1 /* 2 * OMAP4+ CPU idle Routines 3 * 4 * Copyright (C) 2011-2013 Texas Instruments, Inc. 5 * Santosh Shilimkar <santosh.shilimkar@ti.com> 6 * Rajendra Nayak <rnayak@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/sched.h> 14 #include <linux/cpuidle.h> 15 #include <linux/cpu_pm.h> 16 #include <linux/export.h> 17 18 #include <asm/cpuidle.h> 19 #include <asm/proc-fns.h> 20 21 #include "common.h" 22 #include "pm.h" 23 #include "prm.h" 24 #include "clockdomain.h" 25 26 /* Machine specific information */ 27 struct idle_statedata { 28 u32 cpu_state; 29 u32 mpu_logic_state; 30 u32 mpu_state; 31 }; 32 33 static struct idle_statedata omap4_idle_data[] = { 34 { 35 .cpu_state = PWRDM_POWER_ON, 36 .mpu_state = PWRDM_POWER_ON, 37 .mpu_logic_state = PWRDM_POWER_RET, 38 }, 39 { 40 .cpu_state = PWRDM_POWER_OFF, 41 .mpu_state = PWRDM_POWER_RET, 42 .mpu_logic_state = PWRDM_POWER_RET, 43 }, 44 { 45 .cpu_state = PWRDM_POWER_OFF, 46 .mpu_state = PWRDM_POWER_RET, 47 .mpu_logic_state = PWRDM_POWER_OFF, 48 }, 49 }; 50 51 static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS]; 52 static struct clockdomain *cpu_clkdm[NR_CPUS]; 53 54 static atomic_t abort_barrier; 55 static bool cpu_done[NR_CPUS]; 56 static struct idle_statedata *state_ptr = &omap4_idle_data[0]; 57 58 /* Private functions */ 59 60 /** 61 * omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions 62 * @dev: cpuidle device 63 * @drv: cpuidle driver 64 * @index: the index of state to be entered 65 * 66 * Called from the CPUidle framework to program the device to the 67 * specified low power state selected by the governor. 68 * Returns the amount of time spent in the low power state. 69 */ 70 static int omap_enter_idle_simple(struct cpuidle_device *dev, 71 struct cpuidle_driver *drv, 72 int index) 73 { 74 omap_do_wfi(); 75 return index; 76 } 77 78 static int omap_enter_idle_coupled(struct cpuidle_device *dev, 79 struct cpuidle_driver *drv, 80 int index) 81 { 82 struct idle_statedata *cx = state_ptr + index; 83 84 /* 85 * CPU0 has to wait and stay ON until CPU1 is OFF state. 86 * This is necessary to honour hardware recommondation 87 * of triggeing all the possible low power modes once CPU1 is 88 * out of coherency and in OFF mode. 89 */ 90 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { 91 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) { 92 cpu_relax(); 93 94 /* 95 * CPU1 could have already entered & exited idle 96 * without hitting off because of a wakeup 97 * or a failed attempt to hit off mode. Check for 98 * that here, otherwise we could spin forever 99 * waiting for CPU1 off. 100 */ 101 if (cpu_done[1]) 102 goto fail; 103 104 } 105 } 106 107 /* 108 * Call idle CPU PM enter notifier chain so that 109 * VFP and per CPU interrupt context is saved. 110 */ 111 cpu_pm_enter(); 112 113 if (dev->cpu == 0) { 114 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); 115 omap_set_pwrdm_state(mpu_pd, cx->mpu_state); 116 117 /* 118 * Call idle CPU cluster PM enter notifier chain 119 * to save GIC and wakeupgen context. 120 */ 121 if ((cx->mpu_state == PWRDM_POWER_RET) && 122 (cx->mpu_logic_state == PWRDM_POWER_OFF)) 123 cpu_cluster_pm_enter(); 124 } 125 126 omap4_enter_lowpower(dev->cpu, cx->cpu_state); 127 cpu_done[dev->cpu] = true; 128 129 /* Wakeup CPU1 only if it is not offlined */ 130 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { 131 clkdm_wakeup(cpu_clkdm[1]); 132 omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON); 133 clkdm_allow_idle(cpu_clkdm[1]); 134 } 135 136 /* 137 * Call idle CPU PM exit notifier chain to restore 138 * VFP and per CPU IRQ context. 139 */ 140 cpu_pm_exit(); 141 142 /* 143 * Call idle CPU cluster PM exit notifier chain 144 * to restore GIC and wakeupgen context. 145 */ 146 if ((cx->mpu_state == PWRDM_POWER_RET) && 147 (cx->mpu_logic_state == PWRDM_POWER_OFF)) 148 cpu_cluster_pm_exit(); 149 150 fail: 151 cpuidle_coupled_parallel_barrier(dev, &abort_barrier); 152 cpu_done[dev->cpu] = false; 153 154 return index; 155 } 156 157 static struct cpuidle_driver omap4_idle_driver = { 158 .name = "omap4_idle", 159 .owner = THIS_MODULE, 160 .states = { 161 { 162 /* C1 - CPU0 ON + CPU1 ON + MPU ON */ 163 .exit_latency = 2 + 2, 164 .target_residency = 5, 165 .flags = CPUIDLE_FLAG_TIME_VALID, 166 .enter = omap_enter_idle_simple, 167 .name = "C1", 168 .desc = "CPUx ON, MPUSS ON" 169 }, 170 { 171 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */ 172 .exit_latency = 328 + 440, 173 .target_residency = 960, 174 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED | 175 CPUIDLE_FLAG_TIMER_STOP, 176 .enter = omap_enter_idle_coupled, 177 .name = "C2", 178 .desc = "CPUx OFF, MPUSS CSWR", 179 }, 180 { 181 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ 182 .exit_latency = 460 + 518, 183 .target_residency = 1100, 184 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED | 185 CPUIDLE_FLAG_TIMER_STOP, 186 .enter = omap_enter_idle_coupled, 187 .name = "C3", 188 .desc = "CPUx OFF, MPUSS OSWR", 189 }, 190 }, 191 .state_count = ARRAY_SIZE(omap4_idle_data), 192 .safe_state_index = 0, 193 }; 194 195 /* Public functions */ 196 197 /** 198 * omap4_idle_init - Init routine for OMAP4+ idle 199 * 200 * Registers the OMAP4+ specific cpuidle driver to the cpuidle 201 * framework with the valid set of states. 202 */ 203 int __init omap4_idle_init(void) 204 { 205 mpu_pd = pwrdm_lookup("mpu_pwrdm"); 206 cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm"); 207 cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm"); 208 if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1])) 209 return -ENODEV; 210 211 cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm"); 212 cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm"); 213 if (!cpu_clkdm[0] || !cpu_clkdm[1]) 214 return -ENODEV; 215 216 return cpuidle_register(&omap4_idle_driver, cpu_online_mask); 217 } 218