[PATCH v2 4/4] usb: xhci: tegra: Support USB wakeup function for Tegra234

[Haotien Hsu <haotienh@nvidia.com>]

When the system is suspended, USB hot-plugging/unplugging can trigger
wake events of the Tegra USB host controller.
Enable support for USB wake-up events by parsing device-tree to see if
the interrupts for the wake-up events are present and if so configure
those interrupts. Note that if wake-up events are not present, still
allow the USB host controller to probe as normal.

Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
---
V1->V2
- Fix the -Wunused-variable warning in xhci-tegra.c.
---
 drivers/usb/host/xhci-tegra.c | 82 ++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index b5c362c2051d..b419f0917feb 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -155,6 +155,8 @@
 #define FW_IOCTL_TYPE_SHIFT			24
 #define FW_IOCTL_CFGTBL_READ		17
 
+#define WAKE_IRQ_START_INDEX			2
+
 struct tegra_xusb_fw_header {
 	__le32 boot_loadaddr_in_imem;
 	__le32 boot_codedfi_offset;
@@ -228,6 +230,7 @@ struct tegra_xusb_soc {
 	unsigned int num_supplies;
 	const struct tegra_xusb_phy_type *phy_types;
 	unsigned int num_types;
+	unsigned int max_num_wakes;
 	const struct tegra_xusb_context_soc *context;
 
 	struct {
@@ -263,6 +266,7 @@ struct tegra_xusb {
 	int xhci_irq;
 	int mbox_irq;
 	int padctl_irq;
+	int *wake_irqs;
 
 	void __iomem *ipfs_base;
 	void __iomem *fpci_base;
@@ -313,6 +317,7 @@ struct tegra_xusb {
 	bool suspended;
 	struct tegra_xusb_context context;
 	u8 lp0_utmi_pad_mask;
+	int num_wakes;
 };
 
 static struct hc_driver __read_mostly tegra_xhci_hc_driver;
@@ -1534,6 +1539,58 @@ static void tegra_xusb_deinit_usb_phy(struct tegra_xusb *tegra)
 			otg_set_host(tegra->usbphy[i]->otg, NULL);
 }
 
+static int tegra_xusb_setup_wakeup(struct platform_device *pdev, struct tegra_xusb *tegra)
+{
+	unsigned int i;
+
+	if (tegra->soc->max_num_wakes == 0)
+		return 0;
+
+	tegra->wake_irqs = devm_kcalloc(tegra->dev,
+					tegra->soc->max_num_wakes,
+					sizeof(*tegra->wake_irqs), GFP_KERNEL);
+	if (!tegra->wake_irqs)
+		return -ENOMEM;
+
+	/*
+	 * USB wake events are independent of each other, so it is not necessary for a platform
+	 * to utilize all wake-up events supported for a given device. The USB host can operate
+	 * even if wake-up events are not defined or fail to be configured. Therefore, we only
+	 * return critical errors, such as -ENOMEM.
+	 */
+	for (i = 0; i < tegra->soc->max_num_wakes; i++) {
+		struct irq_data *data;
+
+		tegra->wake_irqs[i] = platform_get_irq(pdev, i + WAKE_IRQ_START_INDEX);
+		if (tegra->wake_irqs[i] < 0)
+			break;
+
+		data = irq_get_irq_data(tegra->wake_irqs[i]);
+		if (!data) {
+			dev_warn(tegra->dev, "get wake event %d irq data fail\n", i);
+			irq_dispose_mapping(tegra->wake_irqs[i]);
+			break;
+		}
+
+		irq_set_irq_type(tegra->wake_irqs[i], irqd_get_trigger_type(data));
+	}
+
+	tegra->num_wakes = i;
+	dev_dbg(tegra->dev, "setup %d wake events\n", tegra->num_wakes);
+
+	return 0;
+}
+
+static void tegra_xusb_dispose_wake(struct tegra_xusb *tegra)
+{
+	unsigned int i;
+
+	for (i = 0; i < tegra->num_wakes; i++)
+		irq_dispose_mapping(tegra->wake_irqs[i]);
+
+	tegra->num_wakes = 0;
+}
+
 static int tegra_xusb_probe(struct platform_device *pdev)
 {
 	struct tegra_xusb *tegra;
@@ -1584,9 +1641,15 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 	if (tegra->mbox_irq < 0)
 		return tegra->mbox_irq;
 
+	err = tegra_xusb_setup_wakeup(pdev, tegra);
+	if (err)
+		return err;
+
 	tegra->padctl = tegra_xusb_padctl_get(&pdev->dev);
-	if (IS_ERR(tegra->padctl))
-		return PTR_ERR(tegra->padctl);
+	if (IS_ERR(tegra->padctl)) {
+		err = PTR_ERR(tegra->padctl);
+		goto dispose_wake;
+	}
 
 	np = of_parse_phandle(pdev->dev.of_node, "nvidia,xusb-padctl", 0);
 	if (!np) {
@@ -1910,6 +1973,8 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 put_padctl:
 	of_node_put(np);
 	tegra_xusb_padctl_put(tegra->padctl);
+dispose_wake:
+	tegra_xusb_dispose_wake(tegra);
 	return err;
 }
 
@@ -1942,6 +2007,8 @@ static void tegra_xusb_remove(struct platform_device *pdev)
 	if (tegra->padctl_irq)
 		pm_runtime_disable(&pdev->dev);
 
+	tegra_xusb_dispose_wake(tegra);
+
 	pm_runtime_put(&pdev->dev);
 
 	tegra_xusb_disable(tegra);
@@ -2352,8 +2419,13 @@ static __maybe_unused int tegra_xusb_suspend(struct device *dev)
 		pm_runtime_disable(dev);
 
 		if (device_may_wakeup(dev)) {
+			unsigned int i;
+
 			if (enable_irq_wake(tegra->padctl_irq))
 				dev_err(dev, "failed to enable padctl wakes\n");
+
+			for (i = 0; i < tegra->num_wakes; i++)
+				enable_irq_wake(tegra->wake_irqs[i]);
 		}
 	}
 
@@ -2381,8 +2453,13 @@ static __maybe_unused int tegra_xusb_resume(struct device *dev)
 	}
 
 	if (device_may_wakeup(dev)) {
+		unsigned int i;
+
 		if (disable_irq_wake(tegra->padctl_irq))
 			dev_err(dev, "failed to disable padctl wakes\n");
+
+		for (i = 0; i < tegra->num_wakes; i++)
+			disable_irq_wake(tegra->wake_irqs[i]);
 	}
 	tegra->suspended = false;
 	mutex_unlock(&tegra->lock);
@@ -2633,6 +2710,7 @@ static const struct tegra_xusb_soc tegra234_soc = {
 	.num_supplies = ARRAY_SIZE(tegra194_supply_names),
 	.phy_types = tegra194_phy_types,
 	.num_types = ARRAY_SIZE(tegra194_phy_types),
+	.max_num_wakes = 7,
 	.context = &tegra186_xusb_context,
 	.ports = {
 		.usb3 = { .offset = 0, .count = 4, },
-- 
2.34.1