drivers/gpu/drm/omapdrm/omap_fbdev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
   4  * Author: Rob Clark <[email protected]>
   5  */
   6
   7 #include <linux/fb.h>
   8
   9 #include <drm/drm_drv.h>
  10 #include <drm/drm_crtc_helper.h>
  11 #include <drm/drm_fb_helper.h>
  12 #include <drm/drm_file.h>
  13 #include <drm/drm_fourcc.h>
  14 #include <drm/drm_framebuffer.h>
  15 #include <drm/drm_gem_framebuffer_helper.h>
  16 #include <drm/drm_managed.h>
  17 #include <drm/drm_util.h>
  18
  19 #include "omap_drv.h"
  20 #include "omap_fbdev.h"
  21
  22 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
  23 static bool ywrap_enabled = true;
  24 module_param_named(ywrap, ywrap_enabled, bool, 0644);
  25
  26 /*
  27  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
  28  */
  29
  30 struct omap_fbdev {
  31         struct drm_device *dev;
  32         bool ywrap_enabled;
  33
  34         /* for deferred dmm roll when getting called in atomic ctx */
  35         struct work_struct work;
  36 };
  37
  38 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
  39
  40 static void pan_worker(struct work_struct *work)
  41 {
  42         struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
  43         struct drm_fb_helper *helper = fbdev->dev->fb_helper;
  44         struct fb_info *fbi = helper->info;
  45         struct drm_gem_object *bo = drm_gem_fb_get_obj(helper->fb, 0);
  46         int npages;
  47
  48         /* DMM roll shifts in 4K pages: */
  49         npages = fbi->fix.line_length >> PAGE_SHIFT;
  50         omap_gem_roll(bo, fbi->var.yoffset * npages);
  51 }
  52
  53 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,
  54                                    drm_fb_helper_damage_range,
  55                                    drm_fb_helper_damage_area)
  56
  57 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
  58 {
  59         struct drm_fb_helper *helper = get_fb(fbi);
  60         struct omap_drm_private *priv;
  61         struct omap_fbdev *fbdev;
  62
  63         if (!helper)
  64                 goto fallback;
  65
  66         priv = helper->dev->dev_private;
  67         fbdev = priv->fbdev;
  68
  69         if (!fbdev->ywrap_enabled)
  70                 goto fallback;
  71
  72         if (drm_can_sleep())
  73                 pan_worker(&fbdev->work);
  74         else
  75                 queue_work(priv->wq, &fbdev->work);
  76
  77         return 0;
  78
  79 fallback:
  80         return drm_fb_helper_pan_display(var, fbi);
  81 }
  82
  83 static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
  84 {
  85         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
  86
  87         return fb_deferred_io_mmap(info, vma);
  88 }
  89
  90 static void omap_fbdev_fb_destroy(struct fb_info *info)
  91 {
  92         struct drm_fb_helper *helper = info->par;
  93         struct drm_framebuffer *fb = helper->fb;
  94         struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
  95
  96         DBG();
  97
  98         fb_deferred_io_cleanup(info);
  99         drm_fb_helper_fini(helper);
 100
 101         omap_gem_unpin(bo);
 102         drm_framebuffer_remove(fb);
 103
 104         drm_client_release(&helper->client);
 105         drm_fb_helper_unprepare(helper);
 106         kfree(helper);
 107 }
 108
 109 /*
 110  * For now, we cannot use FB_DEFAULT_DEFERRED_OPS and fb_deferred_io_mmap()
 111  * because we use write-combine.
 112  */
 113 static const struct fb_ops omap_fb_ops = {
 114         .owner = THIS_MODULE,
 115         __FB_DEFAULT_DEFERRED_OPS_RDWR(omap_fbdev),
 116         .fb_check_var   = drm_fb_helper_check_var,
 117         .fb_set_par     = drm_fb_helper_set_par,
 118         .fb_setcmap     = drm_fb_helper_setcmap,
 119         .fb_blank       = drm_fb_helper_blank,
 120         .fb_pan_display = omap_fbdev_pan_display,
 121         __FB_DEFAULT_DEFERRED_OPS_DRAW(omap_fbdev),
 122         .fb_ioctl       = drm_fb_helper_ioctl,
 123         .fb_mmap        = omap_fbdev_fb_mmap,
 124         .fb_destroy     = omap_fbdev_fb_destroy,
 125 };
 126
 127 static int omap_fbdev_create(struct drm_fb_helper *helper,
 128                 struct drm_fb_helper_surface_size *sizes)
 129 {
 130         struct drm_device *dev = helper->dev;
 131         struct omap_drm_private *priv = dev->dev_private;
 132         struct omap_fbdev *fbdev = priv->fbdev;
 133         struct drm_framebuffer *fb = NULL;
 134         union omap_gem_size gsize;
 135         struct fb_info *fbi = NULL;
 136         struct drm_mode_fb_cmd2 mode_cmd = {0};
 137         struct drm_gem_object *bo;
 138         dma_addr_t dma_addr;
 139         int ret;
 140
 141         sizes->surface_bpp = 32;
 142         sizes->surface_depth = 24;
 143
 144         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 145                         sizes->surface_height, sizes->surface_bpp,
 146                         sizes->fb_width, sizes->fb_height);
 147
 148         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 149                         sizes->surface_depth);
 150
 151         mode_cmd.width = sizes->surface_width;
 152         mode_cmd.height = sizes->surface_height;
 153
 154         mode_cmd.pitches[0] =
 155                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 156
 157         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 158         if (fbdev->ywrap_enabled) {
 159                 /* need to align pitch to page size if using DMM scrolling */
 160                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 161         }
 162
 163         /* allocate backing bo */
 164         gsize = (union omap_gem_size){
 165                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 166         };
 167         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 168         bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 169         if (!bo) {
 170                 dev_err(dev->dev, "failed to allocate buffer object\n");
 171                 ret = -ENOMEM;
 172                 goto fail;
 173         }
 174
 175         fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
 176         if (IS_ERR(fb)) {
 177                 dev_err(dev->dev, "failed to allocate fb\n");
 178                 /* note: if fb creation failed, we can't rely on fb destroy
 179                  * to unref the bo:
 180                  */
 181                 drm_gem_object_put(bo);
 182                 ret = PTR_ERR(fb);
 183                 goto fail;
 184         }
 185
 186         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 187          * but is needed as long as we use fb_mmap() to mmap to userspace
 188          * (since this happens using fix.smem_start).  Possibly we could
 189          * implement our own mmap using GEM mmap support to avoid this
 190          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 191          * to it).  Then we just need to be sure that we are able to re-
 192          * pin it in case of an opps.
 193          */
 194         ret = omap_gem_pin(bo, &dma_addr);
 195         if (ret) {
 196                 dev_err(dev->dev, "could not pin framebuffer\n");
 197                 ret = -ENOMEM;
 198                 goto fail;
 199         }
 200
 201         fbi = drm_fb_helper_alloc_info(helper);
 202         if (IS_ERR(fbi)) {
 203                 dev_err(dev->dev, "failed to allocate fb info\n");
 204                 ret = PTR_ERR(fbi);
 205                 goto fail;
 206         }
 207
 208         DBG("fbi=%p, dev=%p", fbi, dev);
 209
 210         helper->fb = fb;
 211
 212         fbi->fbops = &omap_fb_ops;
 213
 214         drm_fb_helper_fill_info(fbi, helper, sizes);
 215
 216         fbi->flags |= FBINFO_VIRTFB;
 217         fbi->screen_buffer = omap_gem_vaddr(bo);
 218         fbi->screen_size = bo->size;
 219         fbi->fix.smem_start = dma_addr;
 220         fbi->fix.smem_len = bo->size;
 221
 222         /* deferred I/O */
 223         helper->fbdefio.delay = HZ / 20;
 224         helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
 225
 226         fbi->fbdefio = &helper->fbdefio;
 227         ret = fb_deferred_io_init(fbi);
 228         if (ret)
 229                 goto fail;
 230
 231         /* if we have DMM, then we can use it for scrolling by just
 232          * shuffling pages around in DMM rather than doing sw blit.
 233          */
 234         if (fbdev->ywrap_enabled) {
 235                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 236                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 237                 fbi->fix.ywrapstep = 1;
 238         }
 239
 240
 241         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 242         DBG("allocated %dx%d fb", fb->width, fb->height);
 243
 244         return 0;
 245
 246 fail:
 247
 248         if (ret) {
 249                 if (fb)
 250                         drm_framebuffer_remove(fb);
 251         }
 252
 253         return ret;
 254 }
 255
 256 static int omap_fbdev_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
 257 {
 258         if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
 259                 return 0;
 260
 261         if (helper->fb->funcs->dirty)
 262                 return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
 263
 264         return 0;
 265 }
 266
 267 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
 268         .fb_probe = omap_fbdev_create,
 269         .fb_dirty = omap_fbdev_dirty,
 270 };
 271
 272 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 273 {
 274         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 275                 /* these are not the fb's you're looking for */
 276                 return NULL;
 277         }
 278         return fbi->par;
 279 }
 280
 281 /*
 282  * struct drm_client
 283  */
 284
 285 static void omap_fbdev_client_unregister(struct drm_client_dev *client)
 286 {
 287         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
 288
 289         if (fb_helper->info) {
 290                 drm_fb_helper_unregister_info(fb_helper);
 291         } else {
 292                 drm_client_release(&fb_helper->client);
 293                 drm_fb_helper_unprepare(fb_helper);
 294                 kfree(fb_helper);
 295         }
 296 }
 297
 298 static int omap_fbdev_client_restore(struct drm_client_dev *client)
 299 {
 300         drm_fb_helper_lastclose(client->dev);
 301
 302         return 0;
 303 }
 304
 305 static int omap_fbdev_client_hotplug(struct drm_client_dev *client)
 306 {
 307         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
 308         struct drm_device *dev = client->dev;
 309         int ret;
 310
 311         if (dev->fb_helper)
 312                 return drm_fb_helper_hotplug_event(dev->fb_helper);
 313
 314         ret = drm_fb_helper_init(dev, fb_helper);
 315         if (ret)
 316                 goto err_drm_err;
 317
 318         ret = drm_fb_helper_initial_config(fb_helper);
 319         if (ret)
 320                 goto err_drm_fb_helper_fini;
 321
 322         return 0;
 323
 324 err_drm_fb_helper_fini:
 325         drm_fb_helper_fini(fb_helper);
 326 err_drm_err:
 327         drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
 328         return ret;
 329 }
 330
 331 static const struct drm_client_funcs omap_fbdev_client_funcs = {
 332         .owner          = THIS_MODULE,
 333         .unregister     = omap_fbdev_client_unregister,
 334         .restore        = omap_fbdev_client_restore,
 335         .hotplug        = omap_fbdev_client_hotplug,
 336 };
 337
 338 void omap_fbdev_setup(struct drm_device *dev)
 339 {
 340         struct omap_drm_private *priv = dev->dev_private;
 341         struct omap_fbdev *fbdev;
 342         struct drm_fb_helper *helper;
 343         int ret;
 344
 345         drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
 346         drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 347
 348         fbdev = drmm_kzalloc(dev, sizeof(*fbdev), GFP_KERNEL);
 349         if (!fbdev)
 350                 return;
 351         fbdev->dev = dev;
 352         INIT_WORK(&fbdev->work, pan_worker);
 353
 354         priv->fbdev = fbdev;
 355
 356         helper = kzalloc(sizeof(*helper), GFP_KERNEL);
 357         if (!helper)
 358                 return;
 359         drm_fb_helper_prepare(dev, helper, 32, &omap_fb_helper_funcs);
 360
 361         ret = drm_client_init(dev, &helper->client, "fbdev", &omap_fbdev_client_funcs);
 362         if (ret)
 363                 goto err_drm_client_init;
 364
 365         drm_client_register(&helper->client);
 366
 367         return;
 368
 369 err_drm_client_init:
 370         drm_fb_helper_unprepare(helper);
 371         kfree(helper);
 372 }