72 lines
1.3 KiB
C
72 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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*
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* RISCV generic CPU idle driver.
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*
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* Copyright (C) 2020 ALLWINNERTECH.
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* Author: liush <liush@allwinnertech.com>
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*/
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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 <linux/platform_device.h>
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#include <asm/sbi.h>
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#include "dt_idle_states.h"
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#define MAX_IDLE_STATES 1
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static int riscv_enter_idle(struct cpuidle_device *dev,
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struct cpuidle_driver *drv, int index)
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{
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struct sbiret ret;
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ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
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0, 0, 0, 0, 0, 0);
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return ret.error;
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}
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static struct cpuidle_driver riscv_idle_driver = {
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.name = "riscv_idle",
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.owner = THIS_MODULE,
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.states[0] = {
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.enter = riscv_enter_idle,
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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 = "RISCV WFI",
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},
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.state_count = MAX_IDLE_STATES,
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};
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static int __init riscv_idle_init(void)
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{
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int ret;
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struct cpuidle_driver *drv;
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drv = kmemdup(&riscv_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(0);
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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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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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device_initcall(riscv_idle_init);
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