/*
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Rafał Miłecki <zajec5@gmail.com>
 */
#include "drmP.h"
#include "radeon.h"

#define RADEON_IDLE_LOOP_MS 100
#define RADEON_RECLOCK_DELAY_MS 200

static void radeon_pm_check_limits(struct radeon_device *rdev);
static void radeon_pm_set_clocks_locked(struct radeon_device *rdev);
static void radeon_pm_set_clocks(struct radeon_device *rdev);
static void radeon_pm_reclock_work_handler(struct work_struct *work);
static void radeon_pm_idle_work_handler(struct work_struct *work);
static int radeon_debugfs_pm_init(struct radeon_device *rdev);

static const char *pm_state_names[4] = {
	"PM_STATE_DISABLED",
	"PM_STATE_MINIMUM",
	"PM_STATE_PAUSED",
	"PM_STATE_ACTIVE"
};

int radeon_pm_init(struct radeon_device *rdev)
{
	rdev->pm.state = PM_STATE_DISABLED;
	rdev->pm.planned_action = PM_ACTION_NONE;
	rdev->pm.downclocked = false;
	rdev->pm.vblank_callback = false;

	radeon_pm_check_limits(rdev);

	if (radeon_debugfs_pm_init(rdev)) {
		DRM_ERROR("Failed to register debugfs file for PM!\n");
	}

	INIT_WORK(&rdev->pm.reclock_work, radeon_pm_reclock_work_handler);
	INIT_DELAYED_WORK(&rdev->pm.idle_work, radeon_pm_idle_work_handler);

	if (radeon_dynpm != -1 && radeon_dynpm) {
		rdev->pm.state = PM_STATE_PAUSED;
		DRM_INFO("radeon: dynamic power management enabled\n");
	}

	DRM_INFO("radeon: power management initialized\n");

	return 0;
}

static void radeon_pm_check_limits(struct radeon_device *rdev)
{
	rdev->pm.min_gpu_engine_clock = rdev->clock.default_sclk - 5000;
	rdev->pm.min_gpu_memory_clock = rdev->clock.default_mclk - 5000;
}

void radeon_pm_compute_clocks(struct radeon_device *rdev)
{
	struct drm_device *ddev = rdev->ddev;
	struct drm_connector *connector;
	struct radeon_crtc *radeon_crtc;
	int count = 0;

	if (rdev->pm.state == PM_STATE_DISABLED)
		return;

	mutex_lock(&rdev->pm.mutex);

	rdev->pm.active_crtcs = 0;
	list_for_each_entry(connector,
		&ddev->mode_config.connector_list, head) {
		if (connector->encoder &&
			connector->dpms != DRM_MODE_DPMS_OFF) {
			radeon_crtc = to_radeon_crtc(connector->encoder->crtc);
			rdev->pm.active_crtcs |= (1 << radeon_crtc->crtc_id);
			++count;
		}
	}

	if (count > 1) {
		if (rdev->pm.state == PM_STATE_ACTIVE) {
			wait_queue_head_t wait;
			init_waitqueue_head(&wait);

			cancel_delayed_work(&rdev->pm.idle_work);

			rdev->pm.state = PM_STATE_PAUSED;
			rdev->pm.planned_action = PM_ACTION_UPCLOCK;
			rdev->pm.vblank_callback = true;

			mutex_unlock(&rdev->pm.mutex);

			wait_event_timeout(wait, !rdev->pm.downclocked,
				msecs_to_jiffies(300));
			if (!rdev->pm.downclocked)
				radeon_pm_set_clocks(rdev);

			DRM_DEBUG("radeon: dynamic power management deactivated\n");
		} else {
			mutex_unlock(&rdev->pm.mutex);
		}
	} else if (count == 1) {
		rdev->pm.min_mode_engine_clock = rdev->pm.min_gpu_engine_clock;
		rdev->pm.min_mode_memory_clock = rdev->pm.min_gpu_memory_clock;
		/* TODO: Increase clocks if needed for current mode */

		if (rdev->pm.state == PM_STATE_MINIMUM) {
			rdev->pm.state = PM_STATE_ACTIVE;
			rdev->pm.planned_action = PM_ACTION_UPCLOCK;
			radeon_pm_set_clocks_locked(rdev);

			queue_delayed_work(rdev->wq, &rdev->pm.idle_work,
				msecs_to_jiffies(RADEON_IDLE_LOOP_MS));
		}
		else if (rdev->pm.state == PM_STATE_PAUSED) {
			rdev->pm.state = PM_STATE_ACTIVE;
			queue_delayed_work(rdev->wq, &rdev->pm.idle_work,
				msecs_to_jiffies(RADEON_IDLE_LOOP_MS));
			DRM_DEBUG("radeon: dynamic power management activated\n");
		}

		mutex_unlock(&rdev->pm.mutex);
	}
	else { /* count == 0 */
		if (rdev->pm.state != PM_STATE_MINIMUM) {
			cancel_delayed_work(&rdev->pm.idle_work);

			rdev->pm.state = PM_STATE_MINIMUM;
			rdev->pm.planned_action = PM_ACTION_MINIMUM;
			radeon_pm_set_clocks_locked(rdev);
		}

		mutex_unlock(&rdev->pm.mutex);
	}
}

static void radeon_pm_set_clocks_locked(struct radeon_device *rdev)
{
	/*radeon_fence_wait_last(rdev);*/
	switch (rdev->pm.planned_action) {
	case PM_ACTION_UPCLOCK:
		radeon_set_engine_clock(rdev, rdev->clock.default_sclk);
		rdev->pm.downclocked = false;
		break;
	case PM_ACTION_DOWNCLOCK:
		radeon_set_engine_clock(rdev,
			rdev->pm.min_mode_engine_clock);
		rdev->pm.downclocked = true;
		break;
	case PM_ACTION_MINIMUM:
		radeon_set_engine_clock(rdev,
			rdev->pm.min_gpu_engine_clock);
		break;
	case PM_ACTION_NONE:
		DRM_ERROR("%s: PM_ACTION_NONE\n", __func__);
		break;
	}

	rdev->pm.planned_action = PM_ACTION_NONE;
}

static void radeon_pm_set_clocks(struct radeon_device *rdev)
{
	mutex_lock(&rdev->pm.mutex);
	/* new VBLANK irq may come before handling previous one */
	if (rdev->pm.vblank_callback) {
		mutex_lock(&rdev->cp.mutex);
		if (rdev->pm.req_vblank & (1 << 0)) {
			rdev->pm.req_vblank &= ~(1 << 0);
			drm_vblank_put(rdev->ddev, 0);
		}
		if (rdev->pm.req_vblank & (1 << 1)) {
			rdev->pm.req_vblank &= ~(1 << 1);
			drm_vblank_put(rdev->ddev, 1);
		}
		rdev->pm.vblank_callback = false;
		radeon_pm_set_clocks_locked(rdev);
		mutex_unlock(&rdev->cp.mutex);
	}
	mutex_unlock(&rdev->pm.mutex);
}

static void radeon_pm_reclock_work_handler(struct work_struct *work)
{
	struct radeon_device *rdev;
	rdev = container_of(work, struct radeon_device,
				pm.reclock_work);
	radeon_pm_set_clocks(rdev);
}

static void radeon_pm_idle_work_handler(struct work_struct *work)
{
	struct radeon_device *rdev;
	rdev = container_of(work, struct radeon_device,
				pm.idle_work.work);

	mutex_lock(&rdev->pm.mutex);
	if (rdev->pm.state == PM_STATE_ACTIVE &&
		!rdev->pm.vblank_callback) {
		unsigned long irq_flags;
		int not_processed = 0;

		read_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
		if (!list_empty(&rdev->fence_drv.emited)) {
			struct list_head *ptr;
			list_for_each(ptr, &rdev->fence_drv.emited) {
				/* count up to 3, that's enought info */
				if (++not_processed >= 3)
					break;
			}
		}
		read_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);

		if (not_processed >= 3) { /* should upclock */
			if (rdev->pm.planned_action == PM_ACTION_DOWNCLOCK) {
				rdev->pm.planned_action = PM_ACTION_NONE;
			} else if (rdev->pm.planned_action == PM_ACTION_NONE &&
				rdev->pm.downclocked) {
				rdev->pm.planned_action =
					PM_ACTION_UPCLOCK;
				rdev->pm.action_timeout = jiffies +
				msecs_to_jiffies(RADEON_RECLOCK_DELAY_MS);
			}
		} else if (not_processed == 0) { /* should downclock */
			if (rdev->pm.planned_action == PM_ACTION_UPCLOCK) {
				rdev->pm.planned_action = PM_ACTION_NONE;
			} else if (rdev->pm.planned_action == PM_ACTION_NONE &&
				!rdev->pm.downclocked) {
				rdev->pm.planned_action =
					PM_ACTION_DOWNCLOCK;
				rdev->pm.action_timeout = jiffies +
				msecs_to_jiffies(RADEON_RECLOCK_DELAY_MS);
			}
		}

		if (rdev->pm.planned_action != PM_ACTION_NONE &&
			jiffies > rdev->pm.action_timeout) {
			if (rdev->pm.active_crtcs & (1 << 0)) {
				rdev->pm.req_vblank |= (1 << 0);
				drm_vblank_get(rdev->ddev, 0);
			}
			if (rdev->pm.active_crtcs & (1 << 1)) {
				rdev->pm.req_vblank |= (1 << 1);
				drm_vblank_get(rdev->ddev, 1);
			}
			rdev->pm.vblank_callback = true;
		}
	}
	mutex_unlock(&rdev->pm.mutex);

	queue_delayed_work(rdev->wq, &rdev->pm.idle_work,
					msecs_to_jiffies(RADEON_IDLE_LOOP_MS));
}

/*
 * Debugfs info
 */
#if defined(CONFIG_DEBUG_FS)

static int radeon_debugfs_pm_info(struct seq_file *m, void *data)
{
	struct drm_info_node *node = (struct drm_info_node *) m->private;
	struct drm_device *dev = node->minor->dev;
	struct radeon_device *rdev = dev->dev_private;

	seq_printf(m, "state: %s\n", pm_state_names[rdev->pm.state]);
	seq_printf(m, "default engine clock: %u0 kHz\n", rdev->clock.default_sclk);
	seq_printf(m, "current engine clock: %u0 kHz\n", radeon_get_engine_clock(rdev));
	seq_printf(m, "default memory clock: %u0 kHz\n", rdev->clock.default_mclk);
	if (rdev->asic->get_memory_clock)
		seq_printf(m, "current memory clock: %u0 kHz\n", radeon_get_memory_clock(rdev));

	return 0;
}

static struct drm_info_list radeon_pm_info_list[] = {
	{"radeon_pm_info", radeon_debugfs_pm_info, 0, NULL},
};
#endif

static int radeon_debugfs_pm_init(struct radeon_device *rdev)
{
#if defined(CONFIG_DEBUG_FS)
	return radeon_debugfs_add_files(rdev, radeon_pm_info_list, ARRAY_SIZE(radeon_pm_info_list));
#else
	return 0;
#endif
}