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