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/clients/drm_client_setup.h>
  10 #include <drm/drm_drv.h>
  11 #include <drm/drm_crtc_helper.h>
  12 #include <drm/drm_fb_helper.h>
  13 #include <drm/drm_file.h>
  14 #include <drm/drm_fourcc.h>
  15 #include <drm/drm_framebuffer.h>
  16 #include <drm/drm_gem_framebuffer_helper.h>
  17 #include <drm/drm_managed.h>
  18 #include <drm/drm_util.h>
  19
  20 #include "omap_drv.h"
  21 #include "omap_fbdev.h"
  22
  23 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
  24 static bool ywrap_enabled = true;
  25 module_param_named(ywrap, ywrap_enabled, bool, 0644);
  26
  27 /*
  28  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
  29  */
  30
  31 struct omap_fbdev {
  32         struct drm_device *dev;
  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->dev->fb_helper;
  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 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,
  55                                    drm_fb_helper_damage_range,
  56                                    drm_fb_helper_damage_area)
  57
  58 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
  59 {
  60         struct drm_fb_helper *helper = get_fb(fbi);
  61         struct omap_drm_private *priv;
  62         struct omap_fbdev *fbdev;
  63
  64         if (!helper)
  65                 goto fallback;
  66
  67         priv = helper->dev->dev_private;
  68         fbdev = priv->fbdev;
  69
  70         if (!fbdev->ywrap_enabled)
  71                 goto fallback;
  72
  73         if (drm_can_sleep())
  74                 pan_worker(&fbdev->work);
  75         else
  76                 queue_work(priv->wq, &fbdev->work);
  77
  78         return 0;
  79
  80 fallback:
  81         return drm_fb_helper_pan_display(var, fbi);
  82 }
  83
  84 static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
  85 {
  86         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
  87
  88         return fb_deferred_io_mmap(info, vma);
  89 }
  90
  91 static void omap_fbdev_fb_destroy(struct fb_info *info)
  92 {
  93         struct drm_fb_helper *helper = info->par;
  94         struct drm_framebuffer *fb = helper->fb;
  95         struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
  96
  97         DBG();
  98
  99         fb_deferred_io_cleanup(info);
 100         drm_fb_helper_fini(helper);
 101
 102         omap_gem_unpin(bo);
 103         drm_framebuffer_remove(fb);
 104
 105         drm_client_release(&helper->client);
 106         drm_fb_helper_unprepare(helper);
 107         kfree(helper);
 108 }
 109
 110 /*
 111  * For now, we cannot use FB_DEFAULT_DEFERRED_OPS and fb_deferred_io_mmap()
 112  * because we use write-combine.
 113  */
 114 static const struct fb_ops omap_fb_ops = {
 115         .owner = THIS_MODULE,
 116         __FB_DEFAULT_DEFERRED_OPS_RDWR(omap_fbdev),
 117         .fb_check_var   = drm_fb_helper_check_var,
 118         .fb_set_par     = drm_fb_helper_set_par,
 119         .fb_setcmap     = drm_fb_helper_setcmap,
 120         .fb_blank       = drm_fb_helper_blank,
 121         .fb_pan_display = omap_fbdev_pan_display,
 122         __FB_DEFAULT_DEFERRED_OPS_DRAW(omap_fbdev),
 123         .fb_ioctl       = drm_fb_helper_ioctl,
 124         .fb_mmap        = omap_fbdev_fb_mmap,
 125         .fb_destroy     = omap_fbdev_fb_destroy,
 126 };
 127
 128 static int omap_fbdev_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
 129 {
 130         if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
 131                 return 0;
 132
 133         if (helper->fb->funcs->dirty)
 134                 return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
 135
 136         return 0;
 137 }
 138
 139 static const struct drm_fb_helper_funcs omap_fbdev_helper_funcs = {
 140         .fb_dirty = omap_fbdev_dirty,
 141 };
 142
 143 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
 144 {
 145         if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
 146                 /* these are not the fb's you're looking for */
 147                 return NULL;
 148         }
 149         return fbi->par;
 150 }
 151
 152 int omap_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
 153                                   struct drm_fb_helper_surface_size *sizes)
 154 {
 155         struct drm_device *dev = helper->dev;
 156         struct omap_drm_private *priv = dev->dev_private;
 157         struct omap_fbdev *fbdev = priv->fbdev;
 158         struct drm_framebuffer *fb = NULL;
 159         union omap_gem_size gsize;
 160         struct fb_info *fbi = NULL;
 161         struct drm_mode_fb_cmd2 mode_cmd = {0};
 162         struct drm_gem_object *bo;
 163         dma_addr_t dma_addr;
 164         int ret;
 165
 166         sizes->surface_bpp = 32;
 167         sizes->surface_depth = 24;
 168
 169         DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
 170                         sizes->surface_height, sizes->surface_bpp,
 171                         sizes->fb_width, sizes->fb_height);
 172
 173         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 174                         sizes->surface_depth);
 175
 176         mode_cmd.width = sizes->surface_width;
 177         mode_cmd.height = sizes->surface_height;
 178
 179         mode_cmd.pitches[0] =
 180                         DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
 181
 182         fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
 183         if (fbdev->ywrap_enabled) {
 184                 /* need to align pitch to page size if using DMM scrolling */
 185                 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
 186         }
 187
 188         /* allocate backing bo */
 189         gsize = (union omap_gem_size){
 190                 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
 191         };
 192         DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
 193         bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
 194         if (!bo) {
 195                 dev_err(dev->dev, "failed to allocate buffer object\n");
 196                 ret = -ENOMEM;
 197                 goto fail;
 198         }
 199
 200         fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
 201         if (IS_ERR(fb)) {
 202                 dev_err(dev->dev, "failed to allocate fb\n");
 203                 /* note: if fb creation failed, we can't rely on fb destroy
 204                  * to unref the bo:
 205                  */
 206                 drm_gem_object_put(bo);
 207                 ret = PTR_ERR(fb);
 208                 goto fail;
 209         }
 210
 211         /* note: this keeps the bo pinned.. which is perhaps not ideal,
 212          * but is needed as long as we use fb_mmap() to mmap to userspace
 213          * (since this happens using fix.smem_start).  Possibly we could
 214          * implement our own mmap using GEM mmap support to avoid this
 215          * (non-tiled buffer doesn't need to be pinned for fbcon to write
 216          * to it).  Then we just need to be sure that we are able to re-
 217          * pin it in case of an opps.
 218          */
 219         ret = omap_gem_pin(bo, &dma_addr);
 220         if (ret) {
 221                 dev_err(dev->dev, "could not pin framebuffer\n");
 222                 ret = -ENOMEM;
 223                 goto fail;
 224         }
 225
 226         fbi = drm_fb_helper_alloc_info(helper);
 227         if (IS_ERR(fbi)) {
 228                 dev_err(dev->dev, "failed to allocate fb info\n");
 229                 ret = PTR_ERR(fbi);
 230                 goto fail;
 231         }
 232
 233         DBG("fbi=%p, dev=%p", fbi, dev);
 234
 235         helper->funcs = &omap_fbdev_helper_funcs;
 236         helper->fb = fb;
 237
 238         fbi->fbops = &omap_fb_ops;
 239
 240         drm_fb_helper_fill_info(fbi, helper, sizes);
 241
 242         fbi->flags |= FBINFO_VIRTFB;
 243         fbi->screen_buffer = omap_gem_vaddr(bo);
 244         fbi->screen_size = bo->size;
 245         fbi->fix.smem_start = dma_addr;
 246         fbi->fix.smem_len = bo->size;
 247
 248         /* deferred I/O */
 249         helper->fbdefio.delay = HZ / 20;
 250         helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
 251
 252         fbi->fbdefio = &helper->fbdefio;
 253         ret = fb_deferred_io_init(fbi);
 254         if (ret)
 255                 goto fail;
 256
 257         /* if we have DMM, then we can use it for scrolling by just
 258          * shuffling pages around in DMM rather than doing sw blit.
 259          */
 260         if (fbdev->ywrap_enabled) {
 261                 DRM_INFO("Enabling DMM ywrap scrolling\n");
 262                 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
 263                 fbi->fix.ywrapstep = 1;
 264         }
 265
 266
 267         DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
 268         DBG("allocated %dx%d fb", fb->width, fb->height);
 269
 270         return 0;
 271
 272 fail:
 273
 274         if (ret) {
 275                 if (fb)
 276                         drm_framebuffer_remove(fb);
 277         }
 278
 279         return ret;
 280 }
 281
 282 void omap_fbdev_setup(struct drm_device *dev)
 283 {
 284         struct omap_drm_private *priv = dev->dev_private;
 285         struct omap_fbdev *fbdev;
 286
 287         drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
 288         drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 289
 290         fbdev = drmm_kzalloc(dev, sizeof(*fbdev), GFP_KERNEL);
 291         if (!fbdev)
 292                 return;
 293         fbdev->dev = dev;
 294         INIT_WORK(&fbdev->work, pan_worker);
 295
 296         priv->fbdev = fbdev;
 297
 298         drm_client_setup(dev, NULL);
 299 }