soc: qcom: Add snapshot of smp2p sleepstate driver

This snapshot is taken as of msm-5.10 'commit <9650dfff5aba>
("misc: hdcp: add API to talk to OPS service")'.

Change-Id: I974c616cc11a36db4ecda2c9e10a1fb25a92a597
Signed-off-by: Chris Lew <quic_clew@quicinc.com>

drivers/soc/qcom/Kconfig

@@ -226,6 +226,16 @@ config QCOM_SMSM
 	  Say yes here to support the Qualcomm Shared Memory State Machine.
 	  The state machine is represented by bits in shared memory.
 
+config QCOM_SMP2P_SLEEPSTATE
+	tristate "SMP2P Sleepstate notifier"
+	depends on QCOM_SMP2P
+	help
+	  When this option is enabled, notifications are sent to remote procs
+	  for the power state changes on the local processor. The notifications
+	  are sent through the smp2p framework. This driver can also receive
+	  notifications from the remote to prevent suspend on the local
+	  processor.
+
 config QTI_PMIC_GLINK
 	tristate "Enable support for PMIC GLINK"
 	depends on RPMSG

drivers/soc/qcom/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
 obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
 obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
+obj-$(CONFIG_QCOM_SMP2P_SLEEPSTATE) += smp2p_sleepstate.o
 obj-$(CONFIG_QTI_PMIC_GLINK) += pmic_glink.o
 obj-$(CONFIG_QTI_BATTERY_GLINK_DEBUG) += qti_battery_debug.o
 obj-$(CONFIG_QTI_CHARGER_ULOG_GLINK) += charger-ulog-glink.o

drivers/soc/qcom/smp2p_sleepstate.c

@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014-2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/platform_device.h>
+#include <linux/soc/qcom/smem_state.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/pm_wakeup.h>
+
+#define PROC_AWAKE_ID 12 /* 12th bit */
+#define AWAKE_BIT BIT(PROC_AWAKE_ID)
+static struct qcom_smem_state *state;
+static struct wakeup_source *notify_ws;
+
+/**
+ * sleepstate_pm_notifier() - PM notifier callback function.
+ * @nb:		Pointer to the notifier block.
+ * @event:	Suspend state event from PM module.
+ * @unused:	Null pointer from PM module.
+ *
+ * This function is register as callback function to get notifications
+ * from the PM module on the system suspend state.
+ */
+static int sleepstate_pm_notifier(struct notifier_block *nb,
+				  unsigned long event, void *unused)
+{
+	switch (event) {
+	case PM_SUSPEND_PREPARE:
+		qcom_smem_state_update_bits(state, AWAKE_BIT, 0);
+		break;
+
+	case PM_POST_SUSPEND:
+		qcom_smem_state_update_bits(state, AWAKE_BIT, AWAKE_BIT);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block sleepstate_pm_nb = {
+	.notifier_call = sleepstate_pm_notifier,
+	.priority = INT_MAX,
+};
+
+static irqreturn_t smp2p_sleepstate_handler(int irq, void *ctxt)
+{
+	__pm_wakeup_event(notify_ws, 200);
+	return IRQ_HANDLED;
+}
+
+static int smp2p_sleepstate_probe(struct platform_device *pdev)
+{
+	int ret;
+	int irq;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+
+	state = qcom_smem_state_get(&pdev->dev, 0, &ret);
+	if (IS_ERR(state))
+		return PTR_ERR(state);
+	qcom_smem_state_update_bits(state, AWAKE_BIT, AWAKE_BIT);
+
+	ret = register_pm_notifier(&sleepstate_pm_nb);
+	if (ret) {
+		dev_err(dev, "%s: power state notif error %d\n", __func__, ret);
+		return ret;
+	}
+
+	notify_ws = wakeup_source_register(&pdev->dev, "smp2p-sleepstate");
+	if (!notify_ws) {
+		return -ENOMEM;
+		goto err_ws;
+	}
+
+	irq = of_irq_get_byname(node, "smp2p-sleepstate-in");
+	if (irq <= 0) {
+		dev_err(dev, "failed to get irq for smp2p_sleep_state\n");
+		ret = -EPROBE_DEFER;
+		goto err;
+	}
+	dev_dbg(dev, "got smp2p-sleepstate-in irq %d\n", irq);
+	ret = devm_request_threaded_irq(dev, irq, NULL,
+					smp2p_sleepstate_handler,
+					IRQF_ONESHOT | IRQF_TRIGGER_RISING,
+					"smp2p_sleepstate", dev);
+	if (ret) {
+		dev_err(dev, "fail to register smp2p threaded_irq=%d\n", irq);
+		goto err;
+	}
+	return 0;
+err:
+	wakeup_source_unregister(notify_ws);
+	__pm_relax(notify_ws);
+err_ws:
+	unregister_pm_notifier(&sleepstate_pm_nb);
+	return ret;
+}
+
+static const struct of_device_id smp2p_slst_match_table[] = {
+	{.compatible = "qcom,smp2p-sleepstate"},
+	{},
+};
+
+static struct platform_driver smp2p_sleepstate_driver = {
+	.probe = smp2p_sleepstate_probe,
+	.driver = {
+		.name = "smp2p_sleepstate",
+		.of_match_table = smp2p_slst_match_table,
+	},
+};
+
+static int __init smp2p_sleepstate_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&smp2p_sleepstate_driver);
+	if (ret) {
+		pr_err("%s: register failed %d\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+module_init(smp2p_sleepstate_init);
+MODULE_DESCRIPTION("SMP2P SLEEP STATE");
+MODULE_LICENSE("GPL");