drivers/video/clps711xfb.c

   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
  34 struct 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  */
  43 static unsigned int lcd_ac_prescale = 13;
  44
  45 /*
  46  *    Set a single color register. Return != 0 for invalid regno.
  47  */
  48 static int
  49 clps7111fb_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  */
  88 static int
  89 clps7111fb_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  */
 109 static int
 110 clps7111fb_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
 159 static 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
 170 static 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
 181 static void __devinit 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
 269 static int __devinit 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
 291 out:    return err;
 292 }
 293
 294 static int __devexit clps711x_fb_remove(struct platform_device *pdev)
 295 {
 296         unregister_framebuffer(cfb);
 297         kfree(cfb);
 298
 299         return 0;
 300 }
 301
 302 static struct platform_driver clps711x_fb_driver = {
 303         .driver = {
 304                 .name   = "video-clps711x",
 305                 .owner  = THIS_MODULE,
 306         },
 307         .probe  = clps711x_fb_probe,
 308         .remove = __devexit_p(clps711x_fb_remove),
 309 };
 310 module_platform_driver(clps711x_fb_driver);
 311
 312 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 313 MODULE_DESCRIPTION("CLPS711X framebuffer driver");
 314 MODULE_LICENSE("GPL");