drivers/gpu/drm/omapdrm/omap_fbdev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   4  * Author: Rob Clark <rob@ti.com>
   5  */
   6
   7 #include <drm/drm_crtc.h>
   8 #include <drm/drm_util.h>
   9 #include <drm/drm_fb_helper.h>
  10 #include <drm/drm_file.h>
  11 #include <drm/drm_fourcc.h>
  12
  13 #include "omap_drv.h"
  14
  15 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
  16 static bool ywrap_enabled = true;
  17 module_param_named(ywrap, ywrap_enabled, bool, 0644);
  18
  19 /*
  20  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
  21  */
  22
  23 #define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
  24
  25 struct omap_fbdev {
  26         struct drm_fb_helper base;
  27         struct drm_framebuffer *fb;
  28         struct drm_gem_object *bo;
  29         bool ywrap_enabled;
  30
  31         /* for deferred dmm roll when getting called in atomic ctx */
  32         struct work_struct work;
  33 };
  34
  35 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
  36
  37 static void pan_worker(struct work_struct *work)
  38 {
  39         struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
  40         struct fb_info *fbi = fbdev->base.fbdev;
  41         int npages;
  42
  43         /* DMM roll shifts in 4K pages: */
  44         npages = fbi->fix.line_length >> PAGE_SHIFT;
  45         omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
  46 }
  47
  48 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
  49                 struct fb_info *fbi)
  50 {
  51         struct drm_fb_helper *helper = get_fb(fbi);
  52         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
  53
  54         if (!helper)
  55                 goto fallback;
  56
  57         if (!fbdev->ywrap_enabled)
  58                 goto fallback;
  59
  60         if (drm_can_sleep()) {
  61                 pan_worker(&fbdev->work);
  62         } else {
  63                 struct omap_drm_private *priv = helper->dev->dev_private;
  64                 queue_work(priv->wq, &fbdev->work);
  65         }
  66
  67         return 0;
  68
  69 fallback:
  70         return drm_fb_helper_pan_display(var, fbi);
  71 }
  72
  73 static const struct fb_ops omap_fb_ops = {
  74         .owner = THIS_MODULE,
  75
  76         .fb_check_var   = drm_fb_helper_check_var,
  77         .fb_set_par     = drm_fb_helper_set_par,
  78         .fb_setcmap     = drm_fb_helper_setcmap,
  79         .fb_blank       = drm_fb_helper_blank,
  80         .fb_pan_display = omap_fbdev_pan_display,
  81         .fb_ioctl       = drm_fb_helper_ioctl,
  82
  83         .fb_read = drm_fb_helper_sys_read,
  84         .fb_write = drm_fb_helper_sys_write,
  85         .fb_fillrect = drm_fb_helper_sys_fillrect,
  86         .fb_copyarea = drm_fb_helper_sys_copyarea,
  87         .fb_imageblit = drm_fb_helper_sys_imageblit,
  88 };
  89
  90 static int omap_fbdev_create(struct drm_fb_helper *helper,
  91                 struct drm_fb_helper_surface_size *sizes)
  92 {
  93         struct omap_fbdev *fbdev = to_omap_fbdev(helper);
  94         struct drm_device *dev = helper->dev;
  95         struct omap_drm_private *priv = dev->dev_private;
  96         struct drm_framebuffer *fb = NULL;
  97         union omap_gem_size gsize;
  98         struct fb_info *fbi = NULL;
  99         struct drm_mode_fb_cmd2 mode_cmd = {0};
 100         dma_addr_t dma_addr;
 101         int ret;
 102
 103         sizes->surface_bpp = 32;
 104         sizes->surface_depth = 24;
 105
 106         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 107                         sizes->surface_height, sizes->surface_bpp,
 108                         sizes->fb_width, sizes->fb_height);
 109
 110         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 111                         sizes->surface_depth);
 112
 113         mode_cmd.width = sizes->surface_width;
 114         mode_cmd.height = sizes->surface_height;
 115
 116         mode_cmd.pitches[0] =
 117                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 118
 119         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 120         if (fbdev->ywrap_enabled) {
 121                 /* need to align pitch to page size if using DMM scrolling */
 122                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 123         }
 124
 125         /* allocate backing bo */
 126         gsize = (union omap_gem_size){
 127                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 128         };
 129         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 130         fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 131         if (!fbdev->bo) {
 132                 dev_err(dev->dev, "failed to allocate buffer object\n");
 133                 ret = -ENOMEM;
 134                 goto fail;
 135         }
 136
 137         fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
 138         if (IS_ERR(fb)) {
 139                 dev_err(dev->dev, "failed to allocate fb\n");
 140                 /* note: if fb creation failed, we can't rely on fb destroy
 141                  * to unref the bo:
 142                  */
 143                 drm_gem_object_put_unlocked(fbdev->bo);
 144                 ret = PTR_ERR(fb);
 145                 goto fail;
 146         }
 147
 148         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 149          * but is needed as long as we use fb_mmap() to mmap to userspace
 150          * (since this happens using fix.smem_start).  Possibly we could
 151          * implement our own mmap using GEM mmap support to avoid this
 152          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 153          * to it).  Then we just need to be sure that we are able to re-
 154          * pin it in case of an opps.
 155          */
 156         ret = omap_gem_pin(fbdev->bo, &dma_addr);
 157         if (ret) {
 158                 dev_err(dev->dev, "could not pin framebuffer\n");
 159                 ret = -ENOMEM;
 160                 goto fail;
 161         }
 162
 163         fbi = drm_fb_helper_alloc_fbi(helper);
 164         if (IS_ERR(fbi)) {
 165                 dev_err(dev->dev, "failed to allocate fb info\n");
 166                 ret = PTR_ERR(fbi);
 167                 goto fail;
 168         }
 169
 170         DBG("fbi=%p, dev=%p", fbi, dev);
 171
 172         fbdev->fb = fb;
 173         helper->fb = fb;
 174
 175         fbi->fbops = &omap_fb_ops;
 176
 177         drm_fb_helper_fill_info(fbi, helper, sizes);
 178
 179         dev->mode_config.fb_base = dma_addr;
 180
 181         fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
 182         fbi->screen_size = fbdev->bo->size;
 183         fbi->fix.smem_start = dma_addr;
 184         fbi->fix.smem_len = fbdev->bo->size;
 185
 186         /* if we have DMM, then we can use it for scrolling by just
 187          * shuffling pages around in DMM rather than doing sw blit.
 188          */
 189         if (fbdev->ywrap_enabled) {
 190                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 191                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 192                 fbi->fix.ywrapstep = 1;
 193         }
 194
 195
 196         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 197         DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
 198
 199         return 0;
 200
 201 fail:
 202
 203         if (ret) {
 204                 if (fb)
 205                         drm_framebuffer_remove(fb);
 206         }
 207
 208         return ret;
 209 }
 210
 211 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
 212         .fb_probe = omap_fbdev_create,
 213 };
 214
 215 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 216 {
 217         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 218                 /* these are not the fb's you're looking for */
 219                 return NULL;
 220         }
 221         return fbi->par;
 222 }
 223
 224 /* initialize fbdev helper */
 225 void omap_fbdev_init(struct drm_device *dev)
 226 {
 227         struct omap_drm_private *priv = dev->dev_private;
 228         struct omap_fbdev *fbdev = NULL;
 229         struct drm_fb_helper *helper;
 230         int ret = 0;
 231
 232         if (!priv->num_pipes)
 233                 return;
 234
 235         fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 236         if (!fbdev)
 237                 goto fail;
 238
 239         INIT_WORK(&fbdev->work, pan_worker);
 240
 241         helper = &fbdev->base;
 242
 243         drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
 244
 245         ret = drm_fb_helper_init(dev, helper, priv->num_pipes);
 246         if (ret)
 247                 goto fail;
 248
 249         ret = drm_fb_helper_single_add_all_connectors(helper);
 250         if (ret)
 251                 goto fini;
 252
 253         ret = drm_fb_helper_initial_config(helper, 32);
 254         if (ret)
 255                 goto fini;
 256
 257         priv->fbdev = helper;
 258
 259         return;
 260
 261 fini:
 262         drm_fb_helper_fini(helper);
 263 fail:
 264         kfree(fbdev);
 265
 266         dev_warn(dev->dev, "omap_fbdev_init failed\n");
 267 }
 268
 269 void omap_fbdev_fini(struct drm_device *dev)
 270 {
 271         struct omap_drm_private *priv = dev->dev_private;
 272         struct drm_fb_helper *helper = priv->fbdev;
 273         struct omap_fbdev *fbdev;
 274
 275         DBG();
 276
 277         if (!helper)
 278                 return;
 279
 280         drm_fb_helper_unregister_fbi(helper);
 281
 282         drm_fb_helper_fini(helper);
 283
 284         fbdev = to_omap_fbdev(helper);
 285
 286         /* unpin the GEM object pinned in omap_fbdev_create() */
 287         if (fbdev->bo)
 288                 omap_gem_unpin(fbdev->bo);
 289
 290         /* this will free the backing object */
 291         if (fbdev->fb)
 292                 drm_framebuffer_remove(fbdev->fb);
 293
 294         kfree(fbdev);
 295
 296         priv->fbdev = NULL;
 297 }