1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
new file mode 100644
index 000000000000..a553e182ff53
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author: Yakir Yang <ykk@rock-chips.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+
+#include "rockchip_drm_drv.h"
+#include "rockchip_drm_psr.h"
+
+#define PSR_FLUSH_TIMEOUT	msecs_to_jiffies(100)
+
+enum psr_state {
+	PSR_FLUSH,
+	PSR_ENABLE,
+	PSR_DISABLE,
+};
+
+struct psr_drv {
+	struct list_head	list;
+	struct drm_encoder	*encoder;
+
+	spinlock_t		lock;
+	bool			active;
+	enum psr_state		state;
+
+	struct timer_list	flush_timer;
+
+	void (*set)(struct drm_encoder *encoder, bool enable);
+};
+
+static struct psr_drv *find_psr_by_crtc(struct drm_crtc *crtc)
+{
+	struct rockchip_drm_private *drm_drv = crtc->dev->dev_private;
+	struct psr_drv *psr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
+	list_for_each_entry(psr, &drm_drv->psr_list, list) {
+		if (psr->encoder->crtc == crtc)
+			goto out;
+	}
+	psr = ERR_PTR(-ENODEV);
+
+out:
+	spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
+	return psr;
+}
+
+static void psr_set_state_locked(struct psr_drv *psr, enum psr_state state)
+{
+	/*
+	 * Allowed finite state machine:
+	 *
+	 *   PSR_ENABLE  < = = = = = >  PSR_FLUSH
+	 *       | ^                        |
+	 *       | |                        |
+	 *       v |                        |
+	 *   PSR_DISABLE < - - - - - - - - -
+	 */
+	if (state == psr->state || !psr->active)
+		return;
+
+	/* Already disabled in flush, change the state, but not the hardware */
+	if (state == PSR_DISABLE && psr->state == PSR_FLUSH) {
+		psr->state = state;
+		return;
+	}
+
+	psr->state = state;
+
+	/* Actually commit the state change to hardware */
+	switch (psr->state) {
+	case PSR_ENABLE:
+		psr->set(psr->encoder, true);
+		break;
+
+	case PSR_DISABLE:
+	case PSR_FLUSH:
+		psr->set(psr->encoder, false);
+		break;
+	}
+}
+
+static void psr_set_state(struct psr_drv *psr, enum psr_state state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&psr->lock, flags);
+	psr_set_state_locked(psr, state);
+	spin_unlock_irqrestore(&psr->lock, flags);
+}
+
+static void psr_flush_handler(unsigned long data)
+{
+	struct psr_drv *psr = (struct psr_drv *)data;
+	unsigned long flags;
+
+	/* If the state has changed since we initiated the flush, do nothing */
+	spin_lock_irqsave(&psr->lock, flags);
+	if (psr->state == PSR_FLUSH)
+		psr_set_state_locked(psr, PSR_ENABLE);
+	spin_unlock_irqrestore(&psr->lock, flags);
+}
+
+/**
+ * rockchip_drm_psr_activate - activate PSR on the given pipe
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_activate(struct drm_crtc *crtc)
+{
+	struct psr_drv *psr = find_psr_by_crtc(crtc);
+	unsigned long flags;
+
+	if (IS_ERR(psr))
+		return PTR_ERR(psr);
+
+	spin_lock_irqsave(&psr->lock, flags);
+	psr->active = true;
+	spin_unlock_irqrestore(&psr->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_activate);
+
+/**
+ * rockchip_drm_psr_deactivate - deactivate PSR on the given pipe
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_deactivate(struct drm_crtc *crtc)
+{
+	struct psr_drv *psr = find_psr_by_crtc(crtc);
+	unsigned long flags;
+
+	if (IS_ERR(psr))
+		return PTR_ERR(psr);
+
+	spin_lock_irqsave(&psr->lock, flags);
+	psr->active = false;
+	spin_unlock_irqrestore(&psr->lock, flags);
+	del_timer_sync(&psr->flush_timer);
+
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_deactivate);
+
+static void rockchip_drm_do_flush(struct psr_drv *psr)
+{
+	mod_timer(&psr->flush_timer,
+		  round_jiffies_up(jiffies + PSR_FLUSH_TIMEOUT));
+	psr_set_state(psr, PSR_FLUSH);
+}
+
+/**
+ * rockchip_drm_psr_flush - flush a single pipe
+ * @crtc: CRTC of the pipe to flush
+ *
+ * Returns:
+ * 0 on success, -errno on fail
+ */
+int rockchip_drm_psr_flush(struct drm_crtc *crtc)
+{
+	struct psr_drv *psr = find_psr_by_crtc(crtc);
+	if (IS_ERR(psr))
+		return PTR_ERR(psr);
+
+	rockchip_drm_do_flush(psr);
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_flush);
+
+/**
+ * rockchip_drm_psr_flush_all - force to flush all registered PSR encoders
+ * @dev: drm device
+ *
+ * Disable the PSR function for all registered encoders, and then enable the
+ * PSR function back after PSR_FLUSH_TIMEOUT. If encoder PSR state have been
+ * changed during flush time, then keep the state no change after flush
+ * timeout.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+void rockchip_drm_psr_flush_all(struct drm_device *dev)
+{
+	struct rockchip_drm_private *drm_drv = dev->dev_private;
+	struct psr_drv *psr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
+	list_for_each_entry(psr, &drm_drv->psr_list, list)
+		rockchip_drm_do_flush(psr);
+	spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
+}
+EXPORT_SYMBOL(rockchip_drm_psr_flush_all);
+
+/**
+ * rockchip_drm_psr_register - register encoder to psr driver
+ * @encoder: encoder that obtain the PSR function
+ * @psr_set: call back to set PSR state
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_register(struct drm_encoder *encoder,
+			void (*psr_set)(struct drm_encoder *, bool enable))
+{
+	struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
+	struct psr_drv *psr;
+	unsigned long flags;
+
+	if (!encoder || !psr_set)
+		return -EINVAL;
+
+	psr = kzalloc(sizeof(struct psr_drv), GFP_KERNEL);
+	if (!psr)
+		return -ENOMEM;
+
+	setup_timer(&psr->flush_timer, psr_flush_handler, (unsigned long)psr);
+	spin_lock_init(&psr->lock);
+
+	psr->active = true;
+	psr->state = PSR_DISABLE;
+	psr->encoder = encoder;
+	psr->set = psr_set;
+
+	spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
+	list_add_tail(&psr->list, &drm_drv->psr_list);
+	spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_register);
+
+/**
+ * rockchip_drm_psr_unregister - unregister encoder to psr driver
+ * @encoder: encoder that obtain the PSR function
+ * @psr_set: call back to set PSR state
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+void rockchip_drm_psr_unregister(struct drm_encoder *encoder)
+{
+	struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
+	struct psr_drv *psr, *n;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
+	list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) {
+		if (psr->encoder == encoder) {
+			del_timer(&psr->flush_timer);
+			list_del(&psr->list);
+			kfree(psr);
+		}
+	}
+	spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
+}
+EXPORT_SYMBOL(rockchip_drm_psr_unregister);