linux-kirkwood_2.6.29.2.bb : add CPUIDLE support so hopefully we waste

less power while idle

1 files changed, 162 insertions, 0 deletions

diff --git a/recipes/linux/linux-kirkwood/0001--ARM-Kirkwood-CPU-idle-driver.patch b/recipes/linux/linux-kirkwood/0001--ARM-Kirkwood-CPU-idle-driver.patch
new file mode 100644
index 0000000000..29e7851c7f
--- /dev/null
+++ b/recipes/linux/linux-kirkwood/0001--ARM-Kirkwood-CPU-idle-driver.patch
@@ -0,0 +1,162 @@
+From 286f96f0b2e1ee5a124effba59a01f8d4bf69ddf Mon Sep 17 00:00:00 2001
+From: Rabeeh Khoury <rabeeh@marvell.com>
+Date: Tue, 24 Mar 2009 16:10:15 +0200
+Subject: [PATCH] [ARM] Kirkwood: CPU idle driver
+
+The patch adds support for Kirkwood cpu idle.
+Two idle states are defined:
+1. Wait-for-interrupt (replacing default kirkwood wfi)
+2. Wait-for-interrupt and DDR self refresh
+
+Signed-off-by: Rabeeh Khoury <rabeeh@marvell.com>
+Signed-off-by: Nicolas Pitre <nico@marvell.com>
+---
+ arch/arm/configs/kirkwood_defconfig            |    4 +-
+ arch/arm/mach-kirkwood/Makefile                |    2 +
+ arch/arm/mach-kirkwood/cpuidle.c               |   96 ++++++++++++++++++++++++
+ arch/arm/mach-kirkwood/include/mach/kirkwood.h |    1 +
+ 4 files changed, 102 insertions(+), 1 deletions(-)
+ create mode 100644 arch/arm/mach-kirkwood/cpuidle.c
+
+diff --git a/arch/arm/configs/kirkwood_defconfig b/arch/arm/configs/kirkwood_defconfig
+index c367ae4..a99b3eb 100644
+--- a/arch/arm/configs/kirkwood_defconfig
++++ b/arch/arm/configs/kirkwood_defconfig
+@@ -263,7 +263,9 @@ CONFIG_CMDLINE=""
+ #
+ # CPU Power Management
+ #
+-# CONFIG_CPU_IDLE is not set
++CONFIG_CPU_IDLE=y
++CONFIG_CPU_IDLE_GOV_LADDER=y
++CONFIG_CPU_IDLE_GOV_MENU=y
+ 
+ #
+ # Floating point emulation
+diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile
+index 8f03c9b..f21f35d 100644
+--- a/arch/arm/mach-kirkwood/Makefile
++++ b/arch/arm/mach-kirkwood/Makefile
+@@ -5,3 +5,5 @@ obj-$(CONFIG_MACH_RD88F6192_NAS)	+= rd88f6192-nas-setup.o
+ obj-$(CONFIG_MACH_RD88F6281)		+= rd88f6281-setup.o
+ obj-$(CONFIG_MACH_SHEEVAPLUG)		+= sheevaplug-setup.o
+ obj-$(CONFIG_MACH_TS219)		+= ts219-setup.o
++
++obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
+diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c
+new file mode 100644
+index 0000000..43052c7
+--- /dev/null
++++ b/arch/arm/mach-kirkwood/cpuidle.c
+@@ -0,0 +1,96 @@
++/*
++ * arch/arm/mach-kirkwood/cpuidle.c
++ *
++ * CPU idle Marvell Kirkwood SoCs
++ *
++ * 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.
++ *
++ * The cpu idle uses wait-for-interrupt and DDR self refresh in order
++ * to implement two idle states -
++ * #1 wait-for-interrupt
++ * #2 wait-for-interrupt and DDR self refresh
++ */
++
++#include <linux/kernel.h>
++#include <linux/init.h>
++#include <linux/platform_device.h>
++#include <linux/cpuidle.h>
++#include <asm/io.h>
++#include <asm/proc-fns.h>
++#include <mach/kirkwood.h>
++
++#define KIRKWOOD_MAX_STATES	2
++
++static struct cpuidle_driver kirkwood_idle_driver = {
++	.name =         "kirkwood_idle",
++	.owner =        THIS_MODULE,
++};
++
++static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device);
++
++/* Actual code that puts the SoC in different idle states */
++static int kirkwood_enter_idle(struct cpuidle_device *dev,
++			       struct cpuidle_state *state)
++{
++	struct timeval before, after;
++	int idle_time;
++
++	local_irq_disable();
++	do_gettimeofday(&before);
++	if (state == &dev->states[0])
++		/* Wait for interrupt state */
++		cpu_do_idle();
++	else if (state == &dev->states[1]) {
++		/*
++		 * Following write will put DDR in self refresh.
++		 * Note that we have 256 cycles before DDR puts it
++		 * self in self-refresh, so the wait-for-interrupt
++		 * call afterwards won't get the DDR from self refresh
++		 * mode.
++		 */
++		writel(0x7, DDR_OPERATION_BASE);
++		cpu_do_idle();
++	}
++	do_gettimeofday(&after);
++	local_irq_enable();
++	idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
++			(after.tv_usec - before.tv_usec);
++	return idle_time;
++}
++
++/* Initialize CPU idle by registering the idle states */
++static int kirkwood_init_cpuidle(void)
++{
++	struct cpuidle_device *device;
++
++	cpuidle_register_driver(&kirkwood_idle_driver);
++
++	device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id());
++	device->state_count = KIRKWOOD_MAX_STATES;
++
++	/* Wait for interrupt state */
++	device->states[0].enter = kirkwood_enter_idle;
++	device->states[0].exit_latency = 1;
++	device->states[0].target_residency = 10000;
++	device->states[0].flags = CPUIDLE_FLAG_TIME_VALID;
++	strcpy(device->states[0].name, "WFI");
++	strcpy(device->states[0].desc, "Wait for interrupt");
++
++	/* Wait for interrupt and DDR self refresh state */
++	device->states[1].enter = kirkwood_enter_idle;
++	device->states[1].exit_latency = 10;
++	device->states[1].target_residency = 10000;
++	device->states[1].flags = CPUIDLE_FLAG_TIME_VALID;
++	strcpy(device->states[1].name, "DDR SR");
++	strcpy(device->states[1].desc, "WFI and DDR Self Refresh");
++
++	if (cpuidle_register_device(device)) {
++		printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n");
++		return -EIO;
++	}
++	return 0;
++}
++
++device_initcall(kirkwood_init_cpuidle);
+diff --git a/arch/arm/mach-kirkwood/include/mach/kirkwood.h b/arch/arm/mach-kirkwood/include/mach/kirkwood.h
+index 38c9868..e9ae73d 100644
+--- a/arch/arm/mach-kirkwood/include/mach/kirkwood.h
++++ b/arch/arm/mach-kirkwood/include/mach/kirkwood.h
+@@ -86,6 +86,7 @@
+  */
+ #define DDR_VIRT_BASE		(KIRKWOOD_REGS_VIRT_BASE | 0x00000)
+ #define  DDR_WINDOW_CPU_BASE	(DDR_VIRT_BASE | 0x1500)
++#define DDR_OPERATION_BASE	(DDR_VIRT_BASE | 0x1418)
+ 
+ #define DEV_BUS_PHYS_BASE	(KIRKWOOD_REGS_PHYS_BASE | 0x10000)
+ #define DEV_BUS_VIRT_BASE	(KIRKWOOD_REGS_VIRT_BASE | 0x10000)
+-- 
+1.6.0.4
+