Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To:     robh+dt@kernel.org, vkoul@kernel.org,
        yung-chuan.liao@linux.intel.com
Cc:     pierre-louis.bossart@linux.intel.com, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org,
        quic_srivasam@quicinc.com,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: [PATCH 3/3] soundwire: qcom: add wake up interrupt support
Date:   Mon, 21 Feb 2022 10:41:27 +0000
Message-Id: <20220221104127.15670-4-srinivas.kandagatla@linaro.org>
In-Reply-To: <20220221104127.15670-1-srinivas.kandagatla@linaro.org>
References: <20220221104127.15670-1-srinivas.kandagatla@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Some of the Qualcomm SoundWire Controller instances like the ones that are
connected to RX path along with Headset connections support Waking up
Controller from Low power clock stop state.

Add support to this wake up interrupt.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/soundwire/qcom.c | 65 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 3b2eb95a7e96..b9b76031307b 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -14,6 +14,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
+#include <linux/pm_wakeirq.h>
 #include <linux/slimbus.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
@@ -154,6 +155,7 @@ struct qcom_swrm_ctrl {
 	u8 rd_cmd_id;
 	int irq;
 	unsigned int version;
+	int wake_irq;
 	int num_din_ports;
 	int num_dout_ports;
 	int cols_index;
@@ -503,6 +505,46 @@ static int qcom_swrm_enumerate(struct sdw_bus *bus)
 	return 0;
 }
 
+static irqreturn_t qcom_swrm_wake_irq_handler(int irq, void *dev_id)
+{
+	struct qcom_swrm_ctrl *swrm = dev_id;
+	int ret = IRQ_HANDLED;
+	struct sdw_slave *slave;
+
+	clk_prepare_enable(swrm->hclk);
+
+	if (swrm->wake_irq > 0) {
+		if (!irqd_irq_disabled(irq_get_irq_data(swrm->wake_irq)))
+			disable_irq_nosync(swrm->wake_irq);
+	}
+
+	/*
+	 * resume all the slaves which must have potentially generated this
+	 * interrupt, this should also wake the controller at the same time.
+	 * this is much safer than waking controller directly that will deadlock!
+	 */
+	list_for_each_entry(slave, &swrm->bus.slaves, node) {
+		ret = pm_runtime_get_sync(&slave->dev);
+		if (ret < 0 && ret != -EACCES) {
+			dev_err_ratelimited(swrm->dev,
+					    "pm_runtime_get_sync failed in %s, ret %d\n",
+					    __func__, ret);
+			pm_runtime_put_noidle(&slave->dev);
+			ret = IRQ_NONE;
+			goto err;
+		}
+	}
+
+	list_for_each_entry(slave, &swrm->bus.slaves, node) {
+		pm_runtime_mark_last_busy(&slave->dev);
+		pm_runtime_put_autosuspend(&slave->dev);
+	}
+err:
+	clk_disable_unprepare(swrm->hclk);
+	return IRQ_HANDLED;
+}
+
+
 static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
 {
 	struct qcom_swrm_ctrl *swrm = dev_id;
@@ -1340,6 +1382,19 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 		goto err_clk;
 	}
 
+	ctrl->wake_irq = of_irq_get(dev->of_node, 1);
+	if (ctrl->wake_irq > 0) {
+		ret = devm_request_threaded_irq(dev, ctrl->wake_irq, NULL,
+						qcom_swrm_wake_irq_handler,
+						IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+						"swr_wake_irq", ctrl);
+		if (ret) {
+			dev_err(dev, "Failed to request soundwire wake irq\n");
+			goto err_init;
+		}
+	}
+
+
 	ret = sdw_bus_master_add(&ctrl->bus, dev, dev->fwnode);
 	if (ret) {
 		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
@@ -1424,6 +1479,11 @@ static int swrm_runtime_resume(struct device *dev)
 	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
 	int ret;
 
+	if (ctrl->wake_irq > 0) {
+		if (!irqd_irq_disabled(irq_get_irq_data(ctrl->wake_irq)))
+			disable_irq_nosync(ctrl->wake_irq);
+	}
+
 	clk_prepare_enable(ctrl->hclk);
 
 	if (ctrl->clk_stop_bus_reset) {
@@ -1485,6 +1545,11 @@ static int __maybe_unused swrm_runtime_suspend(struct device *dev)
 
 	usleep_range(300, 305);
 
+	if (ctrl->wake_irq > 0) {
+		if (irqd_irq_disabled(irq_get_irq_data(ctrl->wake_irq)))
+			enable_irq(ctrl->wake_irq);
+	}
+
 	return 0;
 }
 
-- 
2.21.0