[PATCH 0/7] drm/tegra: Convert fbdev to DRM client

[PATCH 0/7] drm/tegra: Convert fbdev to DRM client

[Thomas Zimmermann]

Convert tegra's fbdev code to struct drm_client. Replaces the current
ad-hoc integration. The conversion includes a number of cleanups. As
with most other drivers' fbdev emulation, fbdev in tegra is now just
another DRM client that runs after the DRM device has been registered.

Once all drivers' fbdev emulation has been converted to struct drm_client,
we can attempt to add additional in-kernel clients. A DRM-based dmesg
log or a bootsplash are commonly mentioned. DRM can then switch easily
among the existing clients if/when required.

I did the conversion from similar experience with other drivers. But I
don't have the hardware to test this. Any testing is welcome.

Thomas Zimmermann (7):
  drm/tegra: Include <linux/of.h>
  drm/tegra: Include <linux/i2c.h>
  drm/tegra: Removed fb from struct tegra_fbdev
  drm/tegra: Remove struct tegra_fbdev
  drm/tegra: Hide fbdev support behind config option
  drm/tegra: Initialize fbdev DRM client
  drm/tegra: Implement fbdev emulation as in-kernel client

 drivers/gpu/drm/tegra/Makefile |   2 +
 drivers/gpu/drm/tegra/drm.c    |  23 +---
 drivers/gpu/drm/tegra/drm.h    |  27 ++--
 drivers/gpu/drm/tegra/fb.c     | 242 +--------------------------------
 drivers/gpu/drm/tegra/fbdev.c  | 240 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/tegra/output.c |   3 +
 drivers/gpu/drm/tegra/rgb.c    |   1 +
 7 files changed, 265 insertions(+), 273 deletions(-)
 create mode 100644 drivers/gpu/drm/tegra/fbdev.c

-- 
2.40.0

[PATCH 1/7] drm/tegra: Include <linux/of.h>

[Thomas Zimmermann]

Include <linux/of.h> to get the contained declarations. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/output.c | 2 ++
 drivers/gpu/drm/tegra/rgb.c    | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
index a8925dcd7edd..d31c87f48da0 100644
--- a/drivers/gpu/drm/tegra/output.c
+++ b/drivers/gpu/drm/tegra/output.c
@@ -4,6 +4,8 @@
  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <linux/of.h>
+
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_of.h>
 #include <drm/drm_panel.h>
diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
index ff8fce36d2aa..3f060282cd8d 100644
--- a/drivers/gpu/drm/tegra/rgb.c
+++ b/drivers/gpu/drm/tegra/rgb.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/of.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge_connector.h>
-- 
2.40.0

Re: [1/7] drm/tegra: Include <linux/of.h>

[Sui Jingfeng]

Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn 
<mailto:suijingfeng@loongson.cn>>


On 2023/3/30 16:36, Thomas Zimmermann wrote:
> Include <linux/of.h> to get the contained declarations. No functional
> changes.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/tegra/output.c | 2 ++
>   drivers/gpu/drm/tegra/rgb.c    | 1 +
>   2 files changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
> index a8925dcd7edd..d31c87f48da0 100644
> --- a/drivers/gpu/drm/tegra/output.c
> +++ b/drivers/gpu/drm/tegra/output.c
> @@ -4,6 +4,8 @@
>    * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
>    */
>   
> +#include <linux/of.h>
> +
>   #include <drm/drm_atomic_helper.h>
>   #include <drm/drm_of.h>
>   #include <drm/drm_panel.h>
> diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
> index ff8fce36d2aa..3f060282cd8d 100644
> --- a/drivers/gpu/drm/tegra/rgb.c
> +++ b/drivers/gpu/drm/tegra/rgb.c
> @@ -5,6 +5,7 @@
>    */
>   
>   #include <linux/clk.h>
> +#include <linux/of.h>
>   
>   #include <drm/drm_atomic_helper.h>
>   #include <drm/drm_bridge_connector.h>

Re: [1/7] drm/tegra: Include <linux/of.h>

[Thomas Zimmermann]

[-- Attachment #1.1: Type: text/plain, Size: 1530 bytes --]



Am 30.03.23 um 14:51 schrieb Sui Jingfeng:
> 
> Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn 
> <mailto:suijingfeng@loongson.cn>>

Thanks a lot.

> 
> 
> On 2023/3/30 16:36, Thomas Zimmermann wrote:
>> Include <linux/of.h> to get the contained declarations. No functional
>> changes.
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>   drivers/gpu/drm/tegra/output.c | 2 ++
>>   drivers/gpu/drm/tegra/rgb.c    | 1 +
>>   2 files changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/tegra/output.c 
>> b/drivers/gpu/drm/tegra/output.c
>> index a8925dcd7edd..d31c87f48da0 100644
>> --- a/drivers/gpu/drm/tegra/output.c
>> +++ b/drivers/gpu/drm/tegra/output.c
>> @@ -4,6 +4,8 @@
>>    * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
>>    */
>> +#include <linux/of.h>
>> +
>>   #include <drm/drm_atomic_helper.h>
>>   #include <drm/drm_of.h>
>>   #include <drm/drm_panel.h>
>> diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
>> index ff8fce36d2aa..3f060282cd8d 100644
>> --- a/drivers/gpu/drm/tegra/rgb.c
>> +++ b/drivers/gpu/drm/tegra/rgb.c
>> @@ -5,6 +5,7 @@
>>    */
>>   #include <linux/clk.h>
>> +#include <linux/of.h>
>>   #include <drm/drm_atomic_helper.h>
>>   #include <drm/drm_bridge_connector.h>

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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Re: [1/7] drm/tegra: Include <linux/of.h>

[Sui Jingfeng]

Hi,

On 2023/4/3 18:42, Thomas Zimmermann wrote:
>
>
> Am 30.03.23 um 14:51 schrieb Sui Jingfeng:
>>
>> Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn 
>> <mailto:suijingfeng@loongson.cn>>
>
> Thanks a lot.
>

I send my mail with Thunderbird mail client, don't know this does this 
look like this.

Sorry about that. It should be:


Reviewed-by:  Sui Jingfeng <suijingfeng@loongson.cn>


Please correct it manually, others patches also look good to me.

Yet, it beyond my ability to review, I still digging  your patch and 
learning from it. :)

>>
>>
>> On 2023/3/30 16:36, Thomas Zimmermann wrote:
>>> Include <linux/of.h> to get the contained declarations. No functional
>>> changes.
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>>> ---
>>>   drivers/gpu/drm/tegra/output.c | 2 ++
>>>   drivers/gpu/drm/tegra/rgb.c    | 1 +
>>>   2 files changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/tegra/output.c 
>>> b/drivers/gpu/drm/tegra/output.c
>>> index a8925dcd7edd..d31c87f48da0 100644
>>> --- a/drivers/gpu/drm/tegra/output.c
>>> +++ b/drivers/gpu/drm/tegra/output.c
>>> @@ -4,6 +4,8 @@
>>>    * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
>>>    */
>>> +#include <linux/of.h>
>>> +
>>>   #include <drm/drm_atomic_helper.h>
>>>   #include <drm/drm_of.h>
>>>   #include <drm/drm_panel.h>
>>> diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
>>> index ff8fce36d2aa..3f060282cd8d 100644
>>> --- a/drivers/gpu/drm/tegra/rgb.c
>>> +++ b/drivers/gpu/drm/tegra/rgb.c
>>> @@ -5,6 +5,7 @@
>>>    */
>>>   #include <linux/clk.h>
>>> +#include <linux/of.h>
>>>   #include <drm/drm_atomic_helper.h>
>>>   #include <drm/drm_bridge_connector.h>
>

[PATCH 2/7] drm/tegra: Include <linux/i2c.h>

[Thomas Zimmermann]

Include <linux/i2c.h> to get the contained declarations. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/output.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
index d31c87f48da0..dc2dcb5ca1c8 100644
--- a/drivers/gpu/drm/tegra/output.c
+++ b/drivers/gpu/drm/tegra/output.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <linux/i2c.h>
 #include <linux/of.h>
 
 #include <drm/drm_atomic_helper.h>
-- 
2.40.0

Re: [2/7] drm/tegra: Include <linux/i2c.h>

[Sui Jingfeng]

Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn 
<mailto:suijingfeng@loongson.cn>>

On 2023/3/30 16:36, Thomas Zimmermann wrote:
> Include <linux/i2c.h> to get the contained declarations. No functional
> changes.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/tegra/output.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
> index d31c87f48da0..dc2dcb5ca1c8 100644
> --- a/drivers/gpu/drm/tegra/output.c
> +++ b/drivers/gpu/drm/tegra/output.c
> @@ -4,6 +4,7 @@
>    * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
>    */
>   
> +#include <linux/i2c.h>
>   #include <linux/of.h>
>   
>   #include <drm/drm_atomic_helper.h>

[PATCH 3/7] drm/tegra: Removed fb from struct tegra_fbdev

[Thomas Zimmermann]

Fbdev's struct fb_helper stores a pointer to the framebuffer. Remove
struct tegra_fbdev.fb, which contains the same value. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/drm.h |  1 -
 drivers/gpu/drm/tegra/fb.c  | 23 ++++++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 845e60f144c7..8f8e5cda78da 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -32,7 +32,6 @@ struct reset_control;
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 struct tegra_fbdev {
 	struct drm_fb_helper base;
-	struct drm_framebuffer *fb;
 };
 #endif
 
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index bfebe2786d61..1ee4771b77d3 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -217,7 +217,6 @@ static const struct fb_ops tegra_fb_ops = {
 static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 			     struct drm_fb_helper_surface_size *sizes)
 {
-	struct tegra_fbdev *fbdev = to_tegra_fbdev(helper);
 	struct tegra_drm *tegra = helper->dev->dev_private;
 	struct drm_device *drm = helper->dev;
 	struct drm_mode_fb_cmd2 cmd = { 0 };
@@ -252,16 +251,15 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 		return PTR_ERR(info);
 	}
 
-	fbdev->fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
-	if (IS_ERR(fbdev->fb)) {
-		err = PTR_ERR(fbdev->fb);
+	fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
+	if (IS_ERR(fb)) {
+		err = PTR_ERR(fb);
 		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
 			err);
 		drm_gem_object_put(&bo->gem);
-		return PTR_ERR(fbdev->fb);
+		return PTR_ERR(fb);
 	}
 
-	fb = fbdev->fb;
 	helper->fb = fb;
 	helper->info = info;
 
@@ -349,10 +347,13 @@ static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
 
 static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
 {
-	drm_fb_helper_unregister_info(&fbdev->base);
+	struct drm_fb_helper *helper = &fbdev->base;
+	struct drm_framebuffer *fb = helper->fb;
 
-	if (fbdev->fb) {
-		struct tegra_bo *bo = tegra_fb_get_plane(fbdev->fb, 0);
+	drm_fb_helper_unregister_info(helper);
+
+	if (fb) {
+		struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
 
 		/* Undo the special mapping we made in fbdev probe. */
 		if (bo && bo->pages) {
@@ -360,10 +361,10 @@ static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
 			bo->vaddr = NULL;
 		}
 
-		drm_framebuffer_remove(fbdev->fb);
+		drm_framebuffer_remove(fb);
 	}
 
-	drm_fb_helper_fini(&fbdev->base);
+	drm_fb_helper_fini(helper);
 	tegra_fbdev_free(fbdev);
 }
 #endif
-- 
2.40.0

[PATCH 4/7] drm/tegra: Remove struct tegra_fbdev

[Thomas Zimmermann]

Remove struct tegra_fbdev, which is an empty wrapper around struct
drm_fb_helper. Use the latter directly. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/drm.h | 10 -------
 drivers/gpu/drm/tegra/fb.c  | 59 ++++++++++++++-----------------------
 2 files changed, 22 insertions(+), 47 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 8f8e5cda78da..593a60b03189 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -29,12 +29,6 @@
 
 struct reset_control;
 
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-struct tegra_fbdev {
-	struct drm_fb_helper base;
-};
-#endif
-
 struct tegra_drm {
 	struct drm_device *drm;
 
@@ -52,10 +46,6 @@ struct tegra_drm {
 	struct mutex clients_lock;
 	struct list_head clients;
 
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	struct tegra_fbdev *fbdev;
-#endif
-
 	unsigned int hmask, vmask;
 	unsigned int pitch_align;
 	unsigned int num_crtcs;
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 1ee4771b77d3..12eb260d9f51 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -17,13 +17,6 @@
 #include "drm.h"
 #include "gem.h"
 
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-static inline struct tegra_fbdev *to_tegra_fbdev(struct drm_fb_helper *helper)
-{
-	return container_of(helper, struct tegra_fbdev, base);
-}
-#endif
-
 struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,
 				    unsigned int index)
 {
@@ -296,42 +289,42 @@ static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
 	.fb_probe = tegra_fbdev_probe,
 };
 
-static struct tegra_fbdev *tegra_fbdev_create(struct drm_device *drm)
+static struct drm_fb_helper *tegra_fbdev_create(struct drm_device *drm)
 {
-	struct tegra_fbdev *fbdev;
+	struct drm_fb_helper *helper;
 
-	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
-	if (!fbdev) {
+	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
+	if (!helper) {
 		dev_err(drm->dev, "failed to allocate DRM fbdev\n");
 		return ERR_PTR(-ENOMEM);
 	}
 
-	drm_fb_helper_prepare(drm, &fbdev->base, 32, &tegra_fb_helper_funcs);
+	drm_fb_helper_prepare(drm, helper, 32, &tegra_fb_helper_funcs);
 
-	return fbdev;
+	return helper;
 }
 
-static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
+static void tegra_fbdev_free(struct drm_fb_helper *helper)
 {
-	drm_fb_helper_unprepare(&fbdev->base);
-	kfree(fbdev);
+	drm_fb_helper_unprepare(helper);
+	kfree(helper);
 }
 
-static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
+static int tegra_fbdev_init(struct drm_fb_helper *helper,
 			    unsigned int num_crtc,
 			    unsigned int max_connectors)
 {
-	struct drm_device *drm = fbdev->base.dev;
+	struct drm_device *drm = helper->dev;
 	int err;
 
-	err = drm_fb_helper_init(drm, &fbdev->base);
+	err = drm_fb_helper_init(drm, helper);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
 			err);
 		return err;
 	}
 
-	err = drm_fb_helper_initial_config(&fbdev->base);
+	err = drm_fb_helper_initial_config(helper);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to set initial configuration: %d\n",
 			err);
@@ -341,13 +334,12 @@ static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
 	return 0;
 
 fini:
-	drm_fb_helper_fini(&fbdev->base);
+	drm_fb_helper_fini(helper);
 	return err;
 }
 
-static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
+static void tegra_fbdev_exit(struct drm_fb_helper *helper)
 {
-	struct drm_fb_helper *helper = &fbdev->base;
 	struct drm_framebuffer *fb = helper->fb;
 
 	drm_fb_helper_unregister_info(helper);
@@ -365,18 +357,16 @@ static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
 	}
 
 	drm_fb_helper_fini(helper);
-	tegra_fbdev_free(fbdev);
+	tegra_fbdev_free(helper);
 }
 #endif
 
 int tegra_drm_fb_prepare(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-	struct tegra_drm *tegra = drm->dev_private;
-
-	tegra->fbdev = tegra_fbdev_create(drm);
-	if (IS_ERR(tegra->fbdev))
-		return PTR_ERR(tegra->fbdev);
+	drm->fb_helper = tegra_fbdev_create(drm);
+	if (IS_ERR(drm->fb_helper))
+		return PTR_ERR(drm->fb_helper);
 #endif
 
 	return 0;
@@ -385,19 +375,16 @@ int tegra_drm_fb_prepare(struct drm_device *drm)
 void tegra_drm_fb_free(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-	struct tegra_drm *tegra = drm->dev_private;
-
-	tegra_fbdev_free(tegra->fbdev);
+	tegra_fbdev_free(drm->fb_helper);
 #endif
 }
 
 int tegra_drm_fb_init(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-	struct tegra_drm *tegra = drm->dev_private;
 	int err;
 
-	err = tegra_fbdev_init(tegra->fbdev, drm->mode_config.num_crtc,
+	err = tegra_fbdev_init(drm->fb_helper, drm->mode_config.num_crtc,
 			       drm->mode_config.num_connector);
 	if (err < 0)
 		return err;
@@ -409,8 +396,6 @@ int tegra_drm_fb_init(struct drm_device *drm)
 void tegra_drm_fb_exit(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-	struct tegra_drm *tegra = drm->dev_private;
-
-	tegra_fbdev_exit(tegra->fbdev);
+	tegra_fbdev_exit(drm->fb_helper);
 #endif
 }
-- 
2.40.0

[PATCH 5/7] drm/tegra: Hide fbdev support behind config option

[Thomas Zimmermann]

Only build tegra's fbdev emulation if CONFIG_DRM_FBDEV_EMULATION
has been enabled. As part of this change, move the code into its
own source file. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/Makefile |   2 +
 drivers/gpu/drm/tegra/drm.h    |  20 +++
 drivers/gpu/drm/tegra/fb.c     | 228 +--------------------------------
 drivers/gpu/drm/tegra/fbdev.c  | 226 ++++++++++++++++++++++++++++++++
 4 files changed, 252 insertions(+), 224 deletions(-)
 create mode 100644 drivers/gpu/drm/tegra/fbdev.c

diff --git a/drivers/gpu/drm/tegra/Makefile b/drivers/gpu/drm/tegra/Makefile
index bb0d2c144b55..6fc4b504e786 100644
--- a/drivers/gpu/drm/tegra/Makefile
+++ b/drivers/gpu/drm/tegra/Makefile
@@ -29,4 +29,6 @@ tegra-drm-y := \
 
 tegra-drm-y += trace.o
 
+tegra-drm-$(CONFIG_DRM_FBDEV_EMULATION) += fbdev.o
+
 obj-$(CONFIG_DRM_TEGRA) += tegra-drm.o
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 593a60b03189..576f03b8434e 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -185,13 +185,33 @@ struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,
 bool tegra_fb_is_bottom_up(struct drm_framebuffer *framebuffer);
 int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
 			struct tegra_bo_tiling *tiling);
+struct drm_framebuffer *tegra_fb_alloc(struct drm_device *drm,
+				       const struct drm_mode_fb_cmd2 *mode_cmd,
+				       struct tegra_bo **planes,
+				       unsigned int num_planes);
 struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 					struct drm_file *file,
 					const struct drm_mode_fb_cmd2 *cmd);
+
+#ifdef CONFIG_DRM_FBDEV_EMULATION
 int tegra_drm_fb_prepare(struct drm_device *drm);
 void tegra_drm_fb_free(struct drm_device *drm);
 int tegra_drm_fb_init(struct drm_device *drm);
 void tegra_drm_fb_exit(struct drm_device *drm);
+#else
+static inline int tegra_drm_fb_prepare(struct drm_device *drm)
+{
+	return 0;
+}
+static inline void tegra_drm_fb_free(struct drm_device *drm)
+{ }
+static inline int tegra_drm_fb_init(struct drm_device *drm)
+{
+	return 0;
+}
+static inline void tegra_drm_fb_exit(struct drm_device *drm)
+{ }
+#endif
 
 extern struct platform_driver tegra_display_hub_driver;
 extern struct platform_driver tegra_dc_driver;
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 12eb260d9f51..a719af1dc9a5 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -101,10 +101,10 @@ static const struct drm_framebuffer_funcs tegra_fb_funcs = {
 	.create_handle = drm_gem_fb_create_handle,
 };
 
-static struct drm_framebuffer *tegra_fb_alloc(struct drm_device *drm,
-					      const struct drm_mode_fb_cmd2 *mode_cmd,
-					      struct tegra_bo **planes,
-					      unsigned int num_planes)
+struct drm_framebuffer *tegra_fb_alloc(struct drm_device *drm,
+				       const struct drm_mode_fb_cmd2 *mode_cmd,
+				       struct tegra_bo **planes,
+				       unsigned int num_planes)
 {
 	struct drm_framebuffer *fb;
 	unsigned int i;
@@ -179,223 +179,3 @@ struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 
 	return ERR_PTR(err);
 }
-
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
-{
-	struct drm_fb_helper *helper = info->par;
-	struct tegra_bo *bo;
-	int err;
-
-	bo = tegra_fb_get_plane(helper->fb, 0);
-
-	err = drm_gem_mmap_obj(&bo->gem, bo->gem.size, vma);
-	if (err < 0)
-		return err;
-
-	return __tegra_gem_mmap(&bo->gem, vma);
-}
-
-static const struct fb_ops tegra_fb_ops = {
-	.owner = THIS_MODULE,
-	DRM_FB_HELPER_DEFAULT_OPS,
-	.fb_read = drm_fb_helper_sys_read,
-	.fb_write = drm_fb_helper_sys_write,
-	.fb_fillrect = drm_fb_helper_sys_fillrect,
-	.fb_copyarea = drm_fb_helper_sys_copyarea,
-	.fb_imageblit = drm_fb_helper_sys_imageblit,
-	.fb_mmap = tegra_fb_mmap,
-};
-
-static int tegra_fbdev_probe(struct drm_fb_helper *helper,
-			     struct drm_fb_helper_surface_size *sizes)
-{
-	struct tegra_drm *tegra = helper->dev->dev_private;
-	struct drm_device *drm = helper->dev;
-	struct drm_mode_fb_cmd2 cmd = { 0 };
-	unsigned int bytes_per_pixel;
-	struct drm_framebuffer *fb;
-	unsigned long offset;
-	struct fb_info *info;
-	struct tegra_bo *bo;
-	size_t size;
-	int err;
-
-	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
-
-	cmd.width = sizes->surface_width;
-	cmd.height = sizes->surface_height;
-	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
-				  tegra->pitch_align);
-
-	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
-						     sizes->surface_depth);
-
-	size = cmd.pitches[0] * cmd.height;
-
-	bo = tegra_bo_create(drm, size, 0);
-	if (IS_ERR(bo))
-		return PTR_ERR(bo);
-
-	info = drm_fb_helper_alloc_info(helper);
-	if (IS_ERR(info)) {
-		dev_err(drm->dev, "failed to allocate framebuffer info\n");
-		drm_gem_object_put(&bo->gem);
-		return PTR_ERR(info);
-	}
-
-	fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
-	if (IS_ERR(fb)) {
-		err = PTR_ERR(fb);
-		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
-			err);
-		drm_gem_object_put(&bo->gem);
-		return PTR_ERR(fb);
-	}
-
-	helper->fb = fb;
-	helper->info = info;
-
-	info->fbops = &tegra_fb_ops;
-
-	drm_fb_helper_fill_info(info, helper, sizes);
-
-	offset = info->var.xoffset * bytes_per_pixel +
-		 info->var.yoffset * fb->pitches[0];
-
-	if (bo->pages) {
-		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
-				 pgprot_writecombine(PAGE_KERNEL));
-		if (!bo->vaddr) {
-			dev_err(drm->dev, "failed to vmap() framebuffer\n");
-			err = -ENOMEM;
-			goto destroy;
-		}
-	}
-
-	info->screen_base = (void __iomem *)bo->vaddr + offset;
-	info->screen_size = size;
-	info->fix.smem_start = (unsigned long)(bo->iova + offset);
-	info->fix.smem_len = size;
-
-	return 0;
-
-destroy:
-	drm_framebuffer_remove(fb);
-	return err;
-}
-
-static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
-	.fb_probe = tegra_fbdev_probe,
-};
-
-static struct drm_fb_helper *tegra_fbdev_create(struct drm_device *drm)
-{
-	struct drm_fb_helper *helper;
-
-	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
-	if (!helper) {
-		dev_err(drm->dev, "failed to allocate DRM fbdev\n");
-		return ERR_PTR(-ENOMEM);
-	}
-
-	drm_fb_helper_prepare(drm, helper, 32, &tegra_fb_helper_funcs);
-
-	return helper;
-}
-
-static void tegra_fbdev_free(struct drm_fb_helper *helper)
-{
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
-}
-
-static int tegra_fbdev_init(struct drm_fb_helper *helper,
-			    unsigned int num_crtc,
-			    unsigned int max_connectors)
-{
-	struct drm_device *drm = helper->dev;
-	int err;
-
-	err = drm_fb_helper_init(drm, helper);
-	if (err < 0) {
-		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
-			err);
-		return err;
-	}
-
-	err = drm_fb_helper_initial_config(helper);
-	if (err < 0) {
-		dev_err(drm->dev, "failed to set initial configuration: %d\n",
-			err);
-		goto fini;
-	}
-
-	return 0;
-
-fini:
-	drm_fb_helper_fini(helper);
-	return err;
-}
-
-static void tegra_fbdev_exit(struct drm_fb_helper *helper)
-{
-	struct drm_framebuffer *fb = helper->fb;
-
-	drm_fb_helper_unregister_info(helper);
-
-	if (fb) {
-		struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
-
-		/* Undo the special mapping we made in fbdev probe. */
-		if (bo && bo->pages) {
-			vunmap(bo->vaddr);
-			bo->vaddr = NULL;
-		}
-
-		drm_framebuffer_remove(fb);
-	}
-
-	drm_fb_helper_fini(helper);
-	tegra_fbdev_free(helper);
-}
-#endif
-
-int tegra_drm_fb_prepare(struct drm_device *drm)
-{
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	drm->fb_helper = tegra_fbdev_create(drm);
-	if (IS_ERR(drm->fb_helper))
-		return PTR_ERR(drm->fb_helper);
-#endif
-
-	return 0;
-}
-
-void tegra_drm_fb_free(struct drm_device *drm)
-{
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	tegra_fbdev_free(drm->fb_helper);
-#endif
-}
-
-int tegra_drm_fb_init(struct drm_device *drm)
-{
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	int err;
-
-	err = tegra_fbdev_init(drm->fb_helper, drm->mode_config.num_crtc,
-			       drm->mode_config.num_connector);
-	if (err < 0)
-		return err;
-#endif
-
-	return 0;
-}
-
-void tegra_drm_fb_exit(struct drm_device *drm)
-{
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	tegra_fbdev_exit(drm->fb_helper);
-#endif
-}
diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
new file mode 100644
index 000000000000..2400d42f82e4
--- /dev/null
+++ b/drivers/gpu/drm/tegra/fbdev.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012-2013 Avionic Design GmbH
+ * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Based on the KMS/FB DMA helpers
+ *   Copyright (C) 2012 Analog Devices Inc.
+ */
+
+#include <linux/console.h>
+
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_modeset_helper.h>
+
+#include "drm.h"
+#include "gem.h"
+
+static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct drm_fb_helper *helper = info->par;
+	struct tegra_bo *bo;
+	int err;
+
+	bo = tegra_fb_get_plane(helper->fb, 0);
+
+	err = drm_gem_mmap_obj(&bo->gem, bo->gem.size, vma);
+	if (err < 0)
+		return err;
+
+	return __tegra_gem_mmap(&bo->gem, vma);
+}
+
+static const struct fb_ops tegra_fb_ops = {
+	.owner = THIS_MODULE,
+	DRM_FB_HELPER_DEFAULT_OPS,
+	.fb_read = drm_fb_helper_sys_read,
+	.fb_write = drm_fb_helper_sys_write,
+	.fb_fillrect = drm_fb_helper_sys_fillrect,
+	.fb_copyarea = drm_fb_helper_sys_copyarea,
+	.fb_imageblit = drm_fb_helper_sys_imageblit,
+	.fb_mmap = tegra_fb_mmap,
+};
+
+static int tegra_fbdev_probe(struct drm_fb_helper *helper,
+			     struct drm_fb_helper_surface_size *sizes)
+{
+	struct tegra_drm *tegra = helper->dev->dev_private;
+	struct drm_device *drm = helper->dev;
+	struct drm_mode_fb_cmd2 cmd = { 0 };
+	unsigned int bytes_per_pixel;
+	struct drm_framebuffer *fb;
+	unsigned long offset;
+	struct fb_info *info;
+	struct tegra_bo *bo;
+	size_t size;
+	int err;
+
+	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
+
+	cmd.width = sizes->surface_width;
+	cmd.height = sizes->surface_height;
+	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
+				  tegra->pitch_align);
+
+	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+						     sizes->surface_depth);
+
+	size = cmd.pitches[0] * cmd.height;
+
+	bo = tegra_bo_create(drm, size, 0);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	info = drm_fb_helper_alloc_info(helper);
+	if (IS_ERR(info)) {
+		dev_err(drm->dev, "failed to allocate framebuffer info\n");
+		drm_gem_object_put(&bo->gem);
+		return PTR_ERR(info);
+	}
+
+	fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
+	if (IS_ERR(fb)) {
+		err = PTR_ERR(fb);
+		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
+			err);
+		drm_gem_object_put(&bo->gem);
+		return PTR_ERR(fb);
+	}
+
+	helper->fb = fb;
+	helper->info = info;
+
+	info->fbops = &tegra_fb_ops;
+
+	drm_fb_helper_fill_info(info, helper, sizes);
+
+	offset = info->var.xoffset * bytes_per_pixel +
+		 info->var.yoffset * fb->pitches[0];
+
+	if (bo->pages) {
+		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
+				 pgprot_writecombine(PAGE_KERNEL));
+		if (!bo->vaddr) {
+			dev_err(drm->dev, "failed to vmap() framebuffer\n");
+			err = -ENOMEM;
+			goto destroy;
+		}
+	}
+
+	info->screen_base = (void __iomem *)bo->vaddr + offset;
+	info->screen_size = size;
+	info->fix.smem_start = (unsigned long)(bo->iova + offset);
+	info->fix.smem_len = size;
+
+	return 0;
+
+destroy:
+	drm_framebuffer_remove(fb);
+	return err;
+}
+
+static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
+	.fb_probe = tegra_fbdev_probe,
+};
+
+static struct drm_fb_helper *tegra_fbdev_create(struct drm_device *drm)
+{
+	struct drm_fb_helper *helper;
+
+	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
+	if (!helper)
+		return ERR_PTR(-ENOMEM);
+
+	drm_fb_helper_prepare(drm, helper, 32, &tegra_fb_helper_funcs);
+
+	return helper;
+}
+
+static void tegra_fbdev_free(struct drm_fb_helper *helper)
+{
+	drm_fb_helper_unprepare(helper);
+	kfree(helper);
+}
+
+static int tegra_fbdev_init(struct drm_fb_helper *helper,
+			    unsigned int num_crtc,
+			    unsigned int max_connectors)
+{
+	struct drm_device *drm = helper->dev;
+	int err;
+
+	err = drm_fb_helper_init(drm, helper);
+	if (err < 0) {
+		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
+			err);
+		return err;
+	}
+
+	err = drm_fb_helper_initial_config(helper);
+	if (err < 0) {
+		dev_err(drm->dev, "failed to set initial configuration: %d\n",
+			err);
+		goto fini;
+	}
+
+	return 0;
+
+fini:
+	drm_fb_helper_fini(helper);
+	return err;
+}
+
+static void tegra_fbdev_exit(struct drm_fb_helper *helper)
+{
+	struct drm_framebuffer *fb = helper->fb;
+
+	drm_fb_helper_unregister_info(helper);
+
+	if (fb) {
+		struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
+
+		/* Undo the special mapping we made in fbdev probe. */
+		if (bo && bo->pages) {
+			vunmap(bo->vaddr);
+			bo->vaddr = NULL;
+		}
+
+		drm_framebuffer_remove(fb);
+	}
+
+	drm_fb_helper_fini(helper);
+	tegra_fbdev_free(helper);
+}
+
+int tegra_drm_fb_prepare(struct drm_device *drm)
+{
+	drm->fb_helper = tegra_fbdev_create(drm);
+	if (IS_ERR(drm->fb_helper))
+		return PTR_ERR(drm->fb_helper);
+
+	return 0;
+}
+
+void tegra_drm_fb_free(struct drm_device *drm)
+{
+	tegra_fbdev_free(drm->fb_helper);
+}
+
+int tegra_drm_fb_init(struct drm_device *drm)
+{
+	int err;
+
+	err = tegra_fbdev_init(drm->fb_helper, drm->mode_config.num_crtc,
+			       drm->mode_config.num_connector);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+void tegra_drm_fb_exit(struct drm_device *drm)
+{
+	tegra_fbdev_exit(drm->fb_helper);
+}
-- 
2.40.0

[PATCH 6/7] drm/tegra: Initialize fbdev DRM client

[Thomas Zimmermann]

Initialize the fbdev client in the fbdev code with empty helper
functions. Also clean up the client. The helpers will later
implement various functionality of the DRM client. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/fbdev.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
index 2400d42f82e4..31a95a955efb 100644
--- a/drivers/gpu/drm/tegra/fbdev.c
+++ b/drivers/gpu/drm/tegra/fbdev.c
@@ -125,6 +125,30 @@ static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
 	.fb_probe = tegra_fbdev_probe,
 };
 
+/*
+ * struct drm_client
+ */
+
+static void tegra_fbdev_client_unregister(struct drm_client_dev *client)
+{ }
+
+static int tregra_fbdev_client_restore(struct drm_client_dev *client)
+{
+	return 0;
+}
+
+static int tegra_fbdev_client_hotplug(struct drm_client_dev *client)
+{
+	return 0;
+}
+
+static const struct drm_client_funcs tegra_fbdev_client_funcs = {
+	.owner		= THIS_MODULE,
+	.unregister	= tegra_fbdev_client_unregister,
+	.restore	= tegra_fbdev_client_restore,
+	.hotplug	= tegra_fbdev_client_hotplug,
+};
+
 static struct drm_fb_helper *tegra_fbdev_create(struct drm_device *drm)
 {
 	struct drm_fb_helper *helper;
@@ -151,11 +175,15 @@ static int tegra_fbdev_init(struct drm_fb_helper *helper,
 	struct drm_device *drm = helper->dev;
 	int err;
 
+	err = drm_client_init(dev, &helper->client, "fbdev", &tegra_fbdev_client_funcs);
+	if (err)
+		return err;
+
 	err = drm_fb_helper_init(drm, helper);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
 			err);
-		return err;
+		goto err_drm_client_release;
 	}
 
 	err = drm_fb_helper_initial_config(helper);
@@ -169,6 +197,8 @@ static int tegra_fbdev_init(struct drm_fb_helper *helper,
 
 fini:
 	drm_fb_helper_fini(helper);
+err_drm_client_release:
+	drm_client_release(&helper->client);
 	return err;
 }
 
@@ -191,6 +221,7 @@ static void tegra_fbdev_exit(struct drm_fb_helper *helper)
 	}
 
 	drm_fb_helper_fini(helper);
+	drm_client_release(&helper->client);
 	tegra_fbdev_free(helper);
 }
 
-- 
2.40.0

[PATCH 7/7] drm/tegra: Implement fbdev emulation as in-kernel client

[Thomas Zimmermann]

Move code from ad-hoc fbdev callbacks into DRM client functions
and remove the old callbacks. The functions instruct the client
to poll for changed output or restore the display. The DRM core
calls both, the old callbacks and the new client helpers, from
the same places. The new functions perform the same operation as
before, so there's no change in functionality.

Replace all code that initializes or releases fbdev emulation
throughout the driver. Instead initialize the fbdev client by a
single call to tegra_fbdev_setup() after tegra has registered
its DRM device. As in most drivers, tegra's fbdev emulation now
acts like a regular DRM client.

The fbdev client setup consists of the initial preparation and the
hot-plugging of the display. The latter creates the fbdev device
and sets up the fbdev framebuffer. The setup performs display
hot-plugging once. If no display can be detected, DRM probe helpers
re-run the detection on each hotplug event.

A call to drm_dev_unregister() releases the client automatically.
No further action is required within tegra. If the fbdev
framebuffer has been fully set up, struct fb_ops.fb_destroy
implements the release. For partially initialized emulation, the
fbdev client reverts the initial setup.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/drm.c   |  23 +----
 drivers/gpu/drm/tegra/drm.h   |  18 +---
 drivers/gpu/drm/tegra/fbdev.c | 177 +++++++++++++++-------------------
 3 files changed, 86 insertions(+), 132 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 6ca9f396e55b..85ba96cddd51 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -56,9 +56,6 @@ static int tegra_atomic_check(struct drm_device *drm,
 
 static const struct drm_mode_config_funcs tegra_drm_mode_config_funcs = {
 	.fb_create = tegra_fb_create,
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-	.output_poll_changed = drm_fb_helper_output_poll_changed,
-#endif
 	.atomic_check = tegra_atomic_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };
@@ -885,7 +882,6 @@ static const struct drm_driver tegra_drm_driver = {
 			   DRIVER_ATOMIC | DRIVER_RENDER | DRIVER_SYNCOBJ,
 	.open = tegra_drm_open,
 	.postclose = tegra_drm_postclose,
-	.lastclose = drm_fb_helper_lastclose,
 
 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = tegra_debugfs_init,
@@ -1185,15 +1181,11 @@ static int host1x_drm_probe(struct host1x_device *dev)
 	drm->mode_config.funcs = &tegra_drm_mode_config_funcs;
 	drm->mode_config.helper_private = &tegra_drm_mode_config_helpers;
 
-	err = tegra_drm_fb_prepare(drm);
-	if (err < 0)
-		goto config;
-
 	drm_kms_helper_poll_init(drm);
 
 	err = host1x_device_init(dev);
 	if (err < 0)
-		goto fbdev;
+		goto poll;
 
 	/*
 	 * Now that all display controller have been initialized, the maximum
@@ -1256,18 +1248,14 @@ static int host1x_drm_probe(struct host1x_device *dev)
 	if (err < 0)
 		goto hub;
 
-	err = tegra_drm_fb_init(drm);
+	err = drm_dev_register(drm, 0);
 	if (err < 0)
 		goto hub;
 
-	err = drm_dev_register(drm, 0);
-	if (err < 0)
-		goto fb;
+	tegra_fbdev_setup(drm);
 
 	return 0;
 
-fb:
-	tegra_drm_fb_exit(drm);
 hub:
 	if (tegra->hub)
 		tegra_display_hub_cleanup(tegra->hub);
@@ -1280,10 +1268,8 @@ static int host1x_drm_probe(struct host1x_device *dev)
 	}
 
 	host1x_device_exit(dev);
-fbdev:
+poll:
 	drm_kms_helper_poll_fini(drm);
-	tegra_drm_fb_free(drm);
-config:
 	drm_mode_config_cleanup(drm);
 domain:
 	if (tegra->domain)
@@ -1304,7 +1290,6 @@ static int host1x_drm_remove(struct host1x_device *dev)
 	drm_dev_unregister(drm);
 
 	drm_kms_helper_poll_fini(drm);
-	tegra_drm_fb_exit(drm);
 	drm_atomic_helper_shutdown(drm);
 	drm_mode_config_cleanup(drm);
 
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 576f03b8434e..f9d18e8cf6ab 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -15,7 +15,6 @@
 #include <drm/drm_bridge.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_encoder.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_fixed.h>
 #include <drm/drm_probe_helper.h>
 #include <uapi/drm/tegra_drm.h>
@@ -194,22 +193,9 @@ struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 					const struct drm_mode_fb_cmd2 *cmd);
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-int tegra_drm_fb_prepare(struct drm_device *drm);
-void tegra_drm_fb_free(struct drm_device *drm);
-int tegra_drm_fb_init(struct drm_device *drm);
-void tegra_drm_fb_exit(struct drm_device *drm);
+void tegra_fbdev_setup(struct drm_device *drm);
 #else
-static inline int tegra_drm_fb_prepare(struct drm_device *drm)
-{
-	return 0;
-}
-static inline void tegra_drm_fb_free(struct drm_device *drm)
-{ }
-static inline int tegra_drm_fb_init(struct drm_device *drm)
-{
-	return 0;
-}
-static inline void tegra_drm_fb_exit(struct drm_device *drm)
+static inline void tegra_fbdev_setup(struct drm_device *drm)
 { }
 #endif
 
diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
index 31a95a955efb..dc6dda641d1c 100644
--- a/drivers/gpu/drm/tegra/fbdev.c
+++ b/drivers/gpu/drm/tegra/fbdev.c
@@ -9,6 +9,9 @@
 
 #include <linux/console.h>
 
+#include <drm/drm_drv.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -32,6 +35,26 @@ static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	return __tegra_gem_mmap(&bo->gem, vma);
 }
 
+static void tegra_fbdev_fb_destroy(struct fb_info *info)
+{
+	struct drm_fb_helper *helper = info->par;
+	struct drm_framebuffer *fb = helper->fb;
+	struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
+
+	drm_fb_helper_fini(helper);
+
+	/* Undo the special mapping we made in fbdev probe. */
+	if (bo->pages) {
+		vunmap(bo->vaddr);
+		bo->vaddr = NULL;
+	}
+	drm_framebuffer_remove(fb);
+
+	drm_client_release(&helper->client);
+	drm_fb_helper_unprepare(helper);
+	kfree(helper);
+}
+
 static const struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
@@ -41,6 +64,7 @@ static const struct fb_ops tegra_fb_ops = {
 	.fb_copyarea = drm_fb_helper_sys_copyarea,
 	.fb_imageblit = drm_fb_helper_sys_imageblit,
 	.fb_mmap = tegra_fb_mmap,
+	.fb_destroy = tegra_fbdev_fb_destroy,
 };
 
 static int tegra_fbdev_probe(struct drm_fb_helper *helper,
@@ -130,16 +154,52 @@ static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
  */
 
 static void tegra_fbdev_client_unregister(struct drm_client_dev *client)
-{ }
+{
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+	if (fb_helper->info) {
+		drm_fb_helper_unregister_info(fb_helper);
+	} else {
+		drm_client_release(&fb_helper->client);
+		drm_fb_helper_unprepare(fb_helper);
+		kfree(fb_helper);
+	}
+}
 
-static int tregra_fbdev_client_restore(struct drm_client_dev *client)
+static int tegra_fbdev_client_restore(struct drm_client_dev *client)
 {
+	drm_fb_helper_lastclose(client->dev);
+
 	return 0;
 }
 
 static int tegra_fbdev_client_hotplug(struct drm_client_dev *client)
 {
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+	struct drm_device *dev = client->dev;
+	int ret;
+
+	if (dev->fb_helper)
+		return drm_fb_helper_hotplug_event(dev->fb_helper);
+
+	ret = drm_fb_helper_init(dev, fb_helper);
+	if (ret)
+		goto err_drm_err;
+
+	if (!drm_drv_uses_atomic_modeset(dev))
+		drm_helper_disable_unused_functions(dev);
+
+	ret = drm_fb_helper_initial_config(fb_helper);
+	if (ret)
+		goto err_drm_fb_helper_fini;
+
 	return 0;
+
+err_drm_fb_helper_fini:
+	drm_fb_helper_fini(fb_helper);
+err_drm_err:
+	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
+	return ret;
 }
 
 static const struct drm_client_funcs tegra_fbdev_client_funcs = {
@@ -149,109 +209,32 @@ static const struct drm_client_funcs tegra_fbdev_client_funcs = {
 	.hotplug	= tegra_fbdev_client_hotplug,
 };
 
-static struct drm_fb_helper *tegra_fbdev_create(struct drm_device *drm)
+void tegra_fbdev_setup(struct drm_device *dev)
 {
 	struct drm_fb_helper *helper;
+	int ret;
+
+	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
+	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 
 	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
 	if (!helper)
-		return ERR_PTR(-ENOMEM);
-
-	drm_fb_helper_prepare(drm, helper, 32, &tegra_fb_helper_funcs);
-
-	return helper;
-}
-
-static void tegra_fbdev_free(struct drm_fb_helper *helper)
-{
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
-}
-
-static int tegra_fbdev_init(struct drm_fb_helper *helper,
-			    unsigned int num_crtc,
-			    unsigned int max_connectors)
-{
-	struct drm_device *drm = helper->dev;
-	int err;
-
-	err = drm_client_init(dev, &helper->client, "fbdev", &tegra_fbdev_client_funcs);
-	if (err)
-		return err;
-
-	err = drm_fb_helper_init(drm, helper);
-	if (err < 0) {
-		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
-			err);
-		goto err_drm_client_release;
-	}
+		return;
+	drm_fb_helper_prepare(dev, helper, 32, &tegra_fb_helper_funcs);
 
-	err = drm_fb_helper_initial_config(helper);
-	if (err < 0) {
-		dev_err(drm->dev, "failed to set initial configuration: %d\n",
-			err);
-		goto fini;
-	}
+	ret = drm_client_init(dev, &helper->client, "fbdev", &tegra_fbdev_client_funcs);
+	if (ret)
+		goto err_drm_client_init;
 
-	return 0;
+	ret = tegra_fbdev_client_hotplug(&helper->client);
+	if (ret)
+		drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
 
-fini:
-	drm_fb_helper_fini(helper);
-err_drm_client_release:
-	drm_client_release(&helper->client);
-	return err;
-}
+	drm_client_register(&helper->client);
 
-static void tegra_fbdev_exit(struct drm_fb_helper *helper)
-{
-	struct drm_framebuffer *fb = helper->fb;
-
-	drm_fb_helper_unregister_info(helper);
-
-	if (fb) {
-		struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
-
-		/* Undo the special mapping we made in fbdev probe. */
-		if (bo && bo->pages) {
-			vunmap(bo->vaddr);
-			bo->vaddr = NULL;
-		}
-
-		drm_framebuffer_remove(fb);
-	}
-
-	drm_fb_helper_fini(helper);
-	drm_client_release(&helper->client);
-	tegra_fbdev_free(helper);
-}
+	return;
 
-int tegra_drm_fb_prepare(struct drm_device *drm)
-{
-	drm->fb_helper = tegra_fbdev_create(drm);
-	if (IS_ERR(drm->fb_helper))
-		return PTR_ERR(drm->fb_helper);
-
-	return 0;
-}
-
-void tegra_drm_fb_free(struct drm_device *drm)
-{
-	tegra_fbdev_free(drm->fb_helper);
-}
-
-int tegra_drm_fb_init(struct drm_device *drm)
-{
-	int err;
-
-	err = tegra_fbdev_init(drm->fb_helper, drm->mode_config.num_crtc,
-			       drm->mode_config.num_connector);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-void tegra_drm_fb_exit(struct drm_device *drm)
-{
-	tegra_fbdev_exit(drm->fb_helper);
+err_drm_client_init:
+	drm_fb_helper_unprepare(helper);
+	kfree(helper);
 }
-- 
2.40.0

Re: [PATCH 0/7] drm/tegra: Convert fbdev to DRM client

[Thierry Reding]

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On Thu, Mar 30, 2023 at 10:36:00AM +0200, Thomas Zimmermann wrote:
> Convert tegra's fbdev code to struct drm_client. Replaces the current
> ad-hoc integration. The conversion includes a number of cleanups. As
> with most other drivers' fbdev emulation, fbdev in tegra is now just
> another DRM client that runs after the DRM device has been registered.
> 
> Once all drivers' fbdev emulation has been converted to struct drm_client,
> we can attempt to add additional in-kernel clients. A DRM-based dmesg
> log or a bootsplash are commonly mentioned. DRM can then switch easily
> among the existing clients if/when required.
> 
> I did the conversion from similar experience with other drivers. But I
> don't have the hardware to test this. Any testing is welcome.
> 
> Thomas Zimmermann (7):
>   drm/tegra: Include <linux/of.h>
>   drm/tegra: Include <linux/i2c.h>
>   drm/tegra: Removed fb from struct tegra_fbdev
>   drm/tegra: Remove struct tegra_fbdev
>   drm/tegra: Hide fbdev support behind config option
>   drm/tegra: Initialize fbdev DRM client
>   drm/tegra: Implement fbdev emulation as in-kernel client
> 
>  drivers/gpu/drm/tegra/Makefile |   2 +
>  drivers/gpu/drm/tegra/drm.c    |  23 +---
>  drivers/gpu/drm/tegra/drm.h    |  27 ++--
>  drivers/gpu/drm/tegra/fb.c     | 242 +--------------------------------
>  drivers/gpu/drm/tegra/fbdev.c  | 240 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/tegra/output.c |   3 +
>  drivers/gpu/drm/tegra/rgb.c    |   1 +
>  7 files changed, 265 insertions(+), 273 deletions(-)
>  create mode 100644 drivers/gpu/drm/tegra/fbdev.c

Seems to be working just fine. Applied, thanks.

Thierry

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Re: [PATCH 0/7] drm/tegra: Convert fbdev to DRM client

[Thomas Zimmermann]

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Am 05.04.23 um 16:55 schrieb Thierry Reding:
> On Thu, Mar 30, 2023 at 10:36:00AM +0200, Thomas Zimmermann wrote:
>> Convert tegra's fbdev code to struct drm_client. Replaces the current
>> ad-hoc integration. The conversion includes a number of cleanups. As
>> with most other drivers' fbdev emulation, fbdev in tegra is now just
>> another DRM client that runs after the DRM device has been registered.
>>
>> Once all drivers' fbdev emulation has been converted to struct drm_client,
>> we can attempt to add additional in-kernel clients. A DRM-based dmesg
>> log or a bootsplash are commonly mentioned. DRM can then switch easily
>> among the existing clients if/when required.
>>
>> I did the conversion from similar experience with other drivers. But I
>> don't have the hardware to test this. Any testing is welcome.
>>
>> Thomas Zimmermann (7):
>>    drm/tegra: Include <linux/of.h>
>>    drm/tegra: Include <linux/i2c.h>
>>    drm/tegra: Removed fb from struct tegra_fbdev
>>    drm/tegra: Remove struct tegra_fbdev
>>    drm/tegra: Hide fbdev support behind config option
>>    drm/tegra: Initialize fbdev DRM client
>>    drm/tegra: Implement fbdev emulation as in-kernel client
>>
>>   drivers/gpu/drm/tegra/Makefile |   2 +
>>   drivers/gpu/drm/tegra/drm.c    |  23 +---
>>   drivers/gpu/drm/tegra/drm.h    |  27 ++--
>>   drivers/gpu/drm/tegra/fb.c     | 242 +--------------------------------
>>   drivers/gpu/drm/tegra/fbdev.c  | 240 ++++++++++++++++++++++++++++++++
>>   drivers/gpu/drm/tegra/output.c |   3 +
>>   drivers/gpu/drm/tegra/rgb.c    |   1 +
>>   7 files changed, 265 insertions(+), 273 deletions(-)
>>   create mode 100644 drivers/gpu/drm/tegra/fbdev.c
> 
> Seems to be working just fine. Applied, thanks.

Thanks a lot!

> 
> Thierry

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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Re: [PATCH 0/7] drm/tegra: Convert fbdev to DRM client

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

On Thu, 30 Mar 2023 10:36:00 +0200, Thomas Zimmermann wrote:
> Convert tegra's fbdev code to struct drm_client. Replaces the current
> ad-hoc integration. The conversion includes a number of cleanups. As
> with most other drivers' fbdev emulation, fbdev in tegra is now just
> another DRM client that runs after the DRM device has been registered.
> 
> Once all drivers' fbdev emulation has been converted to struct drm_client,
> we can attempt to add additional in-kernel clients. A DRM-based dmesg
> log or a bootsplash are commonly mentioned. DRM can then switch easily
> among the existing clients if/when required.
> 
> [...]

Applied, thanks!

[1/7] drm/tegra: Include <linux/of.h>
      commit: 162b2ae95e0887ea75883bc419d55dd714b8fbf5
[2/7] drm/tegra: Include <linux/i2c.h>
      commit: 0e4ec6d97a2c6e96a5ec8d0edc00aa658238ed3f
[3/7] drm/tegra: Removed fb from struct tegra_fbdev
      commit: 5705d5b6a21e75c095df29deec8a13aa6b59f83c
[4/7] drm/tegra: Remove struct tegra_fbdev
      commit: fc5646b848222601d8be78b66b6498130437abe1
[5/7] drm/tegra: Hide fbdev support behind config option
      commit: 63ab4848d1d2eda1658ae82a3cb6eb7e03d28cec
[6/7] drm/tegra: Initialize fbdev DRM client
      commit: d9d1e306e70db905f29d05952c1499fd3c6ef6ef
[7/7] drm/tegra: Implement fbdev emulation as in-kernel client
      commit: 8e5113c627334ed32748d95ababd548171d2333d

Best regards,
-- 
Thierry Reding <treding@nvidia.com>