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