@@ -52,6 +52,17 @@ static LIST_HEAD(kernel_fb_helper_list);
* mode setting driver. They can be used mostly independantely from the crtc
* helper functions used by many drivers to implement the kernel mode setting
* interfaces.
+ *
+ * Initialization is done as a two-step process with drm_fb_helper_init() and
+ * drm_fb_helper_initial_config(), teardown is done with drm_fb_helper_fini().
+ *
+ * At runtime drivers should restore the fbdev console by calling
+ * drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They can
+ * also notify the fb helper code from updates to the output configuration by
+ * calling drm_fb_helper_hotplug_event().
+ *
+ * All other functions exported by the fb helper library can be used to
+ * implement the fbdev driver interface by the driver.
*/
/* simple single crtc case helper function */
@@ -162,6 +173,10 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
}
+/**
+ * drm_fb_helper_debug_enter - implementation for ->fb_debug_enter
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_debug_enter(struct fb_info *info)
{
struct drm_fb_helper *helper = info->par;
@@ -207,6 +222,10 @@ static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc)
return NULL;
}
+/**
+ * drm_fb_helper_debug_leave - implementation for ->fb_debug_leave
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_debug_leave(struct fb_info *info)
{
struct drm_fb_helper *helper = info->par;
@@ -377,6 +396,11 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
drm_modeset_unlock_all(dev);
}
+/**
+ * drm_fb_helper_blank - implementation for ->fb_blank
+ * @blank: desired blanking state
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_blank(int blank, struct fb_info *info)
{
switch (blank) {
@@ -420,6 +444,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
kfree(helper->crtc_info);
}
+/**
+ * drm_fb_helper_init - initialize a drm_fb_helper structure
+ * @dev: drm device
+ * @fb_helper: driver-allocated fbdev helper structure to initialize
+ * @crtc_count: crtc count
+ * @max_conn_count: max connector count
+ *
+ * This allocates the structures for the fbdev helper with the given limits.
+ * Note that this won't yet touch the hw (through the driver interfaces) nor
+ * register the fbdev. This is only done in drm_fb_helper_initial_config() to
+ * allow driver writes more control over the exact init sequence.
+ *
+ * Drivers must also set fb_helper->funcs before calling
+ * drm_fb_helper_initial_config().
+ *
+ * RETURNS:
+ * Zero if everything went ok, nonzero otherwise.
+ */
int drm_fb_helper_init(struct drm_device *dev,
struct drm_fb_helper *fb_helper,
int crtc_count, int max_conn_count)
@@ -552,6 +594,11 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
return 0;
}
+/**
+ * drm_fb_helper_setcmap - implementation for ->fb_setcmap
+ * @cmap: cmap to set
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
@@ -591,6 +638,10 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
}
EXPORT_SYMBOL(drm_fb_helper_setcmap);
+/**
+ * drm_fb_helper_check_var - implementation for ->fb_check_var
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
struct fb_info *info)
{
@@ -683,7 +734,14 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
}
EXPORT_SYMBOL(drm_fb_helper_check_var);
-/* this will let fbcon do the mode init */
+/**
+ * drm_fb_helper_set_par - implementation for ->fb_set_par
+ * @info: fbdev registered by the helper.
+ *
+ * This will let fbcon do the mode init and is called at initialization time by
+ * the fbdev core when registering the driver, and later on through the hotplug
+ * callback.
+ */
int drm_fb_helper_set_par(struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
@@ -715,6 +773,11 @@ int drm_fb_helper_set_par(struct fb_info *info)
}
EXPORT_SYMBOL(drm_fb_helper_set_par);
+/**
+ * drm_fb_helper_pan_display - implementation for ->fb_pan_display
+ * @var: updated screen information
+ * @info: fbdev registered by the helper.
+ */
int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
@@ -876,6 +939,12 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
return 0;
}
+/**
+ * drm_fb_helper_fill_fix - implementation for ->fb_fill_fix
+ * @info: fbdev registered by the helper.
+ * @pitch: desired pitch
+ * @depth: desired depth
+ */
void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
uint32_t depth)
{
@@ -896,6 +965,12 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
}
EXPORT_SYMBOL(drm_fb_helper_fill_fix);
+/**
+ * drm_fb_helper_fill_var - implementation for ->fb_fill_var
+ * @info: fbdev registered by the helper.
+ * @fb_width: desired fb width
+ * @fb_height: desired fb height
+ */
void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
uint32_t fb_width, uint32_t fb_height)
{
@@ -1358,18 +1433,17 @@ out:
}
/**
- * drm_helper_initial_config - setup a sane initial connector configuration
+ * drm_fb_helper_initial_config - setup a sane initial connector configuration
* @fb_helper: fb_helper device struct
* @bpp_sel: bpp value to use for the framebuffer configuration
*
- * LOCKING:
- * Called at init time by the driver to set up the @fb_helper initial
- * configuration, must take the mode config lock.
- *
* Scans the CRTCs and connectors and tries to put together an initial setup.
* At the moment, this is a cloned configuration across all heads with
* a new framebuffer object as the backing store.
*
+ * Note that this also registers the fbdev and so allows userspace to call into
+ * the driver through the fbdev interfaces.
+ *
* RETURNS:
* Zero if everything went ok, nonzero otherwise.
*/
@@ -1400,12 +1474,17 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
* probing all the outputs attached to the fb
* @fb_helper: the drm_fb_helper
*
- * LOCKING:
- * Called at runtime, must take mode config lock.
- *
* Scan the connectors attached to the fb_helper and try to put together a
* setup after *notification of a change in output configuration.
*
+ * Called at runtime, takes the mode config locks to be able to check/change the
+ * modeset configuration. Must be run from process context (which usually means
+ * either the output polling work or a work item launch from the driver's
+ * hotplug interrupt).
+ *
+ * Note that the driver must ensure that this is only called _after_ the fb has
+ * been fully set up, i.e. after the call to drm_fb_helper_initial_config.
+ *
* RETURNS:
* 0 on success and a non-zero error code otherwise.
*/
Now that the fbdev helper interface for drivers is trimmed down, update the kerneldoc for all the remaining exported functions. I've tried to beat the DocBook a bit by reordering the function references a bit into a more sensible ordering. But that didn't work out at all. Hence just extend the in-code DOC: section a bit. Also remove the LOCKING: sections - especially for the setup functions they're totally bogus. But that's not a documentation problem, but simply an artifact of the current rather hazardous locking around drm init and even more so around fbdev setup ... Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> --- drivers/gpu/drm/drm_fb_helper.c | 97 +++++++++++++++++++++++++++++++++++---- 1 file changed, 88 insertions(+), 9 deletions(-)