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 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
  55                 struct fb_info *fbi)
  56 {
  57         struct drm_fb_helper *helper = get_fb(fbi);
  58         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
  59
  60         if (!helper)
  61                 goto fallback;
  62
  63         if (!fbdev->ywrap_enabled)
  64                 goto fallback;
  65
  66         if (drm_can_sleep()) {
  67                 pan_worker(&fbdev->work);
  68         } else {
  69                 struct omap_drm_private *priv = helper->dev->dev_private;
  70                 queue_work(priv->wq, &fbdev->work);
  71         }
  72
  73         return 0;
  74
  75 fallback:
  76         return drm_fb_helper_pan_display(var, fbi);
  77 }
  78
  79 static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
  80 {
  81         struct drm_fb_helper *helper = info->par;
  82         struct drm_framebuffer *fb = helper->fb;
  83         struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
  84
  85         return drm_gem_mmap_obj(bo, omap_gem_mmap_size(bo), vma);
  86 }
  87
  88 static void omap_fbdev_fb_destroy(struct fb_info *info)
  89 {
  90         struct drm_fb_helper *helper = info->par;
  91         struct drm_framebuffer *fb = helper->fb;
  92         struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
  93         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
  94
  95         DBG();
  96
  97         drm_fb_helper_fini(helper);
  98
  99         omap_gem_unpin(bo);
 100         drm_framebuffer_remove(fb);
 101
 102         drm_client_release(&helper->client);
 103         drm_fb_helper_unprepare(helper);
 104         kfree(fbdev);
 105 }
 106
 107 static const struct fb_ops omap_fb_ops = {
 108         .owner = THIS_MODULE,
 109         __FB_DEFAULT_DMAMEM_OPS_RDWR,
 110         .fb_check_var   = drm_fb_helper_check_var,
 111         .fb_set_par     = drm_fb_helper_set_par,
 112         .fb_setcmap     = drm_fb_helper_setcmap,
 113         .fb_blank       = drm_fb_helper_blank,
 114         .fb_pan_display = omap_fbdev_pan_display,
 115         __FB_DEFAULT_DMAMEM_OPS_DRAW,
 116         .fb_ioctl       = drm_fb_helper_ioctl,
 117         .fb_mmap        = omap_fbdev_fb_mmap,
 118         .fb_destroy     = omap_fbdev_fb_destroy,
 119 };
 120
 121 static int omap_fbdev_create(struct drm_fb_helper *helper,
 122                 struct drm_fb_helper_surface_size *sizes)
 123 {
 124         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 125         struct drm_device *dev = helper->dev;
 126         struct omap_drm_private *priv = dev->dev_private;
 127         struct drm_framebuffer *fb = NULL;
 128         union omap_gem_size gsize;
 129         struct fb_info *fbi = NULL;
 130         struct drm_mode_fb_cmd2 mode_cmd = {0};
 131         struct drm_gem_object *bo;
 132         dma_addr_t dma_addr;
 133         int ret;
 134
 135         sizes->surface_bpp = 32;
 136         sizes->surface_depth = 24;
 137
 138         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 139                         sizes->surface_height, sizes->surface_bpp,
 140                         sizes->fb_width, sizes->fb_height);
 141
 142         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 143                         sizes->surface_depth);
 144
 145         mode_cmd.width = sizes->surface_width;
 146         mode_cmd.height = sizes->surface_height;
 147
 148         mode_cmd.pitches[0] =
 149                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 150
 151         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 152         if (fbdev->ywrap_enabled) {
 153                 /* need to align pitch to page size if using DMM scrolling */
 154                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 155         }
 156
 157         /* allocate backing bo */
 158         gsize = (union omap_gem_size){
 159                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 160         };
 161         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 162         bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 163         if (!bo) {
 164                 dev_err(dev->dev, "failed to allocate buffer object\n");
 165                 ret = -ENOMEM;
 166                 goto fail;
 167         }
 168
 169         fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
 170         if (IS_ERR(fb)) {
 171                 dev_err(dev->dev, "failed to allocate fb\n");
 172                 /* note: if fb creation failed, we can't rely on fb destroy
 173                  * to unref the bo:
 174                  */
 175                 drm_gem_object_put(bo);
 176                 ret = PTR_ERR(fb);
 177                 goto fail;
 178         }
 179
 180         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 181          * but is needed as long as we use fb_mmap() to mmap to userspace
 182          * (since this happens using fix.smem_start).  Possibly we could
 183          * implement our own mmap using GEM mmap support to avoid this
 184          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 185          * to it).  Then we just need to be sure that we are able to re-
 186          * pin it in case of an opps.
 187          */
 188         ret = omap_gem_pin(bo, &dma_addr);
 189         if (ret) {
 190                 dev_err(dev->dev, "could not pin framebuffer\n");
 191                 ret = -ENOMEM;
 192                 goto fail;
 193         }
 194
 195         fbi = drm_fb_helper_alloc_info(helper);
 196         if (IS_ERR(fbi)) {
 197                 dev_err(dev->dev, "failed to allocate fb info\n");
 198                 ret = PTR_ERR(fbi);
 199                 goto fail;
 200         }
 201
 202         DBG("fbi=%p, dev=%p", fbi, dev);
 203
 204         helper->fb = fb;
 205
 206         fbi->fbops = &omap_fb_ops;
 207
 208         drm_fb_helper_fill_info(fbi, helper, sizes);
 209
 210         fbi->flags |= FBINFO_VIRTFB;
 211         fbi->screen_buffer = omap_gem_vaddr(bo);
 212         fbi->screen_size = bo->size;
 213         fbi->fix.smem_start = dma_addr;
 214         fbi->fix.smem_len = bo->size;
 215
 216         /* if we have DMM, then we can use it for scrolling by just
 217          * shuffling pages around in DMM rather than doing sw blit.
 218          */
 219         if (fbdev->ywrap_enabled) {
 220                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 221                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 222                 fbi->fix.ywrapstep = 1;
 223         }
 224
 225
 226         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 227         DBG("allocated %dx%d fb", fb->width, fb->height);
 228
 229         return 0;
 230
 231 fail:
 232
 233         if (ret) {
 234                 if (fb)
 235                         drm_framebuffer_remove(fb);
 236         }
 237
 238         return ret;
 239 }
 240
 241 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
 242         .fb_probe = omap_fbdev_create,
 243 };
 244
 245 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 246 {
 247         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 248                 /* these are not the fb's you're looking for */
 249                 return NULL;
 250         }
 251         return fbi->par;
 252 }
 253
 254 /*
 255  * struct drm_client
 256  */
 257
 258 static void omap_fbdev_client_unregister(struct drm_client_dev *client)
 259 {
 260         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
 261
 262         if (fb_helper->info) {
 263                 drm_fb_helper_unregister_info(fb_helper);
 264         } else {
 265                 drm_client_release(&fb_helper->client);
 266                 drm_fb_helper_unprepare(fb_helper);
 267                 kfree(fb_helper);
 268         }
 269 }
 270
 271 static int omap_fbdev_client_restore(struct drm_client_dev *client)
 272 {
 273         drm_fb_helper_lastclose(client->dev);
 274
 275         return 0;
 276 }
 277
 278 static int omap_fbdev_client_hotplug(struct drm_client_dev *client)
 279 {
 280         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
 281         struct drm_device *dev = client->dev;
 282         int ret;
 283
 284         if (dev->fb_helper)
 285                 return drm_fb_helper_hotplug_event(dev->fb_helper);
 286
 287         ret = drm_fb_helper_init(dev, fb_helper);
 288         if (ret)
 289                 goto err_drm_err;
 290
 291         ret = drm_fb_helper_initial_config(fb_helper);
 292         if (ret)
 293                 goto err_drm_fb_helper_fini;
 294
 295         return 0;
 296
 297 err_drm_fb_helper_fini:
 298         drm_fb_helper_fini(fb_helper);
 299 err_drm_err:
 300         drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
 301         return ret;
 302 }
 303
 304 static const struct drm_client_funcs omap_fbdev_client_funcs = {
 305         .owner          = THIS_MODULE,
 306         .unregister     = omap_fbdev_client_unregister,
 307         .restore        = omap_fbdev_client_restore,
 308         .hotplug        = omap_fbdev_client_hotplug,
 309 };
 310
 311 void omap_fbdev_setup(struct drm_device *dev)
 312 {
 313         struct omap_fbdev *fbdev;
 314         struct drm_fb_helper *helper;
 315         int ret;
 316
 317         drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
 318         drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 319
 320         fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 321         if (!fbdev)
 322                 return;
 323         helper = &fbdev->base;
 324
 325         drm_fb_helper_prepare(dev, helper, 32, &omap_fb_helper_funcs);
 326
 327         ret = drm_client_init(dev, &helper->client, "fbdev", &omap_fbdev_client_funcs);
 328         if (ret)
 329                 goto err_drm_client_init;
 330
 331         INIT_WORK(&fbdev->work, pan_worker);
 332
 333         drm_client_register(&helper->client);
 334
 335         return;
 336
 337 err_drm_client_init:
 338         drm_fb_helper_unprepare(helper);
 339         kfree(fbdev);
 340 }