From: Rob Herring <[email protected]>
Add support for core powergating on Calxeda platforms. Initially, this
supports ECX-1000 (highbank), but support will be added for ECX-2000
later.
Signed-off-by: Rob Herring <[email protected]>
Cc: Len Brown <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
---
It's not really clear where we want ARM cpuidle drivers. We're moving
everything else out of arch/arm, and my understanding is Len doesn't want
them in drivers/idle. It seems kind of silly to me to have the framework
and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't
make any difference to me.
Rob
drivers/cpuidle/Kconfig | 10 +++
drivers/cpuidle/Makefile | 2 +
drivers/cpuidle/cpuidle-calxeda.c | 161 +++++++++++++++++++++++++++++++++++++
3 files changed, 173 insertions(+)
create mode 100644 drivers/cpuidle/cpuidle-calxeda.c
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index a76b689..d2d007b 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -21,3 +21,13 @@ config CPU_IDLE_GOV_MENU
config ARCH_NEEDS_CPU_IDLE_COUPLED
def_bool n
+
+if CPU_IDLE
+
+config CPU_IDLE_CALXEDA
+ bool "CPU Idle Driver for Calxeda processors"
+ depends on ARCH_HIGHBANK
+ help
+ Select this to enable cpuidle on Calxeda processors.
+
+endif
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 38c8f69..03ee874 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -4,3 +4,5 @@
obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
+
+obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
diff --git a/drivers/cpuidle/cpuidle-calxeda.c b/drivers/cpuidle/cpuidle-calxeda.c
new file mode 100644
index 0000000..e1aab38
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-calxeda.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2012 Calxeda, Inc.
+ *
+ * Based on arch/arm/plat-mxc/cpuidle.c:
+ * 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/>.
+ */
+
+#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 struct cpuidle_device __percpu *calxeda_idle_cpuidle_devices;
+
+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 void calxeda_idle_cpuidle_devices_uninit(void)
+{
+ int i;
+ struct cpuidle_device *dev;
+
+ for_each_possible_cpu(i) {
+ dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, i);
+ cpuidle_unregister_device(dev);
+ }
+
+ free_percpu(calxeda_idle_cpuidle_devices);
+}
+
+static struct cpuidle_driver calxeda_idle_driver = {
+ .name = "calxeda_idle",
+ .en_core_tk_irqen = 1,
+ .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)
+{
+ int cpu_id;
+ int ret;
+ struct cpuidle_device *dev;
+ struct cpuidle_driver *drv = &calxeda_idle_driver;
+
+ if (!of_machine_is_compatible("calxeda,highbank"))
+ return -ENODEV;
+
+ ret = cpuidle_register_driver(drv);
+ if (ret)
+ return ret;
+
+ calxeda_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ if (calxeda_idle_cpuidle_devices == NULL) {
+ ret = -ENOMEM;
+ goto unregister_drv;
+ }
+
+ /* initialize state data for each cpuidle_device */
+ for_each_possible_cpu(cpu_id) {
+ dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, cpu_id);
+ dev->cpu = cpu_id;
+ dev->state_count = drv->state_count;
+
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("Failed to register cpu %u, error: %d\n",
+ cpu_id, ret);
+ goto uninit;
+ }
+ }
+
+ return 0;
+
+uninit:
+ calxeda_idle_cpuidle_devices_uninit();
+unregister_drv:
+ cpuidle_unregister_driver(drv);
+ return ret;
+}
+module_init(calxeda_cpuidle_init);
--
1.7.10.4
On Wednesday 07 November 2012, Rob Herring wrote:
> From: Rob Herring <[email protected]>
>
> Add support for core powergating on Calxeda platforms. Initially, this
> supports ECX-1000 (highbank), but support will be added for ECX-2000
> later.
>
> Signed-off-by: Rob Herring <[email protected]>
> Cc: Len Brown <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
> It's not really clear where we want ARM cpuidle drivers. We're moving
> everything else out of arch/arm, and my understanding is Len doesn't want
> them in drivers/idle. It seems kind of silly to me to have the framework
> and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't
> make any difference to me.
Fine with me. I just don't want in in arch/arm because I'm guessing this will
be shared with arm64, which in turn shares idle (and other) drivers with various
powerpc, mips and x86 socs.
Arnd
On Monday, November 12, 2012 10:00:07 PM Arnd Bergmann wrote:
> On Wednesday 07 November 2012, Rob Herring wrote:
> > From: Rob Herring <[email protected]>
> >
> > Add support for core powergating on Calxeda platforms. Initially, this
> > supports ECX-1000 (highbank), but support will be added for ECX-2000
> > later.
> >
> > Signed-off-by: Rob Herring <[email protected]>
> > Cc: Len Brown <[email protected]>
> > Cc: "Rafael J. Wysocki" <[email protected]>
>
> Acked-by: Arnd Bergmann <[email protected]>
>
> > It's not really clear where we want ARM cpuidle drivers. We're moving
> > everything else out of arch/arm, and my understanding is Len doesn't want
> > them in drivers/idle. It seems kind of silly to me to have the framework
> > and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't
> > make any difference to me.
>
> Fine with me. I just don't want in in arch/arm because I'm guessing this will
> be shared with arm64, which in turn shares idle (and other) drivers with various
> powerpc, mips and x86 socs.
Applied to linux-pm.git/linux-next as v3.8 material.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
Rafael,
On Sat, Nov 24, 2012 at 2:03 AM, Rafael J. Wysocki <[email protected]> wrote:
> On Monday, November 12, 2012 10:00:07 PM Arnd Bergmann wrote:
>> On Wednesday 07 November 2012, Rob Herring wrote:
>> > From: Rob Herring <[email protected]>
>> >
>> > Add support for core powergating on Calxeda platforms. Initially, this
>> > supports ECX-1000 (highbank), but support will be added for ECX-2000
>> > later.
>> >
>> > Signed-off-by: Rob Herring <[email protected]>
>> > Cc: Len Brown <[email protected]>
>> > Cc: "Rafael J. Wysocki" <[email protected]>
>>
>> Acked-by: Arnd Bergmann <[email protected]>
>>
>> > It's not really clear where we want ARM cpuidle drivers. We're moving
>> > everything else out of arch/arm, and my understanding is Len doesn't want
>> > them in drivers/idle. It seems kind of silly to me to have the framework
>> > and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't
>> > make any difference to me.
>>
>> Fine with me. I just don't want in in arch/arm because I'm guessing this will
>> be shared with arm64, which in turn shares idle (and other) drivers with various
>> powerpc, mips and x86 socs.
>
> Applied to linux-pm.git/linux-next as v3.8 material.
We already have it in arm-soc. Since there's no maintainer listed for
the directory, it didn't seem like there were any better merge paths.
-Olof
On Saturday, November 24, 2012 03:21:49 PM Olof Johansson wrote:
> Rafael,
>
> On Sat, Nov 24, 2012 at 2:03 AM, Rafael J. Wysocki <[email protected]> wrote:
> > On Monday, November 12, 2012 10:00:07 PM Arnd Bergmann wrote:
> >> On Wednesday 07 November 2012, Rob Herring wrote:
> >> > From: Rob Herring <[email protected]>
> >> >
> >> > Add support for core powergating on Calxeda platforms. Initially, this
> >> > supports ECX-1000 (highbank), but support will be added for ECX-2000
> >> > later.
> >> >
> >> > Signed-off-by: Rob Herring <[email protected]>
> >> > Cc: Len Brown <[email protected]>
> >> > Cc: "Rafael J. Wysocki" <[email protected]>
> >>
> >> Acked-by: Arnd Bergmann <[email protected]>
> >>
> >> > It's not really clear where we want ARM cpuidle drivers. We're moving
> >> > everything else out of arch/arm, and my understanding is Len doesn't want
> >> > them in drivers/idle. It seems kind of silly to me to have the framework
> >> > and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't
> >> > make any difference to me.
> >>
> >> Fine with me. I just don't want in in arch/arm because I'm guessing this will
> >> be shared with arm64, which in turn shares idle (and other) drivers with various
> >> powerpc, mips and x86 socs.
> >
> > Applied to linux-pm.git/linux-next as v3.8 material.
>
> We already have it in arm-soc. Since there's no maintainer listed for
> the directory, it didn't seem like there were any better merge paths.
Cool, I'll drop it then.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.