162 lines
3.8 KiB
C
162 lines
3.8 KiB
C
/*
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* Copyright 2012 Calxeda, Inc.
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*
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* Based on arch/arm/plat-mxc/cpuidle.c:
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* Copyright 2012 Freescale Semiconductor, Inc.
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* Copyright 2012 Linaro Ltd.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/cpuidle.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/time.h>
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#include <linux/delay.h>
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#include <linux/suspend.h>
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#include <asm/cpuidle.h>
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#include <asm/proc-fns.h>
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#include <asm/smp_scu.h>
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#include <asm/suspend.h>
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#include <asm/cacheflush.h>
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#include <asm/cp15.h>
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extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
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extern void *scu_base_addr;
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static struct cpuidle_device __percpu *calxeda_idle_cpuidle_devices;
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static inline unsigned int get_auxcr(void)
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{
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unsigned int val;
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asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val) : : "cc");
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return val;
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}
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static inline void set_auxcr(unsigned int val)
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{
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asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR"
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: : "r" (val) : "cc");
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isb();
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}
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static noinline void calxeda_idle_restore(void)
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{
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set_cr(get_cr() | CR_C);
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set_auxcr(get_auxcr() | 0x40);
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scu_power_mode(scu_base_addr, SCU_PM_NORMAL);
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}
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static int calxeda_idle_finish(unsigned long val)
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{
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/* Already flushed cache, but do it again as the outer cache functions
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* dirty the cache with spinlocks */
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flush_cache_all();
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set_auxcr(get_auxcr() & ~0x40);
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set_cr(get_cr() & ~CR_C);
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scu_power_mode(scu_base_addr, SCU_PM_DORMANT);
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cpu_do_idle();
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/* Restore things if we didn't enter power-gating */
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calxeda_idle_restore();
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return 1;
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}
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static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
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struct cpuidle_driver *drv,
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int index)
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{
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highbank_set_cpu_jump(smp_processor_id(), cpu_resume);
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cpu_suspend(0, calxeda_idle_finish);
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return index;
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}
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static void calxeda_idle_cpuidle_devices_uninit(void)
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{
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int i;
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struct cpuidle_device *dev;
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for_each_possible_cpu(i) {
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dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, i);
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cpuidle_unregister_device(dev);
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}
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free_percpu(calxeda_idle_cpuidle_devices);
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}
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static struct cpuidle_driver calxeda_idle_driver = {
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.name = "calxeda_idle",
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.en_core_tk_irqen = 1,
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.states = {
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ARM_CPUIDLE_WFI_STATE,
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{
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.name = "PG",
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.desc = "Power Gate",
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.flags = CPUIDLE_FLAG_TIME_VALID,
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.exit_latency = 30,
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.power_usage = 50,
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.target_residency = 200,
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.enter = calxeda_pwrdown_idle,
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},
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},
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.state_count = 2,
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};
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static int __init calxeda_cpuidle_init(void)
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{
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int cpu_id;
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int ret;
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struct cpuidle_device *dev;
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struct cpuidle_driver *drv = &calxeda_idle_driver;
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if (!of_machine_is_compatible("calxeda,highbank"))
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return -ENODEV;
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ret = cpuidle_register_driver(drv);
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if (ret)
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return ret;
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calxeda_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
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if (calxeda_idle_cpuidle_devices == NULL) {
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ret = -ENOMEM;
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goto unregister_drv;
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}
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/* initialize state data for each cpuidle_device */
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for_each_possible_cpu(cpu_id) {
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dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, cpu_id);
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dev->cpu = cpu_id;
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dev->state_count = drv->state_count;
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ret = cpuidle_register_device(dev);
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if (ret) {
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pr_err("Failed to register cpu %u, error: %d\n",
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cpu_id, ret);
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goto uninit;
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}
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}
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return 0;
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uninit:
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calxeda_idle_cpuidle_devices_uninit();
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unregister_drv:
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cpuidle_unregister_driver(drv);
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return ret;
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}
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module_init(calxeda_cpuidle_init);
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