[PATCH 02/11] drm/fbdevdrm: Add fbdevdrm device
Thomas Zimmermann
tzimmermann at suse.de
Tue Mar 26 09:17:35 UTC 2019
There's an fbdevdrm device for each supported fbdev device. The fbdevdrm
driver listens for fb events, and creates and destroys fbdevdrm devices
accordingly.
Only hardware-specific fbdev drivers are supported. Generic drivers, such
as vga16fb or vesafb are not handled. DRM-based fbdev drivers are also not
supported. This prevents the situation where a DRM drivers enables
framebuffer emulation and fbdevdrm creates a second DRM device for the
same hardware.
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
drivers/gpu/drm/fbdevdrm/Makefile | 3 +-
drivers/gpu/drm/fbdevdrm/fbdevdrm_device.c | 79 ++++++++++
drivers/gpu/drm/fbdevdrm/fbdevdrm_device.h | 44 ++++++
drivers/gpu/drm/fbdevdrm/fbdevdrm_drv.c | 173 ++++++++++++++++++++-
4 files changed, 296 insertions(+), 3 deletions(-)
create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_device.c
create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_device.h
diff --git a/drivers/gpu/drm/fbdevdrm/Makefile b/drivers/gpu/drm/fbdevdrm/Makefile
index 65e6b43cf682..750940d38509 100644
--- a/drivers/gpu/drm/fbdevdrm/Makefile
+++ b/drivers/gpu/drm/fbdevdrm/Makefile
@@ -1,4 +1,5 @@
ccflags-y = -Iinclude/drm
-fbdevdrm-y := fbdevdrm_drv.o
+fbdevdrm-y := fbdevdrm_device.o \
+ fbdevdrm_drv.o
obj-$(CONFIG_DRM_FBDEVDRM) += fbdevdrm.o
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.c
new file mode 100644
index 000000000000..0abf41cf05bb
--- /dev/null
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.c
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * One purpose of this driver is to allow for easy conversion of framebuffer
+ * drivers to DRM. As a special exception to the GNU GPL, you are allowed to
+ * relicense this file under the terms of a license of your choice if you're
+ * porting a framebuffer driver. In order to do so, update the SPDX license
+ * identifier to the new license and remove this exception.
+ *
+ * If you add code to this file, please ensure that it's compatible with the
+ * stated exception.
+ */
+
+#include "fbdevdrm_device.h"
+#include <drm/drm_drv.h>
+#include <drm/drm_modeset_helper.h>
+#include <drm/drm_print.h>
+#include <linux/fb.h>
+#include <linux/pci.h>
+
+/*
+ * struct fbdrmdev_device
+ */
+
+int fbdevdrm_device_init(struct fbdevdrm_device *fdev, struct drm_driver *drv,
+ struct fb_info *fb_info)
+{
+ int ret;
+
+ ret = drm_dev_init(&fdev->dev, drv, fb_info->device);
+ if (ret)
+ return ret;
+ fdev->dev.dev_private = fdev;
+ fdev->dev.pdev = container_of(fb_info->device, struct pci_dev, dev);
+ fdev->fb_info = fb_info;
+
+ INIT_LIST_HEAD(&fdev->device_list);
+
+ return 0;
+}
+
+void fbdevdrm_device_cleanup(struct fbdevdrm_device *fdev)
+{
+ struct drm_device *dev = &fdev->dev;
+
+ if (!list_empty(&fdev->device_list)) {
+ DRM_ERROR("fbdevdrm: cleaned up device is still enqueued "
+ "in device list\n");
+ }
+
+ drm_dev_fini(dev);
+ dev->dev_private = NULL;
+}
+
+struct fbdevdrm_device* fbdevdrm_device_create(struct drm_driver *drv,
+ struct fb_info *fb_info)
+{
+ struct fbdevdrm_device *fdev;
+ int ret;
+
+ fdev = devm_kzalloc(fb_info->dev, sizeof(*fdev), GFP_KERNEL);
+ if (!fdev)
+ return ERR_PTR(-ENOMEM);
+ ret = fbdevdrm_device_init(fdev, drv, fb_info);
+ if (ret < 0)
+ goto err_devm_kfree;
+ return fdev;
+
+err_devm_kfree:
+ devm_kfree(fb_info->dev, fdev);
+ return ERR_PTR(ret);
+}
+
+void fbdevdrm_device_destroy(struct fbdevdrm_device *fdev)
+{
+ struct device *dev = fdev->fb_info->dev;
+
+ fbdevdrm_device_cleanup(fdev);
+ devm_kfree(dev, fdev);
+}
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.h b/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.h
new file mode 100644
index 000000000000..85878f60bba4
--- /dev/null
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_device.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * One purpose of this driver is to allow for easy conversion of framebuffer
+ * drivers to DRM. As a special exception to the GNU GPL, you are allowed to
+ * relicense this file under the terms of a license of your choice if you're
+ * porting a framebuffer driver. In order to do so, update the SPDX license
+ * identifier to the new license and remove this exception.
+ *
+ * If you add code to this file, please ensure that it's compatible with the
+ * stated exception.
+ */
+
+#ifndef FBDEVDRM_DEVICE_H
+#define FBDEVDRM_DEVICE_H
+
+#include <drm/drm_device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+
+struct drm_driver;
+struct fb_info;
+
+struct fbdevdrm_device {
+ struct drm_device dev;
+ struct fb_info *fb_info;
+
+ struct list_head device_list; /* entry in global device list */
+};
+
+static inline struct fbdevdrm_device* fbdevdrm_device_of_device_list(
+ struct list_head *device_list)
+{
+ return list_entry(device_list, struct fbdevdrm_device, device_list);
+}
+
+int fbdevdrm_device_init(struct fbdevdrm_device *fdev, struct drm_driver *drv,
+ struct fb_info *fb_info);
+void fbdevdrm_device_cleanup(struct fbdevdrm_device *fdev);
+
+struct fbdevdrm_device* fbdevdrm_device_create(struct drm_driver *drv,
+ struct fb_info *fb_info);
+void fbdevdrm_device_destroy(struct fbdevdrm_device *fdev);
+
+#endif
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_drv.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_drv.c
index dcb263b0c386..5be902094dc6 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_drv.c
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_drv.c
@@ -10,8 +10,13 @@
* stated exception.
*/
+#include <drm/drm_drv.h>
+#include <drm/drm_print.h>
+#include <linux/console.h> /* for console_{un/lock}() */
#include <linux/fb.h>
#include <linux/module.h>
+#include <linux/mutex.h>
+#include "fbdevdrm_device.h"
/* DRM porting note: Here are some general information about the driver,
* licensing and maintenance contact. If you're porting an fbdev driver
@@ -29,18 +34,156 @@
#define DRIVER_MINOR 0
#define DRIVER_PATCHLEVEL 1
+/*
+ * DRM driver
+ */
+
+static struct drm_driver fbdevdrm_drv = {
+ /* data fields */
+ .major = DRIVER_MAJOR,
+ .minor = DRIVER_MINOR,
+ .patchlevel = DRIVER_PATCHLEVEL,
+ .name = DRIVER_NAME,
+ .desc = DRIVER_DESCRIPTION,
+ .date = DRIVER_DATE
+};
+
+/* Device list */
+
+static DEFINE_MUTEX(device_list_mutex);
+static LIST_HEAD(device_list);
+
+static void device_list_add(struct fbdevdrm_device *fdev)
+{
+ mutex_lock(&device_list_mutex);
+ list_add(&fdev->device_list, &device_list);
+ mutex_unlock(&device_list_mutex);
+}
+
+static struct fbdevdrm_device* device_list_del(struct fbdevdrm_device *fdev)
+{
+ mutex_lock(&device_list_mutex);
+ list_del(&fdev->device_list);
+ mutex_unlock(&device_list_mutex);
+
+ return fdev;
+}
+
+static struct fbdevdrm_device* device_list_find_by_fb_info(
+ const struct fb_info *fb_info)
+{
+ struct list_head *pos;
+ struct fbdevdrm_device *fdev = NULL;
+
+ mutex_lock(&device_list_mutex);
+ list_for_each(pos, &device_list) {
+ struct fbdevdrm_device *pos_fdev =
+ fbdevdrm_device_of_device_list(pos);
+ if (pos_fdev->fb_info == fb_info) {
+ fdev = pos_fdev;
+ goto out;
+ }
+ }
+out:
+ mutex_unlock(&device_list_mutex);
+ return fdev;
+}
+
/* Module entry points */
+static bool is_generic_driver(const struct fb_info *fb_info)
+{
+ /* DRM porting note: We don't want to bind to vga16fb, vesafb, or any
+ * other generic fbdev driver. Usually, these drivers have limited
+ * capabilitis. We only continue if the fix structure indicates a
+ * hardware-specific drivers . This test will also sort out drivers
+ * registered via DRM's fbdev emulation. If you're porting an fbdev
+ * driver to DRM, you can remove this test. The module's PCI device
+ * ids will contain this information.
+ */
+ return !fb_info->fix.accel &&
+ !!strcmp(fb_info->fix.id, "S3 Virge/DX");
+}
+
+static int on_fb_registered(struct fb_info *fb_info, void *data)
+{
+ struct fbdevdrm_device *fdev;
+ int ret;
+
+ if (is_generic_driver(fb_info)) {
+ DRM_ERROR("fbdevdrm: not binding to %s\n", fb_info->fix.id);
+ return 0;
+ }
+
+ fdev = fbdevdrm_device_create(&fbdevdrm_drv, fb_info);
+ if (IS_ERR(fdev))
+ return PTR_ERR(fdev);
+ device_list_add(fdev);
+
+ ret = drm_dev_register(&fdev->dev, 0);
+ if (ret)
+ goto err_device_list_del;
+
+ return 0;
+
+err_device_list_del:
+ device_list_del(fdev);
+ fbdevdrm_device_destroy(fdev);
+ return ret;
+}
+
+static int on_fb_unregistered(struct fb_info *fb_info, void *data)
+{
+ struct fbdevdrm_device *fdev;
+
+ fdev = device_list_find_by_fb_info(fb_info);
+ if (!fdev)
+ return 0;
+
+ device_list_del(fdev);
+ fbdevdrm_device_destroy(fdev);
+
+ return 0;
+}
+
static int fb_client_notifier_call(struct notifier_block *nb,
unsigned long action, void *data)
{
+ static const char* const event_name[] = {
+#define EVENT_NAME(_ev) \
+ [_ev] = #_ev
+ EVENT_NAME(FB_EVENT_MODE_CHANGE),
+ EVENT_NAME(FB_EVENT_SUSPEND),
+ EVENT_NAME(FB_EVENT_RESUME),
+ EVENT_NAME(FB_EVENT_MODE_DELETE),
+ EVENT_NAME(FB_EVENT_FB_REGISTERED),
+ EVENT_NAME(FB_EVENT_FB_UNREGISTERED),
+ EVENT_NAME(FB_EVENT_GET_CONSOLE_MAP),
+ EVENT_NAME(FB_EVENT_SET_CONSOLE_MAP),
+ EVENT_NAME(FB_EVENT_BLANK),
+ EVENT_NAME(FB_EVENT_NEW_MODELIST),
+ EVENT_NAME(FB_EVENT_MODE_CHANGE_ALL),
+ EVENT_NAME(FB_EVENT_CONBLANK),
+ EVENT_NAME(FB_EVENT_GET_REQ),
+ EVENT_NAME(FB_EVENT_FB_UNBIND),
+ EVENT_NAME(FB_EVENT_REMAP_ALL_CONSOLE),
+ EVENT_NAME(FB_EARLY_EVENT_BLANK),
+ EVENT_NAME(FB_R_EARLY_EVENT_BLANK)
+#undef EVENT_NAME
+ };
+
static int (* const on_event[])(struct fb_info*, void*) = {
+ [FB_EVENT_FB_REGISTERED] = on_fb_registered,
+ [FB_EVENT_FB_UNREGISTERED] = on_fb_unregistered
};
const struct fb_event *event = data;
- if ((action >= ARRAY_SIZE(on_event)) || !on_event[action])
+ if ((action >= ARRAY_SIZE(on_event)) || !on_event[action]) {
+ DRM_ERROR("fbdevdrm: unhandled event %s\n",
+ event_name[action]);
return 0; /* event not handled by us */
+ }
return on_event[action](event->info, event->data);
}
@@ -50,13 +193,39 @@ static struct notifier_block fb_client = {
static int __init fbdevdrm_init(void)
{
- int ret;
+ int ret, i;
ret = fb_register_client(&fb_client);
if (ret < 0)
return ret;
+ /* There might already be registered FB devices. We go
+ * through them manually to create a corresponding DRM
+ * device. For the event notifier, all the locking is
+ * performed by the fbdev framework. Here, we have to
+ * do it by ourselves. */
+
+ console_lock();
+
+ for_each_registered_fb(i) {
+ struct fb_info *fb_info = registered_fb[i];
+ if (!lock_fb_info(fb_info)) {
+ ret = -ENODEV;
+ goto err_console_unlock;
+ }
+ ret = on_fb_registered(fb_info, NULL);
+ unlock_fb_info(fb_info);
+ if (ret < 0)
+ goto err_console_unlock;
+ }
+
+ console_unlock();
+
return 0;
+
+err_console_unlock:
+ console_unlock();
+ return ret;
}
static void __exit fbdevdrm_exit(void)
--
2.21.0
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