[PATCH V3] drm/vkms: Decouple config data for configfs

[Sumera Priyadarsini <sylphrenadin@gmail.com>]

Currently, data for the device instance is held by vkms_device.
Add a separate type, vkms_config to contain configuration details
for the device and various modes to be later used by configfs.
This config data stays constant once the device is created.

Accordingly, add vkms_create and vkms_destroy to initialize/destroy
device through configfs. Currently, they are being called from vkms_init
and vkms_exit, but will be evoked from configfs later on. When configfs
is added, device configuration will be tracked by configfs and only vkms
device lifetime will be handled by vkms_init and vkms_exit functions.

Modify usage of enable_cursor feature to reflect the changes in
relevant files.

Add enable_writeback_connector feature to vkms_config type.

Co-developed-by: Daniel Vetter <danvet.vetter@ffwl.ch>
Signed-off-by: Daniel Vetter <danvet.vetter@ffwl.ch>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>

---
Changes in v2:
- add Co-developed-by tag

Changes in v3:
- correct usage of Co-developed by tag(Melissa)
- add enable_writeback_feature(Melissa)
- modify commit message(Melissa)
---
 drivers/gpu/drm/vkms/vkms_drv.c    | 45 ++++++++++++++++++++++++------
 drivers/gpu/drm/vkms/vkms_drv.h    | 12 ++++++--
 drivers/gpu/drm/vkms/vkms_output.c | 13 +++++----
 3 files changed, 54 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index aef29393b811..fab964900dce 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -34,12 +34,16 @@
 #define DRIVER_MAJOR	1
 #define DRIVER_MINOR	0
 
-static struct vkms_device *vkms_device;
+static struct vkms_config *default_config;
 
-bool enable_cursor = true;
+static bool enable_cursor = true;
 module_param_named(enable_cursor, enable_cursor, bool, 0444);
 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
 
+static bool enable_writeback_connector = true;
+module_param_named(enable_writeback_connector, enable_writeback_connector, bool, 0444);
+MODULE_PARM_DESC(enable_writeback_connector, "Enable/Disable writeback connector support");
+
 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
 
 static void vkms_release(struct drm_device *dev)
@@ -122,10 +126,11 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
 	return vkms_output_init(vkmsdev, 0);
 }
 
-static int __init vkms_init(void)
+static int vkms_create(struct vkms_config *config)
 {
 	int ret;
 	struct platform_device *pdev;
+	struct vkms_device *vkms_device;
 
 	pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 	if (IS_ERR(pdev))
@@ -143,6 +148,8 @@ static int __init vkms_init(void)
 		goto out_devres;
 	}
 	vkms_device->platform = pdev;
+	vkms_device->config = config;
+	config->dev = vkms_device;
 
 	ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 					   DMA_BIT_MASK(64));
@@ -179,21 +186,43 @@ static int __init vkms_init(void)
 	return ret;
 }
 
-static void __exit vkms_exit(void)
+static int __init vkms_init(void)
+{
+	struct vkms_config *config = kmalloc(sizeof(*config), GFP_KERNEL);
+
+	default_config = config;
+
+	config->cursor = enable_cursor;
+	config->writeback = enable_writeback_connector;
+
+	return vkms_create(config);
+}
+
+static void vkms_destroy(struct vkms_config *config)
 {
 	struct platform_device *pdev;
 
-	if (!vkms_device) {
+	if (!config->dev) {
 		DRM_INFO("vkms_device is NULL.\n");
 		return;
 	}
 
-	pdev = vkms_device->platform;
+	pdev = config->dev->platform;
 
-	drm_dev_unregister(&vkms_device->drm);
-	drm_atomic_helper_shutdown(&vkms_device->drm);
+	drm_dev_unregister(&config->dev->drm);
+	drm_atomic_helper_shutdown(&config->dev->drm);
 	devres_release_group(&pdev->dev, NULL);
 	platform_device_unregister(pdev);
+
+	config->dev = NULL;
+}
+
+static void __exit vkms_exit(void)
+{
+	if (default_config->dev)
+		vkms_destroy(default_config);
+
+	kfree(default_config);
 }
 
 module_init(vkms_init);
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 5ed91ff08cb3..caa1fafb6ca7 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -19,8 +19,6 @@
 #define XRES_MAX  8192
 #define YRES_MAX  8192
 
-extern bool enable_cursor;
-
 struct vkms_composer {
 	struct drm_framebuffer fb;
 	struct drm_rect src, dst;
@@ -82,10 +80,18 @@ struct vkms_output {
 	spinlock_t composer_lock;
 };
 
+struct vkms_device;
+struct vkms_config {
+	bool writeback;
+	bool cursor;
+	/* only set when instantiated */
+	struct vkms_device *dev;
+};
 struct vkms_device {
 	struct drm_device drm;
 	struct platform_device *platform;
 	struct vkms_output output;
+	const struct vkms_config *config;
 };
 
 #define drm_crtc_to_vkms_output(target) \
@@ -123,4 +129,4 @@ void vkms_set_composer(struct vkms_output *out, bool enabled);
 /* Writeback */
 int vkms_enable_writeback_connector(struct vkms_device *vkmsdev);
 
-#endif /* _VKMS_DRV_H_ */
+#endif /* _VKMS_DRV_H_ */
\ No newline at end of file
diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
index 4a1848b0318f..f5f6f15c362c 100644
--- a/drivers/gpu/drm/vkms/vkms_output.c
+++ b/drivers/gpu/drm/vkms/vkms_output.c
@@ -41,12 +41,13 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
 	struct drm_crtc *crtc = &output->crtc;
 	struct drm_plane *primary, *cursor = NULL;
 	int ret;
+	int writeback;
 
 	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY, index);
 	if (IS_ERR(primary))
 		return PTR_ERR(primary);
 
-	if (enable_cursor) {
+	if (vkmsdev->config->cursor) {
 		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
 		if (IS_ERR(cursor)) {
 			ret = PTR_ERR(cursor);
@@ -80,9 +81,11 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
 		goto err_attach;
 	}
 
-	ret = vkms_enable_writeback_connector(vkmsdev);
-	if (ret)
-		DRM_ERROR("Failed to init writeback connector\n");
+	if (vkmsdev->config->writeback) {
+		writeback = vkms_enable_writeback_connector(vkmsdev);
+		if (writeback)
+			DRM_ERROR("Failed to init writeback connector\n");
+	}
 
 	drm_mode_config_reset(dev);
 
@@ -98,7 +101,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
 	drm_crtc_cleanup(crtc);
 
 err_crtc:
-	if (enable_cursor)
+	if (vkmsdev->config->cursor)
 		drm_plane_cleanup(cursor);
 
 err_cursor:
-- 
2.25.1