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@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)