linux/drivers/video/cobalt_lcdfb.c
<<
>>
Prefs
   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
  67static inline void lcd_write_control(struct fb_info *info, u8 control)
  68{
  69        writel((u32)control << 24, info->screen_base);
  70}
  71
  72static inline u8 lcd_read_control(struct fb_info *info)
  73{
  74        return readl(info->screen_base) >> 24;
  75}
  76
  77static 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
  82static 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
  93static inline void cpld_wait(struct fb_info *info)
  94{
  95        do {
  96        } while (readl(info->screen_base + CPLD_STATUS) & 1);
  97}
  98
  99static 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
 105static 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
 113static 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
 119static 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
 128static 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
 151static 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
 170static 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
 179static 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
 225static 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
 271static 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
 291static 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
 326static 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
 334static 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        printk(KERN_INFO "fb%d: Cobalt server LCD frame buffer device\n",
 372                info->node);
 373
 374        return 0;
 375}
 376
 377static int cobalt_lcdfb_remove(struct platform_device *dev)
 378{
 379        struct fb_info *info;
 380
 381        info = platform_get_drvdata(dev);
 382        if (info) {
 383                unregister_framebuffer(info);
 384                framebuffer_release(info);
 385        }
 386
 387        return 0;
 388}
 389
 390static struct platform_driver cobalt_lcdfb_driver = {
 391        .probe  = cobalt_lcdfb_probe,
 392        .remove = cobalt_lcdfb_remove,
 393        .driver = {
 394                .name   = "cobalt-lcd",
 395                .owner  = THIS_MODULE,
 396        },
 397};
 398
 399static int __init cobalt_lcdfb_init(void)
 400{
 401        return platform_driver_register(&cobalt_lcdfb_driver);
 402}
 403
 404static void __exit cobalt_lcdfb_exit(void)
 405{
 406        platform_driver_unregister(&cobalt_lcdfb_driver);
 407}
 408
 409module_init(cobalt_lcdfb_init);
 410module_exit(cobalt_lcdfb_exit);
 411
 412MODULE_LICENSE("GPL v2");
 413MODULE_AUTHOR("Yoichi Yuasa");
 414MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");
 415
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.