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