drivers/video/fbdev/ep93xx-fb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/drivers/video/ep93xx-fb.c
   4  *
   5  * Framebuffer support for the EP93xx series.
   6  *
   7  * Copyright (C) 2007 Bluewater Systems Ltd
   8  * Author: Ryan Mallon
   9  *
  10  * Copyright (c) 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
  11  *
  12  * Based on the Cirrus Logic ep93xxfb driver, and various other ep93xxfb
  13  * drivers.
  14  */
  15
  16 #include <linux/platform_device.h>
  17 #include <linux/module.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/slab.h>
  20 #include <linux/clk.h>
  21 #include <linux/fb.h>
  22 #include <linux/io.h>
  23
  24 #include <linux/platform_data/video-ep93xx.h>
  25
  26 /* Vertical Frame Timing Registers */
  27 #define EP93XXFB_VLINES_TOTAL                   0x0000  /* SW locked */
  28 #define EP93XXFB_VSYNC                          0x0004  /* SW locked */
  29 #define EP93XXFB_VACTIVE                        0x0008  /* SW locked */
  30 #define EP93XXFB_VBLANK                         0x0228  /* SW locked */
  31 #define EP93XXFB_VCLK                           0x000c  /* SW locked */
  32
  33 /* Horizontal Frame Timing Registers */
  34 #define EP93XXFB_HCLKS_TOTAL                    0x0010  /* SW locked */
  35 #define EP93XXFB_HSYNC                          0x0014  /* SW locked */
  36 #define EP93XXFB_HACTIVE                        0x0018  /* SW locked */
  37 #define EP93XXFB_HBLANK                         0x022c  /* SW locked */
  38 #define EP93XXFB_HCLK                           0x001c  /* SW locked */
  39
  40 /* Frame Buffer Memory Configuration Registers */
  41 #define EP93XXFB_SCREEN_PAGE                    0x0028
  42 #define EP93XXFB_SCREEN_HPAGE                   0x002c
  43 #define EP93XXFB_SCREEN_LINES                   0x0030
  44 #define EP93XXFB_LINE_LENGTH                    0x0034
  45 #define EP93XXFB_VLINE_STEP                     0x0038
  46 #define EP93XXFB_LINE_CARRY                     0x003c  /* SW locked */
  47 #define EP93XXFB_EOL_OFFSET                     0x0230
  48
  49 /* Other Video Registers */
  50 #define EP93XXFB_BRIGHTNESS                     0x0020
  51 #define EP93XXFB_ATTRIBS                        0x0024  /* SW locked */
  52 #define EP93XXFB_SWLOCK                         0x007c  /* SW locked */
  53 #define EP93XXFB_AC_RATE                        0x0214
  54 #define EP93XXFB_FIFO_LEVEL                     0x0234
  55 #define EP93XXFB_PIXELMODE                      0x0054
  56 #define EP93XXFB_PIXELMODE_32BPP                (0x7 << 0)
  57 #define EP93XXFB_PIXELMODE_24BPP                (0x6 << 0)
  58 #define EP93XXFB_PIXELMODE_16BPP                (0x4 << 0)
  59 #define EP93XXFB_PIXELMODE_8BPP                 (0x2 << 0)
  60 #define EP93XXFB_PIXELMODE_SHIFT_1P_24B         (0x0 << 3)
  61 #define EP93XXFB_PIXELMODE_SHIFT_1P_18B         (0x1 << 3)
  62 #define EP93XXFB_PIXELMODE_COLOR_LUT            (0x0 << 10)
  63 #define EP93XXFB_PIXELMODE_COLOR_888            (0x4 << 10)
  64 #define EP93XXFB_PIXELMODE_COLOR_555            (0x5 << 10)
  65 #define EP93XXFB_PARL_IF_OUT                    0x0058
  66 #define EP93XXFB_PARL_IF_IN                     0x005c
  67
  68 /* Blink Control Registers */
  69 #define EP93XXFB_BLINK_RATE                     0x0040
  70 #define EP93XXFB_BLINK_MASK                     0x0044
  71 #define EP93XXFB_BLINK_PATTRN                   0x0048
  72 #define EP93XXFB_PATTRN_MASK                    0x004c
  73 #define EP93XXFB_BKGRND_OFFSET                  0x0050
  74
  75 /* Hardware Cursor Registers */
  76 #define EP93XXFB_CURSOR_ADR_START               0x0060
  77 #define EP93XXFB_CURSOR_ADR_RESET               0x0064
  78 #define EP93XXFB_CURSOR_SIZE                    0x0068
  79 #define EP93XXFB_CURSOR_COLOR1                  0x006c
  80 #define EP93XXFB_CURSOR_COLOR2                  0x0070
  81 #define EP93XXFB_CURSOR_BLINK_COLOR1            0x021c
  82 #define EP93XXFB_CURSOR_BLINK_COLOR2            0x0220
  83 #define EP93XXFB_CURSOR_XY_LOC                  0x0074
  84 #define EP93XXFB_CURSOR_DSCAN_HY_LOC            0x0078
  85 #define EP93XXFB_CURSOR_BLINK_RATE_CTRL         0x0224
  86
  87 /* LUT Registers */
  88 #define EP93XXFB_GRY_SCL_LUTR                   0x0080
  89 #define EP93XXFB_GRY_SCL_LUTG                   0x0280
  90 #define EP93XXFB_GRY_SCL_LUTB                   0x0300
  91 #define EP93XXFB_LUT_SW_CONTROL                 0x0218
  92 #define EP93XXFB_LUT_SW_CONTROL_SWTCH           (1 << 0)
  93 #define EP93XXFB_LUT_SW_CONTROL_SSTAT           (1 << 1)
  94 #define EP93XXFB_COLOR_LUT                      0x0400
  95
  96 /* Video Signature Registers */
  97 #define EP93XXFB_VID_SIG_RSLT_VAL               0x0200
  98 #define EP93XXFB_VID_SIG_CTRL                   0x0204
  99 #define EP93XXFB_VSIG                           0x0208
 100 #define EP93XXFB_HSIG                           0x020c
 101 #define EP93XXFB_SIG_CLR_STR                    0x0210
 102
 103 /* Minimum / Maximum resolutions supported */
 104 #define EP93XXFB_MIN_XRES                       64
 105 #define EP93XXFB_MIN_YRES                       64
 106 #define EP93XXFB_MAX_XRES                       1024
 107 #define EP93XXFB_MAX_YRES                       768
 108
 109 struct ep93xx_fbi {
 110         struct ep93xxfb_mach_info       *mach_info;
 111         struct clk                      *clk;
 112         struct resource                 *res;
 113         void __iomem                    *mmio_base;
 114         unsigned int                    pseudo_palette[256];
 115 };
 116
 117 static int check_screenpage_bug = 1;
 118 module_param(check_screenpage_bug, int, 0644);
 119 MODULE_PARM_DESC(check_screenpage_bug,
 120                  "Check for bit 27 screen page bug. Default = 1");
 121
 122 static inline unsigned int ep93xxfb_readl(struct ep93xx_fbi *fbi,
 123                                           unsigned int off)
 124 {
 125         return __raw_readl(fbi->mmio_base + off);
 126 }
 127
 128 static inline void ep93xxfb_writel(struct ep93xx_fbi *fbi,
 129                                    unsigned int val, unsigned int off)
 130 {
 131         __raw_writel(val, fbi->mmio_base + off);
 132 }
 133
 134 /*
 135  * Write to one of the locked raster registers.
 136  */
 137 static inline void ep93xxfb_out_locked(struct ep93xx_fbi *fbi,
 138                                        unsigned int val, unsigned int reg)
 139 {
 140         /*
 141          * We don't need a lock or delay here since the raster register
 142          * block will remain unlocked until the next access.
 143          */
 144         ep93xxfb_writel(fbi, 0xaa, EP93XXFB_SWLOCK);
 145         ep93xxfb_writel(fbi, val, reg);
 146 }
 147
 148 static void ep93xxfb_set_video_attribs(struct fb_info *info)
 149 {
 150         struct ep93xx_fbi *fbi = info->par;
 151         unsigned int attribs;
 152
 153         attribs = EP93XXFB_ENABLE;
 154         attribs |= fbi->mach_info->flags;
 155         ep93xxfb_out_locked(fbi, attribs, EP93XXFB_ATTRIBS);
 156 }
 157
 158 static int ep93xxfb_set_pixelmode(struct fb_info *info)
 159 {
 160         struct ep93xx_fbi *fbi = info->par;
 161         unsigned int val;
 162
 163         info->var.transp.offset = 0;
 164         info->var.transp.length = 0;
 165
 166         switch (info->var.bits_per_pixel) {
 167         case 8:
 168                 val = EP93XXFB_PIXELMODE_8BPP | EP93XXFB_PIXELMODE_COLOR_LUT |
 169                         EP93XXFB_PIXELMODE_SHIFT_1P_18B;
 170
 171                 info->var.red.offset    = 0;
 172                 info->var.red.length    = 8;
 173                 info->var.green.offset  = 0;
 174                 info->var.green.length  = 8;
 175                 info->var.blue.offset   = 0;
 176                 info->var.blue.length   = 8;
 177                 info->fix.visual        = FB_VISUAL_PSEUDOCOLOR;
 178                 break;
 179
 180         case 16:
 181                 val = EP93XXFB_PIXELMODE_16BPP | EP93XXFB_PIXELMODE_COLOR_555 |
 182                         EP93XXFB_PIXELMODE_SHIFT_1P_18B;
 183
 184                 info->var.red.offset    = 11;
 185                 info->var.red.length    = 5;
 186                 info->var.green.offset  = 5;
 187                 info->var.green.length  = 6;
 188                 info->var.blue.offset   = 0;
 189                 info->var.blue.length   = 5;
 190                 info->fix.visual        = FB_VISUAL_TRUECOLOR;
 191                 break;
 192
 193         case 24:
 194                 val = EP93XXFB_PIXELMODE_24BPP | EP93XXFB_PIXELMODE_COLOR_888 |
 195                         EP93XXFB_PIXELMODE_SHIFT_1P_24B;
 196
 197                 info->var.red.offset    = 16;
 198                 info->var.red.length    = 8;
 199                 info->var.green.offset  = 8;
 200                 info->var.green.length  = 8;
 201                 info->var.blue.offset   = 0;
 202                 info->var.blue.length   = 8;
 203                 info->fix.visual        = FB_VISUAL_TRUECOLOR;
 204                 break;
 205
 206         case 32:
 207                 val = EP93XXFB_PIXELMODE_32BPP | EP93XXFB_PIXELMODE_COLOR_888 |
 208                         EP93XXFB_PIXELMODE_SHIFT_1P_24B;
 209
 210                 info->var.red.offset    = 16;
 211                 info->var.red.length    = 8;
 212                 info->var.green.offset  = 8;
 213                 info->var.green.length  = 8;
 214                 info->var.blue.offset   = 0;
 215                 info->var.blue.length   = 8;
 216                 info->fix.visual        = FB_VISUAL_TRUECOLOR;
 217                 break;
 218
 219         default:
 220                 return -EINVAL;
 221         }
 222
 223         ep93xxfb_writel(fbi, val, EP93XXFB_PIXELMODE);
 224         return 0;
 225 }
 226
 227 static void ep93xxfb_set_timing(struct fb_info *info)
 228 {
 229         struct ep93xx_fbi *fbi = info->par;
 230         unsigned int vlines_total, hclks_total, start, stop;
 231
 232         vlines_total = info->var.yres + info->var.upper_margin +
 233                 info->var.lower_margin + info->var.vsync_len - 1;
 234
 235         hclks_total = info->var.xres + info->var.left_margin +
 236                 info->var.right_margin + info->var.hsync_len - 1;
 237
 238         ep93xxfb_out_locked(fbi, vlines_total, EP93XXFB_VLINES_TOTAL);
 239         ep93xxfb_out_locked(fbi, hclks_total, EP93XXFB_HCLKS_TOTAL);
 240
 241         start = vlines_total;
 242         stop = vlines_total - info->var.vsync_len;
 243         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VSYNC);
 244
 245         start = vlines_total - info->var.vsync_len - info->var.upper_margin;
 246         stop = info->var.lower_margin - 1;
 247         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VBLANK);
 248         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VACTIVE);
 249
 250         start = vlines_total;
 251         stop = vlines_total + 1;
 252         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VCLK);
 253
 254         start = hclks_total;
 255         stop = hclks_total - info->var.hsync_len;
 256         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HSYNC);
 257
 258         start = hclks_total - info->var.hsync_len - info->var.left_margin;
 259         stop = info->var.right_margin - 1;
 260         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HBLANK);
 261         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HACTIVE);
 262
 263         start = hclks_total;
 264         stop = hclks_total;
 265         ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HCLK);
 266
 267         ep93xxfb_out_locked(fbi, 0x0, EP93XXFB_LINE_CARRY);
 268 }
 269
 270 static int ep93xxfb_set_par(struct fb_info *info)
 271 {
 272         struct ep93xx_fbi *fbi = info->par;
 273
 274         clk_set_rate(fbi->clk, 1000 * PICOS2KHZ(info->var.pixclock));
 275
 276         ep93xxfb_set_timing(info);
 277
 278         info->fix.line_length = info->var.xres_virtual *
 279                 info->var.bits_per_pixel / 8;
 280
 281         ep93xxfb_writel(fbi, info->fix.smem_start, EP93XXFB_SCREEN_PAGE);
 282         ep93xxfb_writel(fbi, info->var.yres - 1, EP93XXFB_SCREEN_LINES);
 283         ep93xxfb_writel(fbi, ((info->var.xres * info->var.bits_per_pixel)
 284                               / 32) - 1, EP93XXFB_LINE_LENGTH);
 285         ep93xxfb_writel(fbi, info->fix.line_length / 4, EP93XXFB_VLINE_STEP);
 286         ep93xxfb_set_video_attribs(info);
 287         return 0;
 288 }
 289
 290 static int ep93xxfb_check_var(struct fb_var_screeninfo *var,
 291                               struct fb_info *info)
 292 {
 293         int err;
 294
 295         err = ep93xxfb_set_pixelmode(info);
 296         if (err)
 297                 return err;
 298
 299         var->xres = max_t(unsigned int, var->xres, EP93XXFB_MIN_XRES);
 300         var->xres = min_t(unsigned int, var->xres, EP93XXFB_MAX_XRES);
 301         var->xres_virtual = max(var->xres_virtual, var->xres);
 302
 303         var->yres = max_t(unsigned int, var->yres, EP93XXFB_MIN_YRES);
 304         var->yres = min_t(unsigned int, var->yres, EP93XXFB_MAX_YRES);
 305         var->yres_virtual = max(var->yres_virtual, var->yres);
 306
 307         return 0;
 308 }
 309
 310 static int ep93xxfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 311 {
 312         unsigned int offset = vma->vm_pgoff << PAGE_SHIFT;
 313
 314         vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
 315
 316         if (offset < info->fix.smem_len) {
 317                 return dma_mmap_wc(info->device, vma, info->screen_base,
 318                                    info->fix.smem_start, info->fix.smem_len);
 319         }
 320
 321         return -EINVAL;
 322 }
 323
 324 static int ep93xxfb_blank(int blank_mode, struct fb_info *info)
 325 {
 326         struct ep93xx_fbi *fbi = info->par;
 327         unsigned int attribs = ep93xxfb_readl(fbi, EP93XXFB_ATTRIBS);
 328
 329         if (blank_mode) {
 330                 if (fbi->mach_info->blank)
 331                         fbi->mach_info->blank(blank_mode, info);
 332                 ep93xxfb_out_locked(fbi, attribs & ~EP93XXFB_ENABLE,
 333                                     EP93XXFB_ATTRIBS);
 334                 clk_disable(fbi->clk);
 335         } else {
 336                 clk_enable(fbi->clk);
 337                 ep93xxfb_out_locked(fbi, attribs | EP93XXFB_ENABLE,
 338                                     EP93XXFB_ATTRIBS);
 339                 if (fbi->mach_info->blank)
 340                         fbi->mach_info->blank(blank_mode, info);
 341         }
 342
 343         return 0;
 344 }
 345
 346 static inline int ep93xxfb_convert_color(int val, int width)
 347 {
 348         return ((val << width) + 0x7fff - val) >> 16;
 349 }
 350
 351 static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
 352                               unsigned int green, unsigned int blue,
 353                               unsigned int transp, struct fb_info *info)
 354 {
 355         struct ep93xx_fbi *fbi = info->par;
 356         unsigned int *pal = info->pseudo_palette;
 357         unsigned int ctrl, i, rgb, lut_current, lut_stat;
 358
 359         switch (info->fix.visual) {
 360         case FB_VISUAL_PSEUDOCOLOR:
 361                 if (regno > 255)
 362                         return 1;
 363                 rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
 364                         ((blue & 0xff00) >> 8);
 365
 366                 pal[regno] = rgb;
 367                 ep93xxfb_writel(fbi, rgb, (EP93XXFB_COLOR_LUT + (regno << 2)));
 368                 ctrl = ep93xxfb_readl(fbi, EP93XXFB_LUT_SW_CONTROL);
 369                 lut_stat = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SSTAT);
 370                 lut_current = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SWTCH);
 371
 372                 if (lut_stat == lut_current) {
 373                         for (i = 0; i < 256; i++) {
 374                                 ep93xxfb_writel(fbi, pal[i],
 375                                         EP93XXFB_COLOR_LUT + (i << 2));
 376                         }
 377
 378                         ep93xxfb_writel(fbi,
 379                                         ctrl ^ EP93XXFB_LUT_SW_CONTROL_SWTCH,
 380                                         EP93XXFB_LUT_SW_CONTROL);
 381                 }
 382                 break;
 383
 384         case FB_VISUAL_TRUECOLOR:
 385                 if (regno > 16)
 386                         return 1;
 387
 388                 red = ep93xxfb_convert_color(red, info->var.red.length);
 389                 green = ep93xxfb_convert_color(green, info->var.green.length);
 390                 blue = ep93xxfb_convert_color(blue, info->var.blue.length);
 391                 transp = ep93xxfb_convert_color(transp,
 392                                                 info->var.transp.length);
 393
 394                 pal[regno] = (red << info->var.red.offset) |
 395                         (green << info->var.green.offset) |
 396                         (blue << info->var.blue.offset) |
 397                         (transp << info->var.transp.offset);
 398                 break;
 399
 400         default:
 401                 return 1;
 402         }
 403
 404         return 0;
 405 }
 406
 407 static const struct fb_ops ep93xxfb_ops = {
 408         .owner          = THIS_MODULE,
 409         __FB_DEFAULT_IOMEM_OPS_RDWR,
 410         .fb_check_var   = ep93xxfb_check_var,
 411         .fb_set_par     = ep93xxfb_set_par,
 412         .fb_blank       = ep93xxfb_blank,
 413         __FB_DEFAULT_IOMEM_OPS_DRAW,
 414         .fb_setcolreg   = ep93xxfb_setcolreg,
 415         .fb_mmap        = ep93xxfb_mmap,
 416 };
 417
 418 static int ep93xxfb_alloc_videomem(struct fb_info *info)
 419 {
 420         char __iomem *virt_addr;
 421         dma_addr_t phys_addr;
 422         unsigned int fb_size;
 423
 424         /* Maximum 16bpp -> used memory is maximum x*y*2 bytes */
 425         fb_size = EP93XXFB_MAX_XRES * EP93XXFB_MAX_YRES * 2;
 426
 427         virt_addr = dma_alloc_wc(info->device, fb_size, &phys_addr, GFP_KERNEL);
 428         if (!virt_addr)
 429                 return -ENOMEM;
 430
 431         /*
 432          * There is a bug in the ep93xx framebuffer which causes problems
 433          * if bit 27 of the physical address is set.
 434          * See: https://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
 435          * There does not seem to be any official errata for this, but I
 436          * have confirmed the problem exists on my hardware (ep9315) at
 437          * least.
 438          */
 439         if (check_screenpage_bug && phys_addr & (1 << 27)) {
 440                 fb_err(info, "ep93xx framebuffer bug. phys addr (0x%x) "
 441                        "has bit 27 set: cannot init framebuffer\n",
 442                        phys_addr);
 443
 444                 dma_free_coherent(info->device, fb_size, virt_addr, phys_addr);
 445                 return -ENOMEM;
 446         }
 447
 448         info->fix.smem_start = phys_addr;
 449         info->fix.smem_len = fb_size;
 450         info->screen_base = virt_addr;
 451
 452         return 0;
 453 }
 454
 455 static void ep93xxfb_dealloc_videomem(struct fb_info *info)
 456 {
 457         if (info->screen_base)
 458                 dma_free_coherent(info->device, info->fix.smem_len,
 459                                   info->screen_base, info->fix.smem_start);
 460 }
 461
 462 static int ep93xxfb_probe(struct platform_device *pdev)
 463 {
 464         struct ep93xxfb_mach_info *mach_info = dev_get_platdata(&pdev->dev);
 465         struct fb_info *info;
 466         struct ep93xx_fbi *fbi;
 467         struct resource *res;
 468         char *video_mode;
 469         int err;
 470
 471         if (!mach_info)
 472                 return -EINVAL;
 473
 474         info = framebuffer_alloc(sizeof(struct ep93xx_fbi), &pdev->dev);
 475         if (!info)
 476                 return -ENOMEM;
 477
 478         platform_set_drvdata(pdev, info);
 479         fbi = info->par;
 480         fbi->mach_info = mach_info;
 481
 482         err = fb_alloc_cmap(&info->cmap, 256, 0);
 483         if (err)
 484                 goto failed_cmap;
 485
 486         err = ep93xxfb_alloc_videomem(info);
 487         if (err)
 488                 goto failed_videomem;
 489
 490         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 491         if (!res) {
 492                 err = -ENXIO;
 493                 goto failed_resource;
 494         }
 495
 496         /*
 497          * FIXME - We don't do a request_mem_region here because we are
 498          * sharing the register space with the backlight driver (see
 499          * drivers/video/backlight/ep93xx_bl.c) and doing so will cause
 500          * the second loaded driver to return -EBUSY.
 501          *
 502          * NOTE: No locking is required; the backlight does not touch
 503          * any of the framebuffer registers.
 504          */
 505         fbi->res = res;
 506         fbi->mmio_base = devm_ioremap(&pdev->dev, res->start,
 507                                       resource_size(res));
 508         if (!fbi->mmio_base) {
 509                 err = -ENXIO;
 510                 goto failed_resource;
 511         }
 512
 513         strcpy(info->fix.id, pdev->name);
 514         info->fbops             = &ep93xxfb_ops;
 515         info->fix.type          = FB_TYPE_PACKED_PIXELS;
 516         info->fix.accel         = FB_ACCEL_NONE;
 517         info->var.activate      = FB_ACTIVATE_NOW;
 518         info->var.vmode         = FB_VMODE_NONINTERLACED;
 519         info->node              = -1;
 520         info->state             = FBINFO_STATE_RUNNING;
 521         info->pseudo_palette    = &fbi->pseudo_palette;
 522
 523         fb_get_options("ep93xx-fb", &video_mode);
 524         err = fb_find_mode(&info->var, info, video_mode,
 525                            NULL, 0, NULL, 16);
 526         if (err == 0) {
 527                 fb_err(info, "No suitable video mode found\n");
 528                 err = -EINVAL;
 529                 goto failed_resource;
 530         }
 531
 532         if (mach_info->setup) {
 533                 err = mach_info->setup(pdev);
 534                 if (err)
 535                         goto failed_resource;
 536         }
 537
 538         err = ep93xxfb_check_var(&info->var, info);
 539         if (err)
 540                 goto failed_check;
 541
 542         fbi->clk = devm_clk_get(&pdev->dev, NULL);
 543         if (IS_ERR(fbi->clk)) {
 544                 err = PTR_ERR(fbi->clk);
 545                 fbi->clk = NULL;
 546                 goto failed_check;
 547         }
 548
 549         ep93xxfb_set_par(info);
 550         err = clk_prepare_enable(fbi->clk);
 551         if (err)
 552                 goto failed_check;
 553
 554         err = register_framebuffer(info);
 555         if (err)
 556                 goto failed_framebuffer;
 557
 558         fb_info(info, "registered. Mode = %dx%d-%d\n",
 559                 info->var.xres, info->var.yres, info->var.bits_per_pixel);
 560         return 0;
 561
 562 failed_framebuffer:
 563         clk_disable_unprepare(fbi->clk);
 564 failed_check:
 565         if (fbi->mach_info->teardown)
 566                 fbi->mach_info->teardown(pdev);
 567 failed_resource:
 568         ep93xxfb_dealloc_videomem(info);
 569 failed_videomem:
 570         fb_dealloc_cmap(&info->cmap);
 571 failed_cmap:
 572         kfree(info);
 573
 574         return err;
 575 }
 576
 577 static void ep93xxfb_remove(struct platform_device *pdev)
 578 {
 579         struct fb_info *info = platform_get_drvdata(pdev);
 580         struct ep93xx_fbi *fbi = info->par;
 581
 582         unregister_framebuffer(info);
 583         clk_disable_unprepare(fbi->clk);
 584         ep93xxfb_dealloc_videomem(info);
 585         fb_dealloc_cmap(&info->cmap);
 586
 587         if (fbi->mach_info->teardown)
 588                 fbi->mach_info->teardown(pdev);
 589
 590         kfree(info);
 591 }
 592
 593 static struct platform_driver ep93xxfb_driver = {
 594         .probe          = ep93xxfb_probe,
 595         .remove         = ep93xxfb_remove,
 596         .driver = {
 597                 .name   = "ep93xx-fb",
 598         },
 599 };
 600 module_platform_driver(ep93xxfb_driver);
 601
 602 MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
 603 MODULE_ALIAS("platform:ep93xx-fb");
 604 MODULE_AUTHOR("Ryan Mallon, "
 605               "H Hartley Sweeten <hsweeten@visionengravers.com");
 606 MODULE_LICENSE("GPL");