OMAP4 CPUDILE driver is converted mainly based on notes from the
coupled cpuidle patch series.

The changes include :
- Register both CPUs and C-states to cpuidle driver.
- Set struct cpuidle_device.coupled_cpus
- Set struct cpuidle_device.safe_state to non coupled state.
- Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
  state that affects multiple cpus.
- Separate ->enter hooks for coupled & simple idle.
- CPU0 wait loop for CPU1 power transition.
- CPU1 wakeup mechanism for the idle exit.
- Enabling ARCH_NEEDS_CPU_IDLE_COUPLED for OMAP4.

Thanks to Kevin Hilman and Colin Cross on the suggestions/fixes
on the intermediate version of this patch.

Signed-off-by: Santosh Shilimkar <santosh.shilim...@ti.com>
CC: Kevin Hilman <khil...@ti.com>
Cc: Colin Cross <ccr...@android.com>
---
 arch/arm/mach-omap2/Kconfig       |    1 +
 arch/arm/mach-omap2/cpuidle44xx.c |  167 ++++++++++++++++++++++---------------
 2 files changed, 101 insertions(+), 67 deletions(-)

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index e20c8ab..250786e 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -54,6 +54,7 @@ config ARCH_OMAP4
        select PM_OPP if PM
        select USB_ARCH_HAS_EHCI
        select ARM_CPU_SUSPEND if PM
+       select ARCH_NEEDS_CPU_IDLE_COUPLED if CPU_IDLE
 
 comment "OMAP Core Type"
        depends on ARCH_OMAP2
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c 
b/arch/arm/mach-omap2/cpuidle44xx.c
index f386cbe..5724393 100644
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -21,6 +21,7 @@
 #include "common.h"
 #include "pm.h"
 #include "prm.h"
+#include "clockdomain.h"
 
 #ifdef CONFIG_CPU_IDLE
 
@@ -44,10 +45,11 @@ static struct cpuidle_params cpuidle_params_table[] = {
 #define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
 
 struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES];
-static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
+static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
+static struct clockdomain *cpu_clkdm[NR_CPUS];
 
 /**
- * omap4_enter_idle - Programs OMAP4 to enter the specified state
+ * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
  * @dev: cpuidle device
  * @drv: cpuidle driver
  * @index: the index of state to be entered
@@ -56,34 +58,40 @@ static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
  * specified low power state selected by the governor.
  * Returns the amount of time spent in the low power state.
  */
-static int omap4_enter_idle(struct cpuidle_device *dev,
+static int omap4_enter_idle_simple(struct cpuidle_device *dev,
+                                  struct cpuidle_driver *drv,
+                                  int index)
+{
+       local_fiq_disable();
+       omap_do_wfi();
+       local_fiq_enable();
+
+       return index;
+}
+
+static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
                        struct cpuidle_driver *drv,
                        int index)
 {
        struct omap4_idle_statedata *cx =
                        cpuidle_get_statedata(&dev->states_usage[index]);
-       u32 cpu1_state;
        int cpu_id = smp_processor_id();
 
        local_fiq_disable();
 
+       clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
+
        /*
-        * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state.
+        * CPU0 has to wait and stay ON until CPU1 is OFF state.
         * This is necessary to honour hardware recommondation
         * of triggeing all the possible low power modes once CPU1 is
         * out of coherency and in OFF mode.
-        * Update dev->last_state so that governor stats reflects right
-        * data.
         */
-       cpu1_state = pwrdm_read_pwrst(cpu1_pd);
-       if (cpu1_state != PWRDM_POWER_OFF) {
-               index = drv->safe_state_index;
-               cx = cpuidle_get_statedata(&dev->states_usage[index]);
+       if (dev->cpu == 0) {
+               while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF)
+                       cpu_relax();
        }
 
-       if (index > 0)
-               clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
-
        /*
         * Call idle CPU PM enter notifier chain so that
         * VFP and per CPU interrupt context is saved.
@@ -91,25 +99,35 @@ static int omap4_enter_idle(struct cpuidle_device *dev,
        if (cx->cpu_state == PWRDM_POWER_OFF)
                cpu_pm_enter();
 
-       pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
-       omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
-
-       /*
-        * Call idle CPU cluster PM enter notifier chain
-        * to save GIC and wakeupgen context.
-        */
-       if ((cx->mpu_state == PWRDM_POWER_RET) &&
-               (cx->mpu_logic_state == PWRDM_POWER_OFF))
-                       cpu_cluster_pm_enter();
+       if (dev->cpu == 0) {
+               pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
+               omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
+
+               /*
+                * Call idle CPU cluster PM enter notifier chain
+                * to save GIC and wakeupgen context.
+                */
+               if ((cx->mpu_state == PWRDM_POWER_RET) &&
+                       (cx->mpu_logic_state == PWRDM_POWER_OFF))
+                               cpu_cluster_pm_enter();
+       }
 
        omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 
+       if (dev->cpu == 0) {
+               /* Wakeup CPU1 only if it is not offlined */
+               if (cpumask_test_cpu(1, cpu_online_mask)) {
+                       clkdm_wakeup(cpu_clkdm[1]);
+                       clkdm_allow_idle(cpu_clkdm[1]);
+               }
+       }
+
        /*
         * Call idle CPU PM exit notifier chain to restore
         * VFP and per CPU IRQ context. Only CPU0 state is
         * considered since CPU1 is managed by CPU hotplug.
         */
-       if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF)
+       if (pwrdm_read_prev_pwrst(cpu_pd[dev->cpu]) == PWRDM_POWER_OFF)
                cpu_pm_exit();
 
        /*
@@ -119,8 +137,7 @@ static int omap4_enter_idle(struct cpuidle_device *dev,
        if (omap4_mpuss_read_prev_context_state())
                cpu_cluster_pm_exit();
 
-       if (index > 0)
-               clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
+       clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
 
        local_fiq_enable();
 
@@ -136,14 +153,17 @@ struct cpuidle_driver omap4_idle_driver = {
 };
 
 static inline void _fill_cstate(struct cpuidle_driver *drv,
-                                       int idx, const char *descr)
+                                       int idx, const char *descr, int flags)
 {
        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            = omap4_enter_idle;
+       state->flags            = (CPUIDLE_FLAG_TIME_VALID | flags);
+       if (state->flags & CPUIDLE_FLAG_COUPLED)
+               state->enter            = omap4_enter_idle_coupled;
+       else
+               state->enter            = omap4_enter_idle_simple;
        sprintf(state->name, "C%d", idx + 1);
        strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
 }
@@ -177,47 +197,60 @@ int __init omap4_idle_init(void)
        unsigned int cpu_id = 0;
 
        mpu_pd = pwrdm_lookup("mpu_pwrdm");
-       cpu0_pd = pwrdm_lookup("cpu0_pwrdm");
-       cpu1_pd = pwrdm_lookup("cpu1_pwrdm");
-       if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
+       cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
+       cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
+       if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
                return -ENODEV;
 
+       cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
+       cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
+       if (!cpu_clkdm[0] || !cpu_clkdm[1])
+               return -ENODEV;
 
-       drv->safe_state_index = -1;
-       dev = &per_cpu(omap4_idle_dev, cpu_id);
-       dev->cpu = cpu_id;
-
-       /* C1 - CPU0 ON + CPU1 ON + MPU ON */
-       _fill_cstate(drv, 0, "MPUSS ON");
-       drv->safe_state_index = 0;
-       cx = _fill_cstate_usage(dev, 0);
-       cx->valid = 1;  /* C1 is always valid */
-       cx->cpu_state = PWRDM_POWER_ON;
-       cx->mpu_state = PWRDM_POWER_ON;
-       cx->mpu_logic_state = PWRDM_POWER_RET;
-
-       /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
-       _fill_cstate(drv, 1, "MPUSS CSWR");
-       cx = _fill_cstate_usage(dev, 1);
-       cx->cpu_state = PWRDM_POWER_OFF;
-       cx->mpu_state = PWRDM_POWER_RET;
-       cx->mpu_logic_state = PWRDM_POWER_RET;
-
-       /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
-       _fill_cstate(drv, 2, "MPUSS OSWR");
-       cx = _fill_cstate_usage(dev, 2);
-       cx->cpu_state = PWRDM_POWER_OFF;
-       cx->mpu_state = PWRDM_POWER_RET;
-       cx->mpu_logic_state = PWRDM_POWER_OFF;
-
-       drv->state_count = OMAP4_NUM_STATES;
-       cpuidle_register_driver(&omap4_idle_driver);
-
-       dev->state_count = OMAP4_NUM_STATES;
-       if (cpuidle_register_device(dev)) {
-               pr_err("%s: CPUidle register device failed\n", __func__);
-                       return -EIO;
+       for_each_cpu(cpu_id, cpu_online_mask) {
+               drv->safe_state_index = -1;
+               dev = &per_cpu(omap4_idle_dev, cpu_id);
+               dev->cpu = cpu_id;
+               dev->state_count = 0;
+               dev->coupled_cpus = *cpu_online_mask;
+               drv->state_count = 0;
+
+               /* C1 - CPU0 ON + CPU1 ON + MPU ON */
+               _fill_cstate(drv, 0, "MPUSS ON", 0);
+               drv->safe_state_index = 0;
+               cx = _fill_cstate_usage(dev, 0);
+               cx->valid = 1;  /* C1 is always valid */
+               cx->cpu_state = PWRDM_POWER_ON;
+               cx->mpu_state = PWRDM_POWER_ON;
+               cx->mpu_logic_state = PWRDM_POWER_RET;
+               dev->state_count++;
+               drv->state_count++;
+
+               /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
+               _fill_cstate(drv, 1, "MPUSS CSWR", CPUIDLE_FLAG_COUPLED);
+               cx = _fill_cstate_usage(dev, 1);
+               cx->cpu_state = PWRDM_POWER_OFF;
+               cx->mpu_state = PWRDM_POWER_RET;
+               cx->mpu_logic_state = PWRDM_POWER_RET;
+               dev->state_count++;
+               drv->state_count++;
+
+               /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
+               _fill_cstate(drv, 2, "MPUSS OSWR", CPUIDLE_FLAG_COUPLED);
+               cx = _fill_cstate_usage(dev, 2);
+               cx->cpu_state = PWRDM_POWER_OFF;
+               cx->mpu_state = PWRDM_POWER_RET;
+               cx->mpu_logic_state = PWRDM_POWER_OFF;
+               dev->state_count++;
+               drv->state_count++;
+
+               cpuidle_register_driver(&omap4_idle_driver);
+
+               if (cpuidle_register_device(dev)) {
+                       pr_err("%s: CPUidle register failed\n", __func__);
+                               return -EIO;
                }
+       }
 
        return 0;
 }
-- 
1.7.5.4

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