diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/configs/kirkwood_defconfig | 4 | ||||
| -rw-r--r-- | arch/arm/mach-kirkwood/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/mach-kirkwood/cpuidle.c | 96 | ||||
| -rw-r--r-- | arch/arm/mach-kirkwood/include/mach/kirkwood.h | 1 |
4 files changed, 102 insertions, 1 deletions
diff --git a/arch/arm/configs/kirkwood_defconfig b/arch/arm/configs/kirkwood_defconfig index dcf8153a947..bde56f40668 100644 --- a/arch/arm/configs/kirkwood_defconfig +++ b/arch/arm/configs/kirkwood_defconfig @@ -270,7 +270,9 @@ 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 8f03c9b9bdd..f21f35d8386 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 00000000000..f68d33f1f39 --- /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 <linux/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 b3e13958821..f20ff646048 100644 --- a/arch/arm/mach-kirkwood/include/mach/kirkwood.h +++ b/arch/arm/mach-kirkwood/include/mach/kirkwood.h @@ -48,6 +48,7 @@ */ #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) |