is currently accessed by parent
 	 * glue drivers, before allowing the parent to suspend.
 	 */
-	platform_set_drvdata(pdev, NULL);
-	pm_runtime_set_suspended(&pdev->dev);
+	dev_set_drvdata(dwc->dev, NULL);
+	pm_runtime_set_suspended(dwc->dev);
 
 	dwc3_free_event_buffers(dwc);
 
 	if (dwc->usb_psy)
 		power_supply_put(dwc->usb_psy);
 }
+EXPORT_SYMBOL_GPL(dwc3_core_remove);
+
+static void dwc3_remove(struct platform_device *pdev)
+{
+	dwc3_core_remove(platform_get_drvdata(pdev));
+}
 
 #ifdef CONFIG_PM
 static int dwc3_core_init_for_resume(struct dwc3 *dwc)
@@ -2544,9 +2563,8 @@  static int dwc3_runtime_checks(struct dwc3 *dwc)
 	return 0;
 }
 
-static int dwc3_runtime_suspend(struct device *dev)
+int dwc3_runtime_suspend(struct dwc3 *dwc)
 {
-	struct dwc3     *dwc = dev_get_drvdata(dev);
 	int		ret;
 
 	if (dwc3_runtime_checks(dwc))
@@ -2558,10 +2576,11 @@  static int dwc3_runtime_suspend(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dwc3_runtime_suspend);
 
-static int dwc3_runtime_resume(struct device *dev)
+int dwc3_runtime_resume(struct dwc3 *dwc)
 {
-	struct dwc3     *dwc = dev_get_drvdata(dev);
+	struct device *dev = dwc->dev;
 	int		ret;
 
 	ret = dwc3_resume_common(dwc, PMSG_AUTO_RESUME);
@@ -2571,7 +2590,7 @@  static int dwc3_runtime_resume(struct device *dev)
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (dwc->pending_events) {
-			pm_runtime_put(dwc->dev);
+			pm_runtime_put(dev);
 			dwc->pending_events = false;
 			enable_irq(dwc->irq_gadget);
 		}
@@ -2586,10 +2605,11 @@  static int dwc3_runtime_resume(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dwc3_runtime_resume);
 
-static int dwc3_runtime_idle(struct device *dev)
+int dwc3_runtime_idle(struct dwc3 *dwc)
 {
-	struct dwc3     *dwc = dev_get_drvdata(dev);
+	struct device *dev = dwc->dev;
 
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:
@@ -2607,12 +2627,28 @@  static int dwc3_runtime_idle(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dwc3_runtime_idle);
+
+static int dwc3_plat_runtime_suspend(struct device *dev)
+{
+	return dwc3_runtime_suspend(dev_get_drvdata(dev));
+}
+
+static int dwc3_plat_runtime_resume(struct device *dev)
+{
+	return dwc3_runtime_resume(dev_get_drvdata(dev));
+}
+
+static int dwc3_plat_runtime_idle(struct device *dev)
+{
+	return dwc3_runtime_idle(dev_get_drvdata(dev));
+}
 #endif /* CONFIG_PM */
 
 #ifdef CONFIG_PM_SLEEP
-static int dwc3_suspend(struct device *dev)
+int dwc3_pm_suspend(struct dwc3 *dwc)
 {
-	struct dwc3	*dwc = dev_get_drvdata(dev);
+	struct device *dev = dwc->dev;
 	int		ret;
 
 	ret = dwc3_suspend_common(dwc, PMSG_SUSPEND);
@@ -2623,10 +2659,11 @@  static int dwc3_suspend(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dwc3_pm_suspend);
 
-static int dwc3_resume(struct device *dev)
+int dwc3_pm_resume(struct dwc3 *dwc)
 {
-	struct dwc3	*dwc = dev_get_drvdata(dev);
+	struct device *dev = dwc->dev;
 	int		ret = 0;
 
 	pinctrl_pm_select_default_state(dev);
@@ -2645,10 +2682,10 @@  static int dwc3_resume(struct device *dev)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(dwc3_pm_resume);
 
-static void dwc3_complete(struct device *dev)
+void dwc3_pm_complete(struct dwc3 *dwc)
 {
-	struct dwc3	*dwc = dev_get_drvdata(dev);
 	u32		reg;
 
 	if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST &&
@@ -2658,21 +2695,36 @@  static void dwc3_complete(struct device *dev)
 		dwc3_writel(dwc->regs, DWC3_GUCTL3, reg);
 	}
 }
+EXPORT_SYMBOL_GPL(dwc3_pm_complete);
+
+static int dwc3_plat_suspend(struct device *dev)
+{
+	return dwc3_pm_suspend(dev_get_drvdata(dev));
+}
+
+static int dwc3_plat_resume(struct device *dev)
+{
+	return dwc3_pm_resume(dev_get_drvdata(dev));
+}
+
+static void dwc3_plat_complete(struct device *dev)
+{
+	dwc3_pm_complete(dev_get_drvdata(dev));
+}
 #else
-#define dwc3_complete NULL
+#define dwc3_plat_complete NULL
 #endif /* CONFIG_PM_SLEEP */
 
 static const struct dev_pm_ops dwc3_dev_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
-	.complete = dwc3_complete,
-
+	SET_SYSTEM_SLEEP_PM_OPS(dwc3_plat_suspend, dwc3_plat_resume)
+	.complete = dwc3_plat_complete,
 	/*
 	 * Runtime suspend halts the controller on disconnection. It relies on
 	 * platforms with custom connection notification to start the controller
 	 * again.
 	 */
-	SET_RUNTIME_PM_OPS(dwc3_runtime_suspend, dwc3_runtime_resume,
-			dwc3_runtime_idle)
+	SET_RUNTIME_PM_OPS(dwc3_plat_runtime_suspend, dwc3_plat_runtime_resume,
+			   dwc3_plat_runtime_idle)
 };
 
 #ifdef CONFIG_OF
diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
new file mode 100644
index 0000000000000000000000000000000000000000..e73cfc466012f07214291abe56454934ab014013
--- /dev/null
+++ b/drivers/usb/dwc3/glue.h
@@ -0,0 +1,32 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * glue.h - DesignWare USB3 DRD glue header
+ */
+
+#ifndef __DRIVERS_USB_DWC3_GLUE_H
+#define __DRIVERS_USB_DWC3_GLUE_H
+
+#include <linux/types.h>
+#include "core.h"
+
+/**
+ * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
+ * @dwc: Reference to dwc3 context structure
+ * @res: resource for the DWC3 core mmio region
+ */
+struct dwc3_probe_data {
+	struct dwc3 *dwc;
+	struct resource *res;
+};
+
+int dwc3_core_probe(const struct dwc3_probe_data *data);
+void dwc3_core_remove(struct dwc3 *dwc);
+
+int dwc3_runtime_suspend(struct dwc3 *dwc);
+int dwc3_runtime_resume(struct dwc3 *dwc);
+int dwc3_runtime_idle(struct dwc3 *dwc);
+int dwc3_pm_suspend(struct dwc3 *dwc);
+int dwc3_pm_resume(struct dwc3 *dwc);
+void dwc3_pm_complete(struct dwc3 *dwc);
+
+#endif