/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 *
 * (C) COPYRIGHT 2010-2024 ARM Limited. All rights reserved.
 *
 * This program is free software and is provided to you under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation, and any use by you of this program is subject to the terms
 * of such GNU license.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you can access it online at
 * http://www.gnu.org/licenses/gpl-2.0.html.
 *
 */

/**
 * DOC: Power management API definitions
 */

#ifndef _KBASE_PM_H_
#define _KBASE_PM_H_

#include <linux/types.h>

struct kbase_device;

#define PM_ENABLE_IRQS 0x01
#define PM_HW_ISSUES_DETECT 0x02

/* Case 1: the GPU was granted by the Arbiter, it will have
 * already been reset. The following flag ensures it is not reset
 * twice.
 * Case 2: GPU already in reset state after power on, then no soft-reset is needed.
 */
#define PM_NO_RESET 0x04

/**
 * kbase_pm_init - Initialize the power management framework.
 *
 * @kbdev: The kbase device structure for the device
 *              (must be a valid pointer)
 *
 * Must be called before any other power management function
 *
 * Return: 0 if the power management framework was successfully initialized.
 */
int kbase_pm_init(struct kbase_device *kbdev);

/**
 * kbase_pm_powerup - Power up GPU after all modules have been initialized
 *                    and interrupt handlers installed.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 * @flags:     Flags to pass on to kbase_pm_init_hw
 *
 * Return: 0 if powerup was successful.
 */
int kbase_pm_powerup(struct kbase_device *kbdev, unsigned int flags);

/**
 * kbase_pm_halt - Halt the power management framework.
 *
 * @kbdev: The kbase device structure for the device (must be a valid pointer)
 *
 * Should ensure that no new interrupts are generated,
 * but allow any currently running interrupt handlers to complete successfully.
 * The GPU is forced off by the time this function returns, regardless of
 * whether or not the active power policy asks for the GPU to be powered off.
 */
void kbase_pm_halt(struct kbase_device *kbdev);

/**
 * kbase_pm_term - Terminate the power management framework.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 *
 * No power management functions may be called after this
 * (except @ref kbase_pm_init)
 */
void kbase_pm_term(struct kbase_device *kbdev);

/**
 * kbase_pm_context_active - Increment the count of active contexts.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 *
 * This function should be called when a context is about to submit a job.
 * It informs the active power policy that the GPU is going to be in use shortly
 * and the policy is expected to start turning on the GPU.
 *
 * This function will block until the GPU is available.
 *
 * This function ASSERTS if a suspend is occuring/has occurred whilst this is
 * in use. Use kbase_pm_contect_active_unless_suspending() instead.
 *
 * @note a Suspend is only visible to Kernel threads; user-space threads in a
 * syscall cannot witness a suspend, because they are frozen before the suspend
 * begins.
 */
void kbase_pm_context_active(struct kbase_device *kbdev);

/** Handler codes for doing kbase_pm_context_active_handle_suspend() */
enum kbase_pm_suspend_handler {
	/** A suspend is not expected/not possible - this is the same as
	 * kbase_pm_context_active()
	 */
	KBASE_PM_SUSPEND_HANDLER_NOT_POSSIBLE,
	/** If we're suspending, fail and don't increase the active count */
	KBASE_PM_SUSPEND_HANDLER_DONT_INCREASE,
	/** If we're suspending, succeed and allow the active count to increase
	 * if it didn't go from 0->1 (i.e., we didn't re-activate the GPU).
	 *
	 * This should only be used when there is a bounded time on the activation
	 * (e.g. guarantee it's going to be idled very soon after)
	 */
	KBASE_PM_SUSPEND_HANDLER_DONT_REACTIVATE,
	/** Special case when Arbiter has notified we can use GPU.
	 * Active count should always start at 0 in this case.
	 */
	KBASE_PM_SUSPEND_HANDLER_VM_GPU_GRANTED,
};

/**
 * kbase_pm_context_active_handle_suspend - Suspend 'safe' variant of kbase_pm_context_active()
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 * @suspend_handler: The handler code for how to handle a suspend that might occur
 *
 * If a suspend is in progress, this allows for various different ways of
 * handling the suspend. Refer to @ref enum kbase_pm_suspend_handler for details.
 *
 * We returns a status code indicating whether we're allowed to keep the GPU
 * active during the suspend, depending on the handler code. If the status code
 * indicates a failure, the caller must abort whatever operation it was
 * attempting, and potentially queue it up for after the OS has resumed.
 *
 * Return: 0 on success, non-zero othrewise.
 */
int kbase_pm_context_active_handle_suspend(struct kbase_device *kbdev,
					   enum kbase_pm_suspend_handler suspend_handler);

/**
 * kbase_pm_context_active_handle_suspend_locked - Same as kbase_pm_context_active_handle_suspend(),
 *                                                 except that pm.lock is held by the caller.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 * @suspend_handler: The handler code for how to handle a suspend that might occur
 *
 * Return: 0 on success, non-zero othrewise.
 */
int kbase_pm_context_active_handle_suspend_locked(struct kbase_device *kbdev,
						  enum kbase_pm_suspend_handler suspend_handler);

/**
 * kbase_pm_context_idle - Decrement the reference count of active contexts.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 *
 * This function should be called when a context becomes idle.
 * After this call the GPU may be turned off by the power policy so the calling
 * code should ensure that it does not access the GPU's registers.
 */
void kbase_pm_context_idle(struct kbase_device *kbdev);

/**
 * kbase_pm_context_idle_locked - Same as kbase_pm_context_idle(), except that
 *                                pm.lock is held by the caller.
 *
 * @kbdev:     The kbase device structure for the device (must be a valid pointer)
 */
void kbase_pm_context_idle_locked(struct kbase_device *kbdev);

/* NOTE: kbase_pm_is_active() is in mali_kbase.h, because it is an inline
 * function
 */

/**
 * kbase_pm_suspend - Suspend the GPU and prevent any further register accesses
 *                    to it from Kernel threads.
 *
 * @kbdev: The kbase device structure for the device (must be a valid pointer)
 *
 * This is called in response to an OS suspend event, and calls into the various
 * kbase components to complete the suspend.
 *
 * @note the mechanisms used here rely on all user-space threads being frozen
 * by the OS before we suspend. Otherwise, an IOCTL could occur that powers up
 * the GPU e.g. via atom submission.
 *
 * Return: 0 on success.
 */
int kbase_pm_suspend(struct kbase_device *kbdev);

/**
 * kbase_pm_resume - Resume the GPU, allow register accesses to it,
 *                   and resume running atoms on the GPU.
 *
 * @kbdev: The kbase device structure for the device (must be a valid pointer)
 *
 * This is called in response to an OS resume event, and calls into the various
 * kbase components to complete the resume.
 *
 * Also called when using VM arbiter, when GPU access has been granted.
 */
void kbase_pm_resume(struct kbase_device *kbdev);

/**
 * kbase_pm_vsync_callback - vsync callback
 *
 * @buffer_updated: 1 if a new frame was displayed, 0 otherwise
 * @data: Pointer to the kbase device as returned by kbase_find_device()
 *
 * Callback function used to notify the power management code that a vsync has
 * occurred on the display.
 */
void kbase_pm_vsync_callback(int buffer_updated, void *data);

/**
 * kbase_pm_driver_suspend() - Put GPU and driver in suspend state
 * @kbdev: The kbase device structure for the device (must be a valid pointer)
 *
 * Suspend the GPU and prevent any further register accesses to it from Kernel
 * threads.
 *
 * This is called in response to an OS suspend event, and calls into the various
 * kbase components to complete the suspend.
 *
 * Despite kbase_pm_suspend(), it will ignore to update Arbiter
 * status if there is one.
 *
 * @note the mechanisms used here rely on all user-space threads being frozen
 * by the OS before we suspend. Otherwise, an IOCTL could occur that powers up
 * the GPU e.g. via atom submission.
 *
 * Return: 0 on success.
 */
int kbase_pm_driver_suspend(struct kbase_device *kbdev);

/**
 * kbase_pm_driver_resume() - Put GPU and driver in resume
 * @kbdev: The kbase device structure for the device (must be a valid pointer)
 * @arb_gpu_start: Arbiter has notified we can use GPU
 *
 * Resume the GPU, allow register accesses to it, and resume running atoms on
 * the GPU.
 *
 * This is called in response to an OS resume event, and calls into the various
 * kbase components to complete the resume.
 *
 * Also called when using VM arbiter, when GPU access has been granted.
 *
 * Despite kbase_pm_resume(), it will ignore to update Arbiter
 * status if there is one.
 */
void kbase_pm_driver_resume(struct kbase_device *kbdev, bool arb_gpu_start);

/**
 * kbase_pm_handle_gpu_lost() - Handle GPU Lost for the VM
 * @kbdev: Device pointer
 *
 * Handles the case that the Arbiter has forced the GPU away from the VM,
 * so that interrupts will not be received and registers are no longer
 * accessible because replaced by dummy RAM.
 * Kill any running tasks and put the driver into a GPU powered-off state.
 */
void kbase_pm_handle_gpu_lost(struct kbase_device *kbdev);

#endif /* _KBASE_PM_H_ */