drivers/video/fbdev/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 #include <linux/platform_device.h>
  30
  31 #include <mach/hardware.h>
  32 #include <asm/mach-types.h>
  33 #include <linux/uaccess.h>
  34
  35 struct 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  */
  44 static unsigned int lcd_ac_prescale = 13;
  45
  46 /*
  47  *    Set a single color register. Return != 0 for invalid regno.
  48  */
  49 static int
  50 clps7111fb_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  */
  89 static int
  90 clps7111fb_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  */
 110 static int
 111 clps7111fb_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
 160 static 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
 171 static 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
 182 static 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
 270 static 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
 292 out:    return err;
 293 }
 294
 295 static int clps711x_fb_remove(struct platform_device *pdev)
 296 {
 297         unregister_framebuffer(cfb);
 298         kfree(cfb);
 299
 300         return 0;
 301 }
 302
 303 static struct platform_driver clps711x_fb_driver = {
 304         .driver = {
 305                 .name   = "video-clps711x",
 306         },
 307         .probe  = clps711x_fb_probe,
 308         .remove = 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");