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