Re: [PATCH 01/02] OMAP3 CPUidle driver

Kevin Hilman
2008-06-16T23:21:24Z

"Rajendra Nayak" <rnayak@ti.com> writes:

> 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.

Can you explain why you need the IRQ/FIQ disable added to cpuidle_idle_call()

Kevin

> 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);
>
> --
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