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linux/drivers/gpu/drm/drm_fb_helper.c

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/*
* 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>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
MODULE_AUTHOR("David Airlie, Jesse Barnes");
MODULE_DESCRIPTION("DRM KMS helper");
MODULE_LICENSE("GPL and additional rights");
static LIST_HEAD(kernel_fb_helper_list);
/**
* DOC: fbdev helpers
*
* The fb helper functions are useful to provide an fbdev on top of a drm kernel
* 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.
*/
/**
* 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;
struct drm_connector *connector;
int i;
list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
struct drm_fb_helper_connector *fb_helper_connector;
fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
if (!fb_helper_connector)
goto fail;
fb_helper_connector->connector = connector;
fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
}
return 0;
fail:
for (i = 0; i < fb_helper->connector_count; i++) {
kfree(fb_helper->connector_info[i]);
fb_helper->connector_info[i] = NULL;
}
fb_helper->connector_count = 0;
return -ENOMEM;
}
EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
static int drm_fb_helper_parse_command_line(struct drm_fb_helper *fb_helper)
{
struct drm_fb_helper_connector *fb_helper_conn;
int i;
for (i = 0; i < fb_helper->connector_count; i++) {
struct drm_cmdline_mode *mode;
struct drm_connector *connector;
char *option = NULL;
fb_helper_conn = fb_helper->connector_info[i];
connector = fb_helper_conn->connector;
mode = &fb_helper_conn->cmdline_mode;
/* do something on return - turn off connector maybe */
if (fb_get_options(drm_get_connector_name(connector), &option))
continue;
if (drm_mode_parse_command_line_for_connector(option,
connector,
mode)) {
if (mode->force) {
const char *s;
switch (mode->force) {
case DRM_FORCE_OFF:
s = "OFF";
break;
case DRM_FORCE_ON_DIGITAL:
s = "ON - dig";
break;
default:
case DRM_FORCE_ON:
s = "ON";
break;
}
DRM_INFO("forcing %s connector %s\n",
drm_get_connector_name(connector), s);
connector->force = mode->force;
}
DRM_DEBUG_KMS("cmdline mode for connector %s %dx%d@%dHz%s%s%s\n",
drm_get_connector_name(connector),
mode->xres, mode->yres,
mode->refresh_specified ? mode->refresh : 60,
mode->rb ? " reduced blanking" : "",
mode->margins ? " with margins" : "",
mode->interlace ? " interlaced" : "");
}
}
return 0;
}
static void drm_fb_helper_save_lut_atomic(struct drm_crtc *crtc, struct drm_fb_helper *helper)
{
uint16_t *r_base, *g_base, *b_base;
int i;
r_base = crtc->gamma_store;
g_base = r_base + crtc->gamma_size;
b_base = g_base + crtc->gamma_size;
for (i = 0; i < crtc->gamma_size; i++)
helper->funcs->gamma_get(crtc, &r_base[i], &g_base[i], &b_base[i], i);
}
static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
{
uint16_t *r_base, *g_base, *b_base;
if (crtc->funcs->gamma_set == NULL)
return;
r_base = crtc->gamma_store;
g_base = r_base + crtc->gamma_size;
b_base = g_base + crtc->gamma_size;
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;
struct drm_crtc_helper_funcs *funcs;
int i;
if (list_empty(&kernel_fb_helper_list))
return false;
list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
for (i = 0; i < helper->crtc_count; i++) {
struct drm_mode_set *mode_set =
&helper->crtc_info[i].mode_set;
if (!mode_set->crtc->enabled)
continue;
funcs = mode_set->crtc->helper_private;
drm_fb_helper_save_lut_atomic(mode_set->crtc, helper);
funcs->mode_set_base_atomic(mode_set->crtc,
mode_set->fb,
mode_set->x,
mode_set->y,
ENTER_ATOMIC_MODE_SET);
}
}
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_debug_enter);
/* Find the real fb for a given fb helper CRTC */
static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc)
{
struct drm_device *dev = crtc->dev;
struct drm_crtc *c;
list_for_each_entry(c, &dev->mode_config.crtc_list, head) {
if (crtc->base.id == c->base.id)
return c->fb;
}
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;
struct drm_crtc *crtc;
struct drm_crtc_helper_funcs *funcs;
struct drm_framebuffer *fb;
int i;
for (i = 0; i < helper->crtc_count; i++) {
struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set;
crtc = mode_set->crtc;
funcs = crtc->helper_private;
fb = drm_mode_config_fb(crtc);
if (!crtc->enabled)
continue;
if (!fb) {
DRM_ERROR("no fb to restore??\n");
continue;
}
drm_fb_helper_restore_lut_atomic(mode_set->crtc);
funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
crtc->y, LEAVE_ATOMIC_MODE_SET);
}
return 0;
}
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.
*/
bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
{
bool error = false;
int i, ret;
drm_warn_on_modeset_not_all_locked(fb_helper->dev);
for (i = 0; i < fb_helper->crtc_count; i++) {
struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
ret = drm_mode_set_config_internal(mode_set);
if (ret)
error = true;
}
return error;
}
EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);
/*
* restore fbcon display for all kms driver's using this helper, used for sysrq
* and panic handling.
*/
static bool drm_fb_helper_force_kernel_mode(void)
{
bool ret, error = false;
struct drm_fb_helper *helper;
if (list_empty(&kernel_fb_helper_list))
return false;
list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
if (helper->dev->switch_power_state == DRM_SWITCH_POWER_OFF)
continue;
ret = drm_fb_helper_restore_fbdev_mode(helper);
if (ret)
error = true;
}
return error;
}
static int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed,
void *panic_str)
{
/*
* It's a waste of time and effort to switch back to text console
* if the kernel should reboot before panic messages can be seen.
*/
if (panic_timeout < 0)
return 0;
pr_err("panic occurred, switching back to text console\n");
return drm_fb_helper_force_kernel_mode();
}
static struct notifier_block paniced = {
.notifier_call = drm_fb_helper_panic,
};
static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
{
struct drm_device *dev = fb_helper->dev;
struct drm_crtc *crtc;
int bound = 0, crtcs_bound = 0;
list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
if (crtc->fb)
crtcs_bound++;
if (crtc->fb == fb_helper->fb)
bound++;
}
if (bound < crtcs_bound)
return false;
return true;
}
#ifdef CONFIG_MAGIC_SYSRQ
static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
{
bool ret;
ret = drm_fb_helper_force_kernel_mode();
if (ret == true)
DRM_ERROR("Failed to restore crtc configuration\n");
}
static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
static void drm_fb_helper_sysrq(int dummy1)
{
schedule_work(&drm_fb_helper_restore_work);
}
static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
.handler = drm_fb_helper_sysrq,
.help_msg = "force-fb(V)",
.action_msg = "Restore framebuffer console",
};
#else
static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
#endif
static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
{
struct drm_fb_helper *fb_helper = info->par;
struct drm_device *dev = fb_helper->dev;
struct drm_crtc *crtc;
struct drm_connector *connector;
int i, j;
/*
* fbdev->blank can be called from irq context in case of a panic.
* Since we already have our own special panic handler which will
* restore the fbdev console mode completely, just bail out early.
*/
if (oops_in_progress)
return;
/*
* For each CRTC in this fb, turn the connectors on/off.
*/
drm_modeset_lock_all(dev);
if (!drm_fb_helper_is_bound(fb_helper)) {
drm_modeset_unlock_all(dev);
return;
}
for (i = 0; i < fb_helper->crtc_count; i++) {
crtc = fb_helper->crtc_info[i].mode_set.crtc;
if (!crtc->enabled)
continue;
/* Walk the connectors & encoders on this fb turning them on/off */
for (j = 0; j < fb_helper->connector_count; j++) {
connector = fb_helper->connector_info[j]->connector;
connector->funcs->dpms(connector, dpms_mode);
drm_object_property_set_value(&connector->base,
dev->mode_config.dpms_property, 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) {
/* Display: On; HSync: On, VSync: On */
case FB_BLANK_UNBLANK:
drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
break;
/* Display: Off; HSync: On, VSync: On */
case FB_BLANK_NORMAL:
drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
break;
/* Display: Off; HSync: Off, VSync: On */
case FB_BLANK_HSYNC_SUSPEND:
drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
break;
/* Display: Off; HSync: On, VSync: Off */
case FB_BLANK_VSYNC_SUSPEND:
drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
break;
/* Display: Off; HSync: Off, VSync: Off */
case FB_BLANK_POWERDOWN:
drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
break;
}
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_blank);
static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
{
int i;
for (i = 0; i < helper->connector_count; i++)
kfree(helper->connector_info[i]);
kfree(helper->connector_info);
for (i = 0; i < helper->crtc_count; i++) {
kfree(helper->crtc_info[i].mode_set.connectors);
if (helper->crtc_info[i].mode_set.mode)
drm_mode_destroy(helper->dev, helper->crtc_info[i].mode_set.mode);
}
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)
{
struct drm_crtc *crtc;
int i;
fb_helper->dev = dev;
INIT_LIST_HEAD(&fb_helper->kernel_fb_list);
fb_helper->crtc_info = kcalloc(crtc_count, sizeof(struct drm_fb_helper_crtc), GFP_KERNEL);
if (!fb_helper->crtc_info)
return -ENOMEM;
fb_helper->crtc_count = crtc_count;
fb_helper->connector_info = kcalloc(dev->mode_config.num_connector, sizeof(struct drm_fb_helper_connector *), GFP_KERNEL);
if (!fb_helper->connector_info) {
kfree(fb_helper->crtc_info);
return -ENOMEM;
}
fb_helper->connector_count = 0;
for (i = 0; i < crtc_count; i++) {
fb_helper->crtc_info[i].mode_set.connectors =
kcalloc(max_conn_count,
sizeof(struct drm_connector *),
GFP_KERNEL);
if (!fb_helper->crtc_info[i].mode_set.connectors)
goto out_free;
fb_helper->crtc_info[i].mode_set.num_connectors = 0;
}
i = 0;
list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
fb_helper->crtc_info[i].mode_set.crtc = crtc;
i++;
}
return 0;
out_free:
drm_fb_helper_crtc_free(fb_helper);
return -ENOMEM;
}
EXPORT_SYMBOL(drm_fb_helper_init);
void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
{
if (!list_empty(&fb_helper->kernel_fb_list)) {
list_del(&fb_helper->kernel_fb_list);
if (list_empty(&kernel_fb_helper_list)) {
pr_info("drm: unregistered panic notifier\n");
atomic_notifier_chain_unregister(&panic_notifier_list,
&paniced);
unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
}
}
drm_fb_helper_crtc_free(fb_helper);
}
EXPORT_SYMBOL(drm_fb_helper_fini);
static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
u16 blue, u16 regno, struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
struct drm_framebuffer *fb = fb_helper->fb;
int pindex;
if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
u32 *palette;
u32 value;
/* place color in psuedopalette */
if (regno > 16)
return -EINVAL;
palette = (u32 *)info->pseudo_palette;
red >>= (16 - info->var.red.length);
green >>= (16 - info->var.green.length);
blue >>= (16 - info->var.blue.length);
value = (red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset);
if (info->var.transp.length > 0) {
u32 mask = (1 << info->var.transp.length) - 1;
mask <<= info->var.transp.offset;
value |= mask;
}
palette[regno] = value;
return 0;
}
pindex = regno;
if (fb->bits_per_pixel == 16) {
pindex = regno << 3;
if (fb->depth == 16 && regno > 63)
return -EINVAL;
if (fb->depth == 15 && regno > 31)
return -EINVAL;
if (fb->depth == 16) {
u16 r, g, b;
int i;
if (regno < 32) {
for (i = 0; i < 8; i++)
fb_helper->funcs->gamma_set(crtc, red,
green, blue, pindex + i);
}
fb_helper->funcs->gamma_get(crtc, &r,
&g, &b,
pindex >> 1);
for (i = 0; i < 4; i++)
fb_helper->funcs->gamma_set(crtc, r,
green, b,
(pindex >> 1) + i);
}
}
if (fb->depth != 16)
fb_helper->funcs->gamma_set(crtc, red, green, blue, pindex);
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;
struct drm_crtc_helper_funcs *crtc_funcs;
u16 *red, *green, *blue, *transp;
struct drm_crtc *crtc;
int i, j, rc = 0;
int start;
for (i = 0; i < fb_helper->crtc_count; i++) {
crtc = fb_helper->crtc_info[i].mode_set.crtc;
crtc_funcs = crtc->helper_private;
red = cmap->red;
green = cmap->green;
blue = cmap->blue;
transp = cmap->transp;
start = cmap->start;
for (j = 0; j < cmap->len; j++) {
u16 hred, hgreen, hblue, htransp = 0xffff;
hred = *red++;
hgreen = *green++;
hblue = *blue++;
if (transp)
htransp = *transp++;
rc = setcolreg(crtc, hred, hgreen, hblue, start++, info);
if (rc)
return rc;
}
crtc_funcs->load_lut(crtc);
}
return rc;
}
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)
{
struct drm_fb_helper *fb_helper = info->par;
struct drm_framebuffer *fb = fb_helper->fb;
int depth;
if (var->pixclock != 0 || in_dbg_master())
return -EINVAL;
/* Need to resize the fb object !!! */
if (var->bits_per_pixel > fb->bits_per_pixel ||
var->xres > fb->width || var->yres > fb->height ||
var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
DRM_DEBUG("fb userspace requested width/height/bpp is greater than current fb "
"request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
var->xres, var->yres, var->bits_per_pixel,
var->xres_virtual, var->yres_virtual,
fb->width, fb->height, fb->bits_per_pixel);
return -EINVAL;
}
switch (var->bits_per_pixel) {
case 16:
depth = (var->green.length == 6) ? 16 : 15;
break;
case 32:
depth = (var->transp.length > 0) ? 32 : 24;
break;
default:
depth = var->bits_per_pixel;
break;
}
switch (depth) {
case 8:
var->red.offset = 0;
var->green.offset = 0;
var->blue.offset = 0;
var->red.length = 8;
var->green.length = 8;
var->blue.length = 8;
var->transp.length = 0;
var->transp.offset = 0;
break;
case 15:
var->red.offset = 10;
var->green.offset = 5;
var->blue.offset = 0;
var->red.length = 5;
var->green.length = 5;
var->blue.length = 5;
var->transp.length = 1;
var->transp.offset = 15;
break;
case 16:
var->red.offset = 11;
var->green.offset = 5;
var->blue.offset = 0;
var->red.length = 5;
var->green.length = 6;
var->blue.length = 5;
var->transp.length = 0;
var->transp.offset = 0;
break;
case 24:
var->red.offset = 16;
var->green.offset = 8;
var->blue.offset = 0;
var->red.length = 8;
var->green.length = 8;
var->blue.length = 8;
var->transp.length = 0;
var->transp.offset = 0;
break;
case 32:
var->red.offset = 16;
var->green.offset = 8;
var->blue.offset = 0;
var->red.length = 8;
var->green.length = 8;
var->blue.length = 8;
var->transp.length = 8;
var->transp.offset = 24;
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_check_var);
/**
* 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;
struct drm_device *dev = fb_helper->dev;
struct fb_var_screeninfo *var = &info->var;
int ret;
int i;
if (var->pixclock != 0) {
DRM_ERROR("PIXEL CLOCK SET\n");
return -EINVAL;
}
drm_modeset_lock_all(dev);
for (i = 0; i < fb_helper->crtc_count; i++) {
ret = drm_mode_set_config_internal(&fb_helper->crtc_info[i].mode_set);
if (ret) {
drm_modeset_unlock_all(dev);
return ret;
}
}
drm_modeset_unlock_all(dev);
if (fb_helper->delayed_hotplug) {
fb_helper->delayed_hotplug = false;
drm_fb_helper_hotplug_event(fb_helper);
}
return 0;
}
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)
{
struct drm_fb_helper *fb_helper = info->par;
struct drm_device *dev = fb_helper->dev;
struct drm_mode_set *modeset;
struct drm_crtc *crtc;
int ret = 0;
int i;
drm_modeset_lock_all(dev);
if (!drm_fb_helper_is_bound(fb_helper)) {
drm_modeset_unlock_all(dev);
return -EBUSY;
}
for (i = 0; i < fb_helper->crtc_count; i++) {
crtc = fb_helper->crtc_info[i].mode_set.crtc;
modeset = &fb_helper->crtc_info[i].mode_set;
modeset->x = var->xoffset;
modeset->y = var->yoffset;
if (modeset->num_connectors) {
ret = drm_mode_set_config_internal(modeset);
if (!ret) {
info->var.xoffset = var->xoffset;
info->var.yoffset = var->yoffset;
}
}
}
drm_modeset_unlock_all(dev);
return ret;
}
EXPORT_SYMBOL(drm_fb_helper_pan_display);
/*
* 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)
{
int ret = 0;
int crtc_count = 0;
int i;
struct fb_info *info;
struct drm_fb_helper_surface_size sizes;
int gamma_size = 0;
memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
sizes.surface_depth = 24;
sizes.surface_bpp = 32;
sizes.fb_width = (unsigned)-1;
sizes.fb_height = (unsigned)-1;
/* if driver picks 8 or 16 by default use that
for both depth/bpp */
if (preferred_bpp != sizes.surface_bpp)
sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
/* first up get a count of crtcs now in use and new min/maxes width/heights */
for (i = 0; i < fb_helper->connector_count; i++) {
struct drm_fb_helper_connector *fb_helper_conn = fb_helper->connector_info[i];
struct drm_cmdline_mode *cmdline_mode;
cmdline_mode = &fb_helper_conn->cmdline_mode;
if (cmdline_mode->bpp_specified) {
switch (cmdline_mode->bpp) {
case 8:
sizes.surface_depth = sizes.surface_bpp = 8;
break;
case 15:
sizes.surface_depth = 15;
sizes.surface_bpp = 16;
break;
case 16:
sizes.surface_depth = sizes.surface_bpp = 16;
break;
case 24:
sizes.surface_depth = sizes.surface_bpp = 24;
break;
case 32:
sizes.surface_depth = 24;
sizes.surface_bpp = 32;
break;
}
break;
}
}
crtc_count = 0;
for (i = 0; i < fb_helper->crtc_count; i++) {
struct drm_display_mode *desired_mode;
desired_mode = fb_helper->crtc_info[i].desired_mode;
if (desired_mode) {
if (gamma_size == 0)
gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size;
if (desired_mode->hdisplay < sizes.fb_width)
sizes.fb_width = desired_mode->hdisplay;
if (desired_mode->vdisplay < sizes.fb_height)
sizes.fb_height = desired_mode->vdisplay;
if (desired_mode->hdisplay > sizes.surface_width)
sizes.surface_width = desired_mode->hdisplay;
if (desired_mode->vdisplay > sizes.surface_height)
sizes.surface_height = desired_mode->vdisplay;
crtc_count++;
}
}
if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
/* hmm everyone went away - assume VGA cable just fell out
and will come back later. */
DRM_INFO("Cannot find any crtc or sizes - going 1024x768\n");
sizes.fb_width = sizes.surface_width = 1024;
sizes.fb_height = sizes.surface_height = 768;
}
/* push down into drivers */
ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
if (ret < 0)
return ret;
info = fb_helper->fbdev;
/*
* Set the fb pointer - usually drm_setup_crtcs does this for hotplug
* events, but at init time drm_setup_crtcs needs to be called before
* the fb is allocated (since we need to figure out the desired size of
* the fb before we can allocate it ...). Hence we need to fix things up
* here again.
*/
for (i = 0; i < fb_helper->crtc_count; i++)
if (fb_helper->crtc_info[i].mode_set.num_connectors)
fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
info->var.pixclock = 0;
if (register_framebuffer(info) < 0)
return -EINVAL;
dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
info->node, info->fix.id);
/* Switch back to kernel console on panic */
/* multi card linked list maybe */
if (list_empty(&kernel_fb_helper_list)) {
dev_info(fb_helper->dev->dev, "registered panic notifier\n");
atomic_notifier_chain_register(&panic_notifier_list,
&paniced);
register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
}
list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
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)
{
info->fix.type = FB_TYPE_PACKED_PIXELS;
info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
FB_VISUAL_TRUECOLOR;
info->fix.mmio_start = 0;
info->fix.mmio_len = 0;
info->fix.type_aux = 0;
info->fix.xpanstep = 1; /* doing it in hw */
info->fix.ypanstep = 1; /* doing it in hw */
info->fix.ywrapstep = 0;
info->fix.accel = FB_ACCEL_NONE;
info->fix.type_aux = 0;
info->fix.line_length = pitch;
return;
}
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)
{
struct drm_framebuffer *fb = fb_helper->fb;
info->pseudo_palette = fb_helper->pseudo_palette;
info->var.xres_virtual = fb->width;
info->var.yres_virtual = fb->height;
info->var.bits_per_pixel = fb->bits_per_pixel;
info->var.accel_flags = FB_ACCELF_TEXT;
info->var.xoffset = 0;
info->var.yoffset = 0;
info->var.activate = FB_ACTIVATE_NOW;
info->var.height = -1;
info->var.width = -1;
switch (fb->depth) {
case 8:
info->var.red.offset = 0;
info->var.green.offset = 0;
info->var.blue.offset = 0;
info->var.red.length = 8; /* 8bit DAC */
info->var.green.length = 8;
info->var.blue.length = 8;
info->var.transp.offset = 0;
info->var.transp.length = 0;
break;
case 15:
info->var.red.offset = 10;
info->var.green.offset = 5;
info->var.blue.offset = 0;
info->var.red.length = 5;
info->var.green.length = 5;
info->var.blue.length = 5;
info->var.transp.offset = 15;
info->var.transp.length = 1;
break;
case 16:
info->var.red.offset = 11;
info->var.green.offset = 5;
info->var.blue.offset = 0;
info->var.red.length = 5;
info->var.green.length = 6;
info->var.blue.length = 5;
info->var.transp.offset = 0;
break;
case 24:
info->var.red.offset = 16;
info->var.green.offset = 8;
info->var.blue.offset = 0;
info->var.red.length = 8;
info->var.green.length = 8;
info->var.blue.length = 8;
info->var.transp.offset = 0;
info->var.transp.length = 0;
break;
case 32:
info->var.red.offset = 16;
info->var.green.offset = 8;
info->var.blue.offset = 0;
info->var.red.length = 8;
info->var.green.length = 8;
info->var.blue.length = 8;
info->var.transp.offset = 24;
info->var.transp.length = 8;
break;
default:
break;
}
info->var.xres = fb_width;
info->var.yres = fb_height;
}
EXPORT_SYMBOL(drm_fb_helper_fill_var);
static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper,
uint32_t maxX,
uint32_t maxY)
{
struct drm_connector *connector;
int count = 0;
int i;
for (i = 0; i < fb_helper->connector_count; i++) {
connector = fb_helper->connector_info[i]->connector;
count += connector->funcs->fill_modes(connector, maxX, maxY);
}
return count;
}
static struct drm_display_mode *drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector, int width, int height)
{
struct drm_display_mode *mode;
list_for_each_entry(mode, &fb_connector->connector->modes, head) {
if (drm_mode_width(mode) > width ||
drm_mode_height(mode) > height)
continue;
if (mode->type & DRM_MODE_TYPE_PREFERRED)
return mode;
}
return NULL;
}
static bool drm_has_cmdline_mode(struct drm_fb_helper_connector *fb_connector)
{
struct drm_cmdline_mode *cmdline_mode;
cmdline_mode = &fb_connector->cmdline_mode;
return cmdline_mode->specified;
}
static struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
int width, int height)
{
struct drm_cmdline_mode *cmdline_mode;
struct drm_display_mode *mode = NULL;
cmdline_mode = &fb_helper_conn->cmdline_mode;
if (cmdline_mode->specified == false)
return mode;
/* attempt to find a matching mode in the list of modes
* we have gotten so far, if not add a CVT mode that conforms
*/
if (cmdline_mode->rb || cmdline_mode->margins)
goto create_mode;
list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
/* check width/height */
if (mode->hdisplay != cmdline_mode->xres ||
mode->vdisplay != cmdline_mode->yres)
continue;
if (cmdline_mode->refresh_specified) {
if (mode->vrefresh != cmdline_mode->refresh)
continue;
}
if (cmdline_mode->interlace) {
if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
continue;
}
return mode;
}
create_mode:
mode = drm_mode_create_from_cmdline_mode(fb_helper_conn->connector->dev,
cmdline_mode);
list_add(&mode->head, &fb_helper_conn->connector->modes);
return mode;
}
static bool drm_connector_enabled(struct drm_connector *connector, bool strict)
{
bool enable;
if (strict)
enable = connector->status == connector_status_connected;
else
enable = connector->status != connector_status_disconnected;
return enable;
}
static void drm_enable_connectors(struct drm_fb_helper *fb_helper,
bool *enabled)
{
bool any_enabled = false;
struct drm_connector *connector;
int i = 0;
for (i = 0; i < fb_helper->connector_count; i++) {
connector = fb_helper->connector_info[i]->connector;
enabled[i] = drm_connector_enabled(connector, true);
DRM_DEBUG_KMS("connector %d enabled? %s\n", connector->base.id,
enabled[i] ? "yes" : "no");
any_enabled |= enabled[i];
}
if (any_enabled)
return;
for (i = 0; i < fb_helper->connector_count; i++) {
connector = fb_helper->connector_info[i]->connector;
enabled[i] = drm_connector_enabled(connector, false);
}
}
static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
struct drm_display_mode **modes,
bool *enabled, int width, int height)
{
int count, i, j;
bool can_clone = false;
struct drm_fb_helper_connector *fb_helper_conn;
struct drm_display_mode *dmt_mode, *mode;
/* only contemplate cloning in the single crtc case */
if (fb_helper->crtc_count > 1)
return false;
count = 0;
for (i = 0; i < fb_helper->connector_count; i++) {
if (enabled[i])
count++;
}
/* only contemplate cloning if more than one connector is enabled */
if (count <= 1)
return false;
/* check the command line or if nothing common pick 1024x768 */
can_clone = true;
for (i = 0; i < fb_helper->connector_count; i++) {
if (!enabled[i])
continue;
fb_helper_conn = fb_helper->connector_info[i];
modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
if (!modes[i]) {
can_clone = false;
break;
}
for (j = 0; j < i; j++) {
if (!enabled[j])
continue;
if (!drm_mode_equal(modes[j], modes[i]))
can_clone = false;
}
}
if (can_clone) {
DRM_DEBUG_KMS("can clone using command line\n");
return true;
}
/* try and find a 1024x768 mode on each connector */
can_clone = true;
dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60, false);
for (i = 0; i < fb_helper->connector_count; i++) {
if (!enabled[i])
continue;
fb_helper_conn = fb_helper->connector_info[i];
list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
if (drm_mode_equal(mode, dmt_mode))
modes[i] = mode;
}
if (!modes[i])
can_clone = false;
}
if (can_clone) {
DRM_DEBUG_KMS("can clone using 1024x768\n");
return true;
}
DRM_INFO("kms: can't enable cloning when we probably wanted to.\n");
return false;
}
static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
struct drm_display_mode **modes,
bool *enabled, int width, int height)
{
struct drm_fb_helper_connector *fb_helper_conn;
int i;
for (i = 0; i < fb_helper->connector_count; i++) {
fb_helper_conn = fb_helper->connector_info[i];
if (enabled[i] == false)
continue;
DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
fb_helper_conn->connector->base.id);
/* got for command line mode first */
modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
if (!modes[i]) {
DRM_DEBUG_KMS("looking for preferred mode on connector %d\n",
fb_helper_conn->connector->base.id);
modes[i] = drm_has_preferred_mode(fb_helper_conn, width, height);
}
/* No preferred modes, pick one off the list */
if (!modes[i] && !list_empty(&fb_helper_conn->connector->modes)) {
list_for_each_entry(modes[i], &fb_helper_conn->connector->modes, head)
break;
}
DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
"none");
}
return true;
}
static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
struct drm_fb_helper_crtc **best_crtcs,
struct drm_display_mode **modes,
int n, int width, int height)
{
int c, o;
struct drm_device *dev = fb_helper->dev;
struct drm_connector *connector;
struct drm_connector_helper_funcs *connector_funcs;
struct drm_encoder *encoder;
struct drm_fb_helper_crtc *best_crtc;
int my_score, best_score, score;
struct drm_fb_helper_crtc **crtcs, *crtc;
struct drm_fb_helper_connector *fb_helper_conn;
if (n == fb_helper->connector_count)
return 0;
fb_helper_conn = fb_helper->connector_info[n];
connector = fb_helper_conn->connector;
best_crtcs[n] = NULL;
best_crtc = NULL;
best_score = drm_pick_crtcs(fb_helper, best_crtcs, modes, n+1, width, height);
if (modes[n] == NULL)
return best_score;
crtcs = kzalloc(dev->mode_config.num_connector *
sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
if (!crtcs)
return best_score;
my_score = 1;
if (connector->status == connector_status_connected)
my_score++;
if (drm_has_cmdline_mode(fb_helper_conn))
my_score++;
if (drm_has_preferred_mode(fb_helper_conn, width, height))
my_score++;
connector_funcs = connector->helper_private;
encoder = connector_funcs->best_encoder(connector);
if (!encoder)
goto out;
/* select a crtc for this connector and then attempt to configure
remaining connectors */
for (c = 0; c < fb_helper->crtc_count; c++) {
crtc = &fb_helper->crtc_info[c];
if ((encoder->possible_crtcs & (1 << c)) == 0)
continue;
for (o = 0; o < n; o++)
if (best_crtcs[o] == crtc)
break;
if (o < n) {
/* ignore cloning unless only a single crtc */
if (fb_helper->crtc_count > 1)
continue;
if (!drm_mode_equal(modes[o], modes[n]))
continue;
}
crtcs[n] = crtc;
memcpy(crtcs, best_crtcs, n * sizeof(struct drm_fb_helper_crtc *));
score = my_score + drm_pick_crtcs(fb_helper, crtcs, modes, n + 1,
width, height);
if (score > best_score) {
best_crtc = crtc;
best_score = score;
memcpy(best_crtcs, crtcs,
dev->mode_config.num_connector *
sizeof(struct drm_fb_helper_crtc *));
}
}
out:
kfree(crtcs);
return best_score;
}
static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
{
struct drm_device *dev = fb_helper->dev;
struct drm_fb_helper_crtc **crtcs;
struct drm_display_mode **modes;
struct drm_mode_set *modeset;
bool *enabled;
int width, height;
int i, ret;
DRM_DEBUG_KMS("\n");
width = dev->mode_config.max_width;
height = dev->mode_config.max_height;
crtcs = kcalloc(dev->mode_config.num_connector,
sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
modes = kcalloc(dev->mode_config.num_connector,
sizeof(struct drm_display_mode *), GFP_KERNEL);
enabled = kcalloc(dev->mode_config.num_connector,
sizeof(bool), GFP_KERNEL);
if (!crtcs || !modes || !enabled) {
DRM_ERROR("Memory allocation failed\n");
goto out;
}
drm_enable_connectors(fb_helper, enabled);
ret = drm_target_cloned(fb_helper, modes, enabled, width, height);
if (!ret) {
ret = drm_target_preferred(fb_helper, modes, enabled, width, height);
if (!ret)
DRM_ERROR("Unable to find initial modes\n");
}
DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n", width, height);
drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height);
/* need to set the modesets up here for use later */
/* fill out the connector<->crtc mappings into the modesets */
for (i = 0; i < fb_helper->crtc_count; i++) {
modeset = &fb_helper->crtc_info[i].mode_set;
modeset->num_connectors = 0;
modeset->fb = NULL;
}
for (i = 0; i < fb_helper->connector_count; i++) {
struct drm_display_mode *mode = modes[i];
struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
modeset = &fb_crtc->mode_set;
if (mode && fb_crtc) {
DRM_DEBUG_KMS("desired mode %s set on crtc %d\n",
mode->name, fb_crtc->mode_set.crtc->base.id);
fb_crtc->desired_mode = mode;
if (modeset->mode)
drm_mode_destroy(dev, modeset->mode);
modeset->mode = drm_mode_duplicate(dev,
fb_crtc->desired_mode);
modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;
modeset->fb = fb_helper->fb;
}
}
/* Clear out any old modes if there are no more connected outputs. */
for (i = 0; i < fb_helper->crtc_count; i++) {
modeset = &fb_helper->crtc_info[i].mode_set;
if (modeset->num_connectors == 0) {
BUG_ON(modeset->fb);
BUG_ON(modeset->num_connectors);
if (modeset->mode)
drm_mode_destroy(dev, modeset->mode);
modeset->mode = NULL;
}
}
out:
kfree(crtcs);
kfree(modes);
kfree(enabled);
}
/**
* 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
*
* 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.
*/
bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
{
struct drm_device *dev = fb_helper->dev;
int count = 0;
drm_fb_helper_parse_command_line(fb_helper);
count = drm_fb_helper_probe_connector_modes(fb_helper,
dev->mode_config.max_width,
dev->mode_config.max_height);
/*
* we shouldn't end up with no modes here.
*/
if (count == 0)
dev_info(fb_helper->dev->dev, "No connectors reported connected with modes\n");
drm_setup_crtcs(fb_helper);
return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
}
EXPORT_SYMBOL(drm_fb_helper_initial_config);
/**
* drm_fb_helper_hotplug_event - respond to a hotplug notification by
* probing all the outputs attached to the fb
* @fb_helper: the drm_fb_helper
*
* 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.
*/
int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
{
struct drm_device *dev = fb_helper->dev;
int count = 0;
u32 max_width, max_height, bpp_sel;
if (!fb_helper->fb)
return 0;
drm_modeset_lock_all(dev);
if (!drm_fb_helper_is_bound(fb_helper)) {
fb_helper->delayed_hotplug = true;
drm_modeset_unlock_all(dev);
return 0;
}
DRM_DEBUG_KMS("\n");
max_width = fb_helper->fb->width;
max_height = fb_helper->fb->height;
bpp_sel = fb_helper->fb->bits_per_pixel;
count = drm_fb_helper_probe_connector_modes(fb_helper, max_width,
max_height);
drm_setup_crtcs(fb_helper);
drm_modeset_unlock_all(dev);
drm_fb_helper_set_par(fb_helper->fbdev);
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
* but the module doesn't depend on any fb console symbols. At least
* attempt to load fbcon to avoid leaving the system without a usable console.
*/
#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
static int __init drm_fb_helper_modinit(void)
{
const char *name = "fbcon";
struct module *fbcon;
mutex_lock(&module_mutex);
fbcon = find_module(name);
mutex_unlock(&module_mutex);
if (!fbcon)
request_module_nowait(name);
return 0;
}
module_init(drm_fb_helper_modinit);
#endif
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