f28fd3b6f7
The PRCMU driver defines this as a DT node but there are no bindings for it and it needs no data from the device tree. Just spawn the device directly in the same way as the watchdog. Name it "db8500-cpuidle" since there are no ambitions to support any more SoCs than this one. This rids this annoying boot message: [ 0.032610] cpuidle-dbx500: Failed to locate of_node [id: 0] However I think the device still spawns and work just fine, despite not finding a device tree node. Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
125 lines
3.0 KiB
C
125 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (c) 2012 Linaro : Daniel Lezcano <daniel.lezcano@linaro.org> (IBM)
|
|
*
|
|
* Based on the work of Rickard Andersson <rickard.andersson@stericsson.com>
|
|
* and Jonas Aaberg <jonas.aberg@stericsson.com>.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/atomic.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/mfd/dbx500-prcmu.h>
|
|
#include <linux/platform_data/arm-ux500-pm.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include <asm/cpuidle.h>
|
|
|
|
static atomic_t master = ATOMIC_INIT(0);
|
|
static DEFINE_SPINLOCK(master_lock);
|
|
|
|
static inline int ux500_enter_idle(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv, int index)
|
|
{
|
|
int this_cpu = smp_processor_id();
|
|
bool recouple = false;
|
|
|
|
if (atomic_inc_return(&master) == num_online_cpus()) {
|
|
|
|
/* With this lock, we prevent the other cpu to exit and enter
|
|
* this function again and become the master */
|
|
if (!spin_trylock(&master_lock))
|
|
goto wfi;
|
|
|
|
/* decouple the gic from the A9 cores */
|
|
if (prcmu_gic_decouple()) {
|
|
spin_unlock(&master_lock);
|
|
goto out;
|
|
}
|
|
|
|
/* If an error occur, we will have to recouple the gic
|
|
* manually */
|
|
recouple = true;
|
|
|
|
/* At this state, as the gic is decoupled, if the other
|
|
* cpu is in WFI, we have the guarantee it won't be wake
|
|
* up, so we can safely go to retention */
|
|
if (!prcmu_is_cpu_in_wfi(this_cpu ? 0 : 1))
|
|
goto out;
|
|
|
|
/* The prcmu will be in charge of watching the interrupts
|
|
* and wake up the cpus */
|
|
if (prcmu_copy_gic_settings())
|
|
goto out;
|
|
|
|
/* Check in the meantime an interrupt did
|
|
* not occur on the gic ... */
|
|
if (prcmu_gic_pending_irq())
|
|
goto out;
|
|
|
|
/* ... and the prcmu */
|
|
if (prcmu_pending_irq())
|
|
goto out;
|
|
|
|
/* Go to the retention state, the prcmu will wait for the
|
|
* cpu to go WFI and this is what happens after exiting this
|
|
* 'master' critical section */
|
|
if (prcmu_set_power_state(PRCMU_AP_IDLE, true, true))
|
|
goto out;
|
|
|
|
/* When we switch to retention, the prcmu is in charge
|
|
* of recoupling the gic automatically */
|
|
recouple = false;
|
|
|
|
spin_unlock(&master_lock);
|
|
}
|
|
wfi:
|
|
cpu_do_idle();
|
|
out:
|
|
atomic_dec(&master);
|
|
|
|
if (recouple) {
|
|
prcmu_gic_recouple();
|
|
spin_unlock(&master_lock);
|
|
}
|
|
|
|
return index;
|
|
}
|
|
|
|
static struct cpuidle_driver ux500_idle_driver = {
|
|
.name = "ux500_idle",
|
|
.owner = THIS_MODULE,
|
|
.states = {
|
|
ARM_CPUIDLE_WFI_STATE,
|
|
{
|
|
.enter = ux500_enter_idle,
|
|
.exit_latency = 70,
|
|
.target_residency = 260,
|
|
.flags = CPUIDLE_FLAG_TIMER_STOP,
|
|
.name = "ApIdle",
|
|
.desc = "ARM Retention",
|
|
},
|
|
},
|
|
.safe_state_index = 0,
|
|
.state_count = 2,
|
|
};
|
|
|
|
static int dbx500_cpuidle_probe(struct platform_device *pdev)
|
|
{
|
|
/* Configure wake up reasons */
|
|
prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) |
|
|
PRCMU_WAKEUP(ABB));
|
|
|
|
return cpuidle_register(&ux500_idle_driver, NULL);
|
|
}
|
|
|
|
static struct platform_driver dbx500_cpuidle_plat_driver = {
|
|
.driver = {
|
|
.name = "db8500-cpuidle",
|
|
},
|
|
.probe = dbx500_cpuidle_probe,
|
|
};
|
|
builtin_platform_driver(dbx500_cpuidle_plat_driver);
|