@@ -4286,6 +4286,14 @@ S: Supported
F: drivers/cpuidle/cpuidle-exynos.c
F: arch/arm/mach-exynos/pm.c
+CPUIDLE DRIVER - ARM PSCI
+M: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+M: Sudeep Holla <sudeep.holla@arm.com>
+L: linux-pm@vger.kernel.org
+L: linux-arm-kernel@lists.infradead.org
+S: Supported
+F: drivers/cpuidle/cpuidle-psci.c
+
CPU IDLE TIME MANAGEMENT FRAMEWORK
M: "Rafael J. Wysocki" <rjw@rjwysocki.net>
M: Daniel Lezcano <daniel.lezcano@linaro.org>
@@ -13,6 +13,16 @@ config ARM_CPUIDLE
initialized by calling the CPU operations init idle hook
provided by architecture code.
+config ARM_PSCI_CPUIDLE
+ bool
+ depends on ARM_PSCI_FW
+ select DT_IDLE_STATES
+ select CPU_IDLE_MULTIPLE_DRIVERS
+ help
+ Select this to enable PSCI firmware based CPUidle driver for ARM.
+ It provides an idle driver that is capable of detecting and
+ managing idle states through the PSCI firmware interface.
+
config ARM_BIG_LITTLE_CPUIDLE
bool "Support for ARM big.LITTLE processors"
depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS
@@ -20,6 +20,7 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o
obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o
obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o
obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o
+obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o
###############################################################################
# MIPS drivers
new file mode 100644
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PSCI CPU idle driver.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ */
+
+#define pr_fmt(fmt) "CPUidle PSCI: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/psci.h>
+#include <linux/slab.h>
+
+#include <asm/cpuidle.h>
+
+#include "dt_idle_states.h"
+
+static int psci_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ return CPU_PM_CPU_IDLE_ENTER(psci_cpu_suspend_enter, idx);
+}
+
+static struct cpuidle_driver psci_idle_driver __initdata = {
+ .name = "psci_idle",
+ .owner = THIS_MODULE,
+ /*
+ * PSCI idle states relies on architectural WFI to
+ * be represented as state index 0.
+ */
+ .states[0] = {
+ .enter = psci_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .name = "WFI",
+ .desc = "ARM WFI",
+ }
+};
+
+static const struct of_device_id psci_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = psci_enter_idle_state },
+ { },
+};
+
+static int __init psci_idle_init_cpu(int cpu)
+{
+ struct cpuidle_driver *drv;
+ struct device_node *cpu_node;
+ const char *enable_method;
+ int ret = 0;
+
+ cpu_node = of_cpu_device_node_get(cpu);
+ if (!cpu_node)
+ return -ENODEV;
+
+ /*
+ * Check whether the enable-method for the cpu is PSCI, fail
+ * if it is not.
+ */
+ enable_method = of_get_property(cpu_node, "enable-method", NULL);
+ if (!enable_method || (strcmp(enable_method, "psci")))
+ ret = -ENODEV;
+
+ of_node_put(cpu_node);
+ if (ret)
+ return ret;
+
+ drv = kmemdup(&psci_idle_driver, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+ /*
+ * Initialize idle states data, starting at index 1, since
+ * by default idle state 0 is the quiescent state reached
+ * by the cpu by executing the wfi instruction.
+ *
+ * If no DT idle states are detected (ret == 0) let the driver
+ * initialization fail accordingly since there is no reason to
+ * initialize the idle driver if only wfi is supported, the
+ * default archictectural back-end already executes wfi
+ * on idle entry.
+ */
+ ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
+ if (ret <= 0) {
+ ret = ret ? : -ENODEV;
+ goto out_kfree_drv;
+ }
+
+ /*
+ * Initialize PSCI idle states.
+ */
+ ret = psci_cpu_init_idle(cpu);
+ if (ret) {
+ pr_err("CPU %d failed to PSCI idle\n", cpu);
+ goto out_kfree_drv;
+ }
+
+ ret = cpuidle_register(drv, NULL);
+ if (ret)
+ goto out_kfree_drv;
+
+ return 0;
+
+out_kfree_drv:
+ kfree(drv);
+ return ret;
+}
+
+/*
+ * psci_idle_init - Initializes PSCI cpuidle driver
+ *
+ * Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
+ * to register cpuidle driver then rollback to cancel all CPUs
+ * registration.
+ */
+static int __init psci_idle_init(void)
+{
+ int cpu, ret;
+ struct cpuidle_driver *drv;
+ struct cpuidle_device *dev;
+
+ for_each_possible_cpu(cpu) {
+ ret = psci_idle_init_cpu(cpu);
+ if (ret)
+ goto out_fail;
+ }
+
+ return 0;
+
+out_fail:
+ while (--cpu >= 0) {
+ dev = per_cpu(cpuidle_devices, cpu);
+ drv = cpuidle_get_cpu_driver(dev);
+ cpuidle_unregister(drv);
+ kfree(drv);
+ }
+
+ return ret;
+}
+device_initcall(psci_idle_init);