linux/include/drm/drm_fb_helper.h
Archit Taneja a03fdcb186 drm: Add top level Kconfig option for DRM fbdev emulation
Legacy fbdev emulation support via DRM is achieved through KMS FB helpers.
Most modesetting drivers enable provide fbdev emulation by default by
selecting KMS FB helpers. A few provide a separate Kconfig option for the
user to enable or disbale fbdev emulation.

Enabling fbdev emulation is finally a distro-level decision. Having a top
level Kconfig option for fbdev emulation helps by providing a uniform way
to enable/disable fbdev emulation for any modesetting driver. It also lets
us remove unnecessary driver specific Kconfig options that causes bloat.

With a top level Kconfig in place, we can stub out the fb helper functions
when not needed without breaking functionality. Having stub functions also
prevents drivers to require wrapping fb helper function calls with #ifdefs.

DRM_FBDEV_EMULATION defaults to y since many drivers enable fbdev
emulation by default and majority of distributions expect the fbdev
interface in the kernel.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:13:08 +02:00

374 lines
11 KiB
C

/*
* Copyright (c) 2006-2009 Red Hat Inc.
* Copyright (c) 2006-2008 Intel Corporation
* Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
*
* DRM framebuffer helper functions
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*
* Authors:
* Dave Airlie <airlied@linux.ie>
* Jesse Barnes <jesse.barnes@intel.com>
*/
#ifndef DRM_FB_HELPER_H
#define DRM_FB_HELPER_H
struct drm_fb_helper;
#include <linux/kgdb.h>
struct drm_fb_offset {
int x, y;
};
struct drm_fb_helper_crtc {
struct drm_mode_set mode_set;
struct drm_display_mode *desired_mode;
int x, y;
};
/**
* struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
* @fb_width: fbdev width
* @fb_height: fbdev height
* @surface_width: scanout buffer width
* @surface_height: scanout buffer height
* @surface_bpp: scanout buffer bpp
* @surface_depth: scanout buffer depth
*
* Note that the scanout surface width/height may be larger than the fbdev
* width/height. In case of multiple displays, the scanout surface is sized
* according to the largest width/height (so it is large enough for all CRTCs
* to scanout). But the fbdev width/height is sized to the minimum width/
* height of all the displays. This ensures that fbcon fits on the smallest
* of the attached displays.
*
* So what is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
* rather than the surface size.
*/
struct drm_fb_helper_surface_size {
u32 fb_width;
u32 fb_height;
u32 surface_width;
u32 surface_height;
u32 surface_bpp;
u32 surface_depth;
};
/**
* struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
* @gamma_set: Set the given gamma lut register on the given crtc.
* @gamma_get: Read the given gamma lut register on the given crtc, used to
* save the current lut when force-restoring the fbdev for e.g.
* kdbg.
* @fb_probe: Driver callback to allocate and initialize the fbdev info
* structure. Furthermore it also needs to allocate the drm
* framebuffer used to back the fbdev.
* @initial_config: Setup an initial fbdev display configuration
*
* Driver callbacks used by the fbdev emulation helper library.
*/
struct drm_fb_helper_funcs {
void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
u16 blue, int regno);
void (*gamma_get)(struct drm_crtc *crtc, u16 *red, u16 *green,
u16 *blue, int regno);
int (*fb_probe)(struct drm_fb_helper *helper,
struct drm_fb_helper_surface_size *sizes);
bool (*initial_config)(struct drm_fb_helper *fb_helper,
struct drm_fb_helper_crtc **crtcs,
struct drm_display_mode **modes,
struct drm_fb_offset *offsets,
bool *enabled, int width, int height);
};
struct drm_fb_helper_connector {
struct drm_connector *connector;
};
struct drm_fb_helper {
struct drm_framebuffer *fb;
struct drm_device *dev;
int crtc_count;
struct drm_fb_helper_crtc *crtc_info;
int connector_count;
int connector_info_alloc_count;
struct drm_fb_helper_connector **connector_info;
const struct drm_fb_helper_funcs *funcs;
struct fb_info *fbdev;
u32 pseudo_palette[17];
struct list_head kernel_fb_list;
/* we got a hotplug but fbdev wasn't running the console
delay until next set_par */
bool delayed_hotplug;
};
#ifdef CONFIG_DRM_FBDEV_EMULATION
void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
const struct drm_fb_helper_funcs *funcs);
int drm_fb_helper_init(struct drm_device *dev,
struct drm_fb_helper *helper, int crtc_count,
int max_conn);
void drm_fb_helper_fini(struct drm_fb_helper *helper);
int drm_fb_helper_blank(int blank, struct fb_info *info);
int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info);
int drm_fb_helper_set_par(struct fb_info *info);
int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
struct fb_info *info);
bool drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
uint32_t fb_width, uint32_t fb_height);
void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
uint32_t depth);
void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
size_t count, loff_t *ppos);
ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
size_t count, loff_t *ppos);
void drm_fb_helper_sys_fillrect(struct fb_info *info,
const struct fb_fillrect *rect);
void drm_fb_helper_sys_copyarea(struct fb_info *info,
const struct fb_copyarea *area);
void drm_fb_helper_sys_imageblit(struct fb_info *info,
const struct fb_image *image);
void drm_fb_helper_cfb_fillrect(struct fb_info *info,
const struct fb_fillrect *rect);
void drm_fb_helper_cfb_copyarea(struct fb_info *info,
const struct fb_copyarea *area);
void drm_fb_helper_cfb_imageblit(struct fb_info *info,
const struct fb_image *image);
void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, int state);
int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
int drm_fb_helper_debug_enter(struct fb_info *info);
int drm_fb_helper_debug_leave(struct fb_info *info);
struct drm_display_mode *
drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
int width, int height);
struct drm_display_mode *
drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
int width, int height);
int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
struct drm_connector *connector);
#else
static inline void drm_fb_helper_prepare(struct drm_device *dev,
struct drm_fb_helper *helper,
const struct drm_fb_helper_funcs *funcs)
{
}
static inline int drm_fb_helper_init(struct drm_device *dev,
struct drm_fb_helper *helper, int crtc_count,
int max_conn)
{
return 0;
}
static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
{
}
static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
{
return 0;
}
static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
return 0;
}
static inline int drm_fb_helper_set_par(struct fb_info *info)
{
return 0;
}
static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
struct fb_info *info)
{
return 0;
}
static inline bool
drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
{
return true;
}
static inline struct fb_info *
drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
{
return NULL;
}
static inline void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
{
}
static inline void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper)
{
}
static inline void drm_fb_helper_fill_var(struct fb_info *info,
struct drm_fb_helper *fb_helper,
uint32_t fb_width, uint32_t fb_height)
{
}
static inline void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
uint32_t depth)
{
}
static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
struct fb_info *info)
{
return 0;
}
static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
{
}
static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
char __user *buf, size_t count,
loff_t *ppos)
{
return -ENODEV;
}
static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
const char __user *buf,
size_t count, loff_t *ppos)
{
return -ENODEV;
}
static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
const struct fb_fillrect *rect)
{
}
static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
const struct fb_copyarea *area)
{
}
static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
const struct fb_image *image)
{
}
static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
const struct fb_fillrect *rect)
{
}
static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
const struct fb_copyarea *area)
{
}
static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
const struct fb_image *image)
{
}
static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
int state)
{
}
static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
{
return 0;
}
static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
int bpp_sel)
{
return 0;
}
static inline int
drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
{
return 0;
}
static inline int drm_fb_helper_debug_enter(struct fb_info *info)
{
return 0;
}
static inline int drm_fb_helper_debug_leave(struct fb_info *info)
{
return 0;
}
static inline struct drm_display_mode *
drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
int width, int height)
{
return NULL;
}
static inline struct drm_display_mode *
drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
int width, int height)
{
return NULL;
}
static inline int
drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
struct drm_connector *connector)
{
return 0;
}
static inline int
drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
struct drm_connector *connector)
{
return 0;
}
#endif
#endif