diff options
Diffstat (limited to 'arch/arm/mach-kirkwood/cpuidle.c')
-rw-r--r-- | arch/arm/mach-kirkwood/cpuidle.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c new file mode 100644 index 00000000..0f171094 --- /dev/null +++ b/arch/arm/mach-kirkwood/cpuidle.c @@ -0,0 +1,73 @@ +/* + * 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 <linux/export.h> +#include <asm/proc-fns.h> +#include <asm/cpuidle.h> +#include <mach/kirkwood.h> + +#define KIRKWOOD_MAX_STATES 2 + +/* Actual code that puts the SoC in different idle states */ +static int kirkwood_enter_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + writel(0x7, DDR_OPERATION_BASE); + cpu_do_idle(); + + return index; +} + +static struct cpuidle_driver kirkwood_idle_driver = { + .name = "kirkwood_idle", + .owner = THIS_MODULE, + .en_core_tk_irqen = 1, + .states[0] = ARM_CPUIDLE_WFI_STATE, + .states[1] = { + .enter = kirkwood_enter_idle, + .exit_latency = 10, + .target_residency = 100000, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "DDR SR", + .desc = "WFI and DDR Self Refresh", + }, + .state_count = KIRKWOOD_MAX_STATES, +}; + +static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device); + +/* Initialize CPU idle by registering the idle states */ +static int kirkwood_init_cpuidle(void) +{ + struct cpuidle_device *device; + + device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id()); + device->state_count = KIRKWOOD_MAX_STATES; + + cpuidle_register_driver(&kirkwood_idle_driver); + if (cpuidle_register_device(device)) { + printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n"); + return -EIO; + } + return 0; +} + +device_initcall(kirkwood_init_cpuidle); |