[PATCH v4 2/4] drm/rockchip: add an common abstracted PSR driver

[Yakir Yang]

The PSR driver have exported four symbols for specific device driver:
- rockchip_drm_psr_register()
- rockchip_drm_psr_unregister()
- rockchip_drm_psr_enable()
- rockchip_drm_psr_disable()
- rockchip_drm_psr_flush()

Encoder driver should call the register/unregister interfaces to hook
itself into common PSR driver, encoder have implement the 'psr_set'
callback which use the set PSR state in hardware side.

Crtc driver would call the enable/disable interfaces when vblank is
enable/disable, after that the common PSR driver would call the encoder
registered callback to set the PSR state.

Fb driver would call the flush interface in 'fb->dirty' callback, this
helper function would force all PSR enabled encoders to exit from PSR
for 3 seconds.

Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx>
---
Changes in v4:
- Tuck the global "psr_list" & "psr_list_mutex" in struct rockchip_drm_private. (Sean)
- Move the access of "psr->state" under "psr->state_mutex"'s protect. (Sean)
- Let "psr->state = PSR_FLUSH" under "psr->state_mutex"'s protect. (Sean)
- Collect psr_enable() and psr_disable() into psr_set_state()
- s/5\ second/PSR_FLUSH_TIMEOUT/ (Sean)
- Flush the psr callback in vop_crtc_disable(). (StÃphane, reviewed in Google gerrit)
    [https://chromium-review.googlesource.com/#/c/349084/6/drivers/gpu/drm/rockchip/rockchip_drm_vop.c@475]
- Add the missing file head with license. (StÃphane, reviewed in Google gerrit)
    [https://chromium-review.googlesource.com/#/c/357563/1/drivers/gpu/drm/rockchip/rockchip_drm_psr.h@3]

Changes in v3:
- split the psr flow into an common abstracted PSR driver
- implement the 'fb->dirty' callback function (Daniel)
- avoid to use notify to acqiure for vact event (Daniel)
- remove psr_active() callback which introduce in v2

Changes in v2: None

 drivers/gpu/drm/rockchip/Makefile           |   2 +-
 drivers/gpu/drm/rockchip/rockchip_drm_drv.c |   4 +
 drivers/gpu/drm/rockchip/rockchip_drm_drv.h |   3 +
 drivers/gpu/drm/rockchip/rockchip_drm_fb.c  |  12 ++
 drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 223 ++++++++++++++++++++++++++++
 drivers/gpu/drm/rockchip/rockchip_drm_psr.h |  26 ++++
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c |  29 ++++
 7 files changed, 298 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_drm_psr.c
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_drm_psr.h

diff --git a/drivers/gpu/drm/rockchip/Makefile b/drivers/gpu/drm/rockchip/Makefile
index 05d0713..9746365 100644
--- a/drivers/gpu/drm/rockchip/Makefile
+++ b/drivers/gpu/drm/rockchip/Makefile
@@ -3,7 +3,7 @@
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
 rockchipdrm-y := rockchip_drm_drv.o rockchip_drm_fb.o \
-		rockchip_drm_gem.o rockchip_drm_vop.o
+		rockchip_drm_gem.o rockchip_drm_psr.o rockchip_drm_vop.o
 rockchipdrm-$(CONFIG_DRM_FBDEV_EMULATION) += rockchip_drm_fbdev.o
 
 obj-$(CONFIG_ROCKCHIP_ANALOGIX_DP) += analogix_dp-rockchip.o
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index d665fb0..26c12b3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -156,6 +156,9 @@ static int rockchip_drm_bind(struct device *dev)
 
 	drm_dev->dev_private = private;
 
+	INIT_LIST_HEAD(&private->psr_list);
+	mutex_init(&private->psr_list_mutex);
+
 	drm_mode_config_init(drm_dev);
 
 	rockchip_drm_mode_config_init(drm_dev);
@@ -218,6 +221,7 @@ static int rockchip_drm_bind(struct device *dev)
 
 	if (is_support_iommu)
 		arm_iommu_release_mapping(mapping);
+
 	return 0;
 err_fbdev_fini:
 	rockchip_drm_fbdev_fini(drm_dev);
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
index 239b830..9c34c9e 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
@@ -61,6 +61,9 @@ struct rockchip_drm_private {
 	struct drm_gem_object *fbdev_bo;
 	const struct rockchip_crtc_funcs *crtc_funcs[ROCKCHIP_MAX_CRTC];
 	struct drm_atomic_state *state;
+
+	struct list_head psr_list;
+	struct mutex psr_list_mutex;
 };
 
 int rockchip_register_crtc_funcs(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
index 20f12bc..36afd9c 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
@@ -21,6 +21,7 @@
 
 #include "rockchip_drm_drv.h"
 #include "rockchip_drm_gem.h"
+#include "rockchip_drm_psr.h"
 
 #define to_rockchip_fb(x) container_of(x, struct rockchip_drm_fb, fb)
 
@@ -66,9 +67,20 @@ static int rockchip_drm_fb_create_handle(struct drm_framebuffer *fb,
 				     rockchip_fb->obj[0], handle);
 }
 
+static int rockchip_drm_fb_dirty(struct drm_framebuffer *fb,
+				 struct drm_file *file,
+				 unsigned int flags, unsigned int color,
+				 struct drm_clip_rect *clips,
+				 unsigned int num_clips)
+{
+	rockchip_drm_psr_flush(fb->dev);
+	return 0;
+}
+
 static const struct drm_framebuffer_funcs rockchip_drm_fb_funcs = {
 	.destroy	= rockchip_drm_fb_destroy,
 	.create_handle	= rockchip_drm_fb_create_handle,
+	.dirty		= rockchip_drm_fb_dirty,
 };
 
 static struct rockchip_drm_fb *
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 0000000..e79ea18
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
@@ -0,0 +1,223 @@
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author: Yakir Yang <ykk@xxxxxxxxxxxxxx>
+ *
+ * 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(3000) /* 3 seconds */
+
+static LIST_HEAD(psr_list);
+static DEFINE_MUTEX(psr_list_mutex);
+
+enum psr_state {
+	PSR_FLUSH,
+	PSR_ENABLE,
+	PSR_DISABLE,
+};
+
+struct psr_drv {
+	struct list_head list;
+	enum psr_state state;
+	struct mutex state_mutex;
+
+	struct timer_list flush_timer;
+
+	struct drm_encoder *encoder;
+	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;
+
+	mutex_lock(&drm_drv->psr_list_mutex);
+	list_for_each_entry(psr, &drm_drv->psr_list, list) {
+		if (psr->encoder->crtc == crtc) {
+			mutex_unlock(&drm_drv->psr_list_mutex);
+			return psr;
+		}
+	}
+	mutex_unlock(&drm_drv->psr_list_mutex);
+
+	return ERR_PTR(-ENODEV);
+}
+
+static void psr_set_state(struct psr_drv *psr, enum psr_state state)
+{
+	mutex_lock(&psr->state_mutex);
+
+	if (psr->state == state) {
+		mutex_unlock(&psr->state_mutex);
+		return;
+	}
+
+	psr->state = state;
+	switch (state) {
+	case PSR_ENABLE:
+		psr->set(psr->encoder, true);
+		break;
+
+	case PSR_DISABLE:
+	case PSR_FLUSH:
+		psr->set(psr->encoder, false);
+		break;
+	};
+
+	mutex_unlock(&psr->state_mutex);
+}
+
+static void psr_flush_handler(unsigned long data)
+{
+	struct psr_drv *psr = (struct psr_drv *)data;
+
+	if (!psr || psr->state != PSR_FLUSH)
+		return;
+
+	psr_set_state(psr, PSR_ENABLE);
+}
+
+/**
+ * rockchip_drm_psr_enable - enable the encoder PSR which bind to given CRTC
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_enable(struct drm_crtc *crtc)
+{
+	struct psr_drv *psr = find_psr_by_crtc(crtc);
+
+	if (IS_ERR(psr))
+		return PTR_ERR(psr);
+
+	psr_set_state(psr, PSR_ENABLE);
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_enable);
+
+/**
+ * rockchip_drm_psr_disable - disable the encoder PSR which bind to given CRTC
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_disable(struct drm_crtc *crtc)
+{
+	struct psr_drv *psr = find_psr_by_crtc(crtc);
+
+	if (IS_ERR(psr))
+		return PTR_ERR(psr);
+
+	psr_set_state(psr, PSR_DISABLE);
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_disable);
+
+/**
+ * rockchip_drm_psr_flush - 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(struct drm_device *dev)
+{
+	struct rockchip_drm_private *drm_drv = dev->dev_private;
+	struct psr_drv *psr;
+
+	mutex_lock(&drm_drv->psr_list_mutex);
+	list_for_each_entry(psr, &drm_drv->psr_list, list) {
+		if (psr->state == PSR_DISABLE)
+			continue;
+
+		mod_timer(&psr->flush_timer,
+			  round_jiffies_up(jiffies + PSR_FLUSH_TIMEOUT));
+
+		psr_set_state(psr, PSR_FLUSH);
+	}
+	mutex_unlock(&drm_drv->psr_list_mutex);
+}
+EXPORT_SYMBOL(rockchip_drm_psr_flush);
+
+/**
+ * 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;
+
+	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);
+
+	mutex_init(&psr->state_mutex);
+
+	psr->state = PSR_DISABLE;
+	psr->encoder = encoder;
+	psr->set = psr_set;
+
+	mutex_lock(&drm_drv->psr_list_mutex);
+	list_add_tail(&psr->list, &drm_drv->psr_list);
+	mutex_unlock(&drm_drv->psr_list_mutex);
+
+	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;
+
+	mutex_lock(&drm_drv->psr_list_mutex);
+	list_for_each_entry(psr, &drm_drv->psr_list, list) {
+		if (psr->encoder == encoder) {
+			del_timer(&psr->flush_timer);
+			list_del(&psr->list);
+			kfree(psr);
+		}
+	}
+	mutex_unlock(&drm_drv->psr_list_mutex);
+}
+EXPORT_SYMBOL(rockchip_drm_psr_unregister);
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.h b/drivers/gpu/drm/rockchip/rockchip_drm_psr.h
new file mode 100644
index 0000000..c35b688
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author: Yakir Yang <ykk@xxxxxxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef __ROCKCHIP_DRM_PSR___
+#define __ROCKCHIP_DRM_PSR___
+
+void rockchip_drm_psr_flush(struct drm_device *dev);
+int rockchip_drm_psr_enable(struct drm_crtc *crtc);
+int rockchip_drm_psr_disable(struct drm_crtc *crtc);
+
+int rockchip_drm_psr_register(struct drm_encoder *encoder,
+			void (*psr_set)(struct drm_encoder *, bool enable));
+void rockchip_drm_psr_unregister(struct drm_encoder *encoder);
+
+#endif /* __ROCKCHIP_DRM_PSR__ */
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 69d32f1..e702fb3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -34,6 +34,7 @@
 #include "rockchip_drm_drv.h"
 #include "rockchip_drm_gem.h"
 #include "rockchip_drm_fb.h"
+#include "rockchip_drm_psr.h"
 #include "rockchip_drm_vop.h"
 
 #define __REG_SET_RELAXED(x, off, mask, shift, v, write_mask) \
@@ -87,6 +88,8 @@
 #define to_vop_win(x) container_of(x, struct vop_win, base)
 #define to_vop_plane_state(x) container_of(x, struct vop_plane_state, base)
 
+#define VOP_PSR_SET_DELAY_TIME		msecs_to_jiffies(10)
+
 struct vop_plane_state {
 	struct drm_plane_state base;
 	int format;
@@ -121,6 +124,9 @@ struct vop {
 	/* protected by dev->event_lock */
 	struct drm_pending_vblank_event *event;
 
+	bool psr_enabled;
+	struct delayed_work psr_work;
+
 	struct completion line_flag_completion;
 
 	const struct vop_data *data;
@@ -629,6 +635,9 @@ static void vop_crtc_disable(struct drm_crtc *crtc)
 
 		crtc->state->event = NULL;
 	}
+
+	vop->psr_enabled = false;
+	INIT_DELAYED_WORK(&vop->psr_work, vop_psr_work);
 }
 
 static void vop_plane_destroy(struct drm_plane *plane)
@@ -923,6 +932,16 @@ static const struct drm_plane_funcs vop_plane_funcs = {
 	.atomic_destroy_state = vop_atomic_plane_destroy_state,
 };
 
+static void vop_psr_work(struct work_struct *work)
+{
+	struct vop *vop = container_of(work, typeof(*vop), psr_work.work);
+
+	if (vop->psr_enabled)
+		rockchip_drm_psr_enable(&vop->crtc);
+	else
+		rockchip_drm_psr_disable(&vop->crtc);
+}
+
 static int vop_crtc_enable_vblank(struct drm_crtc *crtc)
 {
 	struct vop *vop = to_vop(crtc);
@@ -937,6 +956,9 @@ static int vop_crtc_enable_vblank(struct drm_crtc *crtc)
 
 	spin_unlock_irqrestore(&vop->irq_lock, flags);
 
+	vop->psr_enabled = false;
+	schedule_delayed_work(&vop->psr_work, VOP_PSR_SET_DELAY_TIME);
+
 	return 0;
 }
 
@@ -953,6 +975,9 @@ static void vop_crtc_disable_vblank(struct drm_crtc *crtc)
 	VOP_INTR_SET_TYPE(vop, enable, FS_INTR, 0);
 
 	spin_unlock_irqrestore(&vop->irq_lock, flags);
+
+	vop->psr_enabled = true;
+	schedule_delayed_work(&vop->psr_work, VOP_PSR_SET_DELAY_TIME);
 }
 
 static void vop_crtc_wait_for_update(struct drm_crtc *crtc)
@@ -1597,6 +1622,10 @@ static int vop_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 
 	pm_runtime_enable(&pdev->dev);
+
+	vop->psr_enabled = false;
+	INIT_DELAYED_WORK(&vop->psr_work, vop_psr_work);
+
 	return 0;
 }
 
-- 
1.9.1