drivers/video/cobalt_lcdfb.c

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