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