[RFC PATCH 2/3] power: sequencing: qcom-wcn: support SW_CTRL wake IRQ

[Linghui Wu <linghui.wu@oss.qualcomm.com>]

Some WCN3990-family designs route SW_CTRL to an interrupt capable of
waking the application processor. Requesting the IRQ resource also enables
the Qualcomm TLMM power-save wakeup path when WAKEUP_PRESENT is advertised.

When the PMU is marked as a wakeup source, retrieve the dedicated "wakeup"
interrupt and register it as a dedicated wake IRQ. Keep it disabled during
normal operation and let the PM core arm it for system suspend.

Signed-off-by: Linghui Wu <linghui.wu@oss.qualcomm.com>
---
 drivers/power/sequencing/pwrseq-qcom-wcn.c | 30 ++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/power/sequencing/pwrseq-qcom-wcn.c b/drivers/power/sequencing/pwrseq-qcom-wcn.c
index d41793e1fcd..e052187ffb9 100644
--- a/drivers/power/sequencing/pwrseq-qcom-wcn.c
+++ b/drivers/power/sequencing/pwrseq-qcom-wcn.c
@@ -11,6 +11,8 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/pm_wakeup.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pwrseq/provider.h>
@@ -454,11 +456,17 @@ static int pwrseq_qcom_wcn3990_match(struct pwrseq_device *pwrseq,
 	return pwrseq_qcom_wcn_match_regulator(pwrseq, dev, "vdd-1.8-xo-supply");
 }
 
+static void pwrseq_qcom_wcn_clear_wake_irq(void *data)
+{
+	dev_pm_clear_wake_irq(data);
+}
+
 static int pwrseq_qcom_wcn_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct pwrseq_qcom_wcn_ctx *ctx;
 	struct pwrseq_config config;
+	int wake_irq;
 	int i, ret;
 
 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
@@ -496,6 +504,28 @@ static int pwrseq_qcom_wcn_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(ctx->bt_gpio),
 				     "Failed to get the Bluetooth enable GPIO\n");
 
+	if (device_property_read_bool(dev, "wakeup-source")) {
+		wake_irq = platform_get_irq_byname(pdev, "wakeup");
+		if (wake_irq < 0)
+			return dev_err_probe(dev, wake_irq,
+					     "Failed to get the SW_CTRL wake IRQ\n");
+
+		ret = devm_device_init_wakeup(dev);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to enable wakeup\n");
+
+		ret = dev_pm_set_dedicated_wake_irq(dev, wake_irq);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to set the SW_CTRL wake IRQ\n");
+
+		ret = devm_add_action_or_reset(dev,
+					       pwrseq_qcom_wcn_clear_wake_irq, dev);
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 * FIXME: This should actually be GPIOD_OUT_LOW, but doing so would
 	 * cause the WLAN power to be toggled, resulting in PCIe link down.
-- 
2.43.0