OMAP3: cpuidle: re-organize the C-states data

The current implementation defines an internal structure and a
C-states array. Using those structures is redundant to the
structs used by the cpuidle framework.

This patch provides a clean-up of the internal struct, removes the
internal C-states array, stores the data using the existing cpuidle
per C-state struct and registers the mach specific data to cpuidle
C-state driver_data (accessed using cpuidle_[gs]et_statedata).
Also removes unused macros, fields and code and compacts the repeating
code using an inline helper function.

The result is more compact and more readable code as well as
reduced data RAM usage.

Also retain C1 as the only always valid C-state and system safe state.

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 101 insertions, 204 deletions

diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index d7bc31a2b3af..f9c8676b1f4c 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -36,35 +36,6 @@
 
 #ifdef CONFIG_CPU_IDLE
 
-#define OMAP3_MAX_STATES 7
-#define OMAP3_STATE_C1 0 /* C1 - MPU WFI + Core active */
-#define OMAP3_STATE_C2 1 /* C2 - MPU WFI + Core inactive */
-#define OMAP3_STATE_C3 2 /* C3 - MPU CSWR + Core inactive */
-#define OMAP3_STATE_C4 3 /* C4 - MPU OFF + Core iactive */
-#define OMAP3_STATE_C5 4 /* C5 - MPU RET + Core RET */
-#define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
-#define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */
-
-#define OMAP3_STATE_MAX OMAP3_STATE_C7
-
-#define CPUIDLE_FLAG_CHECK_BM   0x10000 /* use omap3_enter_idle_bm() */
-
-struct omap3_processor_cx {
-        u8 valid;
-        u8 type;
-        u32 exit_latency;
-        u32 mpu_state;
-        u32 core_state;
-        u32 target_residency;
-        u32 flags;
-        const char *desc;
-};
-
-struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
-struct omap3_processor_cx current_cx_state;
-struct powerdomain *mpu_pd, *core_pd, *per_pd;
-struct powerdomain *cam_pd;
-
 /*
  * The latencies/thresholds for various C states have
  * to be configured from the respective board files.
@@ -88,6 +59,17 @@ static struct cpuidle_params cpuidle_params_table[] = {
         /* 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 omap3_idle_bm_check(void)
 {
@@ -121,12 +103,10 @@ static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
 static int omap3_enter_idle(struct cpuidle_device *dev,
                         struct cpuidle_state *state)
 {
-        struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
+        struct omap3_idle_statedata *cx = cpuidle_get_statedata(state);
         struct timespec ts_preidle, ts_postidle, ts_idle;
         u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
 
-        current_cx_state = *cx;
-
         /* Used to keep track of the total time in idle */
         getnstimeofday(&ts_preidle);
 
@@ -139,7 +119,8 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
         if (omap_irq_pending() || need_resched())
                 goto return_sleep_time;
 
-        if (cx->type == OMAP3_STATE_C1) {
+        /* Deny idle for C1 */
+        if (state == &dev->states[0]) {
                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
                 pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
         }
@@ -147,7 +128,8 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
         /* Execute ARM wfi */
         omap_sram_idle();
 
-        if (cx->type == OMAP3_STATE_C1) {
+        /* Re-allow idle for C1 */
+        if (state == &dev->states[0]) {
                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
                 pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
         }
@@ -169,26 +151,26 @@ return_sleep_time:
  *
  * If the current state is valid, it 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[]).
+ * valid.
  */
 static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
-                                                struct cpuidle_state *curr)
+                                              struct cpuidle_state *curr)
 {
         struct cpuidle_state *next = NULL;
-        struct omap3_processor_cx *cx;
+        struct omap3_idle_statedata *cx;
 
-        cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);
+        cx = cpuidle_get_statedata(curr);
 
         /* Check if current state is valid */
         if (cx->valid) {
                 return curr;
         } else {
-                u8 idx = OMAP3_STATE_MAX;
+                int idx = OMAP3_NUM_STATES - 1;
 
                 /*
                  * Reach the current state starting at highest C-state
                  */
-                for (; idx >= OMAP3_STATE_C1; idx--) {
+                for (; idx >= 0; idx--) {
                         if (&dev->states[idx] == curr) {
                                 next = &dev->states[idx];
                                 break;
@@ -205,9 +187,7 @@ static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
                  * Start search from the next (lower) state.
                  */
                 idx--;
-                for (; idx >= OMAP3_STATE_C1; idx--) {
-                        struct omap3_processor_cx *cx;
-
+                for (; idx >= 0; idx--) {
                         cx = cpuidle_get_statedata(&dev->states[idx]);
                         if (cx->valid) {
                                 next = &dev->states[idx];
@@ -215,7 +195,7 @@ static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
                         }
                 }
                 /*
-                 * C1 and C2 are always valid.
+                 * C1 is always valid.
                  * So, no need to check for 'next==NULL' outside this loop.
                  */
         }
@@ -228,9 +208,8 @@ static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
  * @dev: cpuidle device
  * @state: The target state to be programmed
  *
- * Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. This
- * function checks for any pending activity and then programs the
- * device to the specified or a safer state.
+ * 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_state *state)
@@ -238,10 +217,10 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
         struct cpuidle_state *new_state = next_valid_state(dev, state);
         u32 core_next_state, per_next_state = 0, per_saved_state = 0;
         u32 cam_state;
-        struct omap3_processor_cx *cx;
+        struct omap3_idle_statedata *cx;
         int ret;
 
-        if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
+        if (omap3_idle_bm_check()) {
                 BUG_ON(!dev->safe_state);
                 new_state = dev->safe_state;
                 goto select_state;
@@ -307,8 +286,8 @@ void omap3_cpuidle_update_states(u32 mpu_deepest_state, u32 core_deepest_state)
 {
         int i;
 
-        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
-                struct omap3_processor_cx *cx = &omap3_power_states[i];
+        for (i = 0; i < OMAP3_NUM_STATES; i++) {
+                struct omap3_idle_statedata *cx = &omap3_idle_data[i];
 
                 if ((cx->mpu_state >= mpu_deepest_state) &&
                     (cx->core_state >= core_deepest_state)) {
@@ -326,9 +305,8 @@ void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
         if (!cpuidle_board_params)
                 return;
 
-        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
-                cpuidle_params_table[i].valid =
-                        cpuidle_board_params[i].valid;
+        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 =
@@ -337,185 +315,104 @@ void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
         return;
 }
 
-/* omap3_init_power_states - Initialises the OMAP3 specific C states.
- *
- * Below is the desciption of each C state.
- *      C1 . MPU WFI + Core active
- *      C2 . MPU WFI + Core inactive
- *      C3 . MPU CSWR + Core inactive
- *      C4 . MPU OFF + Core inactive
- *      C5 . MPU CSWR + Core CSWR
- *      C6 . MPU OFF + Core CSWR
- *      C7 . MPU OFF + Core OFF
- */
-void omap_init_power_states(void)
-{
-        /* C1 . MPU WFI + Core active */
-        omap3_power_states[OMAP3_STATE_C1].valid =
-                        cpuidle_params_table[OMAP3_STATE_C1].valid;
-        omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
-        omap3_power_states[OMAP3_STATE_C1].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C1].exit_latency;
-        omap3_power_states[OMAP3_STATE_C1].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C1].target_residency;
-        omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
-        omap3_power_states[OMAP3_STATE_C1].desc = "MPU ON + CORE ON";
-
-        /* C2 . MPU WFI + Core inactive */
-        omap3_power_states[OMAP3_STATE_C2].valid =
-                        cpuidle_params_table[OMAP3_STATE_C2].valid;
-        omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
-        omap3_power_states[OMAP3_STATE_C2].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C2].exit_latency;
-        omap3_power_states[OMAP3_STATE_C2].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C2].target_residency;
-        omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C2].desc = "MPU ON + CORE ON";
-
-        /* C3 . MPU CSWR + Core inactive */
-        omap3_power_states[OMAP3_STATE_C3].valid =
-                        cpuidle_params_table[OMAP3_STATE_C3].valid;
-        omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
-        omap3_power_states[OMAP3_STATE_C3].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C3].exit_latency;
-        omap3_power_states[OMAP3_STATE_C3].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C3].target_residency;
-        omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
-        omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C3].desc = "MPU RET + CORE ON";
-
-        /* C4 . MPU OFF + Core inactive */
-        omap3_power_states[OMAP3_STATE_C4].valid =
-                        cpuidle_params_table[OMAP3_STATE_C4].valid;
-        omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
-        omap3_power_states[OMAP3_STATE_C4].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C4].exit_latency;
-        omap3_power_states[OMAP3_STATE_C4].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C4].target_residency;
-        omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
-        omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
-        omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C4].desc = "MPU OFF + CORE ON";
-
-        /* C5 . MPU CSWR + Core CSWR*/
-        omap3_power_states[OMAP3_STATE_C5].valid =
-                        cpuidle_params_table[OMAP3_STATE_C5].valid;
-        omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
-        omap3_power_states[OMAP3_STATE_C5].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C5].exit_latency;
-        omap3_power_states[OMAP3_STATE_C5].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C5].target_residency;
-        omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
-        omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
-        omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C5].desc = "MPU RET + CORE RET";
-
-        /* C6 . MPU OFF + Core CSWR */
-        omap3_power_states[OMAP3_STATE_C6].valid =
-                        cpuidle_params_table[OMAP3_STATE_C6].valid;
-        omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
-        omap3_power_states[OMAP3_STATE_C6].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C6].exit_latency;
-        omap3_power_states[OMAP3_STATE_C6].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C6].target_residency;
-        omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
-        omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
-        omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C6].desc = "MPU OFF + CORE RET";
-
-        /* C7 . MPU OFF + Core OFF */
-        omap3_power_states[OMAP3_STATE_C7].valid =
-                        cpuidle_params_table[OMAP3_STATE_C7].valid;
-        omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
-        omap3_power_states[OMAP3_STATE_C7].exit_latency =
-                        cpuidle_params_table[OMAP3_STATE_C7].exit_latency;
-        omap3_power_states[OMAP3_STATE_C7].target_residency =
-                        cpuidle_params_table[OMAP3_STATE_C7].target_residency;
-        omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
-        omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
-        omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
-                                CPUIDLE_FLAG_CHECK_BM;
-        omap3_power_states[OMAP3_STATE_C7].desc = "MPU OFF + CORE OFF";
-
-        /*
-         * 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)) {
-                omap3_power_states[OMAP3_STATE_C7].valid = 0;
-                cpuidle_params_table[OMAP3_STATE_C7].valid = 0;
-                pr_warn("%s: core off state C7 disabled due to i583\n",
-                                __func__);
-        }
-}
-
 struct cpuidle_driver omap3_idle_driver = {
         .name =         "omap3_idle",
         .owner =        THIS_MODULE,
 };
 
+/* Fill in the state data from the mach tables and register the driver_data */
+static inline struct omap3_idle_statedata *_fill_cstate(
+                                        struct cpuidle_device *dev,
+                                        int idx, const char *descr)
+{
+        struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
+        struct cpuidle_state *state = &dev->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;
+        cx->valid               = cpuidle_params_table[idx].valid;
+        sprintf(state->name, "C%d", idx + 1);
+        strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
+        cpuidle_set_statedata(state, cx);
+
+        return cx;
+}
+
 /**
  * omap3_idle_init - Init routine for OMAP3 idle
  *
- * Registers the OMAP3 specific cpuidle driver with the cpuidle
+ * Registers the OMAP3 specific cpuidle driver to the cpuidle
  * framework with the valid set of states.
  */
 int __init omap3_idle_init(void)
 {
-        int i, count = 0;
-        struct omap3_processor_cx *cx;
-        struct cpuidle_state *state;
         struct cpuidle_device *dev;
+        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");
 
-        omap_init_power_states();
         cpuidle_register_driver(&omap3_idle_driver);
-
         dev = &per_cpu(omap3_idle_dev, smp_processor_id());
 
-        for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
-                cx = &omap3_power_states[i];
-                state = &dev->states[count];
-
-                if (!cx->valid)
-                        continue;
-                cpuidle_set_statedata(state, cx);
-                state->exit_latency = cx->exit_latency;
-                state->target_residency = cx->target_residency;
-                state->flags = cx->flags;
-                state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
-                        omap3_enter_idle_bm : omap3_enter_idle;
-                if (cx->type == OMAP3_STATE_C1)
-                        dev->safe_state = state;
-                sprintf(state->name, "C%d", count+1);
-                strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
-                count++;
-        }
+        /* C1 . MPU WFI + Core active */
+        cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
+        (&dev->states[0])->enter = omap3_enter_idle;
+        dev->safe_state = &dev->states[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 */
+        cx = _fill_cstate(dev, 1, "MPU ON + CORE ON");
+        cx->mpu_state = PWRDM_POWER_ON;
+        cx->core_state = PWRDM_POWER_ON;
+
+        /* C3 . MPU CSWR + Core inactive */
+        cx = _fill_cstate(dev, 2, "MPU RET + CORE ON");
+        cx->mpu_state = PWRDM_POWER_RET;
+        cx->core_state = PWRDM_POWER_ON;
+
+        /* C4 . MPU OFF + Core inactive */
+        cx = _fill_cstate(dev, 3, "MPU OFF + CORE ON");
+        cx->mpu_state = PWRDM_POWER_OFF;
+        cx->core_state = PWRDM_POWER_ON;
+
+        /* C5 . MPU RET + Core RET */
+        cx = _fill_cstate(dev, 4, "MPU RET + CORE RET");
+        cx->mpu_state = PWRDM_POWER_RET;
+        cx->core_state = PWRDM_POWER_RET;
 
-        if (!count)
-                return -EINVAL;
-        dev->state_count = count;
+        /* C6 . MPU OFF + Core RET */
+        cx = _fill_cstate(dev, 5, "MPU OFF + CORE RET");
+        cx->mpu_state = PWRDM_POWER_OFF;
+        cx->core_state = PWRDM_POWER_RET;
+
+        /* C7 . MPU OFF + Core OFF */
+        cx = _fill_cstate(dev, 6, "MPU OFF + CORE OFF");
+        /*
+         * 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;
 
         if (enable_off_mode)
                 omap3_cpuidle_update_states(PWRDM_POWER_OFF, PWRDM_POWER_OFF);
         else
                 omap3_cpuidle_update_states(PWRDM_POWER_RET, PWRDM_POWER_RET);
 
+        dev->state_count = OMAP3_NUM_STATES;
         if (cpuidle_register_device(dev)) {
                 printk(KERN_ERR "%s: CPUidle register device failed\n",
                        __func__);