On 17/02/2014 09:49, Daniel Lezcano wrote:

On 02/13/2014 06:33 PM, Gregory CLEMENT wrote:

quoted

Add the wfi, cpu idle and cpu deep idle power states support for the
Armada XP SoCs.

All the latencies and the power consumption values used at the
"armada_370_xp_idle_driver" structure are preliminary and will be
modified in the future after running some measurements and analysis.

Based on the work of Nadav Haklai.

Signed-off-by: Nadav Haklai <redacted>
Signed-off-by: Gregory CLEMENT <redacted>
---
  drivers/cpuidle/Kconfig.arm             |   5 ++
  drivers/cpuidle/Makefile                |   1 +
  drivers/cpuidle/cpuidle-armada-370-xp.c | 120 ++++++++++++++++++++++++++++++++
  3 files changed, 126 insertions(+)
  create mode 100644 drivers/cpuidle/cpuidle-armada-370-xp.c

diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index d988948a89a0..f377eb0840e3 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm

@@ -1,6 +1,11 @@
  #
  # ARM CPU Idle drivers
  #
+config ARM_ARMADA_370_XP_CPUIDLE
+	bool "CPU Idle Driver for Armada 370/XP family processors"
+	depends on ARCH_MVEBU
+	help
+	  Select this to enable cpuidle on Armada 370/XP processors.

  config ARM_BIG_LITTLE_CPUIDLE
  	bool "Support for ARM big.LITTLE processors"

diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index f71ae1b373c5..9902d052bd87 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile

@@ -7,6 +7,7 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o

  ##################################################################################
  # ARM SoC drivers
+obj-$(CONFIG_ARM_ARMADA_370_XP_CPUIDLE) += cpuidle-armada-370-xp.o
  obj-$(CONFIG_ARM_BIG_LITTLE_CPUIDLE)	+= cpuidle-big_little.o
  obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE)	+= cpuidle-calxeda.o
  obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o

diff --git a/drivers/cpuidle/cpuidle-armada-370-xp.c b/drivers/cpuidle/cpuidle-armada-370-xp.c
new file mode 100644
index 000000000000..57c69812e79d
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-armada-370-xp.c

@@ -0,0 +1,120 @@
+/*
+ * Marvell Armada 370 and Armada XP SoC cpuidle driver
+ *
+ * Copyright (C) 2013 Marvell
+ *
+ * Nadav Haklai <nadavh@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Maintainer: Gregory CLEMENT <gregory.clement@free-electrons.com>
+ */

Hi Gregory,

quoted

+#include <linux/cpu_pm.h>
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/suspend.h>
+#include <asm/suspend.h>
+#include <linux/smp.h>
+#include <asm/cpuidle.h>
+#include <asm/smp_plat.h>
+#include <linux/platform_device.h>
+#include <asm/cp15.h>
+#include <asm/cacheflush.h>

the convention for the drivers inside this directory is to not include 
<asm/*>.

Well it is not the case yet:

git grep asm drivers/cpuidle/cpuidle-* | wc -l
25

Most of the time it was asm/cpuidle.h which was needed for using
ARM_CPUIDLE_WFI_STATE. However I try to remove most of the header from
asm/ by following your other advises.

quoted

+#define ARMADA_370_XP_MAX_STATES	3
+#define ARMADA_370_XP_FLAG_DEEP_IDLE	0x10000
+extern void armada_370_xp_pmsu_idle_prepare(bool deepidle);
+extern void ll_clear_cpu_coherent(void);
+extern void ll_set_cpu_coherent(void);

Here you have to declare three low level functions which should not be 
visible in this driver.

I think you can go one step more in the code encapsulation by doing like 
the cpuidle-at91 driver:
	* Move armada_370_xp_cpu_suspend inside arch/arm/mach-mvebu/pm.c or 
whereever you want
	* Assign the suspend function to the platform device data file
	* Get the suspend function as a callback for suspend from the field above

Ok I have done it in the 5th version.

quoted

+noinline static int armada_370_xp_cpu_suspend(unsigned long deepidle)
+{
+	armada_370_xp_pmsu_idle_prepare(deepidle);
+
+	v7_exit_coherency_flush(all);
+
+	ll_clear_cpu_coherent();
+
+	dsb();
+
+	wfi();
+
+	ll_set_cpu_coherent();
+
+	asm volatile(
+	"mrc	p15, 0, %0, c1, c0, 0 \n\t"
+	"tst	%0, #(1 << 2) \n\t"
+	"orreq	r0, %0, #(1 << 2) \n\t"
+	"mcreq	p15, 0, %0, c1, c0, 0 \n\t"
+	"isb	"
+	: : "r" (0));
+
+	return 0;
+}
+
+static int armada_370_xp_enter_idle(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	bool deepidle = false;
+	cpu_pm_enter();
+
+	if (drv->states[index].flags & ARMADA_370_XP_FLAG_DEEP_IDLE)
+		deepidle = true;
+
+	cpu_suspend(deepidle, armada_370_xp_cpu_suspend);
+
+	cpu_pm_exit();
+
+	return index;
+}
+
+static struct cpuidle_driver armada_370_xp_idle_driver = {
+	.name			= "armada_370_xp_idle",
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= armada_370_xp_enter_idle,
+		.exit_latency		= 10,
+		.power_usage		= 50,
+		.target_residency	= 100,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "MV CPU IDLE",
+		.desc			= "CPU power down",
+	},
+	.states[2]		= {
+		.enter			= armada_370_xp_enter_idle,
+		.exit_latency		= 100,
+		.power_usage		= 5,
+		.target_residency	= 1000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID |
+						ARMADA_370_XP_FLAG_DEEP_IDLE,
+		.name			= "MV CPU DEEP IDLE",
+		.desc			= "CPU and L2 Fabric power down",
+	},
+	.state_count = ARMADA_370_XP_MAX_STATES,
+};
+
+static int armada_370_xp_cpuidle_probe(struct platform_device *pdev)
+{
+	return cpuidle_register(&armada_370_xp_idle_driver, NULL);
+}
+
+static struct platform_driver armada_370_xp_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-armada-370-xp",
+		.owner = THIS_MODULE,
+	},
+	.probe = armada_370_xp_cpuidle_probe,
+};
+
+module_platform_driver(armada_370_xp_cpuidle_plat_driver);
+
+MODULE_AUTHOR("Gregory CLEMENT [off-list ref]");
+MODULE_DESCRIPTION("Armada 370/XP cpu idle driver");
+MODULE_LICENSE("GPL");

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com