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 u32 mpuss_can_lose_context = 0; 84 85 /* 86 * CPU0 has to wait and stay ON until CPU1 is OFF state. 87 * This is necessary to honour hardware recommondation 88 * of triggeing all the possible low power modes once CPU1 is 89 * out of coherency and in OFF mode. 90 */ 91 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { 92 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) { 93 cpu_relax(); 94 95 /* 96 * CPU1 could have already entered & exited idle 97 * without hitting off because of a wakeup 98 * or a failed attempt to hit off mode. Check for 99 * that here, otherwise we could spin forever 100 * waiting for CPU1 off. 101 */ 102 if (cpu_done[1]) 103 goto fail; 104 105 } 106 } 107 108 mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) && 109 (cx->mpu_logic_state == PWRDM_POWER_OFF); 110 111 /* 112 * Call idle CPU PM enter notifier chain so that 113 * VFP and per CPU interrupt context is saved. 114 */ 115 cpu_pm_enter(); 116 117 if (dev->cpu == 0) { 118 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); 119 omap_set_pwrdm_state(mpu_pd, cx->mpu_state); 120 121 /* 122 * Call idle CPU cluster PM enter notifier chain 123 * to save GIC and wakeupgen context. 124 */ 125 if (mpuss_can_lose_context) 126 cpu_cluster_pm_enter(); 127 } 128 129 omap4_enter_lowpower(dev->cpu, cx->cpu_state); 130 cpu_done[dev->cpu] = true; 131 132 /* Wakeup CPU1 only if it is not offlined */ 133 if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { 134 135 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && 136 mpuss_can_lose_context) 137 gic_dist_disable(); 138 139 clkdm_wakeup(cpu_clkdm[1]); 140 omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON); 141 clkdm_allow_idle(cpu_clkdm[1]); 142 143 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && 144 mpuss_can_lose_context) { 145 while (gic_dist_disabled()) { 146 udelay(1); 147 cpu_relax(); 148 } 149 gic_timer_retrigger(); 150 } 151 } 152 153 /* 154 * Call idle CPU PM exit notifier chain to restore 155 * VFP and per CPU IRQ context. 156 */ 157 cpu_pm_exit(); 158 159 /* 160 * Call idle CPU cluster PM exit notifier chain 161 * to restore GIC and wakeupgen context. 162 */ 163 if (dev->cpu == 0 && mpuss_can_lose_context) 164 cpu_cluster_pm_exit(); 165 166 fail: 167 cpuidle_coupled_parallel_barrier(dev, &abort_barrier); 168 cpu_done[dev->cpu] = false; 169 170 return index; 171 } 172 173 static struct cpuidle_driver omap4_idle_driver = { 174 .name = "omap4_idle", 175 .owner = THIS_MODULE, 176 .states = { 177 { 178 /* C1 - CPU0 ON + CPU1 ON + MPU ON */ 179 .exit_latency = 2 + 2, 180 .target_residency = 5, 181 .flags = CPUIDLE_FLAG_TIME_VALID, 182 .enter = omap_enter_idle_simple, 183 .name = "C1", 184 .desc = "CPUx ON, MPUSS ON" 185 }, 186 { 187 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */ 188 .exit_latency = 328 + 440, 189 .target_residency = 960, 190 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED | 191 CPUIDLE_FLAG_TIMER_STOP, 192 .enter = omap_enter_idle_coupled, 193 .name = "C2", 194 .desc = "CPUx OFF, MPUSS CSWR", 195 }, 196 { 197 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ 198 .exit_latency = 460 + 518, 199 .target_residency = 1100, 200 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED | 201 CPUIDLE_FLAG_TIMER_STOP, 202 .enter = omap_enter_idle_coupled, 203 .name = "C3", 204 .desc = "CPUx OFF, MPUSS OSWR", 205 }, 206 }, 207 .state_count = ARRAY_SIZE(omap4_idle_data), 208 .safe_state_index = 0, 209 }; 210 211 /* Public functions */ 212 213 /** 214 * omap4_idle_init - Init routine for OMAP4+ idle 215 * 216 * Registers the OMAP4+ specific cpuidle driver to the cpuidle 217 * framework with the valid set of states. 218 */ 219 int __init omap4_idle_init(void) 220 { 221 mpu_pd = pwrdm_lookup("mpu_pwrdm"); 222 cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm"); 223 cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm"); 224 if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1])) 225 return -ENODEV; 226 227 cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm"); 228 cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm"); 229 if (!cpu_clkdm[0] || !cpu_clkdm[1]) 230 return -ENODEV; 231 232 return cpuidle_register(&omap4_idle_driver, cpu_online_mask); 233 } 234