static int __init tegra_cpufreq_init(void)
{
#ifdef CONFIG_HOTPLUG_CPU
	pm_notifier(tegra_cpufreq_pm_notifier, 0);
#endif
	return cpufreq_register_driver(&s_tegra_cpufreq_driver);
}

static int __init nvrm_init(void)
{
    int ret = 0;
    printk(KERN_INFO "%s called\n", __func__);

    #if defined(CONFIG_PM)
    // Register PM notifier.
    pm_notifier(tegra_pm_notifier, 0);
    tegra_pm_notifier_continue_ok = 0;
    init_waitqueue_head(&tegra_pm_notifier_wait);

    #if defined(CONFIG_HAS_EARLYSUSPEND)
    register_early_suspend(&tegra_display_power);
    #endif

    // Create /sys/power/nvrm/notifier.
    nvrm_kobj = kobject_create_and_add("nvrm", power_kobj);
    sysfs_create_file(nvrm_kobj, &nvrm_lp2policy_attribute.attr);
    sysfs_create_file(nvrm_kobj, &nvrm_notifier_attribute.attr);
    sys_nvrm_notifier = NULL;
    init_waitqueue_head(&sys_nvrm_notifier_wait);
    #endif

    // Register NvRm platform driver.
    ret = platform_driver_register(&nvrm_driver);

    return ret;
}

static int __init machine_kdump_pm_init(void)
{
	pm_notifier(machine_kdump_pm_cb, 0);
	/* Create initial mapping for crashkernel memory */
	arch_kexec_unprotect_crashkres();
	return 0;
}

static int __init cpu_hotplug_pm_sync_init(void)
{
    /*
     * cpu_hotplug_pm_callback has higher priority than x86
     * bsp_pm_callback which depends on cpu_hotplug_pm_callback
     * to disable cpu hotplug to avoid cpu hotplug race.
     */
    pm_notifier(cpu_hotplug_pm_callback, 0);
    return 0;
}

static int __init pbm_module_init(void)
{
	int ret = 0;

	#if 1 /* CONFIG_PBM_PROC_FS */
	mt_pbm_create_procfs();
	#endif

	pm_notifier(_mt_pbm_pm_callback, 0);

	register_dlpt_notify(&kicker_pbm_by_dlpt, DLPT_PRIO_PBM);
	ret = create_pbm_kthread();

	pbm_crit("pbm_module_init : Done\n");

	if (ret) {
		pbm_err("FAILED TO CREATE PBM KTHREAD\n");
		return ret;
	}
	return ret;
}

static int __init suspend_pm_init(void)
{
	pm_notifier(suspend_pm_cb, 0);
	return 0;
}

static int __init machine_kdump_pm_init(void)
{
	pm_notifier(machine_kdump_pm_cb, 0);
	return 0;
}

int pm_ext_init(struct tty_struct *tty)
{
	int res;

	pm_ext_tty = tty;

	/*
	 * NOTE: No need to request AWR since this is done by the board
	 * file.
	 */

	/* AWR should be low initially. */
	gpio_direction_output(GPIO_MODEM_AWR, 0);

	/* Request and configure CWR. */
	res = gpio_request(GPIO_MODEM_CWR, "cwr");
	if (res < 0) {
		printk(KERN_ERR "pm_ext_init: request_gpio_cwr_failed: %d.\n", res);
		goto request_gpio_cwr_failed;
	}

	gpio_direction_input(GPIO_MODEM_CWR);

	/* Report initial state if different from low (WARN). */
	if (gpio_get_value(GPIO_MODEM_CWR)) {
		printk(KERN_WARNING "pm_ext_init: CWR already asserted.\n");
		cwr_notify(pm_ext_tty, true);
	}

	/* Trigger on both falling and rising edges on CWR. */
	res = request_irq(gpio_to_irq(GPIO_MODEM_CWR), cwr_irq,
					  IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
					  "cwr_irq", NULL);
	if (res < 0) {
		printk(KERN_ERR "pm_ext_init: request_irq_failed: %d.\n", res);
		goto request_irq_failed;
	}

	/* Make IRQ wakeup capable. */
	res = enable_irq_wake(gpio_to_irq(GPIO_MODEM_CWR));
	if (res < 0) {
		printk(KERN_ERR "pm_ext_init: enable_irq_wake_failed: %d.\n", res);
		goto enable_irq_wake_failed;
	}

#ifdef CONFIG_HAS_WAKELOCK
	wake_lock_init(&awr_wakelock, WAKE_LOCK_SUSPEND, "caif_awr");
	wake_lock_init(&cwr_wakelock, WAKE_LOCK_SUSPEND, "caif_cwr");
#endif /* CONFIG_HAS_WAKELOCK */

	pm_notifier(pm_notify, 0);

	return 0;

 enable_irq_wake_failed:
 request_irq_failed:
	gpio_free(GPIO_MODEM_CWR);
 request_gpio_cwr_failed:
	gpio_free(GPIO_MODEM_AWR);

	return -ENODEV;
}