linux/drivers/video/cobalt_lcdfb.c
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   1/*
   2 *  Cobalt server LCD frame buffer driver.
   3 *
   4 *  Copyright (C) 2008  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
   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
  64static inline void lcd_write_control(struct fb_info *info, u8 control)
  65{
  66        writel((u32)control << 24, info->screen_base);
  67}
  68
  69static inline u8 lcd_read_control(struct fb_info *info)
  70{
  71        return readl(info->screen_base) >> 24;
  72}
  73
  74static 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
  79static inline u8 lcd_read_data(struct fb_info *info)
  80{
  81        return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24;
  82}
  83
  84static 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
 107static 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
 126static 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
 135static 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
 181static 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
 227static 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
 247static 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
 282static 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
 290static 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
 333static 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
 347static 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
 356static int __init cobalt_lcdfb_init(void)
 357{
 358        return platform_driver_register(&cobalt_lcdfb_driver);
 359}
 360
 361static void __exit cobalt_lcdfb_exit(void)
 362{
 363        platform_driver_unregister(&cobalt_lcdfb_driver);
 364}
 365
 366module_init(cobalt_lcdfb_init);
 367module_exit(cobalt_lcdfb_exit);
 368
 369MODULE_LICENSE("GPL v2");
 370MODULE_AUTHOR("Yoichi Yuasa");
 371MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");
 372