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+/*
+ * linux/arch/arm/mach-omap2/cpuidle34xx.c
+ *
+ * OMAP3 CPU IDLE Routines
+ *
+ * Copyright (C) 2008 Texas Instruments, Inc.
+ * Rajendra Nayak <rnayak@ti.com>
+ *
+ * Copyright (C) 2007 Texas Instruments, Inc.
+ * Karthik Dasu <karthik-dp@ti.com>
+ *
+ * Copyright (C) 2006 Nokia Corporation
+ * Tony Lindgren <tony@atomide.com>
+ *
+ * Copyright (C) 2005 Texas Instruments, Inc.
+ * Richard Woodruff <r-woodruff2@ti.com>
+ *
+ * Based on pm.c for omap2
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/sched.h>
+#include <linux/cpuidle.h>
+#include <linux/export.h>
+#include <linux/cpu_pm.h>
+
+#include <plat/prcm.h>
+#include <plat/irqs.h>
+#include "powerdomain.h"
+#include "clockdomain.h"
+
+#include "pm.h"
+#include "control.h"
+#include "common.h"
+
+#ifdef CONFIG_CPU_IDLE
+
+/*
+ * The latencies/thresholds for various C states have
+ * to be configured from the respective board files.
+ * These are some default values (which might not provide
+ * the best power savings) used on boards which do not
+ * pass these details from the board file.
+ */
+static struct cpuidle_params cpuidle_params_table[] = {
+ /* C1 */
+ {2 + 2, 5, 1},
+ /* C2 */
+ {10 + 10, 30, 1},
+ /* C3 */
+ {50 + 50, 300, 1},
+ /* C4 */
+ {1500 + 1800, 4000, 1},
+ /* C5 */
+ {2500 + 7500, 12000, 1},
+ /* C6 */
+ {3000 + 8500, 15000, 1},
+ /* C7 */
+ {10000 + 30000, 300000, 1},
+};
+#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
+
+/* Mach specific information to be recorded in the C-state driver_data */
+struct omap3_idle_statedata {
+ u32 mpu_state;
+ u32 core_state;
+ u8 valid;
+};
+struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];
+
+struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
+
+static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
+ struct clockdomain *clkdm)
+{
+ clkdm_allow_idle(clkdm);
+ return 0;
+}
+
+static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
+ struct clockdomain *clkdm)
+{
+ clkdm_deny_idle(clkdm);
+ return 0;
+}
+
+static int __omap3_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ struct omap3_idle_statedata *cx =
+ cpuidle_get_statedata(&dev->states_usage[index]);
+ u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
+
+ local_fiq_disable();
+
+ pwrdm_set_next_pwrst(mpu_pd, mpu_state);
+ pwrdm_set_next_pwrst(core_pd, core_state);
+
+ if (omap_irq_pending() || need_resched())
+ goto return_sleep_time;
+
+ /* Deny idle for C1 */
+ if (index == 0) {
+ pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
+ pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
+ }
+
+ /*
+ * Call idle CPU PM enter notifier chain so that
+ * VFP context is saved.
+ */
+ if (mpu_state == PWRDM_POWER_OFF)
+ cpu_pm_enter();
+
+ /* Execute ARM wfi */
+ omap_sram_idle();
+
+ /*
+ * Call idle CPU PM enter notifier chain to restore
+ * VFP context.
+ */
+ if (pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
+ cpu_pm_exit();
+
+ /* Re-allow idle for C1 */
+ if (index == 0) {
+ pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
+ pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
+ }
+
+return_sleep_time:
+
+ local_fiq_enable();
+
+ return index;
+}
+
+/**
+ * omap3_enter_idle - Programs OMAP3 to enter the specified state
+ * @dev: cpuidle device
+ * @drv: cpuidle driver
+ * @index: the index of state to be entered
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static inline int omap3_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ return cpuidle_wrap_enter(dev, drv, index, __omap3_enter_idle);
+}
+
+/**
+ * next_valid_state - Find next valid C-state
+ * @dev: cpuidle device
+ * @drv: cpuidle driver
+ * @index: Index of currently selected c-state
+ *
+ * If the state corresponding to index is valid, index is returned back
+ * to the caller. Else, this function searches for a lower c-state which is
+ * still valid (as defined in omap3_power_states[]) and returns its index.
+ *
+ * A state is valid if the 'valid' field is enabled and
+ * if it satisfies the enable_off_mode condition.
+ */
+static int next_valid_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ struct cpuidle_state_usage *curr_usage = &dev->states_usage[index];
+ struct cpuidle_state *curr = &drv->states[index];
+ struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr_usage);
+ u32 mpu_deepest_state = PWRDM_POWER_RET;
+ u32 core_deepest_state = PWRDM_POWER_RET;
+ int next_index = -1;
+
+ if (enable_off_mode) {
+ mpu_deepest_state = PWRDM_POWER_OFF;
+ /*
+ * Erratum i583: valable for ES rev < Es1.2 on 3630.
+ * CORE OFF mode is not supported in a stable form, restrict
+ * instead the CORE state to RET.
+ */
+ if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
+ core_deepest_state = PWRDM_POWER_OFF;
+ }
+
+ /* Check if current state is valid */
+ if ((cx->valid) &&
+ (cx->mpu_state >= mpu_deepest_state) &&
+ (cx->core_state >= core_deepest_state)) {
+ return index;
+ } else {
+ int idx = OMAP3_NUM_STATES - 1;
+
+ /* Reach the current state starting at highest C-state */
+ for (; idx >= 0; idx--) {
+ if (&drv->states[idx] == curr) {
+ next_index = idx;
+ break;
+ }
+ }
+
+ /* Should never hit this condition */
+ WARN_ON(next_index == -1);
+
+ /*
+ * Drop to next valid state.
+ * Start search from the next (lower) state.
+ */
+ idx--;
+ for (; idx >= 0; idx--) {
+ cx = cpuidle_get_statedata(&dev->states_usage[idx]);
+ if ((cx->valid) &&
+ (cx->mpu_state >= mpu_deepest_state) &&
+ (cx->core_state >= core_deepest_state)) {
+ next_index = idx;
+ break;
+ }
+ }
+ /*
+ * C1 is always valid.
+ * So, no need to check for 'next_index == -1' outside
+ * this loop.
+ */
+ }
+
+ return next_index;
+}
+
+/**
+ * omap3_enter_idle_bm - Checks for any bus activity
+ * @dev: cpuidle device
+ * @drv: cpuidle driver
+ * @index: array index of target state to be programmed
+ *
+ * This function checks for any pending activity and then programs
+ * the device to the specified or a safer state.
+ */
+static int omap3_enter_idle_bm(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ int new_state_idx;
+ u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
+ struct omap3_idle_statedata *cx;
+ int ret;
+
+ /*
+ * Prevent idle completely if CAM is active.
+ * CAM does not have wakeup capability in OMAP3.
+ */
+ cam_state = pwrdm_read_pwrst(cam_pd);
+ if (cam_state == PWRDM_POWER_ON) {
+ new_state_idx = drv->safe_state_index;
+ goto select_state;
+ }
+
+ /*
+ * FIXME: we currently manage device-specific idle states
+ * for PER and CORE in combination with CPU-specific
+ * idle states. This is wrong, and device-specific
+ * idle management needs to be separated out into
+ * its own code.
+ */
+
+ /*
+ * Prevent PER off if CORE is not in retention or off as this
+ * would disable PER wakeups completely.
+ */
+ cx = cpuidle_get_statedata(&dev->states_usage[index]);
+ core_next_state = cx->core_state;
+ per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
+ if ((per_next_state == PWRDM_POWER_OFF) &&
+ (core_next_state > PWRDM_POWER_RET))
+ per_next_state = PWRDM_POWER_RET;
+
+ /* Are we changing PER target state? */
+ if (per_next_state != per_saved_state)
+ pwrdm_set_next_pwrst(per_pd, per_next_state);
+
+ new_state_idx = next_valid_state(dev, drv, index);
+
+select_state:
+ ret = omap3_enter_idle(dev, drv, new_state_idx);
+
+ /* Restore original PER state if it was modified */
+ if (per_next_state != per_saved_state)
+ pwrdm_set_next_pwrst(per_pd, per_saved_state);
+
+ return ret;
+}
+
+DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
+
+void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
+{
+ int i;
+
+ if (!cpuidle_board_params)
+ return;
+
+ for (i = 0; i < OMAP3_NUM_STATES; i++) {
+ cpuidle_params_table[i].valid = cpuidle_board_params[i].valid;
+ cpuidle_params_table[i].exit_latency =
+ cpuidle_board_params[i].exit_latency;
+ cpuidle_params_table[i].target_residency =
+ cpuidle_board_params[i].target_residency;
+ }
+ return;
+}
+
+struct cpuidle_driver omap3_idle_driver = {
+ .name = "omap3_idle",
+ .owner = THIS_MODULE,
+};
+
+/* Helper to fill the C-state common data*/
+static inline void _fill_cstate(struct cpuidle_driver *drv,
+ int idx, const char *descr)
+{
+ struct cpuidle_state *state = &drv->states[idx];
+
+ state->exit_latency = cpuidle_params_table[idx].exit_latency;
+ state->target_residency = cpuidle_params_table[idx].target_residency;
+ state->flags = CPUIDLE_FLAG_TIME_VALID;
+ state->enter = omap3_enter_idle_bm;
+ sprintf(state->name, "C%d", idx + 1);
+ strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
+
+}
+
+/* Helper to register the driver_data */
+static inline struct omap3_idle_statedata *_fill_cstate_usage(
+ struct cpuidle_device *dev,
+ int idx)
+{
+ struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
+ struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];
+
+ cx->valid = cpuidle_params_table[idx].valid;
+ cpuidle_set_statedata(state_usage, cx);
+
+ return cx;
+}
+
+/**
+ * omap3_idle_init - Init routine for OMAP3 idle
+ *
+ * Registers the OMAP3 specific cpuidle driver to the cpuidle
+ * framework with the valid set of states.
+ */
+int __init omap3_idle_init(void)
+{
+ struct cpuidle_device *dev;
+ struct cpuidle_driver *drv = &omap3_idle_driver;
+ struct omap3_idle_statedata *cx;
+
+ mpu_pd = pwrdm_lookup("mpu_pwrdm");
+ core_pd = pwrdm_lookup("core_pwrdm");
+ per_pd = pwrdm_lookup("per_pwrdm");
+ cam_pd = pwrdm_lookup("cam_pwrdm");
+
+
+ drv->safe_state_index = -1;
+ dev = &per_cpu(omap3_idle_dev, smp_processor_id());
+
+ /* C1 . MPU WFI + Core active */
+ _fill_cstate(drv, 0, "MPU ON + CORE ON");
+ (&drv->states[0])->enter = omap3_enter_idle;
+ drv->safe_state_index = 0;
+ cx = _fill_cstate_usage(dev, 0);
+ cx->valid = 1; /* C1 is always valid */
+ cx->mpu_state = PWRDM_POWER_ON;
+ cx->core_state = PWRDM_POWER_ON;
+
+ /* C2 . MPU WFI + Core inactive */
+ _fill_cstate(drv, 1, "MPU ON + CORE ON");
+ cx = _fill_cstate_usage(dev, 1);
+ cx->mpu_state = PWRDM_POWER_ON;
+ cx->core_state = PWRDM_POWER_ON;
+
+ /* C3 . MPU CSWR + Core inactive */
+ _fill_cstate(drv, 2, "MPU RET + CORE ON");
+ cx = _fill_cstate_usage(dev, 2);
+ cx->mpu_state = PWRDM_POWER_RET;
+ cx->core_state = PWRDM_POWER_ON;
+
+ /* C4 . MPU OFF + Core inactive */
+ _fill_cstate(drv, 3, "MPU OFF + CORE ON");
+ cx = _fill_cstate_usage(dev, 3);
+ cx->mpu_state = PWRDM_POWER_OFF;
+ cx->core_state = PWRDM_POWER_ON;
+
+ /* C5 . MPU RET + Core RET */
+ _fill_cstate(drv, 4, "MPU RET + CORE RET");
+ cx = _fill_cstate_usage(dev, 4);
+ cx->mpu_state = PWRDM_POWER_RET;
+ cx->core_state = PWRDM_POWER_RET;
+
+ /* C6 . MPU OFF + Core RET */
+ _fill_cstate(drv, 5, "MPU OFF + CORE RET");
+ cx = _fill_cstate_usage(dev, 5);
+ cx->mpu_state = PWRDM_POWER_OFF;
+ cx->core_state = PWRDM_POWER_RET;
+
+ /* C7 . MPU OFF + Core OFF */
+ _fill_cstate(drv, 6, "MPU OFF + CORE OFF");
+ cx = _fill_cstate_usage(dev, 6);
+ /*
+ * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
+ * enable OFF mode in a stable form for previous revisions.
+ * We disable C7 state as a result.
+ */
+ if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
+ cx->valid = 0;
+ pr_warn("%s: core off state C7 disabled due to i583\n",
+ __func__);
+ }
+ cx->mpu_state = PWRDM_POWER_OFF;
+ cx->core_state = PWRDM_POWER_OFF;
+
+ drv->state_count = OMAP3_NUM_STATES;
+ cpuidle_register_driver(&omap3_idle_driver);
+
+ dev->state_count = OMAP3_NUM_STATES;
+ if (cpuidle_register_device(dev)) {
+ printk(KERN_ERR "%s: CPUidle register device failed\n",
+ __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+#else
+int __init omap3_idle_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_CPU_IDLE */