1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
4 */
5
6 #include <linux/context_tracking.h>
7 #include <linux/cpuidle.h>
8 #include <linux/module.h>
9 #include <asm/cpuidle.h>
10
11 #include <soc/imx/cpuidle.h>
12
13 #include "common.h"
14 #include "cpuidle.h"
15 #include "hardware.h"
16
17 static int num_idle_cpus = 0;
18 static DEFINE_RAW_SPINLOCK(cpuidle_lock);
19
20 static __cpuidle int imx6q_enter_wait(struct cpuidle_device *dev,
21 struct cpuidle_driver *drv, int index)
22 {
23 raw_spin_lock(&cpuidle_lock);
24 if (++num_idle_cpus == num_online_cpus())
25 imx6_set_lpm(WAIT_UNCLOCKED);
26 raw_spin_unlock(&cpuidle_lock);
27
28 ct_cpuidle_enter();
29 cpu_do_idle();
30 ct_cpuidle_exit();
31
32 raw_spin_lock(&cpuidle_lock);
33 if (num_idle_cpus-- == num_online_cpus())
34 imx6_set_lpm(WAIT_CLOCKED);
35 raw_spin_unlock(&cpuidle_lock);
36
37 return index;
38 }
39
40 static struct cpuidle_driver imx6q_cpuidle_driver = {
41 .name = "imx6q_cpuidle",
42 .owner = THIS_MODULE,
43 .states = {
44 /* WFI */
45 ARM_CPUIDLE_WFI_STATE,
46 /* WAIT */
47 {
48 .exit_latency = 50,
49 .target_residency = 75,
50 .flags = CPUIDLE_FLAG_TIMER_STOP | CPUIDLE_FLAG_RCU_IDLE,
51 .enter = imx6q_enter_wait,
52 .name = "WAIT",
53 .desc = "Clock off",
54 },
55 },
56 .state_count = 2,
57 .safe_state_index = 0,
58 };
59
60 /*
61 * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the
62 * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't
63 * applicable to all boards, disable the deeper idle state when the workaround
64 * isn't present and the FEC is in use.
65 */
66 void imx6q_cpuidle_fec_irqs_used(void)
67 {
68 cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, true);
69 }
70 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
71
72 void imx6q_cpuidle_fec_irqs_unused(void)
73 {
74 cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, false);
75 }
76 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
77
78 int __init imx6q_cpuidle_init(void)
79 {
80 /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
81 imx6_set_int_mem_clk_lpm(true);
82
83 return cpuidle_register(&imx6q_cpuidle_driver, NULL);
84 }
85
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