drivers/gpu/drm/omapdrm/omap_fbdev.c

   1 /*
   2  * drivers/gpu/drm/omapdrm/omap_fbdev.c
   3  *
   4  * Copyright (C) 2011 Texas Instruments
   5  * Author: Rob Clark <rob@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <drm/drm_crtc.h>
  21 #include <drm/drm_fb_helper.h>
  22
  23 #include "omap_drv.h"
  24
  25 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
  26 static bool ywrap_enabled = true;
  27 module_param_named(ywrap, ywrap_enabled, bool, 0644);
  28
  29 /*
  30  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
  31  */
  32
  33 #define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
  34
  35 struct omap_fbdev {
  36         struct drm_fb_helper base;
  37         struct drm_framebuffer *fb;
  38         struct drm_gem_object *bo;
  39         bool ywrap_enabled;
  40
  41         /* for deferred dmm roll when getting called in atomic ctx */
  42         struct work_struct work;
  43 };
  44
  45 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
  46
  47 static void pan_worker(struct work_struct *work)
  48 {
  49         struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
  50         struct fb_info *fbi = fbdev->base.fbdev;
  51         int npages;
  52
  53         /* DMM roll shifts in 4K pages: */
  54         npages = fbi->fix.line_length >> PAGE_SHIFT;
  55         omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
  56 }
  57
  58 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
  59                 struct fb_info *fbi)
  60 {
  61         struct drm_fb_helper *helper = get_fb(fbi);
  62         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
  63
  64         if (!helper)
  65                 goto fallback;
  66
  67         if (!fbdev->ywrap_enabled)
  68                 goto fallback;
  69
  70         if (drm_can_sleep()) {
  71                 pan_worker(&fbdev->work);
  72         } else {
  73                 struct omap_drm_private *priv = helper->dev->dev_private;
  74                 queue_work(priv->wq, &fbdev->work);
  75         }
  76
  77         return 0;
  78
  79 fallback:
  80         return drm_fb_helper_pan_display(var, fbi);
  81 }
  82
  83 static struct fb_ops omap_fb_ops = {
  84         .owner = THIS_MODULE,
  85         DRM_FB_HELPER_DEFAULT_OPS,
  86
  87         /* Note: to properly handle manual update displays, we wrap the
  88          * basic fbdev ops which write to the framebuffer
  89          */
  90         .fb_read = drm_fb_helper_sys_read,
  91         .fb_write = drm_fb_helper_sys_write,
  92         .fb_fillrect = drm_fb_helper_sys_fillrect,
  93         .fb_copyarea = drm_fb_helper_sys_copyarea,
  94         .fb_imageblit = drm_fb_helper_sys_imageblit,
  95
  96         .fb_pan_display = omap_fbdev_pan_display,
  97 };
  98
  99 static int omap_fbdev_create(struct drm_fb_helper *helper,
 100                 struct drm_fb_helper_surface_size *sizes)
 101 {
 102         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 103         struct drm_device *dev = helper->dev;
 104         struct omap_drm_private *priv = dev->dev_private;
 105         struct drm_framebuffer *fb = NULL;
 106         union omap_gem_size gsize;
 107         struct fb_info *fbi = NULL;
 108         struct drm_mode_fb_cmd2 mode_cmd = {0};
 109         dma_addr_t paddr;
 110         int ret;
 111
 112         sizes->surface_bpp = 32;
 113         sizes->surface_depth = 24;
 114
 115         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 116                         sizes->surface_height, sizes->surface_bpp,
 117                         sizes->fb_width, sizes->fb_height);
 118
 119         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 120                         sizes->surface_depth);
 121
 122         mode_cmd.width = sizes->surface_width;
 123         mode_cmd.height = sizes->surface_height;
 124
 125         mode_cmd.pitches[0] =
 126                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 127
 128         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 129         if (fbdev->ywrap_enabled) {
 130                 /* need to align pitch to page size if using DMM scrolling */
 131                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 132         }
 133
 134         /* allocate backing bo */
 135         gsize = (union omap_gem_size){
 136                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 137         };
 138         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 139         fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 140         if (!fbdev->bo) {
 141                 dev_err(dev->dev, "failed to allocate buffer object\n");
 142                 ret = -ENOMEM;
 143                 goto fail;
 144         }
 145
 146         fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
 147         if (IS_ERR(fb)) {
 148                 dev_err(dev->dev, "failed to allocate fb\n");
 149                 /* note: if fb creation failed, we can't rely on fb destroy
 150                  * to unref the bo:
 151                  */
 152                 drm_gem_object_unreference_unlocked(fbdev->bo);
 153                 ret = PTR_ERR(fb);
 154                 goto fail;
 155         }
 156
 157         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 158          * but is needed as long as we use fb_mmap() to mmap to userspace
 159          * (since this happens using fix.smem_start).  Possibly we could
 160          * implement our own mmap using GEM mmap support to avoid this
 161          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 162          * to it).  Then we just need to be sure that we are able to re-
 163          * pin it in case of an opps.
 164          */
 165         ret = omap_gem_get_paddr(fbdev->bo, &paddr, true);
 166         if (ret) {
 167                 dev_err(dev->dev,
 168                         "could not map (paddr)!  Skipping framebuffer alloc\n");
 169                 ret = -ENOMEM;
 170                 goto fail;
 171         }
 172
 173         mutex_lock(&dev->struct_mutex);
 174
 175         fbi = drm_fb_helper_alloc_fbi(helper);
 176         if (IS_ERR(fbi)) {
 177                 dev_err(dev->dev, "failed to allocate fb info\n");
 178                 ret = PTR_ERR(fbi);
 179                 goto fail_unlock;
 180         }
 181
 182         DBG("fbi=%p, dev=%p", fbi, dev);
 183
 184         fbdev->fb = fb;
 185         helper->fb = fb;
 186
 187         fbi->par = helper;
 188         fbi->flags = FBINFO_DEFAULT;
 189         fbi->fbops = &omap_fb_ops;
 190
 191         strcpy(fbi->fix.id, MODULE_NAME);
 192
 193         drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
 194         drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
 195
 196         dev->mode_config.fb_base = paddr;
 197
 198         fbi->screen_base = omap_gem_vaddr(fbdev->bo);
 199         fbi->screen_size = fbdev->bo->size;
 200         fbi->fix.smem_start = paddr;
 201         fbi->fix.smem_len = fbdev->bo->size;
 202
 203         /* if we have DMM, then we can use it for scrolling by just
 204          * shuffling pages around in DMM rather than doing sw blit.
 205          */
 206         if (fbdev->ywrap_enabled) {
 207                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 208                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 209                 fbi->fix.ywrapstep = 1;
 210         }
 211
 212
 213         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 214         DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
 215
 216         mutex_unlock(&dev->struct_mutex);
 217
 218         return 0;
 219
 220 fail_unlock:
 221         mutex_unlock(&dev->struct_mutex);
 222 fail:
 223
 224         if (ret) {
 225
 226                 drm_fb_helper_release_fbi(helper);
 227
 228                 if (fb)
 229                         drm_framebuffer_remove(fb);
 230         }
 231
 232         return ret;
 233 }
 234
 235 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
 236         .fb_probe = omap_fbdev_create,
 237 };
 238
 239 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 240 {
 241         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 242                 /* these are not the fb's you're looking for */
 243                 return NULL;
 244         }
 245         return fbi->par;
 246 }
 247
 248 /* initialize fbdev helper */
 249 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
 250 {
 251         struct omap_drm_private *priv = dev->dev_private;
 252         struct omap_fbdev *fbdev = NULL;
 253         struct drm_fb_helper *helper;
 254         int ret = 0;
 255
 256         fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 257         if (!fbdev)
 258                 goto fail;
 259
 260         INIT_WORK(&fbdev->work, pan_worker);
 261
 262         helper = &fbdev->base;
 263
 264         drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
 265
 266         ret = drm_fb_helper_init(dev, helper,
 267                         priv->num_crtcs, priv->num_connectors);
 268         if (ret) {
 269                 dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
 270                 goto fail;
 271         }
 272
 273         ret = drm_fb_helper_single_add_all_connectors(helper);
 274         if (ret)
 275                 goto fini;
 276
 277         ret = drm_fb_helper_initial_config(helper, 32);
 278         if (ret)
 279                 goto fini;
 280
 281         priv->fbdev = helper;
 282
 283         return helper;
 284
 285 fini:
 286         drm_fb_helper_fini(helper);
 287 fail:
 288         kfree(fbdev);
 289
 290         dev_warn(dev->dev, "omap_fbdev_init failed\n");
 291         /* well, limp along without an fbdev.. maybe X11 will work? */
 292
 293         return NULL;
 294 }
 295
 296 void omap_fbdev_free(struct drm_device *dev)
 297 {
 298         struct omap_drm_private *priv = dev->dev_private;
 299         struct drm_fb_helper *helper = priv->fbdev;
 300         struct omap_fbdev *fbdev;
 301
 302         DBG();
 303
 304         drm_fb_helper_unregister_fbi(helper);
 305         drm_fb_helper_release_fbi(helper);
 306
 307         drm_fb_helper_fini(helper);
 308
 309         fbdev = to_omap_fbdev(priv->fbdev);
 310
 311         /* release the ref taken in omap_fbdev_create() */
 312         omap_gem_put_paddr(fbdev->bo);
 313
 314         /* this will free the backing object */
 315         if (fbdev->fb)
 316                 drm_framebuffer_remove(fbdev->fb);
 317
 318         kfree(fbdev);
 319
 320         priv->fbdev = NULL;
 321 }