| 1 | /* |
| 2 | * based on arch/arm/mach-kirkwood/cpuidle.c |
| 3 | * |
| 4 | * CPU idle support for AT91 SoC |
| 5 | * |
| 6 | * This file is licensed under the terms of the GNU General Public |
| 7 | * License version 2. This program is licensed "as is" without any |
| 8 | * warranty of any kind, whether express or implied. |
| 9 | * |
| 10 | * The cpu idle uses wait-for-interrupt and RAM self refresh in order |
| 11 | * to implement two idle states - |
| 12 | * #1 wait-for-interrupt |
| 13 | * #2 wait-for-interrupt and RAM self refresh |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/platform_device.h> |
| 19 | #include <linux/cpuidle.h> |
| 20 | #include <linux/io.h> |
| 21 | #include <linux/export.h> |
| 22 | #include <asm/proc-fns.h> |
| 23 | #include <asm/cpuidle.h> |
| 24 | #include <mach/cpu.h> |
| 25 | |
| 26 | #include "pm.h" |
| 27 | |
| 28 | #define AT91_MAX_STATES 2 |
| 29 | |
| 30 | /* Actual code that puts the SoC in different idle states */ |
| 31 | static int at91_enter_idle(struct cpuidle_device *dev, |
| 32 | struct cpuidle_driver *drv, |
| 33 | int index) |
| 34 | { |
| 35 | if (cpu_is_at91rm9200()) |
| 36 | at91rm9200_standby(); |
| 37 | else if (cpu_is_at91sam9g45()) |
| 38 | at91sam9g45_standby(); |
| 39 | else if (cpu_is_at91sam9263()) |
| 40 | at91sam9263_standby(); |
| 41 | else |
| 42 | at91sam9_standby(); |
| 43 | |
| 44 | return index; |
| 45 | } |
| 46 | |
| 47 | static struct cpuidle_driver at91_idle_driver = { |
| 48 | .name = "at91_idle", |
| 49 | .owner = THIS_MODULE, |
| 50 | .states[0] = ARM_CPUIDLE_WFI_STATE, |
| 51 | .states[1] = { |
| 52 | .enter = at91_enter_idle, |
| 53 | .exit_latency = 10, |
| 54 | .target_residency = 100000, |
| 55 | .flags = CPUIDLE_FLAG_TIME_VALID, |
| 56 | .name = "RAM_SR", |
| 57 | .desc = "WFI and DDR Self Refresh", |
| 58 | }, |
| 59 | .state_count = AT91_MAX_STATES, |
| 60 | }; |
| 61 | |
| 62 | /* Initialize CPU idle by registering the idle states */ |
| 63 | static int __init at91_init_cpuidle(void) |
| 64 | { |
| 65 | return cpuidle_register(&at91_idle_driver, NULL); |
| 66 | } |
| 67 | |
| 68 | device_initcall(at91_init_cpuidle); |