drivers/video/fbdev/vt8500lcdfb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/drivers/video/vt8500lcdfb.c
   4  *
   5  *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
   6  *
   7  * Based on skeletonfb.c and pxafb.c
   8  */
   9
  10 #include <linux/delay.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/errno.h>
  13 #include <linux/fb.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mm.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/slab.h>
  22 #include <linux/string.h>
  23 #include <linux/wait.h>
  24 #include <video/of_display_timing.h>
  25
  26 #include "vt8500lcdfb.h"
  27 #include "wmt_ge_rops.h"
  28
  29 #ifdef CONFIG_OF
  30 #include <linux/of.h>
  31 #include <linux/of_fdt.h>
  32 #include <linux/memblock.h>
  33 #endif
  34
  35
  36 #define to_vt8500lcd_info(__info) container_of(__info, \
  37                                                 struct vt8500lcd_info, fb)
  38
  39 static int vt8500lcd_set_par(struct fb_info *info)
  40 {
  41         struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
  42         int reg_bpp = 5; /* 16bpp */
  43         int i;
  44         unsigned long control0;
  45
  46         if (!fbi)
  47                 return -EINVAL;
  48
  49         if (info->var.bits_per_pixel <= 8) {
  50                 /* palettized */
  51                 info->var.red.offset    = 0;
  52                 info->var.red.length    = info->var.bits_per_pixel;
  53                 info->var.red.msb_right = 0;
  54
  55                 info->var.green.offset  = 0;
  56                 info->var.green.length  = info->var.bits_per_pixel;
  57                 info->var.green.msb_right = 0;
  58
  59                 info->var.blue.offset   = 0;
  60                 info->var.blue.length   = info->var.bits_per_pixel;
  61                 info->var.blue.msb_right = 0;
  62
  63                 info->var.transp.offset = 0;
  64                 info->var.transp.length = 0;
  65                 info->var.transp.msb_right = 0;
  66
  67                 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
  68                 info->fix.line_length = info->var.xres_virtual /
  69                                                 (8/info->var.bits_per_pixel);
  70         } else {
  71                 /* non-palettized */
  72                 info->var.transp.offset = 0;
  73                 info->var.transp.length = 0;
  74                 info->var.transp.msb_right = 0;
  75
  76                 if (info->var.bits_per_pixel == 16) {
  77                         /* RGB565 */
  78                         info->var.red.offset = 11;
  79                         info->var.red.length = 5;
  80                         info->var.red.msb_right = 0;
  81                         info->var.green.offset = 5;
  82                         info->var.green.length = 6;
  83                         info->var.green.msb_right = 0;
  84                         info->var.blue.offset = 0;
  85                         info->var.blue.length = 5;
  86                         info->var.blue.msb_right = 0;
  87                 } else {
  88                         /* Equal depths per channel */
  89                         info->var.red.offset = info->var.bits_per_pixel
  90                                                         * 2 / 3;
  91                         info->var.red.length = info->var.bits_per_pixel / 3;
  92                         info->var.red.msb_right = 0;
  93                         info->var.green.offset = info->var.bits_per_pixel / 3;
  94                         info->var.green.length = info->var.bits_per_pixel / 3;
  95                         info->var.green.msb_right = 0;
  96                         info->var.blue.offset = 0;
  97                         info->var.blue.length = info->var.bits_per_pixel / 3;
  98                         info->var.blue.msb_right = 0;
  99                 }
 100
 101                 info->fix.visual = FB_VISUAL_TRUECOLOR;
 102                 info->fix.line_length = info->var.bits_per_pixel > 16 ?
 103                                         info->var.xres_virtual << 2 :
 104                                         info->var.xres_virtual << 1;
 105         }
 106
 107         for (i = 0; i < 8; i++) {
 108                 if (bpp_values[i] == info->var.bits_per_pixel)
 109                         reg_bpp = i;
 110         }
 111
 112         control0 = readl(fbi->regbase) & ~0xf;
 113         writel(0, fbi->regbase);
 114         while (readl(fbi->regbase + 0x38) & 0x10)
 115                 /* wait */;
 116         writel((((info->var.hsync_len - 1) & 0x3f) << 26)
 117                 | ((info->var.left_margin & 0xff) << 18)
 118                 | (((info->var.xres - 1) & 0x3ff) << 8)
 119                 | (info->var.right_margin & 0xff), fbi->regbase + 0x4);
 120         writel((((info->var.vsync_len - 1) & 0x3f) << 26)
 121                 | ((info->var.upper_margin & 0xff) << 18)
 122                 | (((info->var.yres - 1) & 0x3ff) << 8)
 123                 | (info->var.lower_margin & 0xff), fbi->regbase + 0x8);
 124         writel((((info->var.yres - 1) & 0x400) << 2)
 125                 | ((info->var.xres - 1) & 0x400), fbi->regbase + 0x10);
 126         writel(0x80000000, fbi->regbase + 0x20);
 127         writel(control0 | (reg_bpp << 1) | 0x100, fbi->regbase);
 128
 129         return 0;
 130 }
 131
 132 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
 133 {
 134         chan &= 0xffff;
 135         chan >>= 16 - bf->length;
 136         return chan << bf->offset;
 137 }
 138
 139 static int vt8500lcd_setcolreg(unsigned regno, unsigned red, unsigned green,
 140                            unsigned blue, unsigned transp,
 141                            struct fb_info *info) {
 142         struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
 143         int ret = 1;
 144         unsigned int val;
 145         if (regno >= 256)
 146                 return -EINVAL;
 147
 148         if (info->var.grayscale)
 149                 red = green = blue =
 150                         (19595 * red + 38470 * green + 7471 * blue) >> 16;
 151
 152         switch (fbi->fb.fix.visual) {
 153         case FB_VISUAL_TRUECOLOR:
 154                 if (regno < 16) {
 155                         u32 *pal = fbi->fb.pseudo_palette;
 156
 157                         val  = chan_to_field(red, &fbi->fb.var.red);
 158                         val |= chan_to_field(green, &fbi->fb.var.green);
 159                         val |= chan_to_field(blue, &fbi->fb.var.blue);
 160
 161                         pal[regno] = val;
 162                         ret = 0;
 163                 }
 164                 break;
 165
 166         case FB_VISUAL_STATIC_PSEUDOCOLOR:
 167         case FB_VISUAL_PSEUDOCOLOR:
 168                 writew((red & 0xf800)
 169                       | ((green >> 5) & 0x7e0)
 170                       | ((blue >> 11) & 0x1f),
 171                        fbi->palette_cpu + sizeof(u16) * regno);
 172                 break;
 173         }
 174
 175         return ret;
 176 }
 177
 178 static int vt8500lcd_ioctl(struct fb_info *info, unsigned int cmd,
 179                          unsigned long arg)
 180 {
 181         int ret = 0;
 182         struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
 183
 184         if (cmd == FBIO_WAITFORVSYNC) {
 185                 /* Unmask End of Frame interrupt */
 186                 writel(0xffffffff ^ (1 << 3), fbi->regbase + 0x3c);
 187                 ret = wait_event_interruptible_timeout(fbi->wait,
 188                         readl(fbi->regbase + 0x38) & (1 << 3), HZ / 10);
 189                 /* Mask back to reduce unwanted interrupt traffic */
 190                 writel(0xffffffff, fbi->regbase + 0x3c);
 191                 if (ret < 0)
 192                         return ret;
 193                 if (ret == 0)
 194                         return -ETIMEDOUT;
 195         }
 196
 197         return ret;
 198 }
 199
 200 static int vt8500lcd_pan_display(struct fb_var_screeninfo *var,
 201                                 struct fb_info *info)
 202 {
 203         unsigned pixlen = info->fix.line_length / info->var.xres_virtual;
 204         unsigned off = pixlen * var->xoffset
 205                       + info->fix.line_length * var->yoffset;
 206         struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
 207
 208         writel((1 << 31)
 209              | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
 210              | (off >> 2), fbi->regbase + 0x20);
 211         return 0;
 212 }
 213
 214 /*
 215  * vt8500lcd_blank():
 216  *      Blank the display by setting all palette values to zero.  Note,
 217  *      True Color modes do not really use the palette, so this will not
 218  *      blank the display in all modes.
 219  */
 220 static int vt8500lcd_blank(int blank, struct fb_info *info)
 221 {
 222         int i;
 223
 224         switch (blank) {
 225         case FB_BLANK_POWERDOWN:
 226         case FB_BLANK_VSYNC_SUSPEND:
 227         case FB_BLANK_HSYNC_SUSPEND:
 228         case FB_BLANK_NORMAL:
 229                 if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
 230                     info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
 231                         for (i = 0; i < 256; i++)
 232                                 vt8500lcd_setcolreg(i, 0, 0, 0, 0, info);
 233                 fallthrough;
 234         case FB_BLANK_UNBLANK:
 235                 if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
 236                     info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
 237                         fb_set_cmap(&info->cmap, info);
 238         }
 239         return 0;
 240 }
 241
 242 static const struct fb_ops vt8500lcd_ops = {
 243         .owner          = THIS_MODULE,
 244         __FB_DEFAULT_DMAMEM_OPS_RDWR,
 245         .fb_set_par     = vt8500lcd_set_par,
 246         .fb_setcolreg   = vt8500lcd_setcolreg,
 247         .fb_fillrect    = wmt_ge_fillrect,
 248         .fb_copyarea    = wmt_ge_copyarea,
 249         .fb_imageblit   = sys_imageblit,
 250         .fb_sync        = wmt_ge_sync,
 251         .fb_ioctl       = vt8500lcd_ioctl,
 252         .fb_pan_display = vt8500lcd_pan_display,
 253         .fb_blank       = vt8500lcd_blank,
 254         // .fb_mmap needs DMA mmap
 255 };
 256
 257 static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
 258 {
 259         struct vt8500lcd_info *fbi = dev_id;
 260
 261         if (readl(fbi->regbase + 0x38) & (1 << 3))
 262                 wake_up_interruptible(&fbi->wait);
 263
 264         writel(0xffffffff, fbi->regbase + 0x38);
 265         return IRQ_HANDLED;
 266 }
 267
 268 static int vt8500lcd_probe(struct platform_device *pdev)
 269 {
 270         struct vt8500lcd_info *fbi;
 271         struct resource *res;
 272         struct display_timings *disp_timing;
 273         void *addr;
 274         int irq, ret;
 275
 276         struct fb_videomode     of_mode;
 277         u32                     bpp;
 278         dma_addr_t fb_mem_phys;
 279         unsigned long fb_mem_len;
 280         void *fb_mem_virt;
 281
 282         ret = -ENOMEM;
 283         fbi = NULL;
 284
 285         fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
 286                         + sizeof(u32) * 16, GFP_KERNEL);
 287         if (!fbi)
 288                 return -ENOMEM;
 289
 290         strcpy(fbi->fb.fix.id, "VT8500 LCD");
 291
 292         fbi->fb.fix.type        = FB_TYPE_PACKED_PIXELS;
 293         fbi->fb.fix.xpanstep    = 0;
 294         fbi->fb.fix.ypanstep    = 1;
 295         fbi->fb.fix.ywrapstep   = 0;
 296         fbi->fb.fix.accel       = FB_ACCEL_NONE;
 297
 298         fbi->fb.var.nonstd      = 0;
 299         fbi->fb.var.activate    = FB_ACTIVATE_NOW;
 300         fbi->fb.var.height      = -1;
 301         fbi->fb.var.width       = -1;
 302         fbi->fb.var.vmode       = FB_VMODE_NONINTERLACED;
 303
 304         fbi->fb.fbops           = &vt8500lcd_ops;
 305         fbi->fb.flags           = FBINFO_HWACCEL_COPYAREA
 306                                 | FBINFO_HWACCEL_FILLRECT
 307                                 | FBINFO_HWACCEL_YPAN
 308                                 | FBINFO_VIRTFB
 309                                 | FBINFO_PARTIAL_PAN_OK;
 310         fbi->fb.node            = -1;
 311
 312         addr = fbi;
 313         addr = addr + sizeof(struct vt8500lcd_info);
 314         fbi->fb.pseudo_palette  = addr;
 315
 316         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 317         if (res == NULL) {
 318                 dev_err(&pdev->dev, "no I/O memory resource defined\n");
 319                 return -ENODEV;
 320         }
 321
 322         res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
 323         if (res == NULL) {
 324                 dev_err(&pdev->dev, "failed to request I/O memory\n");
 325                 return -EBUSY;
 326         }
 327
 328         fbi->regbase = ioremap(res->start, resource_size(res));
 329         if (fbi->regbase == NULL) {
 330                 dev_err(&pdev->dev, "failed to map I/O memory\n");
 331                 ret = -EBUSY;
 332                 goto failed_free_res;
 333         }
 334
 335         disp_timing = of_get_display_timings(pdev->dev.of_node);
 336         if (!disp_timing) {
 337                 ret = -EINVAL;
 338                 goto failed_free_io;
 339         }
 340
 341         ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
 342                                                         OF_USE_NATIVE_MODE);
 343         if (ret)
 344                 goto failed_free_io;
 345
 346         ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
 347         if (ret)
 348                 goto failed_free_io;
 349
 350         /* try allocating the framebuffer */
 351         fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
 352         fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
 353                                 GFP_KERNEL);
 354         if (!fb_mem_virt) {
 355                 pr_err("%s: Failed to allocate framebuffer\n", __func__);
 356                 ret = -ENOMEM;
 357                 goto failed_free_io;
 358         }
 359
 360         fbi->fb.fix.smem_start  = fb_mem_phys;
 361         fbi->fb.fix.smem_len    = fb_mem_len;
 362         fbi->fb.screen_buffer   = fb_mem_virt;
 363
 364         fbi->palette_size       = PAGE_ALIGN(512);
 365         fbi->palette_cpu        = dma_alloc_coherent(&pdev->dev,
 366                                                      fbi->palette_size,
 367                                                      &fbi->palette_phys,
 368                                                      GFP_KERNEL);
 369         if (fbi->palette_cpu == NULL) {
 370                 dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
 371                 ret = -ENOMEM;
 372                 goto failed_free_io;
 373         }
 374
 375         irq = platform_get_irq(pdev, 0);
 376         if (irq < 0) {
 377                 dev_err(&pdev->dev, "no IRQ defined\n");
 378                 ret = -ENODEV;
 379                 goto failed_free_palette;
 380         }
 381
 382         ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
 383         if (ret) {
 384                 dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
 385                 ret = -EBUSY;
 386                 goto failed_free_palette;
 387         }
 388
 389         init_waitqueue_head(&fbi->wait);
 390
 391         if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
 392                 dev_err(&pdev->dev, "Failed to allocate color map\n");
 393                 ret = -ENOMEM;
 394                 goto failed_free_irq;
 395         }
 396
 397         fb_videomode_to_var(&fbi->fb.var, &of_mode);
 398
 399         fbi->fb.var.xres_virtual        = of_mode.xres;
 400         fbi->fb.var.yres_virtual        = of_mode.yres * 2;
 401         fbi->fb.var.bits_per_pixel      = bpp;
 402
 403         ret = vt8500lcd_set_par(&fbi->fb);
 404         if (ret) {
 405                 dev_err(&pdev->dev, "Failed to set parameters\n");
 406                 goto failed_free_cmap;
 407         }
 408
 409         writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
 410         writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
 411
 412         platform_set_drvdata(pdev, fbi);
 413
 414         ret = register_framebuffer(&fbi->fb);
 415         if (ret < 0) {
 416                 dev_err(&pdev->dev,
 417                         "Failed to register framebuffer device: %d\n", ret);
 418                 goto failed_free_cmap;
 419         }
 420
 421         /*
 422          * Ok, now enable the LCD controller
 423          */
 424         writel(readl(fbi->regbase) | 1, fbi->regbase);
 425
 426         return 0;
 427
 428 failed_free_cmap:
 429         if (fbi->fb.cmap.len)
 430                 fb_dealloc_cmap(&fbi->fb.cmap);
 431 failed_free_irq:
 432         free_irq(irq, fbi);
 433 failed_free_palette:
 434         dma_free_coherent(&pdev->dev, fbi->palette_size,
 435                           fbi->palette_cpu, fbi->palette_phys);
 436 failed_free_io:
 437         iounmap(fbi->regbase);
 438 failed_free_res:
 439         release_mem_region(res->start, resource_size(res));
 440         return ret;
 441 }
 442
 443 static void vt8500lcd_remove(struct platform_device *pdev)
 444 {
 445         struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
 446         struct resource *res;
 447         int irq;
 448
 449         unregister_framebuffer(&fbi->fb);
 450
 451         writel(0, fbi->regbase);
 452
 453         if (fbi->fb.cmap.len)
 454                 fb_dealloc_cmap(&fbi->fb.cmap);
 455
 456         irq = platform_get_irq(pdev, 0);
 457         free_irq(irq, fbi);
 458
 459         dma_free_coherent(&pdev->dev, fbi->palette_size,
 460                           fbi->palette_cpu, fbi->palette_phys);
 461
 462         iounmap(fbi->regbase);
 463
 464         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 465         release_mem_region(res->start, resource_size(res));
 466 }
 467
 468 static const struct of_device_id via_dt_ids[] = {
 469         { .compatible = "via,vt8500-fb", },
 470         {}
 471 };
 472
 473 static struct platform_driver vt8500lcd_driver = {
 474         .probe          = vt8500lcd_probe,
 475         .remove_new     = vt8500lcd_remove,
 476         .driver         = {
 477                 .name   = "vt8500-lcd",
 478                 .of_match_table = of_match_ptr(via_dt_ids),
 479         },
 480 };
 481
 482 module_platform_driver(vt8500lcd_driver);
 483
 484 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
 485 MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
 486 MODULE_LICENSE("GPL v2");
 487 MODULE_DEVICE_TABLE(of, via_dt_ids);