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