1 /* 2 * OMAP4 CPU idle Routines 3 * 4 * Copyright (C) 2011 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 #include <linux/clockchips.h> 18 19 #include <asm/proc-fns.h> 20 21 #include "common.h" 22 #include "pm.h" 23 #include "prm.h" 24 25 #ifdef CONFIG_CPU_IDLE 26 27 /* Machine specific information to be recorded in the C-state driver_data */ 28 struct omap4_idle_statedata { 29 u32 cpu_state; 30 u32 mpu_logic_state; 31 u32 mpu_state; 32 u8 valid; 33 }; 34 35 static struct cpuidle_params cpuidle_params_table[] = { 36 /* C1 - CPU0 ON + CPU1 ON + MPU ON */ 37 {.exit_latency = 2 + 2 , .target_residency = 5, .valid = 1}, 38 /* C2- CPU0 OFF + CPU1 OFF + MPU CSWR */ 39 {.exit_latency = 328 + 440 , .target_residency = 960, .valid = 1}, 40 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ 41 {.exit_latency = 460 + 518 , .target_residency = 1100, .valid = 1}, 42 }; 43 44 #define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table) 45 46 struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES]; 47 static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd; 48 49 /** 50 * omap4_enter_idle - Programs OMAP4 to enter the specified state 51 * @dev: cpuidle device 52 * @drv: cpuidle driver 53 * @index: the index of state to be entered 54 * 55 * Called from the CPUidle framework to program the device to the 56 * specified low power state selected by the governor. 57 * Returns the amount of time spent in the low power state. 58 */ 59 static int omap4_enter_idle(struct cpuidle_device *dev, 60 struct cpuidle_driver *drv, 61 int index) 62 { 63 struct omap4_idle_statedata *cx = 64 cpuidle_get_statedata(&dev->states_usage[index]); 65 struct timespec ts_preidle, ts_postidle, ts_idle; 66 u32 cpu1_state; 67 int idle_time; 68 int cpu_id = smp_processor_id(); 69 70 /* Used to keep track of the total time in idle */ 71 getnstimeofday(&ts_preidle); 72 73 local_irq_disable(); 74 local_fiq_disable(); 75 76 /* 77 * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state. 78 * This is necessary to honour hardware recommondation 79 * of triggeing all the possible low power modes once CPU1 is 80 * out of coherency and in OFF mode. 81 * Update dev->last_state so that governor stats reflects right 82 * data. 83 */ 84 cpu1_state = pwrdm_read_pwrst(cpu1_pd); 85 if (cpu1_state != PWRDM_POWER_OFF) { 86 index = drv->safe_state_index; 87 cx = cpuidle_get_statedata(&dev->states_usage[index]); 88 } 89 90 if (index > 0) 91 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id); 92 93 /* 94 * Call idle CPU PM enter notifier chain so that 95 * VFP and per CPU interrupt context is saved. 96 */ 97 if (cx->cpu_state == PWRDM_POWER_OFF) 98 cpu_pm_enter(); 99 100 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); 101 omap_set_pwrdm_state(mpu_pd, cx->mpu_state); 102 103 /* 104 * Call idle CPU cluster PM enter notifier chain 105 * to save GIC and wakeupgen context. 106 */ 107 if ((cx->mpu_state == PWRDM_POWER_RET) && 108 (cx->mpu_logic_state == PWRDM_POWER_OFF)) 109 cpu_cluster_pm_enter(); 110 111 omap4_enter_lowpower(dev->cpu, cx->cpu_state); 112 113 /* 114 * Call idle CPU PM exit notifier chain to restore 115 * VFP and per CPU IRQ context. Only CPU0 state is 116 * considered since CPU1 is managed by CPU hotplug. 117 */ 118 if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF) 119 cpu_pm_exit(); 120 121 /* 122 * Call idle CPU cluster PM exit notifier chain 123 * to restore GIC and wakeupgen context. 124 */ 125 if (omap4_mpuss_read_prev_context_state()) 126 cpu_cluster_pm_exit(); 127 128 if (index > 0) 129 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id); 130 131 getnstimeofday(&ts_postidle); 132 ts_idle = timespec_sub(ts_postidle, ts_preidle); 133 134 local_irq_enable(); 135 local_fiq_enable(); 136 137 idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \ 138 USEC_PER_SEC; 139 140 /* Update cpuidle counters */ 141 dev->last_residency = idle_time; 142 143 return index; 144 } 145 146 DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev); 147 148 struct cpuidle_driver omap4_idle_driver = { 149 .name = "omap4_idle", 150 .owner = THIS_MODULE, 151 }; 152 153 static inline void _fill_cstate(struct cpuidle_driver *drv, 154 int idx, const char *descr) 155 { 156 struct cpuidle_state *state = &drv->states[idx]; 157 158 state->exit_latency = cpuidle_params_table[idx].exit_latency; 159 state->target_residency = cpuidle_params_table[idx].target_residency; 160 state->flags = CPUIDLE_FLAG_TIME_VALID; 161 state->enter = omap4_enter_idle; 162 sprintf(state->name, "C%d", idx + 1); 163 strncpy(state->desc, descr, CPUIDLE_DESC_LEN); 164 } 165 166 static inline struct omap4_idle_statedata *_fill_cstate_usage( 167 struct cpuidle_device *dev, 168 int idx) 169 { 170 struct omap4_idle_statedata *cx = &omap4_idle_data[idx]; 171 struct cpuidle_state_usage *state_usage = &dev->states_usage[idx]; 172 173 cx->valid = cpuidle_params_table[idx].valid; 174 cpuidle_set_statedata(state_usage, cx); 175 176 return cx; 177 } 178 179 180 181 /** 182 * omap4_idle_init - Init routine for OMAP4 idle 183 * 184 * Registers the OMAP4 specific cpuidle driver to the cpuidle 185 * framework with the valid set of states. 186 */ 187 int __init omap4_idle_init(void) 188 { 189 struct omap4_idle_statedata *cx; 190 struct cpuidle_device *dev; 191 struct cpuidle_driver *drv = &omap4_idle_driver; 192 unsigned int cpu_id = 0; 193 194 mpu_pd = pwrdm_lookup("mpu_pwrdm"); 195 cpu0_pd = pwrdm_lookup("cpu0_pwrdm"); 196 cpu1_pd = pwrdm_lookup("cpu1_pwrdm"); 197 if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd)) 198 return -ENODEV; 199 200 201 drv->safe_state_index = -1; 202 dev = &per_cpu(omap4_idle_dev, cpu_id); 203 dev->cpu = cpu_id; 204 205 /* C1 - CPU0 ON + CPU1 ON + MPU ON */ 206 _fill_cstate(drv, 0, "MPUSS ON"); 207 drv->safe_state_index = 0; 208 cx = _fill_cstate_usage(dev, 0); 209 cx->valid = 1; /* C1 is always valid */ 210 cx->cpu_state = PWRDM_POWER_ON; 211 cx->mpu_state = PWRDM_POWER_ON; 212 cx->mpu_logic_state = PWRDM_POWER_RET; 213 214 /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */ 215 _fill_cstate(drv, 1, "MPUSS CSWR"); 216 cx = _fill_cstate_usage(dev, 1); 217 cx->cpu_state = PWRDM_POWER_OFF; 218 cx->mpu_state = PWRDM_POWER_RET; 219 cx->mpu_logic_state = PWRDM_POWER_RET; 220 221 /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ 222 _fill_cstate(drv, 2, "MPUSS OSWR"); 223 cx = _fill_cstate_usage(dev, 2); 224 cx->cpu_state = PWRDM_POWER_OFF; 225 cx->mpu_state = PWRDM_POWER_RET; 226 cx->mpu_logic_state = PWRDM_POWER_OFF; 227 228 drv->state_count = OMAP4_NUM_STATES; 229 cpuidle_register_driver(&omap4_idle_driver); 230 231 dev->state_count = OMAP4_NUM_STATES; 232 if (cpuidle_register_device(dev)) { 233 pr_err("%s: CPUidle register device failed\n", __func__); 234 return -EIO; 235 } 236 237 return 0; 238 } 239 #else 240 int __init omap4_idle_init(void) 241 { 242 return 0; 243 } 244 #endif /* CONFIG_CPU_IDLE */ 245