projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 12bb3440 SG |
1 | /* |
| 2 | * Copyright (C) 2012 Freescale Semiconductor, Inc. | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify | |
| 5 | * it under the terms of the GNU General Public License version 2 as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <linux/cpuidle.h> | |
| 10 | #include <linux/module.h> | |
| 11 | #include <asm/cpuidle.h> | |
| 12 | ||
| e5f9dec8 | 13 | #include "common.h" |
| 12bb3440 | 14 | #include "cpuidle.h" |
| a25d67a4 | 15 | #include "hardware.h" |
| 12bb3440 | 16 | |
| e5f9dec8 SG |
17 | static atomic_t master = ATOMIC_INIT(0); |
| 18 | static DEFINE_SPINLOCK(master_lock); | |
| 19 | ||
| 20 | static int imx6q_enter_wait(struct cpuidle_device *dev, | |
| 21 | struct cpuidle_driver *drv, int index) | |
| 22 | { | |
| e5f9dec8 SG |
23 | if (atomic_inc_return(&master) == num_online_cpus()) { |
| 24 | /* | |
| 25 | * With this lock, we prevent other cpu to exit and enter | |
| 26 | * this function again and become the master. | |
| 27 | */ | |
| 28 | if (!spin_trylock(&master_lock)) | |
| 29 | goto idle; | |
| 8fb76a07 | 30 | imx6_set_lpm(WAIT_UNCLOCKED); |
| e5f9dec8 | 31 | cpu_do_idle(); |
| 8fb76a07 | 32 | imx6_set_lpm(WAIT_CLOCKED); |
| e5f9dec8 SG |
33 | spin_unlock(&master_lock); |
| 34 | goto done; | |
| 35 | } | |
| 36 | ||
| 37 | idle: | |
| 38 | cpu_do_idle(); | |
| 39 | done: | |
| 40 | atomic_dec(&master); | |
| e5f9dec8 SG |
41 | |
| 42 | return index; | |
| 43 | } | |
| 44 | ||
| 12bb3440 SG |
45 | static struct cpuidle_driver imx6q_cpuidle_driver = { |
| 46 | .name = "imx6q_cpuidle", | |
| 47 | .owner = THIS_MODULE, | |
| e5f9dec8 SG |
48 | .states = { |
| 49 | /* WFI */ | |
| 50 | ARM_CPUIDLE_WFI_STATE, | |
| 51 | /* WAIT */ | |
| 52 | { | |
| 53 | .exit_latency = 50, | |
| 54 | .target_residency = 75, | |
| b82b6cca | 55 | .flags = CPUIDLE_FLAG_TIMER_STOP, |
| e5f9dec8 SG |
56 | .enter = imx6q_enter_wait, |
| 57 | .name = "WAIT", | |
| 58 | .desc = "Clock off", | |
| 59 | }, | |
| 60 | }, | |
| 61 | .state_count = 2, | |
| 62 | .safe_state_index = 0, | |
| 12bb3440 SG |
63 | }; |
| 64 | ||
| 29380905 LS |
65 | /* |
| 66 | * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the | |
| 67 | * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't | |
| 68 | * applicable to all boards, disable the deeper idle state when the workaround | |
| 69 | * isn't present and the FEC is in use. | |
| 70 | */ | |
| 71 | void imx6q_cpuidle_fec_irqs_used(void) | |
| 72 | { | |
| 73 | imx6q_cpuidle_driver.states[1].disabled = true; | |
| 74 | } | |
| 2cb9caa4 | 75 | EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used); |
| 29380905 LS |
76 | |
| 77 | void imx6q_cpuidle_fec_irqs_unused(void) | |
| 78 | { | |
| 79 | imx6q_cpuidle_driver.states[1].disabled = false; | |
| 80 | } | |
| 2cb9caa4 | 81 | EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused); |
| 29380905 | 82 | |
| 12bb3440 SG |
83 | int __init imx6q_cpuidle_init(void) |
| 84 | { | |
| fa6be65e | 85 | /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */ |
| dfea953a | 86 | imx6q_set_int_mem_clk_lpm(true); |
| e5f9dec8 | 87 | |
| 54a4644b | 88 | return cpuidle_register(&imx6q_cpuidle_driver, NULL); |
| 12bb3440 | 89 | } |