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