[PATCH 01/02] OMAP3 CPUidle driver

Rajendra Nayak
2008-06-10T07:09:09Z

This patch adds the OMAP3 cpuidle driver. Irq enable/disable is done in the core cpuidle driver
before it queries the governor for the next state.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>

---
arch/arm/mach-omap2/Makefile | 2
arch/arm/mach-omap2/cpuidle34xx.c | 293 ++++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/cpuidle34xx.h | 51 ++++++
arch/arm/mach-omap2/pm34xx.c | 5
drivers/cpuidle/cpuidle.c | 10 +
5 files changed, 359 insertions(+), 2 deletions(-)

Index: linux-omap-2.6/arch/arm/mach-omap2/Makefile
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/Makefile 2008-06-09 20:15:33.855303920 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/Makefile 2008-06-09 20:15:39.569121361 +0530
@@ -20,7 +20,7 @@ obj-y += pm.o
obj-$(CONFIG_ARCH_OMAP2) += pm24xx.o
obj-$(CONFIG_ARCH_OMAP2420) += sleep242x.o
obj-$(CONFIG_ARCH_OMAP2430) += sleep243x.o
-obj-$(CONFIG_ARCH_OMAP3) += pm34xx.o sleep34xx.o
+obj-$(CONFIG_ARCH_OMAP3) += pm34xx.o sleep34xx.o cpuidle34xx.o
obj-$(CONFIG_PM_DEBUG) += pm-debug.o
endif

Index: linux-omap-2.6/arch/arm/mach-omap2/cpuidle34xx.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-omap-2.6/arch/arm/mach-omap2/cpuidle34xx.c 2008-06-10 11:41:27.644820323 +0530
@@ -0,0 +1,293 @@
+/*
+ * linux/arch/arm/mach-omap2/cpuidle34xx.c
+ *
+ * OMAP3 CPU IDLE Routines
+ *
+ * Copyright (C) 2007-2008 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>
+ *
+ * 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/cpuidle.h>
+#include <asm/arch/pm.h>
+#include <asm/arch/prcm.h>
+#include <asm/arch/powerdomain.h>
+#include <asm/arch/clockdomain.h>
+#include <asm/arch/irqs.h>
+#include "cpuidle34xx.h"
+
+#ifdef CONFIG_CPU_IDLE
+
+struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
+struct omap3_processor_cx current_cx_state;
+
+static int omap3_idle_bm_check(void)
+{
+ /* Check for omap3_fclks_active() here once available */
+ return 0;
+}
+
+/* omap3_enter_idle - Programs OMAP3 to enter the specified state.
+ * returns the total time during which the system was idle.
+ */
+static int omap3_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_state *state)
+{
+ struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
+ struct timespec ts_preidle, ts_postidle, ts_idle;
+ struct powerdomain *mpu_pd, *core_pd, *per_pd, *neon_pd;
+ int neon_pwrst;
+
+ current_cx_state = *cx;
+
+ if (cx->type == OMAP3_STATE_C0) {
+ /* Do nothing for C0, not even a wfi */
+ return 0;
+ }
+
+ /* Used to keep track of the total time in idle */
+ getnstimeofday(&ts_preidle);
+
+ mpu_pd = pwrdm_lookup("mpu_pwrdm");
+ core_pd = pwrdm_lookup("core_pwrdm");
+ per_pd = pwrdm_lookup("per_pwrdm");
+ neon_pd = pwrdm_lookup("neon_pwrdm");
+
+ /* Reset previous power state registers */
+ pwrdm_clear_all_prev_pwrst(mpu_pd);
+ pwrdm_clear_all_prev_pwrst(neon_pd);
+ pwrdm_clear_all_prev_pwrst(core_pd);
+ pwrdm_clear_all_prev_pwrst(per_pd);
+
+ if (omap_irq_pending())
+ return 0;
+
+ neon_pwrst = pwrdm_read_pwrst(neon_pd);
+
+ /* Program MPU/NEON to target state */
+ if (cx->mpu_state < PWRDM_POWER_ON) {
+ if (neon_pwrst == PWRDM_POWER_ON) {
+ if (cx->mpu_state == PWRDM_POWER_RET)
+ pwrdm_set_next_pwrst(neon_pd, PWRDM_POWER_RET);
+ else if (cx->mpu_state == PWRDM_POWER_OFF)
+ pwrdm_set_next_pwrst(neon_pd, PWRDM_POWER_OFF);
+ }
+ pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
+ }
+
+ /* Program CORE to target state */
+ if (cx->core_state < PWRDM_POWER_ON)
+ pwrdm_set_next_pwrst(core_pd, cx->core_state);
+
+ /* Execute ARM wfi */
+ omap_sram_idle();
+
+ /* Program MPU/NEON to ON */
+ if (cx->mpu_state < PWRDM_POWER_ON) {
+ if (neon_pwrst == PWRDM_POWER_ON)
+ pwrdm_set_next_pwrst(neon_pd, PWRDM_POWER_ON);
+ pwrdm_set_next_pwrst(mpu_pd, PWRDM_POWER_ON);
+ }
+
+ if (cx->core_state < PWRDM_POWER_ON)
+ pwrdm_set_next_pwrst(core_pd, PWRDM_POWER_ON);
+
+ getnstimeofday(&ts_postidle);
+ ts_idle = timespec_sub(ts_postidle, ts_preidle);
+ return timespec_to_ns(&ts_idle);
+}
+
+/*
+ * omap3_enter_idle_bm - enter function for states with CPUIDLE_FLAG_CHECK_BM
+ *
+ * This function checks for all the pre-requisites needed for OMAP3 to enter
+ * CORE RET/OFF state. It then calls omap3_enter_idle to program the desired
+ * C state.
+ */
+static int omap3_enter_idle_bm(struct cpuidle_device *dev,
+ struct cpuidle_state *state)
+{
+ struct cpuidle_state *new_state = NULL;
+ int i, j;
+
+ if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
+
+ /* Find current state in list */
+ for (i = 0; i < OMAP3_MAX_STATES; i++)
+ if (state == &dev->states[i])
+ break;
+ BUG_ON(i == OMAP3_MAX_STATES);
+
+ /* Back up to non 'CHECK_BM' state */
+ for (j = i - 1; j > 0; j--) {
+ struct cpuidle_state *s = &dev->states[j];
+
+ if (!(s->flags & CPUIDLE_FLAG_CHECK_BM)) {
+ new_state = s;
+ break;
+ }
+ }
+
+ pr_debug("%s: Bus activity: Entering %s (instead of %s)\n",
+ __FUNCTION__, new_state->name, state->name);
+ }
+
+ return omap3_enter_idle(dev, new_state ? : state);
+}
+
+DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
+
+/* omap3_init_power_states - Initialises the OMAP3 specific C states.
+ * Below is the desciption of each C state.
+ *
+ C0 . System executing code
+ C1 . MPU WFI + Core active
+ C2 . MPU CSWR + Core active
+ C3 . MPU OFF + Core active
+ C4 . MPU CSWR + Core CSWR
+ C5 . MPU OFF + Core CSWR
+ C6 . MPU OFF + Core OFF
+ */
+void omap_init_power_states(void)
+{
+ /* C0 . System executing code */
+ omap3_power_states[0].valid = 1;
+ omap3_power_states[0].type = OMAP3_STATE_C0;
+ omap3_power_states[0].sleep_latency = 0;
+ omap3_power_states[0].wakeup_latency = 0;
+ omap3_power_states[0].threshold = 0;
+ omap3_power_states[0].mpu_state = PWRDM_POWER_ON;
+ omap3_power_states[0].core_state = PWRDM_POWER_ON;
+ omap3_power_states[0].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_SHALLOW;
+
+ /* C1 . MPU WFI + Core active */
+ omap3_power_states[1].valid = 1;
+ omap3_power_states[1].type = OMAP3_STATE_C1;
+ omap3_power_states[1].sleep_latency = 10;
+ omap3_power_states[1].wakeup_latency = 10;
+ omap3_power_states[1].threshold = 30;
+ omap3_power_states[1].mpu_state = PWRDM_POWER_ON;
+ omap3_power_states[1].core_state = PWRDM_POWER_ON;
+ omap3_power_states[1].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_SHALLOW;
+
+ /* C2 . MPU CSWR + Core active */
+ omap3_power_states[2].valid = 1;
+ omap3_power_states[2].type = OMAP3_STATE_C2;
+ omap3_power_states[2].sleep_latency = 50;
+ omap3_power_states[2].wakeup_latency = 50;
+ omap3_power_states[2].threshold = 300;
+ omap3_power_states[2].mpu_state = PWRDM_POWER_RET;
+ omap3_power_states[2].core_state = PWRDM_POWER_ON;
+ omap3_power_states[2].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_BALANCED;
+
+ /* C3 . MPU OFF + Core active */
+ omap3_power_states[3].valid = 0;
+ omap3_power_states[3].type = OMAP3_STATE_C3;
+ omap3_power_states[3].sleep_latency = 1500;
+ omap3_power_states[3].wakeup_latency = 1800;
+ omap3_power_states[3].threshold = 4000;
+ omap3_power_states[3].mpu_state = PWRDM_POWER_OFF;
+ omap3_power_states[3].core_state = PWRDM_POWER_RET;
+ omap3_power_states[3].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_BALANCED;
+
+ /* C4 . MPU CSWR + Core CSWR*/
+ omap3_power_states[4].valid = 1;
+ omap3_power_states[4].type = OMAP3_STATE_C4;
+ omap3_power_states[4].sleep_latency = 2500;
+ omap3_power_states[4].wakeup_latency = 7500;
+ omap3_power_states[4].threshold = 12000;
+ omap3_power_states[4].mpu_state = PWRDM_POWER_RET;
+ omap3_power_states[4].core_state = PWRDM_POWER_RET;
+ omap3_power_states[4].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_BALANCED | CPUIDLE_FLAG_CHECK_BM;
+
+ /* C5 . MPU OFF + Core CSWR */
+ omap3_power_states[5].valid = 0;
+ omap3_power_states[5].type = OMAP3_STATE_C5;
+ omap3_power_states[5].sleep_latency = 3000;
+ omap3_power_states[5].wakeup_latency = 8500;
+ omap3_power_states[5].threshold = 15000;
+ omap3_power_states[5].mpu_state = PWRDM_POWER_OFF;
+ omap3_power_states[5].core_state = PWRDM_POWER_RET;
+ omap3_power_states[5].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_BALANCED | CPUIDLE_FLAG_CHECK_BM;
+
+ /* C6 . MPU OFF + Core OFF */
+ omap3_power_states[6].valid = 0;
+ omap3_power_states[6].type = OMAP3_STATE_C6;
+ omap3_power_states[6].sleep_latency = 10000;
+ omap3_power_states[6].wakeup_latency = 30000;
+ omap3_power_states[6].threshold = 300000;
+ omap3_power_states[6].mpu_state = PWRDM_POWER_OFF;
+ omap3_power_states[6].core_state = PWRDM_POWER_OFF;
+ omap3_power_states[6].flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_DEEP | CPUIDLE_FLAG_CHECK_BM;
+}
+
+struct cpuidle_driver omap3_idle_driver = {
+ .name = "omap3_idle",
+ .owner = THIS_MODULE,
+};
+/*
+ * omap3_idle_init - Init routine for OMAP3 idle.
+ * Registers the OMAP3 specific cpuidle driver with the cpuidle f/w
+ * with the valid set of states.
+ */
+int omap3_idle_init(void)
+{
+ int i, count = 0;
+ struct omap3_processor_cx *cx;
+ struct cpuidle_state *state;
+ struct cpuidle_device *dev;
+
+ omap_init_power_states();
+ cpuidle_register_driver(&omap3_idle_driver);
+
+ dev = &per_cpu(omap3_idle_dev, smp_processor_id());
+
+ for (i = 0; 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->sleep_latency + cx->wakeup_latency;
+ state->target_residency = cx->threshold;
+ state->flags = cx->flags;
+ state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
+ omap3_enter_idle_bm : omap3_enter_idle;
+ sprintf(state->name, "C%d", count+1);
+ count++;
+ }
+
+ if (!count)
+ return -EINVAL;
+ dev->state_count = count;
+
+ if (cpuidle_register_device(dev)) {
+ printk(KERN_ERR "%s: CPUidle register device failed\n",
+ __FUNCTION__);
+ return -EIO;
+ }
+
+ return 0;
+}
+__initcall(omap3_idle_init);
+#endif /* CONFIG_CPU_IDLE */
Index: linux-omap-2.6/arch/arm/mach-omap2/cpuidle34xx.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-omap-2.6/arch/arm/mach-omap2/cpuidle34xx.h 2008-06-09 20:15:39.569121361 +0530
@@ -0,0 +1,51 @@
+/*
+ * linux/arch/arm/mach-omap2/cpuidle34xx.h
+ *
+ * OMAP3 cpuidle structure definitions
+ *
+ * Copyright (C) 2007-2008 Texas Instruments, Inc.
+ * Written by Rajendra Nayak <rnayak@ti.com>
+ *
+ * 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.
+ *
+ * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * History:
+ *
+ */
+
+#ifndef ARCH_ARM_MACH_OMAP2_CPUIDLE_34XX
+#define ARCH_ARM_MACH_OMAP2_CPUIDLE_34XX
+
+#define OMAP3_MAX_STATES 7
+#define OMAP3_STATE_C0 0 /* C0 - System executing code */
+#define OMAP3_STATE_C1 1 /* C1 - MPU WFI + Core active */
+#define OMAP3_STATE_C2 2 /* C2 - MPU CSWR + Core active */
+#define OMAP3_STATE_C3 3 /* C3 - MPU OFF + Core active */
+#define OMAP3_STATE_C4 4 /* C4 - MPU RET + Core RET */
+#define OMAP3_STATE_C5 5 /* C5 - MPU OFF + Core RET */
+#define OMAP3_STATE_C6 6 /* C6 - MPU OFF + Core OFF */
+
+extern void omap_sram_idle(void);
+extern int omap3_irq_pending(void);
+
+struct omap3_processor_cx {
+ u8 valid;
+ u8 type;
+ u32 sleep_latency;
+ u32 wakeup_latency;
+ u32 mpu_state;
+ u32 core_state;
+ u32 threshold;
+ u32 flags;
+};
+
+void omap_init_power_states(void);
+int omap3_idle_init(void);
+
+#endif /* ARCH_ARM_MACH_OMAP2_CPUIDLE_34XX */
+
Index: linux-omap-2.6/arch/arm/mach-omap2/pm34xx.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/pm34xx.c 2008-06-09 20:15:33.855303920 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/pm34xx.c 2008-06-09 20:16:20.976798343 +0530
@@ -141,7 +141,7 @@ static irqreturn_t prcm_interrupt_handle
return IRQ_HANDLED;
}

-static void omap_sram_idle(void)
+void omap_sram_idle(void)
{
/* Variable to tell what needs to be saved and restored
* in omap_sram_idle*/
@@ -156,6 +156,7 @@ static void omap_sram_idle(void)

mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);
switch (mpu_next_state) {
+ case PWRDM_POWER_ON:
case PWRDM_POWER_RET:
/* No need to save context */
save_state = 0;
@@ -386,7 +387,9 @@ int __init omap3_pm_init(void)

prcm_setup_regs();

+#ifndef CONFIG_CPU_IDLE
pm_idle = omap3_pm_idle;
+#endif

err1:
return ret;
Index: linux-omap-2.6/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-omap-2.6.orig/drivers/cpuidle/cpuidle.c 2008-06-09 20:15:33.856303888 +0530
+++ linux-omap-2.6/drivers/cpuidle/cpuidle.c 2008-06-09 20:15:39.570121329 +0530
@@ -58,6 +58,11 @@ static void cpuidle_idle_call(void)
return;
}

+#ifdef CONFIG_ARCH_OMAP3
+ local_irq_disable();
+ local_fiq_disable();
+#endif
+
/* ask the governor for the next state */
next_state = cpuidle_curr_governor->select(dev);
if (need_resched())
@@ -70,6 +75,11 @@ static void cpuidle_idle_call(void)
target_state->time += (unsigned long long)dev->last_residency;
target_state->usage++;

+#ifdef CONFIG_ARCH_OMAP3
+ local_irq_enable();
+ local_fiq_enable();
+#endif
+
/* give the governor an opportunity to reflect on the outcome */
if (cpuidle_curr_governor->reflect)
cpuidle_curr_governor->reflect(dev);