[PATCH 2/8] usb: cdns3: imx: add glue layer runtime pm implementation

[Peter Chen <peter.chen@nxp.com>]

Add imx glue layer runtime pm implementation, and the runtime
pm is default off.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
 drivers/usb/cdns3/cdns3-imx.c | 179 +++++++++++++++++++++++++++++++++-
 1 file changed, 177 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/cdns3/cdns3-imx.c b/drivers/usb/cdns3/cdns3-imx.c
index aba988e71958..9d247de8e7eb 100644
--- a/drivers/usb/cdns3/cdns3-imx.c
+++ b/drivers/usb/cdns3/cdns3-imx.c
@@ -15,6 +15,8 @@
 #include <linux/io.h>
 #include <linux/of_platform.h>
 #include <linux/iopoll.h>
+#include <linux/pm_runtime.h>
+#include "core.h"
 
 #define USB3_CORE_CTRL1    0x00
 #define USB3_CORE_CTRL2    0x04
@@ -66,11 +68,30 @@
 #define CLK_VALID_COMPARE_BITS	(0xf << 28)
 #define PHY_REFCLK_REQ		(1 << 0)
 
+/* OTG registers definition */
+#define OTGSTS		0x4
+/* OTGSTS */
+#define OTG_NRDY	(1 << 11)
+
+/* xHCI registers definition  */
+#define XECP_PM_PMCSR		0x8018
+#define XECP_AUX_CTRL_REG1	0x8120
+
+/* Register bits definition */
+/* XECP_AUX_CTRL_REG1 */
+#define CFG_RXDET_P3_EN		(1 << 15)
+
+/* XECP_PM_PMCSR */
+#define PS_MASK			(3 << 0)
+#define PS_D0			0
+#define PS_D1			(1 << 0)
+
 struct cdns_imx {
 	struct device *dev;
 	void __iomem *noncore;
 	struct clk_bulk_data *clks;
 	int num_clks;
+	struct platform_device *cdns3_pdev;
 };
 
 static inline u32 cdns_imx_readl(struct cdns_imx *data, u32 offset)
@@ -126,6 +147,20 @@ static int cdns_imx_noncore_init(struct cdns_imx *data)
 	return ret;
 }
 
+static int cdns_imx_platform_suspend(struct device *dev,
+	bool suspend, bool wakeup);
+static struct cdns3_platform_data cdns_imx_pdata = {
+	.platform_suspend = cdns_imx_platform_suspend,
+};
+
+static struct of_dev_auxdata cdns_imx_auxdata[] = {
+	{
+	.compatible = "cdns,usb3",
+	.platform_data = &cdns_imx_pdata,
+	},
+	{},
+};
+
 static int cdns_imx_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -162,14 +197,18 @@ static int cdns_imx_probe(struct platform_device *pdev)
 	if (ret)
 		goto err;
 
-	ret = of_platform_populate(node, NULL, NULL, dev);
+	ret = of_platform_populate(node, NULL, cdns_imx_auxdata, dev);
 	if (ret) {
 		dev_err(dev, "failed to create children: %d\n", ret);
 		goto err;
 	}
 
-	return ret;
+	device_set_wakeup_capable(dev, true);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_forbid(dev);
 
+	return ret;
 err:
 	clk_bulk_disable_unprepare(data->num_clks, data->clks);
 	return ret;
@@ -194,6 +233,141 @@ static int cdns_imx_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static void cdns3_set_wakeup(struct cdns_imx *data, bool enable)
+{
+	u32 value;
+
+	value = cdns_imx_readl(data, USB3_INT_REG);
+	if (enable)
+		value |= OTG_WAKEUP_EN | DEVU3_WAEKUP_EN;
+	else
+		value &= ~(OTG_WAKEUP_EN | DEVU3_WAEKUP_EN);
+
+	cdns_imx_writel(data, USB3_INT_REG, value);
+}
+
+static int cdns_imx_platform_suspend(struct device *dev,
+		bool suspend, bool wakeup)
+{
+	struct cdns3 *cdns = dev_get_drvdata(dev);
+	struct device *parent = dev->parent;
+	struct cdns_imx *data = dev_get_drvdata(parent);
+	void __iomem *otg_regs = cdns->otg_regs;
+	void __iomem *xhci_regs = cdns->xhci_regs;
+	u32 value;
+	int ret = 0;
+
+	if (cdns->role != USB_ROLE_HOST)
+		return 0;
+
+	if (suspend) {
+		/* SW request low power when all usb ports allow to it ??? */
+		value = readl(xhci_regs + XECP_PM_PMCSR);
+		value &= ~PS_MASK;
+		value |= PS_D1;
+		writel(value, xhci_regs + XECP_PM_PMCSR);
+
+		/* mdctrl_clk_sel */
+		value = cdns_imx_readl(data, USB3_CORE_CTRL1);
+		value |= MDCTRL_CLK_SEL;
+		cdns_imx_writel(data, USB3_CORE_CTRL1, value);
+
+		/* wait for mdctrl_clk_status */
+		value = cdns_imx_readl(data, USB3_CORE_STATUS);
+		ret = readl_poll_timeout_atomic(data->noncore + USB3_CORE_STATUS, value,
+			(value & MDCTRL_CLK_STATUS) == MDCTRL_CLK_STATUS,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait mdctrl_clk_status timeout\n");
+
+		/* wait lpm_clk_req to be 0 */
+		value = cdns_imx_readl(data, USB3_INT_REG);
+		ret = readl_poll_timeout_atomic(data->noncore + USB3_INT_REG, value,
+			(value & LPM_CLK_REQ) != LPM_CLK_REQ,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait lpm_clk_req timeout\n");
+
+		/* wait phy_refclk_req to be 0 */
+		value = cdns_imx_readl(data, USB3_SSPHY_STATUS);
+		ret = readl_poll_timeout_atomic(data->noncore + USB3_SSPHY_STATUS, value,
+			(value & PHY_REFCLK_REQ) != PHY_REFCLK_REQ,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait phy_refclk_req timeout\n");
+
+		cdns3_set_wakeup(data, wakeup);
+	} else {
+		/* wait CLK_125_REQ to be 1 */
+		value = cdns_imx_readl(data, USB3_INT_REG);
+		ret = readl_poll_timeout_atomic(data->noncore + USB3_INT_REG, value,
+			(value & CLK_125_REQ) != CLK_125_REQ,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait CLK_125_REQ timeout\n");
+
+		cdns3_set_wakeup(data, false);
+
+		/* SW request D0 */
+		value = readl(xhci_regs + XECP_PM_PMCSR);
+		value &= ~PS_MASK;
+		value |= PS_D0;
+		writel(value, xhci_regs + XECP_PM_PMCSR);
+
+		/* clr CFG_RXDET_P3_EN */
+		value = readl(xhci_regs + XECP_AUX_CTRL_REG1);
+		value &= ~CFG_RXDET_P3_EN;
+		writel(value, xhci_regs + XECP_AUX_CTRL_REG1);
+
+		/* clear mdctrl_clk_sel */
+		value = cdns_imx_readl(data, USB3_CORE_CTRL1);
+		value &= ~MDCTRL_CLK_SEL;
+		cdns_imx_writel(data, USB3_CORE_CTRL1, value);
+
+		/* wait for mdctrl_clk_status is cleared */
+		value = cdns_imx_readl(data, USB3_CORE_STATUS);
+		ret = readl_poll_timeout_atomic(data->noncore + USB3_CORE_STATUS, value,
+			(value & MDCTRL_CLK_STATUS) != MDCTRL_CLK_STATUS,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait mdctrl_clk_status cleared timeout\n");
+
+		/* Wait until OTG_NRDY is 0 */
+		value = readl(otg_regs + OTGSTS);
+		ret = readl_poll_timeout_atomic(otg_regs + OTGSTS, value,
+			(value & OTG_NRDY) != OTG_NRDY,
+			10, 100000);
+		if (ret)
+			dev_warn(parent, "wait OTG ready timeout\n");
+	}
+
+	return ret;
+
+}
+
+static int cdns_imx_resume(struct device *dev)
+{
+	struct cdns_imx *data = dev_get_drvdata(dev);
+
+	return clk_bulk_prepare_enable(data->num_clks, data->clks);
+}
+
+static int cdns_imx_suspend(struct device *dev)
+{
+	struct cdns_imx *data = dev_get_drvdata(dev);
+
+	clk_bulk_disable_unprepare(data->num_clks, data->clks);
+
+	return 0;
+}
+
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops cdns_imx_pm_ops = {
+	SET_RUNTIME_PM_OPS(cdns_imx_suspend, cdns_imx_resume, NULL)
+};
+
 static const struct of_device_id cdns_imx_of_match[] = {
 	{ .compatible = "fsl,imx8qm-usb3", },
 	{},
@@ -206,6 +380,7 @@ static struct platform_driver cdns_imx_driver = {
 	.driver		= {
 		.name	= "cdns3-imx",
 		.of_match_table	= cdns_imx_of_match,
+		.pm	= &cdns_imx_pm_ops,
 	},
 };
 module_platform_driver(cdns_imx_driver);
-- 
2.17.1