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