[RFC PATCH v3 4/5] usb: xhci-mtk: add support runtime pm

[Chunfeng Yun <chunfeng.yun@mediatek.com>]

From: CK Hu <ck.hu@mediatek.com>

add support runtime pm feature

Signed-off-by: Zhanyong Wang <zhanyong.wang@mediatek.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v3:
  1. fix some issues
  2. remove attribute files

v2: fix error caused by request irq suggested by CK
---
 drivers/usb/host/xhci-mtk.c | 285 +++++++++++++++++++++++++++++++++++-
 drivers/usb/host/xhci-mtk.h |  14 ++
 2 files changed, 294 insertions(+), 5 deletions(-)
 mode change 100755 => 100644 drivers/usb/host/xhci-mtk.c

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
old mode 100755
new mode 100644
index 34bd3de090b1..c07d54acbcb7
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -14,6 +14,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
@@ -77,6 +78,72 @@ enum ssusb_uwk_vers {
 	SSUSB_UWK_V3,
 };
 
+int xhci_mtk_runtime_ready;
+
+static int xhci_mtk_runtime_resume(struct device *dev);
+
+static void xhci_mtk_seal_work(struct work_struct *work)
+{
+	struct xhci_hcd_mtk *mtk =
+			container_of(work, struct xhci_hcd_mtk, seal.work);
+	struct usb_hcd *hcd = mtk->hcd;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+	xhci_dbg(xhci, "spm unseals xHCI controller %i\n", mtk->seal_status);
+	if (mtk->seal_status == SEAL_SUSPENDED) {
+		mtk->seal_status = SEAL_RESUMING;
+		pm_runtime_mark_last_busy(mtk->dev);
+		pm_runtime_put_sync_autosuspend(mtk->dev);
+	} else {
+		/*
+		 * FIXME: Sometimes seal_status will keep it on SEAL_RESUMING staus not to expect
+		 * since pm_runtime_put_sync_autosuspend doesn't invoke runtime_resume of callback.
+		 * and to survey why not to invoke runtime_resume callback named
+		 * xhci_mtk_runtime_resume in time in short feature, Herely provide one solution
+		 * that make sure seal_status to match h/w state machine,and MTK xHCI clocks
+		 * on as soon as unseal event received.
+		 */
+		if (mtk->seal_status == SEAL_RESUMING)
+			xhci_mtk_runtime_resume(mtk->dev);
+		else
+			xhci_warn(xhci,
+				"Ignore seal wakeup source disordered in xHCI controller\n");
+	}
+}
+
+static irqreturn_t xhci_mtk_seal_irq(int irq, void *data)
+{
+	struct xhci_hcd_mtk *mtk = data;
+	struct usb_hcd *hcd = mtk->hcd;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+	xhci_dbg(xhci, "seal irq ISR invoked\n");
+
+	schedule_delayed_work(&mtk->seal, 0);
+
+	return IRQ_HANDLED;
+}
+
+static void xhci_mtk_seal_wakeup_enable(struct xhci_hcd_mtk *mtk, bool enable)
+{
+	struct irq_desc *desc;
+	struct device *dev = mtk->dev;
+
+	if (mtk && mtk->seal_irq) {
+		desc = irq_to_desc(mtk->seal_irq);
+		if (enable) {
+			desc->irq_data.chip->irq_ack(&desc->irq_data);
+			enable_irq(mtk->seal_irq);
+			dev_dbg(dev, "%s: enable_irq %i\n",
+				 __func__, mtk->seal_irq);
+		} else {
+			disable_irq(mtk->seal_irq);
+			dev_dbg(dev, "%s: disable_irq %i\n",
+				 __func__, mtk->seal_irq);
+		}
+	}
+}
+
 static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
 {
 	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
@@ -347,7 +414,6 @@ static int usb_wakeup_of_property_parse(struct xhci_hcd_mtk *mtk,
 			mtk->uwk_reg_base, mtk->uwk_vers);
 
 	return PTR_ERR_OR_ZERO(mtk->uwk);
-
 }
 
 static void usb_wakeup_set(struct xhci_hcd_mtk *mtk, bool enable)
@@ -482,9 +548,11 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	pm_runtime_set_active(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev,
+				CONFIG_USB_AUTOSUSPEND_DELAY * 1000);
 	pm_runtime_enable(dev);
-	pm_runtime_get_sync(dev);
-	device_enable_async_suspend(dev);
 
 	ret = xhci_mtk_ldos_enable(mtk);
 	if (ret)
@@ -499,6 +567,14 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 		ret = irq;
 		goto disable_clk;
 	}
+	dev_dbg(dev, "irq %i\n", irq);
+
+	mtk->seal_irq = platform_get_irq_optional(pdev, 1);
+	if (mtk->seal_irq < 0) {
+		ret = mtk->seal_irq;
+		goto disable_clk;
+	}
+	dev_dbg(dev, "seal_irq %i\n", mtk->seal_irq);
 
 	hcd = usb_create_hcd(driver, dev, dev_name(dev));
 	if (!hcd) {
@@ -565,6 +641,27 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 	if (ret)
 		goto dealloc_usb2_hcd;
 
+	INIT_DELAYED_WORK(&mtk->seal, xhci_mtk_seal_work);
+	snprintf(mtk->seal_descr, sizeof(mtk->seal_descr), "seal%s:usb%d",
+		 hcd->driver->description, hcd->self.busnum);
+	ret = devm_request_irq(dev, mtk->seal_irq, &xhci_mtk_seal_irq,
+			  IRQF_TRIGGER_FALLING,	mtk->seal_descr, mtk);
+	if (ret != 0) {
+		dev_err(dev, "seal request interrupt %d failed\n",
+			mtk->seal_irq);
+		goto dealloc_usb2_hcd;
+	}
+	xhci_mtk_seal_wakeup_enable(mtk, false);
+
+	device_enable_async_suspend(dev);
+	xhci_mtk_runtime_ready = 1;
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	dev_dbg(dev, "%s: xhci_mtk_runtime_ready %i",
+		 __func__, xhci_mtk_runtime_ready);
+
 	return 0;
 
 dealloc_usb2_hcd:
@@ -587,7 +684,7 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 	xhci_mtk_ldos_disable(mtk);
 
 disable_pm:
-	pm_runtime_put_sync(dev);
+	pm_runtime_put_sync_autosuspend(dev);
 	pm_runtime_disable(dev);
 	return ret;
 }
@@ -602,6 +699,7 @@ static int xhci_mtk_remove(struct platform_device *dev)
 	pm_runtime_put_noidle(&dev->dev);
 	pm_runtime_disable(&dev->dev);
 
+	xhci_mtk_runtime_ready = 0;
 	usb_remove_hcd(shared_hcd);
 	xhci->shared_hcd = NULL;
 	device_init_wakeup(&dev->dev, false);
@@ -638,6 +736,7 @@ static int __maybe_unused xhci_mtk_suspend(struct device *dev)
 	xhci_mtk_host_disable(mtk);
 	xhci_mtk_clks_disable(mtk);
 	usb_wakeup_set(mtk, true);
+
 	return 0;
 }
 
@@ -659,10 +758,185 @@ static int __maybe_unused xhci_mtk_resume(struct device *dev)
 	return 0;
 }
 
+static int __maybe_unused xhci_mtk_bus_status(struct device *dev)
+{
+	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
+	struct usb_hcd *hcd;
+	struct xhci_hcd *xhci;
+	struct xhci_hub *usb2_rhub;
+	struct xhci_hub *usb3_rhub;
+	struct xhci_bus_state *bus_state;
+	struct xhci_port *port;
+	u32	usb2_suspended_ports = -1;
+	u32	usb3_suspended_ports = -1;
+	u16 status;
+	int num_ports;
+	int ret = 0;
+	int i;
+
+	if (!mtk->hcd)
+		return -ESHUTDOWN;
+
+	hcd = mtk->hcd;
+	xhci = hcd_to_xhci(hcd);
+	if ((xhci->xhc_state & XHCI_STATE_REMOVING) ||
+			(xhci->xhc_state & XHCI_STATE_HALTED)) {
+		return -ESHUTDOWN;
+	}
+
+	usb2_rhub = &xhci->usb2_rhub;
+	if (usb2_rhub) {
+		bus_state  = &usb2_rhub->bus_state;
+		num_ports  = usb2_rhub->num_ports;
+		usb2_suspended_ports  = bus_state->suspended_ports;
+		usb2_suspended_ports ^= (BIT(num_ports) - 1);
+		usb2_suspended_ports &= (BIT(num_ports) - 1);
+		for (i = 0; i < num_ports; i++) {
+			if (usb2_suspended_ports & (1UL << i)) {
+				port = usb2_rhub->ports[i];
+				status = readl(port->addr);
+
+				xhci_dbg(xhci,
+					  "USB20: portsc[%i]: 0x%04X\n",
+					  i, status);
+
+				if (!(status & PORT_CONNECT))
+					usb2_suspended_ports &= ~(1UL << i);
+			}
+		}
+
+		if (usb2_suspended_ports) {
+			ret = -EBUSY;
+			goto ebusy;
+		}
+	}
+
+	usb3_rhub = &xhci->usb3_rhub;
+	if (usb3_rhub) {
+		bus_state  = &usb3_rhub->bus_state;
+		num_ports  = usb3_rhub->num_ports;
+		usb3_suspended_ports  = bus_state->suspended_ports;
+		usb3_suspended_ports ^= (BIT(num_ports) - 1);
+		usb3_suspended_ports &= (BIT(num_ports) - 1);
+		for (i = 0; i < num_ports; i++) {
+			if (usb3_suspended_ports & BIT(i)) {
+				port = usb3_rhub->ports[i];
+				status = readl(port->addr);
+
+				xhci_dbg(xhci, "USB3: portsc[%i]: 0x%04X\n",
+					  i, status);
+
+				if (!(status & PORT_CONNECT))
+					usb3_suspended_ports &= ~BIT(i);
+			}
+		}
+
+		if (usb3_suspended_ports) {
+			ret = -EBUSY;
+			goto ebusy;
+		}
+	}
+
+ebusy:
+	xhci_dbg(xhci, "%s: USB2: 0x%08X, USB3: 0x%08X ret: %i\n",
+		  __func__, usb2_suspended_ports,
+		  usb3_suspended_ports, ret);
+
+	return ret;
+}
+
+static int __maybe_unused xhci_mtk_runtime_suspend(struct device *dev)
+{
+	bool wakeup = device_may_wakeup(dev);
+	struct xhci_hcd_mtk  *mtk = dev_get_drvdata(dev);
+	struct usb_hcd *hcd;
+	struct xhci_hcd *xhci;
+	int ret = 0;
+
+	if (!mtk->hcd)
+		return -ESHUTDOWN;
+
+	hcd = mtk->hcd;
+	xhci = hcd_to_xhci(hcd);
+	if ((xhci->xhc_state & XHCI_STATE_REMOVING) ||
+			(xhci->xhc_state & XHCI_STATE_HALTED)) {
+		return -ESHUTDOWN;
+	}
+
+	mtk->seal_status = SEAL_BUSY;
+	ret = xhci_mtk_bus_status(dev);
+	if (wakeup && !ret) {
+		mtk->seal_status = SEAL_SUSPENDING;
+		xhci_mtk_suspend(dev);
+		xhci_mtk_seal_wakeup_enable(mtk, true);
+		mtk->seal_status = SEAL_SUSPENDED;
+		xhci_dbg(xhci, "%s: seals xHCI controller\n", __func__);
+	}
+
+	xhci_dbg(xhci, "%s: seals wakeup = %i, ret = %i!\n",
+		  __func__, wakeup, ret);
+
+	return ret;
+}
+
+static int __maybe_unused xhci_mtk_runtime_resume(struct device *dev)
+{
+	bool wakeup = device_may_wakeup(dev);
+	struct xhci_hcd_mtk  *mtk = dev_get_drvdata(dev);
+	struct usb_hcd *hcd;
+	struct xhci_hcd *xhci;
+
+	if (!mtk->hcd)
+		return -ESHUTDOWN;
+
+	hcd = mtk->hcd;
+	xhci = hcd_to_xhci(hcd);
+	if ((xhci->xhc_state & XHCI_STATE_REMOVING) ||
+			(xhci->xhc_state & XHCI_STATE_HALTED)) {
+		return -ESHUTDOWN;
+	}
+
+	/*
+	 *  list cases by one extra interrupt named seal to process!!!
+	 *  Who to process these module reinitilization after SPM wakeup
+	 *  case 1: usb remote wakeup, therefore xHCI need reinitilizate also.
+	 *  case 2: other-wakeup-source wakeup, therefore, xHCI need reinit
+	 *  case 3: usb client driver can invoke it in runtime mechanism
+	 *  case 4: user active
+	 */
+	if (wakeup) {
+		xhci_mtk_seal_wakeup_enable(mtk, false);
+		xhci_mtk_resume(dev);
+		xhci_dbg(xhci, "%s: unseals xHCI controller\n", __func__);
+	}
+	mtk->seal_status = SEAL_RESUMED;
+
+	xhci_dbg(xhci, "%s: unseals wakeup = %i\n", __func__, wakeup);
+
+	return 0;
+}
+
+static int __maybe_unused xhci_mtk_runtime_idle(struct device *dev)
+{
+	int ret = 0;
+
+	dev_dbg(dev, "%s: xhci_mtk_runtime_ready %i",
+		 __func__, xhci_mtk_runtime_ready);
+
+	if (!xhci_mtk_runtime_ready)
+		ret = -EAGAIN;
+
+	return ret;
+}
+
 static const struct dev_pm_ops xhci_mtk_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(xhci_mtk_suspend, xhci_mtk_resume)
+	SET_RUNTIME_PM_OPS(xhci_mtk_runtime_suspend,
+			   xhci_mtk_runtime_resume,
+			   xhci_mtk_runtime_idle)
 };
-#define DEV_PM_OPS IS_ENABLED(CONFIG_PM) ? &xhci_mtk_pm_ops : NULL
+
+#define DEV_PM_OPS (IS_ENABLED(CONFIG_PM) ? &xhci_mtk_pm_ops : NULL)
 
 #ifdef CONFIG_OF
 static const struct of_device_id mtk_xhci_of_match[] = {
@@ -686,6 +960,7 @@ MODULE_ALIAS("platform:xhci-mtk");
 
 static int __init xhci_mtk_init(void)
 {
+	xhci_mtk_runtime_ready = 0;
 	xhci_init_driver(&xhci_mtk_hc_driver, &xhci_mtk_overrides);
 	return platform_driver_register(&mtk_xhci_driver);
 }
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index 323b281933b9..103d83ce6a3e 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -133,6 +133,14 @@ struct mu3c_ippc_regs {
 	__le32 reserved3[33]; /* 0x80 ~ 0xff */
 };
 
+enum xhci_mtk_seal {
+	SEAL_BUSY = 0,
+	SEAL_SUSPENDING,
+	SEAL_SUSPENDED,
+	SEAL_RESUMING,
+	SEAL_RESUMED
+};
+
 struct xhci_hcd_mtk {
 	struct device *dev;
 	struct usb_hcd *hcd;
@@ -158,6 +166,12 @@ struct xhci_hcd_mtk {
 	struct regmap *uwk;
 	u32 uwk_reg_base;
 	u32 uwk_vers;
+
+	/* usb eint wakeup source */
+	int seal_irq;
+	enum xhci_mtk_seal seal_status;
+	struct delayed_work  seal;
+	char   seal_descr[32];	/* "seal" + driver + bus # */
 };
 
 static inline struct xhci_hcd_mtk *hcd_to_mtk(struct usb_hcd *hcd)
-- 
2.18.0