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
  86         /* Note: to properly handle manual update displays, we wrap the
  87          * basic fbdev ops which write to the framebuffer
  88          */
  89         .fb_read = drm_fb_helper_sys_read,
  90         .fb_write = drm_fb_helper_sys_write,
  91         .fb_fillrect = drm_fb_helper_sys_fillrect,
  92         .fb_copyarea = drm_fb_helper_sys_copyarea,
  93         .fb_imageblit = drm_fb_helper_sys_imageblit,
  94
  95         .fb_check_var = drm_fb_helper_check_var,
  96         .fb_set_par = drm_fb_helper_set_par,
  97         .fb_pan_display = omap_fbdev_pan_display,
  98         .fb_blank = drm_fb_helper_blank,
  99         .fb_setcmap = drm_fb_helper_setcmap,
 100 };
 101
 102 static int omap_fbdev_create(struct drm_fb_helper *helper,
 103                 struct drm_fb_helper_surface_size *sizes)
 104 {
 105         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 106         struct drm_device *dev = helper->dev;
 107         struct omap_drm_private *priv = dev->dev_private;
 108         struct drm_framebuffer *fb = NULL;
 109         union omap_gem_size gsize;
 110         struct fb_info *fbi = NULL;
 111         struct drm_mode_fb_cmd2 mode_cmd = {0};
 112         dma_addr_t paddr;
 113         int ret;
 114
 115         sizes->surface_bpp = 32;
 116         sizes->surface_depth = 24;
 117
 118         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 119                         sizes->surface_height, sizes->surface_bpp,
 120                         sizes->fb_width, sizes->fb_height);
 121
 122         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 123                         sizes->surface_depth);
 124
 125         mode_cmd.width = sizes->surface_width;
 126         mode_cmd.height = sizes->surface_height;
 127
 128         mode_cmd.pitches[0] =
 129                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 130
 131         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 132         if (fbdev->ywrap_enabled) {
 133                 /* need to align pitch to page size if using DMM scrolling */
 134                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 135         }
 136
 137         /* allocate backing bo */
 138         gsize = (union omap_gem_size){
 139                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 140         };
 141         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 142         fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 143         if (!fbdev->bo) {
 144                 dev_err(dev->dev, "failed to allocate buffer object\n");
 145                 ret = -ENOMEM;
 146                 goto fail;
 147         }
 148
 149         fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
 150         if (IS_ERR(fb)) {
 151                 dev_err(dev->dev, "failed to allocate fb\n");
 152                 /* note: if fb creation failed, we can't rely on fb destroy
 153                  * to unref the bo:
 154                  */
 155                 drm_gem_object_unreference_unlocked(fbdev->bo);
 156                 ret = PTR_ERR(fb);
 157                 goto fail;
 158         }
 159
 160         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 161          * but is needed as long as we use fb_mmap() to mmap to userspace
 162          * (since this happens using fix.smem_start).  Possibly we could
 163          * implement our own mmap using GEM mmap support to avoid this
 164          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 165          * to it).  Then we just need to be sure that we are able to re-
 166          * pin it in case of an opps.
 167          */
 168         ret = omap_gem_get_paddr(fbdev->bo, &paddr, true);
 169         if (ret) {
 170                 dev_err(dev->dev,
 171                         "could not map (paddr)!  Skipping framebuffer alloc\n");
 172                 ret = -ENOMEM;
 173                 goto fail;
 174         }
 175
 176         mutex_lock(&dev->struct_mutex);
 177
 178         fbi = drm_fb_helper_alloc_fbi(helper);
 179         if (IS_ERR(fbi)) {
 180                 dev_err(dev->dev, "failed to allocate fb info\n");
 181                 ret = PTR_ERR(fbi);
 182                 goto fail_unlock;
 183         }
 184
 185         DBG("fbi=%p, dev=%p", fbi, dev);
 186
 187         fbdev->fb = fb;
 188         helper->fb = fb;
 189
 190         fbi->par = helper;
 191         fbi->flags = FBINFO_DEFAULT;
 192         fbi->fbops = &omap_fb_ops;
 193
 194         strcpy(fbi->fix.id, MODULE_NAME);
 195
 196         drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
 197         drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
 198
 199         dev->mode_config.fb_base = paddr;
 200
 201         fbi->screen_base = omap_gem_vaddr(fbdev->bo);
 202         fbi->screen_size = fbdev->bo->size;
 203         fbi->fix.smem_start = paddr;
 204         fbi->fix.smem_len = fbdev->bo->size;
 205
 206         /* if we have DMM, then we can use it for scrolling by just
 207          * shuffling pages around in DMM rather than doing sw blit.
 208          */
 209         if (fbdev->ywrap_enabled) {
 210                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 211                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 212                 fbi->fix.ywrapstep = 1;
 213         }
 214
 215
 216         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 217         DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
 218
 219         mutex_unlock(&dev->struct_mutex);
 220
 221         return 0;
 222
 223 fail_unlock:
 224         mutex_unlock(&dev->struct_mutex);
 225 fail:
 226
 227         if (ret) {
 228
 229                 drm_fb_helper_release_fbi(helper);
 230
 231                 if (fb) {
 232                         drm_framebuffer_unregister_private(fb);
 233                         drm_framebuffer_remove(fb);
 234                 }
 235         }
 236
 237         return ret;
 238 }
 239
 240 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
 241         .fb_probe = omap_fbdev_create,
 242 };
 243
 244 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 245 {
 246         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 247                 /* these are not the fb's you're looking for */
 248                 return NULL;
 249         }
 250         return fbi->par;
 251 }
 252
 253 /* initialize fbdev helper */
 254 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
 255 {
 256         struct omap_drm_private *priv = dev->dev_private;
 257         struct omap_fbdev *fbdev = NULL;
 258         struct drm_fb_helper *helper;
 259         int ret = 0;
 260
 261         fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 262         if (!fbdev)
 263                 goto fail;
 264
 265         INIT_WORK(&fbdev->work, pan_worker);
 266
 267         helper = &fbdev->base;
 268
 269         drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
 270
 271         ret = drm_fb_helper_init(dev, helper,
 272                         priv->num_crtcs, priv->num_connectors);
 273         if (ret) {
 274                 dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
 275                 goto fail;
 276         }
 277
 278         ret = drm_fb_helper_single_add_all_connectors(helper);
 279         if (ret)
 280                 goto fini;
 281
 282         ret = drm_fb_helper_initial_config(helper, 32);
 283         if (ret)
 284                 goto fini;
 285
 286         priv->fbdev = helper;
 287
 288         return helper;
 289
 290 fini:
 291         drm_fb_helper_fini(helper);
 292 fail:
 293         kfree(fbdev);
 294
 295         dev_warn(dev->dev, "omap_fbdev_init failed\n");
 296         /* well, limp along without an fbdev.. maybe X11 will work? */
 297
 298         return NULL;
 299 }
 300
 301 void omap_fbdev_free(struct drm_device *dev)
 302 {
 303         struct omap_drm_private *priv = dev->dev_private;
 304         struct drm_fb_helper *helper = priv->fbdev;
 305         struct omap_fbdev *fbdev;
 306
 307         DBG();
 308
 309         drm_fb_helper_unregister_fbi(helper);
 310         drm_fb_helper_release_fbi(helper);
 311
 312         drm_fb_helper_fini(helper);
 313
 314         fbdev = to_omap_fbdev(priv->fbdev);
 315
 316         /* release the ref taken in omap_fbdev_create() */
 317         omap_gem_put_paddr(fbdev->bo);
 318
 319         /* this will free the backing object */
 320         if (fbdev->fb) {
 321                 drm_framebuffer_unregister_private(fbdev->fb);
 322                 drm_framebuffer_remove(fbdev->fb);
 323         }
 324
 325         kfree(fbdev);
 326
 327         priv->fbdev = NULL;
 328 }