linux-stable/drivers/cpuidle/cpuidle-calxeda.c
Daniel Lezcano a8e39c35b5 cpuidle: add maintainer entry
Currently cpuidle drivers are spread across different archs.

As a result, there are several different paths for cpuidle patch
submissions: cpuidle core changes go through linux-pm, ARM driver
changes go to the arm-soc or SoC-specific trees, sh changes go
through the sh arch tree, pseries changes go through the PowerPC tree
and finally intel changes go through the Len's tree while ACPI idle
changes go through linux-pm.

That makes it difficult to consolidate code and to propagate
modifications from the cpuidle core to the different drivers.

Hopefully, a movement has started to put the majority of cpuidle
drivers under drivers/cpuidle like cpuidle-calxeda.c and
cpuidle-kirkwood.c.

Add a maintainer entry for cpuidle to MAINTAINERS to clarify the
situation and to indicate to new cpuidle driver authors that those
drivers should not go into arch-specific directories.

The upstreaming process is unchanged: Rafael takes patches for
merging into his tree, but with an Acked-by: tag from the driver's
maintainer, so indicate in the drivers' headers who maintains them.

The arrangement will be the same as for cpufreq.

[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>  #for kirkwood
Acked-by: Jason Cooper <jason@lakedaemon.net> #for kirkwood
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-26 22:30:25 +02:00

112 lines
2.8 KiB
C

/*
* Copyright 2012 Calxeda, Inc.
*
* Based on arch/arm/plat-mxc/cpuidle.c: #v3.7
* Copyright 2012 Freescale Semiconductor, Inc.
* Copyright 2012 Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* Maintainer: Rob Herring <rob.herring@calxeda.com>
*/
#include <linux/cpuidle.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/suspend.h>
#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
#include <asm/smp_scu.h>
#include <asm/suspend.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
extern void *scu_base_addr;
static inline unsigned int get_auxcr(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val) : : "cc");
return val;
}
static inline void set_auxcr(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR"
: : "r" (val) : "cc");
isb();
}
static noinline void calxeda_idle_restore(void)
{
set_cr(get_cr() | CR_C);
set_auxcr(get_auxcr() | 0x40);
scu_power_mode(scu_base_addr, SCU_PM_NORMAL);
}
static int calxeda_idle_finish(unsigned long val)
{
/* Already flushed cache, but do it again as the outer cache functions
* dirty the cache with spinlocks */
flush_cache_all();
set_auxcr(get_auxcr() & ~0x40);
set_cr(get_cr() & ~CR_C);
scu_power_mode(scu_base_addr, SCU_PM_DORMANT);
cpu_do_idle();
/* Restore things if we didn't enter power-gating */
calxeda_idle_restore();
return 1;
}
static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
highbank_set_cpu_jump(smp_processor_id(), cpu_resume);
cpu_suspend(0, calxeda_idle_finish);
return index;
}
static struct cpuidle_driver calxeda_idle_driver = {
.name = "calxeda_idle",
.states = {
ARM_CPUIDLE_WFI_STATE,
{
.name = "PG",
.desc = "Power Gate",
.flags = CPUIDLE_FLAG_TIME_VALID,
.exit_latency = 30,
.power_usage = 50,
.target_residency = 200,
.enter = calxeda_pwrdown_idle,
},
},
.state_count = 2,
};
static int __init calxeda_cpuidle_init(void)
{
if (!of_machine_is_compatible("calxeda,highbank"))
return -ENODEV;
return cpuidle_register(&calxeda_idle_driver, NULL);
}
module_init(calxeda_cpuidle_init);