[PATCH 5/9] drm/fb-helper: Add generic fbdev emulation .fb_probe function

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is the first step in getting generic fbdev emulation.
A drm_fb_helper_funcs.fb_probe function is added which uses the
DRM client API to get a framebuffer backed by a dumb buffer.

A transitional hack for tinydrm is needed in order to switch over all
CMA helper drivers in a later patch. This hack will be removed when
tinydrm moves to vmalloc buffers.

Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
---
 drivers/gpu/drm/drm_fb_helper.c | 164 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_fb_helper.h     |  26 +++++++
 2 files changed, 190 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2ee1eaa66188..444c2b4040ea 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -30,11 +30,13 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/console.h>
+#include <linux/dma-buf.h>
 #include <linux/kernel.h>
 #include <linux/sysrq.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <drm/drmP.h>
+#include <drm/drm_client.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
@@ -2928,6 +2930,168 @@ void drm_fb_helper_output_poll_changed(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
 
+/* @user: 1=userspace, 0=fbcon */
+static int drm_fbdev_fb_open(struct fb_info *info, int user)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+
+	if (!try_module_get(fb_helper->dev->driver->fops->owner))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int drm_fbdev_fb_release(struct fb_info *info, int user)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+
+	module_put(fb_helper->dev->driver->fops->owner);
+
+	return 0;
+}
+
+/*
+ * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
+ * unregister_framebuffer() or fb_release().
+ */
+static void drm_fbdev_fb_destroy(struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct fb_ops *fbops = NULL;
+
+	DRM_DEBUG("\n");
+
+	if (fb_helper->fbdev->fbdefio) {
+		fb_deferred_io_cleanup(fb_helper->fbdev);
+		fbops = fb_helper->fbdev->fbops;
+	}
+
+	drm_fb_helper_fini(fb_helper);
+	drm_client_framebuffer_delete(fb_helper->buffer);
+	drm_client_free(fb_helper->client);
+	kfree(fb_helper);
+	kfree(fbops);
+}
+
+static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+
+	if (fb_helper->dev->driver->gem_prime_mmap)
+		return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
+	else
+		return -ENODEV;
+}
+
+static struct fb_ops drm_fbdev_fb_ops = {
+	/* No need to set owner, this module is already pinned by the driver. */
+	DRM_FB_HELPER_DEFAULT_OPS,
+	.fb_open	= drm_fbdev_fb_open,
+	.fb_release	= drm_fbdev_fb_release,
+	.fb_destroy	= drm_fbdev_fb_destroy,
+	.fb_mmap	= drm_fbdev_fb_mmap,
+	.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,
+};
+
+static struct fb_deferred_io drm_fbdev_defio = {
+	.delay		= HZ / 20,
+	.deferred_io	= drm_fb_helper_deferred_io,
+};
+
+/*
+ * TODO: Remove this when tinydrm is converted to vmalloc buffers.
+ */
+static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
+					  struct vm_area_struct *vma)
+{
+	fb_deferred_io_mmap(info, vma);
+	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+	return 0;
+}
+
+int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+				struct drm_fb_helper_surface_size *sizes)
+{
+	struct drm_client_dev *client = fb_helper->client;
+	struct drm_client_buffer *buffer;
+	struct drm_framebuffer *fb;
+	struct fb_info *fbi;
+	u32 format;
+	int ret;
+
+	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
+		      sizes->surface_width, sizes->surface_height,
+		      sizes->surface_bpp);
+
+	format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
+	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
+					       sizes->surface_height, format);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	fb_helper->buffer = buffer;
+	fb_helper->fb = buffer->fb;
+	fb = buffer->fb;
+
+	fbi = drm_fb_helper_alloc_fbi(fb_helper);
+	if (IS_ERR(fbi)) {
+		ret = PTR_ERR(fbi);
+		goto err_free_buffer;
+	}
+
+	fbi->par = fb_helper;
+	fbi->fbops = &drm_fbdev_fb_ops;
+	fbi->screen_size = fb->height * fb->pitches[0];
+	fbi->fix.smem_len = fbi->screen_size;
+	fbi->screen_buffer = buffer->vaddr;
+	strcpy(fbi->fix.id, "DRM emulated");
+
+	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
+	drm_fb_helper_fill_var(fbi, fb_helper, sizes->fb_width, sizes->fb_height);
+
+	if (fb->funcs->dirty) {
+		struct fb_ops *fbops;
+
+		/*
+		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
+		 * instance version is necessary.
+		 */
+		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
+		if (!fbops) {
+			ret = -ENOMEM;
+			goto err_fb_info_destroy;
+		}
+
+		*fbops = *fbi->fbops;
+		fbi->fbops = fbops;
+
+		fbi->fbdefio = &drm_fbdev_defio;
+
+		/* TODO: Remove this when tinydrm is converted to vmalloc buffers. */
+		fbi->fix.smem_start = page_to_phys(virt_to_page(buffer->vaddr));
+
+		fb_deferred_io_init(fbi);
+
+		/* TODO: Remove this when tinydrm is converted to vmalloc buffers. */
+		fbi->fbops->fb_mmap = drm_fbdev_cma_deferred_io_mmap;
+	}
+
+	return 0;
+
+err_fb_info_destroy:
+	drm_fb_helper_fini(fb_helper);
+err_free_buffer:
+	drm_client_framebuffer_delete(buffer);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_generic_probe);
+
 /* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
  * but the module doesn't depend on any fb console symbols.  At least
  * attempt to load fbcon to avoid leaving the system without a usable console.
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index b069433e7fc1..bb38469a9502 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -30,6 +30,8 @@
 #ifndef DRM_FB_HELPER_H
 #define DRM_FB_HELPER_H
 
+struct drm_client_buffer;
+struct drm_client_dev;
 struct drm_fb_helper;
 
 #include <drm/drm_crtc.h>
@@ -232,6 +234,20 @@ struct drm_fb_helper {
 	 * See also: @deferred_setup
 	 */
 	int preferred_bpp;
+
+	/**
+	 * @client:
+	 *
+	 * DRM client used by the generic fbdev emulation.
+	 */
+	struct drm_client_dev *client;
+
+	/**
+	 * @buffer:
+	 *
+	 * Framebuffer used by the generic fbdev emulation.
+	 */
+	struct drm_client_buffer *buffer;
 };
 
 /**
@@ -330,6 +346,9 @@ void drm_fb_helper_fbdev_teardown(struct drm_device *dev);
 
 void drm_fb_helper_lastclose(struct drm_device *dev);
 void drm_fb_helper_output_poll_changed(struct drm_device *dev);
+
+int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+				struct drm_fb_helper_surface_size *sizes);
 #else
 static inline void drm_fb_helper_prepare(struct drm_device *dev,
 					struct drm_fb_helper *helper,
@@ -564,6 +583,13 @@ static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
 {
 }
 
+static inline int
+drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+			    struct drm_fb_helper_surface_size *sizes)
+{
+	return 0;
+}
+
 #endif
 
 static inline int
-- 
2.15.1

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux