Subject: [PATCH 3/6] usb: dwc3: add imx8mp dwc3 glue layer driver

From: Li Jun <[email-masked]>
Date: Tue, 9 Jun 2020 19:12:42 +0800

imx8mp SoC integrate dwc3 3.30b IP and has some customizations to
support low power, which has a seprated wakeup irq and additional
logic to wakeup usb from low power mode both for host mode and
device mode.

Signed-off-by: Li Jun <[email-masked]>
---
 drivers/usb/dwc3/Kconfig       |  10 ++
 drivers/usb/dwc3/Makefile      |   1 +
 drivers/usb/dwc3/dwc3-imx8mp.c | 352 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 363 insertions(+)

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 206caa0..7ef2339 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -138,4 +138,14 @@ config USB_DWC3_QCOM
 	  for peripheral mode support.
 	  Say 'Y' or 'M' if you have one such device.
 
+config USB_DWC3_IMX8MP
+	tristate "NXP iMX8MP Platform"
+	depends on OF && COMMON_CLK
+	depends on (ARCH_MXC && ARM64) || COMPILE_TEST
+	default USB_DWC3
+	help
+	  NXP iMX8M Plus SoC use DesignWare Core IP for USB2/3
+	  functionality.
+	  Say 'Y' or 'M' if you have one such device.
+
 endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index ae86da0..2259f88 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o
 obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
 obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
 obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
+obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
diff --git a/drivers/usb/dwc3/dwc3-imx8mp.c b/drivers/usb/dwc3/dwc3-imx8mp.c
new file mode 100644
index 0000000..d4e9e99
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-imx8mp.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * dwc3-imx8mp.c - NXP imx8mp Specific Glue layer
+ *
+ * Copyright (c) 2020 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+
+#include "core.h"
+
+/* USB wakeup registers */
+#define USB_WAKEUP_CTRL			0x00
+
+/* Global wakeup interrupt enable, also used to clear interrupt */
+#define USB_WAKEUP_EN			BIT(31)
+/* Wakeup from connect or disconnect, only for superspeed */
+#define USB_WAKEUP_SS_CONN		BIT(5)
+/* 0 select vbus_valid, 1 select sessvld */
+#define USB_WAKEUP_VBUS_SRC_SESS_VAL	BIT(4)
+/* Enable signal for wake up from u3 state */
+#define USB_WAKEUP_U3_EN		BIT(3)
+/* Enable signal for wake up from id change */
+#define USB_WAKEUP_ID_EN		BIT(2)
+/* Enable signal for wake up from vbus change */
+#define	USB_WAKEUP_VBUS_EN		BIT(1)
+/* Enable signal for wake up from dp/dm change */
+#define USB_WAKEUP_DPDM_EN		BIT(0)
+
+#define USB_WAKEUP_EN_MASK		GENMASK(5, 0)
+
+struct dwc3_imx8mp {
+	struct device			*dev;
+	struct platform_device		*dwc3;
+	void __iomem			*glue_base;
+	struct clk_bulk_data		*clks;
+	int				num_clks;
+	int				irq;
+	bool				pm_suspended;
+	bool				wakeup_pending;
+};
+
+static const struct clk_bulk_data dwc3_imx8mp_clks[] = {
+	{ .id = "hsio" },
+	{ .id = "bus" },
+	{ .id = "suspend" },
+};
+
+static void dwc3_imx8mp_wakeup_enable(struct dwc3_imx8mp *dwc3_imx)
+{
+	struct dwc3	*dwc3 = platform_get_drvdata(dwc3_imx->dwc3);
+	u32		val;
+
+	if (!dwc3)
+		return;
+
+	val = readl(dwc3_imx->glue_base + USB_WAKEUP_CTRL);
+
+	if ((dwc3->current_dr_role == DWC3_GCTL_PRTCAP_HOST) && dwc3->xhci)
+		val |= USB_WAKEUP_EN | USB_WAKEUP_SS_CONN |
+		       USB_WAKEUP_U3_EN | USB_WAKEUP_DPDM_EN;
+	else if (dwc3->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
+		val |= USB_WAKEUP_EN | USB_WAKEUP_VBUS_EN |
+		       USB_WAKEUP_VBUS_SRC_SESS_VAL;
+
+	writel(val, dwc3_imx->glue_base + USB_WAKEUP_CTRL);
+}
+
+static void dwc3_imx8mp_wakeup_disable(struct dwc3_imx8mp *dwc3_imx)
+{
+	u32 val;
+
+	val = readl(dwc3_imx->glue_base + USB_WAKEUP_CTRL);
+	val &= ~(USB_WAKEUP_EN | USB_WAKEUP_EN_MASK);
+	writel(val, dwc3_imx->glue_base + USB_WAKEUP_CTRL);
+}
+
+static irqreturn_t dwc3_imx8mp_interrupt(int irq, void *_dwc3_imx)
+{
+	struct dwc3_imx8mp	*dwc3_imx = _dwc3_imx;
+	struct dwc3		*dwc = platform_get_drvdata(dwc3_imx->dwc3);
+
+	if (!dwc3_imx->pm_suspended)
+		return IRQ_HANDLED;
+
+	disable_irq_nosync(dwc3_imx->irq);
+	dwc3_imx->wakeup_pending = true;
+
+	if ((dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST) && dwc->xhci)
+		pm_runtime_resume(&dwc->xhci->dev);
+	else if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
+		pm_runtime_get(dwc->dev);
+
+	return IRQ_HANDLED;
+}
+
+static int dwc3_imx8mp_probe(struct platform_device *pdev)
+{
+	struct device		*dev = &pdev->dev;
+	struct device_node	*dwc3_np, *node = dev->of_node;
+	struct dwc3_imx8mp	*dwc3_imx;
+	int			err, irq;
+
+	if (!node) {
+		dev_err(dev, "device node not found\n");
+		return -EINVAL;
+	}
+
+	dwc3_imx = devm_kzalloc(dev, sizeof(*dwc3_imx), GFP_KERNEL);
+	if (!dwc3_imx)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, dwc3_imx);
+
+	dwc3_imx->dev = dev;
+
+	dwc3_imx->glue_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(dwc3_imx->glue_base))
+		return PTR_ERR(dwc3_imx->glue_base);
+
+	dwc3_imx->clks = devm_kmemdup(dev, dwc3_imx8mp_clks,
+			sizeof(dwc3_imx8mp_clks), GFP_KERNEL);
+	if (!dwc3_imx->clks)
+		return -ENOMEM;
+
+	dwc3_imx->num_clks = ARRAY_SIZE(dwc3_imx8mp_clks);
+	err = devm_clk_bulk_get(dev, dwc3_imx->num_clks, dwc3_imx->clks);
+	if (err) {
+		dev_err(dev, "Failed to request all necessary clocks\n");
+		return err;
+	}
+
+	err = clk_bulk_prepare_enable(dwc3_imx->num_clks, dwc3_imx->clks);
+	if (err)
+		return err;
+
+	/* Double enable suspend clk to keep it always on  */
+	err = clk_prepare_enable(dwc3_imx->clks[dwc3_imx->num_clks-1].clk);
+	if (err)
+		goto disable_bulk_clk;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		err = irq;
+		goto disable_clks;
+	}
+	dwc3_imx->irq = irq;
+
+	err = devm_request_threaded_irq(dev, irq, NULL, dwc3_imx8mp_interrupt,
+					IRQF_ONESHOT, dev_name(dev), dwc3_imx);
+	if (err) {
+		dev_err(dev, "failed to request IRQ #%d --> %d\n", irq, err);
+		goto disable_clks;
+	}
+
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	err = pm_runtime_get_sync(dev);
+	if (err < 0)
+		goto disable_rpm;
+
+	dwc3_np = of_get_child_by_name(node, "dwc3");
+	if (!dwc3_np) {
+		dev_err(dev, "failed to find dwc3 core child\n");
+		goto disable_rpm;
+	}
+
+	err = of_platform_populate(node, NULL, NULL, dev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to create dwc3 core\n");
+		goto disable_rpm;
+	}
+
+	dwc3_imx->dwc3 = of_find_device_by_node(dwc3_np);
+	if (!dwc3_imx->dwc3) {
+		dev_err(dev, "failed to get dwc3 platform device\n");
+		err = -ENODEV;
+		goto depopulate;
+	}
+
+	device_set_wakeup_capable(dev, true);
+	pm_runtime_put(dev);
+
+	return 0;
+
+depopulate:
+	of_platform_depopulate(dev);
+disable_rpm:
+	pm_runtime_disable(dev);
+	pm_runtime_put_noidle(dev);
+disable_clks:
+	clk_disable_unprepare(dwc3_imx->clks[dwc3_imx->num_clks-1].clk);
+disable_bulk_clk:
+	clk_bulk_disable_unprepare(dwc3_imx->num_clks, dwc3_imx->clks);
+
+	return err;
+}
+
+static int dwc3_imx8mp_remove(struct platform_device *pdev)
+{
+	struct dwc3_imx8mp *dwc3_imx = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_get_sync(dev);
+	of_platform_depopulate(dev);
+
+	clk_bulk_disable_unprepare(dwc3_imx->num_clks, dwc3_imx->clks);
+	clk_disable_unprepare(dwc3_imx->clks[dwc3_imx->num_clks-1].clk);
+
+	pm_runtime_disable(dev);
+	pm_runtime_put_noidle(dev);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static int dwc3_imx8mp_suspend(struct dwc3_imx8mp *dwc3_imx, pm_message_t msg)
+{
+	if (dwc3_imx->pm_suspended)
+		return 0;
+
+	/* Wakeup enable */
+	if (PMSG_IS_AUTO(msg) || device_may_wakeup(dwc3_imx->dev))
+		dwc3_imx8mp_wakeup_enable(dwc3_imx);
+
+	clk_bulk_disable_unprepare(dwc3_imx->num_clks, dwc3_imx->clks);
+	dwc3_imx->pm_suspended = true;
+
+	return 0;
+}
+
+static int dwc3_imx8mp_resume(struct dwc3_imx8mp *dwc3_imx, pm_message_t msg)
+{
+	struct dwc3	*dwc = platform_get_drvdata(dwc3_imx->dwc3);
+	int ret = 0;
+
+	if (!dwc3_imx->pm_suspended)
+		return 0;
+
+	ret = clk_bulk_prepare_enable(dwc3_imx->num_clks, dwc3_imx->clks);
+	if (ret)
+		return ret;
+
+	/* Wakeup disable */
+	dwc3_imx8mp_wakeup_disable(dwc3_imx);
+	dwc3_imx->pm_suspended = false;
+
+	if (dwc3_imx->wakeup_pending) {
+		dwc3_imx->wakeup_pending = false;
+		if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE) {
+			pm_runtime_mark_last_busy(dwc->dev);
+			pm_runtime_put_autosuspend(dwc->dev);
+		} else {
+			/*
+			 * Add wait for xhci switch from suspend
+			 * clock to normal clock to detect connection.
+			 */
+			usleep_range(9000, 10000);
+		}
+		enable_irq(dwc3_imx->irq);
+	}
+
+	return ret;
+}
+
+static int __maybe_unused dwc3_imx8mp_pm_suspend(struct device *dev)
+{
+	struct dwc3_imx8mp *dwc3_imx = dev_get_drvdata(dev);
+	int ret;
+
+	ret = dwc3_imx8mp_suspend(dwc3_imx, PMSG_SUSPEND);
+
+	if (device_may_wakeup(dwc3_imx->dev))
+		enable_irq_wake(dwc3_imx->irq);
+
+	dev_dbg(dev, "dwc3 imx8mp pm suspend.\n");
+
+	return ret;
+}
+
+static int __maybe_unused dwc3_imx8mp_pm_resume(struct device *dev)
+{
+	struct dwc3_imx8mp *dwc3_imx = dev_get_drvdata(dev);
+	int ret;
+
+	if (device_may_wakeup(dwc3_imx->dev))
+		disable_irq_wake(dwc3_imx->irq);
+
+	ret = dwc3_imx8mp_resume(dwc3_imx, PMSG_RESUME);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	dev_dbg(dev, "dwc3 imx8mp pm resume.\n");
+
+	return ret;
+}
+
+static int __maybe_unused dwc3_imx8mp_runtime_suspend(struct device *dev)
+{
+	struct dwc3_imx8mp *dwc3_imx = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "dwc3 imx8mp runtime suspend.\n");
+
+	return dwc3_imx8mp_suspend(dwc3_imx, PMSG_AUTO_SUSPEND);
+}
+
+static int __maybe_unused dwc3_imx8mp_runtime_resume(struct device *dev)
+{
+	struct dwc3_imx8mp *dwc3_imx = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "dwc3 imx8mp runtime resume.\n");
+
+	return dwc3_imx8mp_resume(dwc3_imx, PMSG_AUTO_RESUME);
+}
+
+static const struct dev_pm_ops dwc3_imx8mp_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(dwc3_imx8mp_pm_suspend, dwc3_imx8mp_pm_resume)
+	SET_RUNTIME_PM_OPS(dwc3_imx8mp_runtime_suspend,
+			   dwc3_imx8mp_runtime_resume, NULL)
+};
+
+static const struct of_device_id dwc3_imx8mp_of_match[] = {
+	{ .compatible = "fsl,imx8mp-dwc3", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dwc3_imx8mp_of_match);
+
+static struct platform_driver dwc3_imx8mp_driver = {
+	.probe		= dwc3_imx8mp_probe,
+	.remove		= dwc3_imx8mp_remove,
+	.driver		= {
+		.name	= "imx8mp-dwc3",
+		.pm	= &dwc3_imx8mp_dev_pm_ops,
+		.of_match_table	= dwc3_imx8mp_of_match,
+	},
+};
+
+module_platform_driver(dwc3_imx8mp_driver);
+
+MODULE_ALIAS("platform:imx8mp-dwc3");
+MODULE_AUTHOR("[email-masked]");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DesignWare USB3 imx8mp Glue Layer");
-- 
2.7.4

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