[PATCH v4 2/9] drm/fb-helper: Add generic fbdev emulation .fb_probe function
Noralf Trønnes
noralf at tronnes.org
Mon Jul 2 13:54:26 UTC 2018
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.
Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
drivers/gpu/drm/drm_fb_helper.c | 192 +++++++++++++++++++++++++++++++++++++++-
include/drm/drm_fb_helper.h | 31 +++++++
2 files changed, 222 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index cab14f253384..0a0a577ebc3c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -30,6 +30,7 @@
#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>
@@ -738,6 +739,24 @@ static void drm_fb_helper_resume_worker(struct work_struct *work)
console_unlock();
}
+static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
+ struct drm_clip_rect *clip)
+{
+ struct drm_framebuffer *fb = fb_helper->fb;
+ unsigned int cpp = drm_format_plane_cpp(fb->format->format, 0);
+ size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
+ void *src = fb_helper->fbdev->screen_buffer + offset;
+ void *dst = fb_helper->buffer->vaddr + offset;
+ size_t len = (clip->x2 - clip->x1) * cpp;
+ unsigned int y;
+
+ for (y = clip->y1; y < clip->y2; y++) {
+ memcpy(dst, src, len);
+ src += fb->pitches[0];
+ dst += fb->pitches[0];
+ }
+}
+
static void drm_fb_helper_dirty_work(struct work_struct *work)
{
struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
@@ -753,8 +772,12 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
spin_unlock_irqrestore(&helper->dirty_lock, flags);
/* call dirty callback only when it has been really touched */
- if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2)
+ if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
+ /* Generic fbdev uses a shadow buffer */
+ if (helper->buffer)
+ drm_fb_helper_dirty_blit_real(helper, &clip_copy);
helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+ }
}
/**
@@ -2921,6 +2944,173 @@ 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_info *fbi = fb_helper->fbdev;
+ struct fb_ops *fbops = NULL;
+ void *shadow = NULL;
+
+ if (fbi->fbdefio) {
+ fb_deferred_io_cleanup(fbi);
+ shadow = fbi->screen_buffer;
+ fbops = fbi->fbops;
+ }
+
+ drm_fb_helper_fini(fb_helper);
+
+ if (shadow) {
+ vfree(shadow);
+ kfree(fbops);
+ }
+
+ drm_client_framebuffer_delete(fb_helper->buffer);
+ drm_client_release(&fb_helper->client);
+ kfree(fb_helper);
+}
+
+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 = {
+ .owner = THIS_MODULE,
+ 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,
+};
+
+/**
+ * drm_fb_helper_generic_probe - Generic fbdev emulation probe helper
+ * @fb_helper: fbdev helper structure
+ * @sizes: describes fbdev size and scanout surface size
+ *
+ * This function uses the client API to crate a framebuffer backed by a dumb buffer.
+ *
+ * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
+ * fb_copyarea, fb_imageblit.
+ *
+ * Returns:
+ * Zero on success or negative error code on failure.
+ */
+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;
+ void *shadow;
+
+ /*
+ * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
+ * instance version is necessary.
+ */
+ fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
+ shadow = vzalloc(fbi->screen_size);
+ if (!fbops || !shadow) {
+ kfree(fbops);
+ vfree(shadow);
+ ret = -ENOMEM;
+ goto err_fb_info_destroy;
+ }
+
+ *fbops = *fbi->fbops;
+ fbi->fbops = fbops;
+ fbi->screen_buffer = shadow;
+ fbi->fbdefio = &drm_fbdev_defio;
+
+ fb_deferred_io_init(fbi);
+ }
+
+ 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..c134bbcfd2e9 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -32,6 +32,7 @@
struct drm_fb_helper;
+#include <drm/drm_client.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
#include <linux/kgdb.h>
@@ -154,6 +155,20 @@ struct drm_fb_helper_connector {
* operations.
*/
struct drm_fb_helper {
+ /**
+ * @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;
+
struct drm_framebuffer *fb;
struct drm_device *dev;
int crtc_count;
@@ -234,6 +249,12 @@ struct drm_fb_helper {
int preferred_bpp;
};
+static inline struct drm_fb_helper *
+drm_fb_helper_from_client(struct drm_client_dev *client)
+{
+ return container_of(client, struct drm_fb_helper, client);
+}
+
/**
* define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
*
@@ -330,6 +351,9 @@ 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 +588,13 @@ 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
More information about the dri-devel
mailing list