diff options
| -rw-r--r-- | Documentation/DocBook/drm.tmpl | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_fb_helper.c | 148 | ||||
| -rw-r--r-- | include/drm/drm_fb_helper.h | 12 |
3 files changed, 146 insertions, 15 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index b26de523ab70..51e1904ac4c7 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2143,6 +2143,7 @@ void intel_crt_init(struct drm_device *dev) <title>fbdev Helper Functions Reference</title> !Pdrivers/gpu/drm/drm_fb_helper.c fbdev helpers !Edrivers/gpu/drm/drm_fb_helper.c +!Iinclude/drm/drm_fb_helper.h </sect2> <sect2> <title>Display Port Helper Functions Reference</title> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index e0d4b04c0eb5..94f304d8b795 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -52,9 +52,36 @@ 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 three-step process with drm_fb_helper_init(), + * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config(). + * Drivers with fancier requirements than the default beheviour can override the + * second step with their own code. 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 + * should also notify the fb helper code from updates to the output + * configuration by calling drm_fb_helper_hotplug_event(). For easier + * integration with the output polling code in drm_crtc_helper.c the modeset + * code proves a ->output_poll_changed callback. + * + * 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 */ +/** + * drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev + * emulation helper + * @fb_helper: fbdev initialized with drm_fb_helper_init + * + * This functions adds all the available connectors for use with the given + * fb_helper. This is a separate step to allow drivers to freely assign + * connectors to the fbdev, e.g. if some are reserved for special purposes or + * not adequate to be used for the fbcon. + * + * Since this is part of the initial setup before the fbdev is published, no + * locking is required. + */ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) { struct drm_device *dev = fb_helper->dev; @@ -163,6 +190,10 @@ 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; @@ -208,6 +239,10 @@ 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; @@ -243,9 +278,9 @@ EXPORT_SYMBOL(drm_fb_helper_debug_leave); * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration * @fb_helper: fbcon to restore * - * This should be called from driver's drm->lastclose callback when implementing - * an fbcon on top of kms using this helper. This ensures that the user isn't - * greeted with a black screen when e.g. X dies. + * This should be called from driver's drm ->lastclose callback + * when implementing an fbcon on top of kms using this helper. This ensures that + * the user isn't greeted with a black screen when e.g. X dies. */ bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper) { @@ -381,6 +416,11 @@ 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) { @@ -424,6 +464,24 @@ 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: maximum number of crtcs to support in this fbdev emulation + * @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 hardware (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 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 +610,11 @@ 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 +654,11 @@ 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 + * @var: screeninfo to check + * @info: fbdev registered by the helper + */ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, struct fb_info *info) { @@ -683,7 +751,14 @@ 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 +790,11 @@ 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) { @@ -753,8 +833,9 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var, EXPORT_SYMBOL(drm_fb_helper_pan_display); /* - * Allocates the backing storage through the ->fb_probe callback and then - * registers the fbdev and sets up the panic notifier. + * Allocates the backing storage and sets up the fbdev info structure through + * the ->fb_probe callback and then registers the fbdev and sets up the panic + * notifier. */ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, int preferred_bpp) @@ -876,6 +957,19 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, return 0; } +/** + * drm_fb_helper_fill_fix - initializes fixed fbdev information + * @info: fbdev registered by the helper + * @pitch: desired pitch + * @depth: desired depth + * + * Helper to fill in the fixed fbdev information useful for a non-accelerated + * fbdev emulations. Drivers which support acceleration methods which impose + * additional constraints need to set up their own limits. + * + * Drivers should call this (or their equivalent setup code) from their + * ->fb_probe callback. + */ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch, uint32_t depth) { @@ -896,6 +990,20 @@ 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 - initalizes variable fbdev information + * @info: fbdev instance to set up + * @fb_helper: fb helper instance to use as template + * @fb_width: desired fb width + * @fb_height: desired fb height + * + * Sets up the variable fbdev metainformation from the given fb helper instance + * and the drm framebuffer allocated in fb_helper->fb. + * + * Drivers should call this (or their equivalent setup code) from their + * ->fb_probe callback after having allocated the fbdev backing + * storage framebuffer. + */ 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 +1466,23 @@ 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. + * + * This function will call down into the ->fb_probe callback to let + * the driver allocate and initialize the fbdev info structure and the drm + * framebuffer used to back the fbdev. drm_fb_helper_fill_var() and + * drm_fb_helper_fill_fix() are provided as helpers to setup simple default + * values for the fbdev info structure. + * * RETURNS: * Zero if everything went ok, nonzero otherwise. */ @@ -1400,12 +1513,17 @@ 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 launched 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. */ diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index 973402d6effe..31e5b97c2e89 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -48,6 +48,18 @@ struct drm_fb_helper_surface_size { 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. Futhermore it also needs to allocate the drm + * framebuffer used to back the fbdev. + * + * 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); |