drivers/video/cobalt_lcdfb.c

   1 /*
   2  *  Cobalt/SEAD3 LCD frame buffer driver.
   3  *
   4  *  Copyright (C) 2008  Yoichi Yuasa <yuasa@linux-mips.org>
   5  *  Copyright (C) 2012  MIPS Technologies, Inc.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include <linux/delay.h>
  22 #include <linux/fb.h>
  23 #include <linux/init.h>
  24 #include <linux/io.h>
  25 #include <linux/ioport.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/module.h>
  29
  30 /*
  31  * Cursor position address
  32  * \X  0    1    2  ...  14   15
  33  * Y+----+----+----+---+----+----+
  34  * 0|0x00|0x01|0x02|...|0x0e|0x0f|
  35  *  +----+----+----+---+----+----+
  36  * 1|0x40|0x41|0x42|...|0x4e|0x4f|
  37  *  +----+----+----+---+----+----+
  38  */
  39 #define LCD_DATA_REG_OFFSET     0x10
  40 #define LCD_XRES_MAX            16
  41 #define LCD_YRES_MAX            2
  42 #define LCD_CHARS_MAX           32
  43
  44 #define LCD_CLEAR               0x01
  45 #define LCD_CURSOR_MOVE_HOME    0x02
  46 #define LCD_RESET               0x06
  47 #define LCD_OFF                 0x08
  48 #define LCD_CURSOR_OFF          0x0c
  49 #define LCD_CURSOR_BLINK_OFF    0x0e
  50 #define LCD_CURSOR_ON           0x0f
  51 #define LCD_ON                  LCD_CURSOR_ON
  52 #define LCD_CURSOR_MOVE_LEFT    0x10
  53 #define LCD_CURSOR_MOVE_RIGHT   0x14
  54 #define LCD_DISPLAY_LEFT        0x18
  55 #define LCD_DISPLAY_RIGHT       0x1c
  56 #define LCD_PRERESET            0x3f    /* execute 4 times continuously */
  57 #define LCD_BUSY                0x80
  58
  59 #define LCD_GRAPHIC_MODE        0x40
  60 #define LCD_TEXT_MODE           0x80
  61 #define LCD_CUR_POS_MASK        0x7f
  62
  63 #define LCD_CUR_POS(x)          ((x) & LCD_CUR_POS_MASK)
  64 #define LCD_TEXT_POS(x)         ((x) | LCD_TEXT_MODE)
  65
  66 #ifdef CONFIG_MIPS_COBALT
  67 static inline void lcd_write_control(struct fb_info *info, u8 control)
  68 {
  69         writel((u32)control << 24, info->screen_base);
  70 }
  71
  72 static inline u8 lcd_read_control(struct fb_info *info)
  73 {
  74         return readl(info->screen_base) >> 24;
  75 }
  76
  77 static inline void lcd_write_data(struct fb_info *info, u8 data)
  78 {
  79         writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET);
  80 }
  81
  82 static inline u8 lcd_read_data(struct fb_info *info)
  83 {
  84         return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
  85 }
  86 #else
  87
  88 #define LCD_CTL                 0x00
  89 #define LCD_DATA                0x08
  90 #define CPLD_STATUS             0x10
  91 #define CPLD_DATA               0x18
  92
  93 static inline void cpld_wait(struct fb_info *info)
  94 {
  95         do {
  96         } while (readl(info->screen_base + CPLD_STATUS) & 1);
  97 }
  98
  99 static inline void lcd_write_control(struct fb_info *info, u8 control)
 100 {
 101         cpld_wait(info);
 102         writel(control, info->screen_base + LCD_CTL);
 103 }
 104
 105 static inline u8 lcd_read_control(struct fb_info *info)
 106 {
 107         cpld_wait(info);
 108         readl(info->screen_base + LCD_CTL);
 109         cpld_wait(info);
 110         return readl(info->screen_base + CPLD_DATA) & 0xff;
 111 }
 112
 113 static inline void lcd_write_data(struct fb_info *info, u8 data)
 114 {
 115         cpld_wait(info);
 116         writel(data, info->screen_base + LCD_DATA);
 117 }
 118
 119 static inline u8 lcd_read_data(struct fb_info *info)
 120 {
 121         cpld_wait(info);
 122         readl(info->screen_base + LCD_DATA);
 123         cpld_wait(info);
 124         return readl(info->screen_base + CPLD_DATA) & 0xff;
 125 }
 126 #endif
 127
 128 static int lcd_busy_wait(struct fb_info *info)
 129 {
 130         u8 val = 0;
 131         int timeout = 10, retval = 0;
 132
 133         do {
 134                 val = lcd_read_control(info);
 135                 val &= LCD_BUSY;
 136                 if (val != LCD_BUSY)
 137                         break;
 138
 139                 if (msleep_interruptible(1))
 140                         return -EINTR;
 141
 142                 timeout--;
 143         } while (timeout);
 144
 145         if (val == LCD_BUSY)
 146                 retval = -EBUSY;
 147
 148         return retval;
 149 }
 150
 151 static void lcd_clear(struct fb_info *info)
 152 {
 153         int i;
 154
 155         for (i = 0; i < 4; i++) {
 156                 udelay(150);
 157
 158                 lcd_write_control(info, LCD_PRERESET);
 159         }
 160
 161         udelay(150);
 162
 163         lcd_write_control(info, LCD_CLEAR);
 164
 165         udelay(150);
 166
 167         lcd_write_control(info, LCD_RESET);
 168 }
 169
 170 static struct fb_fix_screeninfo cobalt_lcdfb_fix = {
 171         .id             = "cobalt-lcd",
 172         .type           = FB_TYPE_TEXT,
 173         .type_aux       = FB_AUX_TEXT_MDA,
 174         .visual         = FB_VISUAL_MONO01,
 175         .line_length    = LCD_XRES_MAX,
 176         .accel          = FB_ACCEL_NONE,
 177 };
 178
 179 static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf,
 180                                  size_t count, loff_t *ppos)
 181 {
 182         char src[LCD_CHARS_MAX];
 183         unsigned long pos;
 184         int len, retval = 0;
 185
 186         pos = *ppos;
 187         if (pos >= LCD_CHARS_MAX || count == 0)
 188                 return 0;
 189
 190         if (count > LCD_CHARS_MAX)
 191                 count = LCD_CHARS_MAX;
 192
 193         if (pos + count > LCD_CHARS_MAX)
 194                 count = LCD_CHARS_MAX - pos;
 195
 196         for (len = 0; len < count; len++) {
 197                 retval = lcd_busy_wait(info);
 198                 if (retval < 0)
 199                         break;
 200
 201                 lcd_write_control(info, LCD_TEXT_POS(pos));
 202
 203                 retval = lcd_busy_wait(info);
 204                 if (retval < 0)
 205                         break;
 206
 207                 src[len] = lcd_read_data(info);
 208                 if (pos == 0x0f)
 209                         pos = 0x40;
 210                 else
 211                         pos++;
 212         }
 213
 214         if (retval < 0 && signal_pending(current))
 215                 return -ERESTARTSYS;
 216
 217         if (copy_to_user(buf, src, len))
 218                 return -EFAULT;
 219
 220         *ppos += len;
 221
 222         return len;
 223 }
 224
 225 static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf,
 226                                   size_t count, loff_t *ppos)
 227 {
 228         char dst[LCD_CHARS_MAX];
 229         unsigned long pos;
 230         int len, retval = 0;
 231
 232         pos = *ppos;
 233         if (pos >= LCD_CHARS_MAX || count == 0)
 234                 return 0;
 235
 236         if (count > LCD_CHARS_MAX)
 237                 count = LCD_CHARS_MAX;
 238
 239         if (pos + count > LCD_CHARS_MAX)
 240                 count = LCD_CHARS_MAX - pos;
 241
 242         if (copy_from_user(dst, buf, count))
 243                 return -EFAULT;
 244
 245         for (len = 0; len < count; len++) {
 246                 retval = lcd_busy_wait(info);
 247                 if (retval < 0)
 248                         break;
 249
 250                 lcd_write_control(info, LCD_TEXT_POS(pos));
 251
 252                 retval = lcd_busy_wait(info);
 253                 if (retval < 0)
 254                         break;
 255
 256                 lcd_write_data(info, dst[len]);
 257                 if (pos == 0x0f)
 258                         pos = 0x40;
 259                 else
 260                         pos++;
 261         }
 262
 263         if (retval < 0 && signal_pending(current))
 264                 return -ERESTARTSYS;
 265
 266         *ppos += len;
 267
 268         return len;
 269 }
 270
 271 static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info)
 272 {
 273         int retval;
 274
 275         retval = lcd_busy_wait(info);
 276         if (retval < 0)
 277                 return retval;
 278
 279         switch (blank_mode) {
 280         case FB_BLANK_UNBLANK:
 281                 lcd_write_control(info, LCD_ON);
 282                 break;
 283         default:
 284                 lcd_write_control(info, LCD_OFF);
 285                 break;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
 292 {
 293         u32 x, y;
 294         int retval;
 295
 296         switch (cursor->set) {
 297         case FB_CUR_SETPOS:
 298                 x = cursor->image.dx;
 299                 y = cursor->image.dy;
 300                 if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX)
 301                         return -EINVAL;
 302
 303                 retval = lcd_busy_wait(info);
 304                 if (retval < 0)
 305                         return retval;
 306
 307                 lcd_write_control(info,
 308                                   LCD_TEXT_POS(info->fix.line_length * y + x));
 309                 break;
 310         default:
 311                 return -EINVAL;
 312         }
 313
 314         retval = lcd_busy_wait(info);
 315         if (retval < 0)
 316                 return retval;
 317
 318         if (cursor->enable)
 319                 lcd_write_control(info, LCD_CURSOR_ON);
 320         else
 321                 lcd_write_control(info, LCD_CURSOR_OFF);
 322
 323         return 0;
 324 }
 325
 326 static struct fb_ops cobalt_lcd_fbops = {
 327         .owner          = THIS_MODULE,
 328         .fb_read        = cobalt_lcdfb_read,
 329         .fb_write       = cobalt_lcdfb_write,
 330         .fb_blank       = cobalt_lcdfb_blank,
 331         .fb_cursor      = cobalt_lcdfb_cursor,
 332 };
 333
 334 static int cobalt_lcdfb_probe(struct platform_device *dev)
 335 {
 336         struct fb_info *info;
 337         struct resource *res;
 338         int retval;
 339
 340         info = framebuffer_alloc(0, &dev->dev);
 341         if (!info)
 342                 return -ENOMEM;
 343
 344         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 345         if (!res) {
 346                 framebuffer_release(info);
 347                 return -EBUSY;
 348         }
 349
 350         info->screen_size = resource_size(res);
 351         info->screen_base = devm_ioremap(&dev->dev, res->start,
 352                                          info->screen_size);
 353         info->fbops = &cobalt_lcd_fbops;
 354         info->fix = cobalt_lcdfb_fix;
 355         info->fix.smem_start = res->start;
 356         info->fix.smem_len = info->screen_size;
 357         info->pseudo_palette = NULL;
 358         info->par = NULL;
 359         info->flags = FBINFO_DEFAULT;
 360
 361         retval = register_framebuffer(info);
 362         if (retval < 0) {
 363                 framebuffer_release(info);
 364                 return retval;
 365         }
 366
 367         platform_set_drvdata(dev, info);
 368
 369         lcd_clear(info);
 370
 371         fb_info(info, "Cobalt server LCD frame buffer device\n");
 372
 373         return 0;
 374 }
 375
 376 static int cobalt_lcdfb_remove(struct platform_device *dev)
 377 {
 378         struct fb_info *info;
 379
 380         info = platform_get_drvdata(dev);
 381         if (info) {
 382                 unregister_framebuffer(info);
 383                 framebuffer_release(info);
 384         }
 385
 386         return 0;
 387 }
 388
 389 static struct platform_driver cobalt_lcdfb_driver = {
 390         .probe  = cobalt_lcdfb_probe,
 391         .remove = cobalt_lcdfb_remove,
 392         .driver = {
 393                 .name   = "cobalt-lcd",
 394                 .owner  = THIS_MODULE,
 395         },
 396 };
 397 module_platform_driver(cobalt_lcdfb_driver);
 398
 399 MODULE_LICENSE("GPL v2");
 400 MODULE_AUTHOR("Yoichi Yuasa");
 401 MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");