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168 lines
4.0 KiB
168 lines
4.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* ARM/ARM64 generic CPU idle driver. |
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* |
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* Copyright (C) 2014 ARM Ltd. |
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* Author: Lorenzo Pieralisi <[email protected]> |
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*/ |
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#define pr_fmt(fmt) "CPUidle arm: " fmt |
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#include <linux/cpu_cooling.h> |
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#include <linux/cpuidle.h> |
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#include <linux/cpumask.h> |
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#include <linux/cpu_pm.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/slab.h> |
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#include <asm/cpuidle.h> |
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#include "dt_idle_states.h" |
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/* |
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* arm_enter_idle_state - Programs CPU to enter the specified state |
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* |
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* dev: cpuidle device |
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* drv: cpuidle driver |
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* idx: state index |
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* |
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* Called from the CPUidle framework to program the device to the |
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* specified target state selected by the governor. |
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*/ |
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static int arm_enter_idle_state(struct cpuidle_device *dev, |
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struct cpuidle_driver *drv, int idx) |
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{ |
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/* |
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* Pass idle state index to arm_cpuidle_suspend which in turn |
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* will call the CPU ops suspend protocol with idle index as a |
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* parameter. |
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*/ |
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return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, idx); |
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} |
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static struct cpuidle_driver arm_idle_driver __initdata = { |
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.name = "arm_idle", |
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.owner = THIS_MODULE, |
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/* |
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* State at index 0 is standby wfi and considered standard |
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* on all ARM platforms. If in some platforms simple wfi |
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* can't be used as "state 0", DT bindings must be implemented |
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* to work around this issue and allow installing a special |
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* handler for idle state index 0. |
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*/ |
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.states[0] = { |
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.enter = arm_enter_idle_state, |
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.exit_latency = 1, |
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.target_residency = 1, |
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.power_usage = UINT_MAX, |
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.name = "WFI", |
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.desc = "ARM WFI", |
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} |
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}; |
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static const struct of_device_id arm_idle_state_match[] __initconst = { |
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{ .compatible = "arm,idle-state", |
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.data = arm_enter_idle_state }, |
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{ }, |
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}; |
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/* |
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* arm_idle_init_cpu |
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* |
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* Registers the arm specific cpuidle driver with the cpuidle |
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* framework. It relies on core code to parse the idle states |
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* and initialize them using driver data structures accordingly. |
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*/ |
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static int __init arm_idle_init_cpu(int cpu) |
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{ |
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int ret; |
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struct cpuidle_driver *drv; |
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drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL); |
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if (!drv) |
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return -ENOMEM; |
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drv->cpumask = (struct cpumask *)cpumask_of(cpu); |
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/* |
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* Initialize idle states data, starting at index 1. This |
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* driver is DT only, if no DT idle states are detected (ret |
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* == 0) let the driver initialization fail accordingly since |
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* there is no reason to initialize the idle driver if only |
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* wfi is supported. |
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*/ |
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ret = dt_init_idle_driver(drv, arm_idle_state_match, 1); |
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if (ret <= 0) { |
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ret = ret ? : -ENODEV; |
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goto out_kfree_drv; |
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} |
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/* |
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* Call arch CPU operations in order to initialize |
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* idle states suspend back-end specific data |
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*/ |
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ret = arm_cpuidle_init(cpu); |
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/* |
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* Allow the initialization to continue for other CPUs, if the |
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* reported failure is a HW misconfiguration/breakage (-ENXIO). |
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* |
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* Some platforms do not support idle operations |
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* (arm_cpuidle_init() returning -EOPNOTSUPP), we should |
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* not flag this case as an error, it is a valid |
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* configuration. |
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*/ |
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if (ret) { |
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if (ret != -EOPNOTSUPP) |
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pr_err("CPU %d failed to init idle CPU ops\n", cpu); |
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ret = ret == -ENXIO ? 0 : ret; |
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goto out_kfree_drv; |
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} |
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ret = cpuidle_register(drv, NULL); |
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if (ret) |
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goto out_kfree_drv; |
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cpuidle_cooling_register(drv); |
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return 0; |
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out_kfree_drv: |
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kfree(drv); |
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return ret; |
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} |
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/* |
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* arm_idle_init - Initializes arm cpuidle driver |
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* |
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* Initializes arm cpuidle driver for all CPUs, if any CPU fails |
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* to register cpuidle driver then rollback to cancel all CPUs |
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* registeration. |
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*/ |
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static int __init arm_idle_init(void) |
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{ |
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int cpu, ret; |
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struct cpuidle_driver *drv; |
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struct cpuidle_device *dev; |
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for_each_possible_cpu(cpu) { |
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ret = arm_idle_init_cpu(cpu); |
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if (ret) |
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goto out_fail; |
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} |
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return 0; |
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out_fail: |
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while (--cpu >= 0) { |
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dev = per_cpu(cpuidle_devices, cpu); |
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drv = cpuidle_get_cpu_driver(dev); |
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cpuidle_unregister(drv); |
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kfree(drv); |
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} |
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return ret; |
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} |
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device_initcall(arm_idle_init);
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