linux/drivers/video/clps711xfb.c
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   1/*
   2 *  linux/drivers/video/clps711xfb.c
   3 *
   4 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 *
  20 *  Framebuffer driver for the CLPS7111 and EP7212 processors.
  21 */
  22#include <linux/mm.h>
  23#include <linux/module.h>
  24#include <linux/kernel.h>
  25#include <linux/slab.h>
  26#include <linux/fb.h>
  27#include <linux/init.h>
  28#include <linux/delay.h>
  29#include <linux/platform_device.h>
  30
  31#include <mach/hardware.h>
  32#include <asm/mach-types.h>
  33#include <linux/uaccess.h>
  34
  35struct fb_info  *cfb;
  36
  37#define CMAP_MAX_SIZE   16
  38
  39/*
  40 * LCD AC Prescale.  This comes from the LCD panel manufacturers specifications.
  41 * This determines how many clocks + 1 of CL1 before the M signal toggles.
  42 * The number of lines on the display must not be divisible by this number.
  43 */
  44static unsigned int lcd_ac_prescale = 13;
  45
  46/*
  47 *    Set a single color register. Return != 0 for invalid regno.
  48 */
  49static int
  50clps7111fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
  51                     u_int transp, struct fb_info *info)
  52{
  53        unsigned int level, mask, shift, pal;
  54
  55        if (regno >= (1 << info->var.bits_per_pixel))
  56                return 1;
  57
  58        /* gray = 0.30*R + 0.58*G + 0.11*B */
  59        level = (red * 77 + green * 151 + blue * 28) >> 20;
  60
  61        /*
  62         * On an LCD, a high value is dark, while a low value is light. 
  63         * So we invert the level.
  64         *
  65         * This isn't true on all machines, so we only do it on EDB7211.
  66         *  --rmk
  67         */
  68        if (machine_is_edb7211()) {
  69                level = 15 - level;
  70        }
  71
  72        shift = 4 * (regno & 7);
  73        level <<= shift;
  74        mask  = 15 << shift;
  75        level &= mask;
  76
  77        regno = regno < 8 ? PALLSW : PALMSW;
  78
  79        pal = clps_readl(regno);
  80        pal = (pal & ~mask) | level;
  81        clps_writel(pal, regno);
  82
  83        return 0;
  84}
  85
  86/*
  87 * Validate the purposed mode.
  88 */     
  89static int
  90clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
  91{
  92        var->transp.msb_right   = 0;
  93        var->transp.offset      = 0;
  94        var->transp.length      = 0;
  95        var->red.msb_right      = 0;
  96        var->red.offset         = 0;
  97        var->red.length         = var->bits_per_pixel;
  98        var->green              = var->red;
  99        var->blue               = var->red;
 100
 101        if (var->bits_per_pixel > 4) 
 102                return -EINVAL;
 103
 104        return 0;
 105}
 106
 107/*
 108 * Set the hardware state.
 109 */ 
 110static int 
 111clps7111fb_set_par(struct fb_info *info)
 112{
 113        unsigned int lcdcon, syscon, pixclock;
 114
 115        switch (info->var.bits_per_pixel) {
 116        case 1:
 117                info->fix.visual = FB_VISUAL_MONO01;
 118                break;
 119        case 2:
 120                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 121                break;
 122        case 4:
 123                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 124                break;
 125        }
 126
 127        info->fix.line_length = info->var.xres_virtual * info->var.bits_per_pixel / 8;
 128
 129        lcdcon = (info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel) / 128 - 1;
 130        lcdcon |= ((info->var.xres_virtual / 16) - 1) << 13;
 131        lcdcon |= lcd_ac_prescale << 25;
 132
 133        /*
 134         * Calculate pixel prescale value from the pixclock.  This is:
 135         *  36.864MHz / pixclock_mhz - 1.
 136         * However, pixclock is in picoseconds, so this ends up being:
 137         *  36864000 * pixclock_ps / 10^12 - 1
 138         * and this will overflow the 32-bit math.  We perform this as
 139         * (9 * 4096000 == 36864000):
 140         *  pixclock_ps * 9 * (4096000 / 10^12) - 1
 141         */
 142        pixclock = 9 * info->var.pixclock / 244140 - 1;
 143        lcdcon |= pixclock << 19;
 144
 145        if (info->var.bits_per_pixel == 4)
 146                lcdcon |= LCDCON_GSMD;
 147        if (info->var.bits_per_pixel >= 2)
 148                lcdcon |= LCDCON_GSEN;
 149
 150        /*
 151         * LCDCON must only be changed while the LCD is disabled
 152         */
 153        syscon = clps_readl(SYSCON1);
 154        clps_writel(syscon & ~SYSCON1_LCDEN, SYSCON1);
 155        clps_writel(lcdcon, LCDCON);
 156        clps_writel(syscon | SYSCON1_LCDEN, SYSCON1);
 157        return 0;
 158}
 159
 160static int clps7111fb_blank(int blank, struct fb_info *info)
 161{
 162        /* Enable/Disable LCD controller. */
 163        if (blank)
 164                clps_writel(clps_readl(SYSCON1) & ~SYSCON1_LCDEN, SYSCON1);
 165        else
 166                clps_writel(clps_readl(SYSCON1) | SYSCON1_LCDEN, SYSCON1);
 167
 168        return 0;
 169}
 170
 171static struct fb_ops clps7111fb_ops = {
 172        .owner          = THIS_MODULE,
 173        .fb_check_var   = clps7111fb_check_var,
 174        .fb_set_par     = clps7111fb_set_par,
 175        .fb_setcolreg   = clps7111fb_setcolreg,
 176        .fb_blank       = clps7111fb_blank,
 177        .fb_fillrect    = cfb_fillrect,
 178        .fb_copyarea    = cfb_copyarea,
 179        .fb_imageblit   = cfb_imageblit,
 180};
 181
 182static void clps711x_guess_lcd_params(struct fb_info *info)
 183{
 184        unsigned int lcdcon, syscon, size;
 185        unsigned long phys_base = PAGE_OFFSET;
 186        void *virt_base = (void *)PAGE_OFFSET;
 187
 188        info->var.xres_virtual   = 640;
 189        info->var.yres_virtual   = 240;
 190        info->var.bits_per_pixel = 4;
 191        info->var.activate       = FB_ACTIVATE_NOW;
 192        info->var.height         = -1;
 193        info->var.width          = -1;
 194        info->var.pixclock       = 93006; /* 10.752MHz pixel clock */
 195
 196        /*
 197         * If the LCD controller is already running, decode the values
 198         * in LCDCON to xres/yres/bpp/pixclock/acprescale
 199         */
 200        syscon = clps_readl(SYSCON1);
 201        if (syscon & SYSCON1_LCDEN) {
 202                lcdcon = clps_readl(LCDCON);
 203
 204                /*
 205                 * Decode GSMD and GSEN bits to bits per pixel
 206                 */
 207                switch (lcdcon & (LCDCON_GSMD | LCDCON_GSEN)) {
 208                case LCDCON_GSMD | LCDCON_GSEN:
 209                        info->var.bits_per_pixel = 4;
 210                        break;
 211
 212                case LCDCON_GSEN:
 213                        info->var.bits_per_pixel = 2;
 214                        break;
 215
 216                default:
 217                        info->var.bits_per_pixel = 1;
 218                        break;
 219                }
 220
 221                /*
 222                 * Decode xres/yres
 223                 */
 224                info->var.xres_virtual = (((lcdcon >> 13) & 0x3f) + 1) * 16;
 225                info->var.yres_virtual = (((lcdcon & 0x1fff) + 1) * 128) /
 226                                          (info->var.xres_virtual *
 227                                           info->var.bits_per_pixel);
 228
 229                /*
 230                 * Calculate pixclock
 231                 */
 232                info->var.pixclock = (((lcdcon >> 19) & 0x3f) + 1) * 244140 / 9;
 233
 234                /*
 235                 * Grab AC prescale
 236                 */
 237                lcd_ac_prescale = (lcdcon >> 25) & 0x1f;
 238        }
 239
 240        info->var.xres = info->var.xres_virtual;
 241        info->var.yres = info->var.yres_virtual;
 242        info->var.grayscale = info->var.bits_per_pixel > 1;
 243
 244        size = info->var.xres * info->var.yres * info->var.bits_per_pixel / 8;
 245
 246        /*
 247         * Might be worth checking to see if we can use the on-board
 248         * RAM if size here...
 249         * CLPS7110 - no on-board SRAM
 250         * EP7212   - 38400 bytes
 251         */
 252        if (size <= 38400) {
 253                printk(KERN_INFO "CLPS711xFB: could use on-board SRAM?\n");
 254        }
 255
 256        if ((syscon & SYSCON1_LCDEN) == 0) {
 257                /*
 258                 * The display isn't running.  Ensure that
 259                 * the display memory is empty.
 260                 */
 261                memset(virt_base, 0, size);
 262        }
 263
 264        info->screen_base    = virt_base;
 265        info->fix.smem_start = phys_base;
 266        info->fix.smem_len   = PAGE_ALIGN(size);
 267        info->fix.type       = FB_TYPE_PACKED_PIXELS;
 268}
 269
 270static int clps711x_fb_probe(struct platform_device *pdev)
 271{
 272        int err = -ENOMEM;
 273
 274        if (fb_get_options("clps711xfb", NULL))
 275                return -ENODEV;
 276
 277        cfb = kzalloc(sizeof(*cfb), GFP_KERNEL);
 278        if (!cfb)
 279                goto out;
 280
 281        strcpy(cfb->fix.id, "clps711x");
 282
 283        cfb->fbops              = &clps7111fb_ops;
 284        cfb->flags              = FBINFO_DEFAULT;
 285
 286        clps711x_guess_lcd_params(cfb);
 287
 288        fb_alloc_cmap(&cfb->cmap, CMAP_MAX_SIZE, 0);
 289
 290        err = register_framebuffer(cfb);
 291
 292out:    return err;
 293}
 294
 295static int clps711x_fb_remove(struct platform_device *pdev)
 296{
 297        unregister_framebuffer(cfb);
 298        kfree(cfb);
 299
 300        return 0;
 301}
 302
 303static struct platform_driver clps711x_fb_driver = {
 304        .driver = {
 305                .name   = "video-clps711x",
 306                .owner  = THIS_MODULE,
 307        },
 308        .probe  = clps711x_fb_probe,
 309        .remove = clps711x_fb_remove,
 310};
 311module_platform_driver(clps711x_fb_driver);
 312
 313MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 314MODULE_DESCRIPTION("CLPS711X framebuffer driver");
 315MODULE_LICENSE("GPL");
 316
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