drivers: soc: qcom: handle system sleep activities

When all the CPUs in the Apps processor subsystem
are powered off, the system may also reduce its
bandwidth and shared resource requirements.

The resource requests are sent through the SMD
from APSS subsystem. The sleep requests also need
to be written to the rpm to save power. This driver
handles the last few steps when entering system sleep.

When notified, the next wakeup timer value is written
to the MPM to be setup in the always-on domain timer.

Change-Id: Iab9e38d602d4f84e506471ec0864d2c6fb550b42
Signed-off-by: Raghavendra Kakarla <rkakarla@codeaurora.org>

drivers/soc/qcom/Kconfig

@@ -646,10 +646,21 @@ config MSM_PM
 	bool
 	select MSM_IDLE_STATS if DEBUG_FS
 	select QTI_SYSTEM_PM if QCOM_RPMH
+	select QTI_SYSTEM_PM_RPM if MSM_RPM_SMD && QGKI && QCOM_MPM
+	bool "Qualcomm Technologies, Inc. (QTI) Power Management Drivers"
+	help
+	  Platform specific power driver to manage cores and l2 low power
+	  modes. It interface with various system driver and put the cores
+	  into low power modes. It implements OS initiated scheme and
+	  determines last CPU to call into PSCI for cluster Low power
+	  modes.
 
 config QTI_SYSTEM_PM
 	bool
 
+config QTI_SYSTEM_PM_RPM
+	bool
+
 if MSM_PM
 menuconfig MSM_IDLE_STATS
 	bool "Collect idle statistics"

drivers/soc/qcom/Makefile

@@ -63,6 +63,7 @@ obj-$(CONFIG_QTI_BATTERY_GLINK_DEBUG) += qti_battery_debug.o
 obj-$(CONFIG_QTI_ALTMODE_GLINK) += altmode-glink.o
 obj-$(CONFIG_QTI_DDR_STATS_LOG) += ddr_stats.o
 obj-$(CONFIG_QTI_SYSTEM_PM) += system_pm.o
+obj-$(CONFIG_QTI_SYSTEM_PM_RPM) += system_pm_rpm.o
 obj-$(CONFIG_MSM_REMOTEQDSS) += remoteqdss.o
 obj-$(CONFIG_MSM_SPSS_UTILS) += spss_utils.o
 obj-$(CONFIG_MSM_IDLE_STATS)	+= lpm-stats.o

drivers/soc/qcom/system_pm_rpm.c

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/tick.h>
+#include <clocksource/arm_arch_timer.h>
+#include <linux/ktime.h>
+#include <asm/arch_timer.h>
+#include <soc/qcom/rpm-notifier.h>
+#include <soc/qcom/lpm_levels.h>
+#include <soc/qcom/mpm.h>
+
+static void system_sleep_exit(bool success)
+{
+	msm_rpm_exit_sleep();
+}
+
+static int system_sleep_update_wakeup(bool from_idle)
+{
+	uint32_t lo = ~0U, hi = ~0U;
+	u64 wakeup;
+
+	/* Read the hardware to get the most accurate value */
+	arch_timer_mem_get_cval(&lo, &hi);
+	wakeup = lo;
+	wakeup |= ((uint64_t)(hi) << 32);
+	msm_mpm_timer_write((uint32_t *)&wakeup);
+
+	return 0;
+}
+
+static int system_sleep_enter(struct cpumask *mask)
+{
+	int ret = 0;
+
+	ret = msm_rpm_enter_sleep(0, mask);
+	if (ret)
+		return ret;
+
+	msm_mpm_enter_sleep(mask);
+
+	return ret;
+}
+
+static bool system_sleep_allowed(void)
+{
+	return !msm_rpm_waiting_for_ack();
+}
+
+static struct system_pm_ops pm_ops = {
+	.enter = system_sleep_enter,
+	.exit = system_sleep_exit,
+	.update_wakeup = system_sleep_update_wakeup,
+	.sleep_allowed = system_sleep_allowed,
+};
+
+static int sys_pm_rpm_probe(struct platform_device *pdev)
+{
+	return register_system_pm_ops(&pm_ops);
+}
+
+static const struct of_device_id sys_pm_drv_match[] = {
+	{ .compatible = "qcom,system-pm-rpm", },
+	{ }
+};
+
+static struct platform_driver sys_pm_rpm_driver = {
+	.probe = sys_pm_rpm_probe,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.suppress_bind_attrs = true,
+		.of_match_table = sys_pm_drv_match,
+	},
+};
+module_platform_driver(sys_pm_rpm_driver);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) SYSTEM PM RPM Driver");
+MODULE_LICENSE("GPL v2");