#include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/mm.h>
  #include <linux/delay.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  
  #include <asm/setup.h>
  #include <asm/irq.h>
  #include <asm/amigahw.h>
  #include <asm/amigaints.h>
  #include <asm/apollohw.h>
  #include <linux/fb.h>
  #include <linux/module.h>
  
  /* apollo video HW definitions */
  
  /*
   * Control Registers.   IOBASE + $x
   *
   * Note: these are the Memory/IO BASE definitions for a mono card set to the
   * alternate address
   *
   * Control 3A and 3B serve identical functions except that 3A
   * deals with control 1 and 3b deals with Color LUT reg.
   */
  
  #define AP_IOBASE       0x3b0	/* Base address of 1 plane board. */
  #define AP_STATUS       isaIO2mem(AP_IOBASE+0)	/* Status register.  Read */
  #define AP_WRITE_ENABLE isaIO2mem(AP_IOBASE+0)	/* Write Enable Register Write */
  #define AP_DEVICE_ID    isaIO2mem(AP_IOBASE+1)	/* Device ID Register. Read */
  #define AP_ROP_1        isaIO2mem(AP_IOBASE+2)	/* Raster Operation reg. Write Word */
  #define AP_DIAG_MEM_REQ isaIO2mem(AP_IOBASE+4)	/* Diagnostic Memory Request. Write Word */
  #define AP_CONTROL_0    isaIO2mem(AP_IOBASE+8)	/* Control Register 0.  Read/Write */
  #define AP_CONTROL_1    isaIO2mem(AP_IOBASE+0xa)	/* Control Register 1.  Read/Write */
  #define AP_CONTROL_3A   isaIO2mem(AP_IOBASE+0xe)	/* Control Register 3a. Read/Write */
  #define AP_CONTROL_2    isaIO2mem(AP_IOBASE+0xc)	/* Control Register 2. Read/Write */
  
  
  #define FRAME_BUFFER_START 0x0FA0000
  #define FRAME_BUFFER_LEN 0x40000
  
  /* CREG 0 */
  #define VECTOR_MODE 0x40	/* 010x.xxxx */
  #define DBLT_MODE   0x80	/* 100x.xxxx */
  #define NORMAL_MODE 0xE0	/* 111x.xxxx */
  #define SHIFT_BITS  0x1F	/* xxx1.1111 */
  	/* other bits are Shift value */
  
  /* CREG 1 */
  #define AD_BLT      0x80	/* 1xxx.xxxx */
  #define NORMAL      0x80 /* 1xxx.xxxx */	/* What is happening here ?? */
  #define INVERSE     0x00 /* 0xxx.xxxx */	/* Clearing this reverses the screen */
  #define PIX_BLT     0x00	/* 0xxx.xxxx */
  
  #define AD_HIBIT        0x40	/* xIxx.xxxx */
  
  #define ROP_EN          0x10	/* xxx1.xxxx */
  #define DST_EQ_SRC      0x00	/* xxx0.xxxx */
  #define nRESET_SYNC     0x08	/* xxxx.1xxx */
  #define SYNC_ENAB       0x02	/* xxxx.xx1x */
  
  #define BLANK_DISP      0x00	/* xxxx.xxx0 */
  #define ENAB_DISP       0x01	/* xxxx.xxx1 */
  
  #define NORM_CREG1      (nRESET_SYNC | SYNC_ENAB | ENAB_DISP)	/* no reset sync */
  
  /* CREG 2 */
  
  /*
   * Following 3 defines are common to 1, 4 and 8 plane.
   */
  
  #define S_DATA_1s   0x00 /* 00xx.xxxx */	/* set source to all 1's -- vector drawing */
  #define S_DATA_PIX  0x40 /* 01xx.xxxx */	/* takes source from ls-bits and replicates over 16 bits */
  #define S_DATA_PLN  0xC0 /* 11xx.xxxx */	/* normal, each data access =16-bits in
  						   one plane of image mem */
  
  /* CREG 3A/CREG 3B */
  #       define RESET_CREG 0x80	/* 1000.0000 */
  
  /* ROP REG  -  all one nibble */
  /*      ********* NOTE : this is used r0,r1,r2,r3 *********** */
  #define ROP(r2,r3,r0,r1) ( (U_SHORT)((r0)|((r1)<<4)|((r2)<<8)|((r3)<<12)) )
  #define DEST_ZERO               0x0
  #define SRC_AND_DEST    0x1
  #define SRC_AND_nDEST   0x2
  #define SRC                             0x3
  #define nSRC_AND_DEST   0x4
  #define DEST                    0x5
  #define SRC_XOR_DEST    0x6
  #define SRC_OR_DEST             0x7
  #define SRC_NOR_DEST    0x8
  #define SRC_XNOR_DEST   0x9
  #define nDEST                   0xA
  #define SRC_OR_nDEST    0xB
  #define nSRC                    0xC
  #define nSRC_OR_DEST    0xD
  #define SRC_NAND_DEST   0xE
  #define DEST_ONE                0xF
  
  #define SWAP(A) ((A>>8) | ((A&0xff) <<8))
  
  /* frame buffer operations */
  
  static int dnfb_blank(int blank, struct fb_info *info);
  static void dnfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
  
  static struct fb_ops dn_fb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_blank	= dnfb_blank,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= dnfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };
  
  struct fb_var_screeninfo dnfb_var = {
  	.xres		= 1280,
  	.yres		= 1024,
  	.xres_virtual	= 2048,
  	.yres_virtual	= 1024,
  	.bits_per_pixel	= 1,
  	.height		= -1,
  	.width		= -1,
  	.vmode		= FB_VMODE_NONINTERLACED,
  };
  
  static struct fb_fix_screeninfo dnfb_fix = {
  	.id		= "Apollo Mono",
  	.smem_start	= (FRAME_BUFFER_START + IO_BASE),
  	.smem_len	= FRAME_BUFFER_LEN,
  	.type		= FB_TYPE_PACKED_PIXELS,
  	.visual		= FB_VISUAL_MONO10,
  	.line_length	= 256,
  };
  
  static int dnfb_blank(int blank, struct fb_info *info)
  {
  	if (blank)
  		out_8(AP_CONTROL_3A, 0x0);
  	else
  		out_8(AP_CONTROL_3A, 0x1);
  	return 0;
  }
  
  static
  void dnfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
  {
  
  	int incr, y_delta, pre_read = 0, x_end, x_word_count;
  	uint start_mask, end_mask, dest;
  	ushort *src, dummy;
  	short i, j;
  
  	incr = (area->dy <= area->sy) ? 1 : -1;
  
  	src = (ushort *)(info->screen_base + area->sy * info->fix.line_length +
  			(area->sx >> 4));
  	dest = area->dy * (info->fix.line_length >> 1) + (area->dx >> 4);
  
  	if (incr > 0) {
  		y_delta = (info->fix.line_length * 8) - area->sx - area->width;
  		x_end = area->dx + area->width - 1;
  		x_word_count = (x_end >> 4) - (area->dx >> 4) + 1;
  		start_mask = 0xffff0000 >> (area->dx & 0xf);
  		end_mask = 0x7ffff >> (x_end & 0xf);
  		out_8(AP_CONTROL_0,
  		     (((area->dx & 0xf) - (area->sx & 0xf)) % 16) | (0x4 << 5));
  		if ((area->dx & 0xf) < (area->sx & 0xf))
  			pre_read = 1;
  	} else {
  		y_delta = -((info->fix.line_length * 8) - area->sx - area->width);
  		x_end = area->dx - area->width + 1;
  		x_word_count = (area->dx >> 4) - (x_end >> 4) + 1;
  		start_mask = 0x7ffff >> (area->dx & 0xf);
  		end_mask = 0xffff0000 >> (x_end & 0xf);
  		out_8(AP_CONTROL_0,
  		     ((-((area->sx & 0xf) - (area->dx & 0xf))) % 16) |
  		     (0x4 << 5));
  		if ((area->dx & 0xf) > (area->sx & 0xf))
  			pre_read = 1;
  	}
  
  	for (i = 0; i < area->height; i++) {
  
  		out_8(AP_CONTROL_3A, 0xc | (dest >> 16));
  
  		if (pre_read) {
  			dummy = *src;
  			src += incr;
  		}
  
  		if (x_word_count) {
  			out_8(AP_WRITE_ENABLE, start_mask);
  			*src = dest;
  			src += incr;
  			dest += incr;
  			out_8(AP_WRITE_ENABLE, 0);
  
  			for (j = 1; j < (x_word_count - 1); j++) {
  				*src = dest;
  				src += incr;
  				dest += incr;
  			}
  
  			out_8(AP_WRITE_ENABLE, start_mask);
  			*src = dest;
  			dest += incr;
  			src += incr;
  		} else {
  			out_8(AP_WRITE_ENABLE, start_mask | end_mask);
  			*src = dest;
  			dest += incr;
  			src += incr;
  		}
  		src += (y_delta / 16);
  		dest += (y_delta / 16);
  	}
  	out_8(AP_CONTROL_0, NORMAL_MODE);
  }
  
  /*
   * Initialization
   */
  
  static int dnfb_probe(struct platform_device *dev)
  {
  	struct fb_info *info;
  	int err = 0;
  
  	info = framebuffer_alloc(0, &dev->dev);
  	if (!info)
  		return -ENOMEM;
  
  	info->fbops = &dn_fb_ops;
  	info->fix = dnfb_fix;
  	info->var = dnfb_var;
  	info->var.red.length = 1;
  	info->var.red.offset = 0;
  	info->var.green = info->var.blue = info->var.red;
  	info->screen_base = (u_char *) info->fix.smem_start;
  
  	err = fb_alloc_cmap(&info->cmap, 2, 0);
  	if (err < 0) {
  		framebuffer_release(info);
  		return err;
  	}
  
  	err = register_framebuffer(info);
  	if (err < 0) {
  		fb_dealloc_cmap(&info->cmap);
  		framebuffer_release(info);
  		return err;
  	}
  	platform_set_drvdata(dev, info);
  
  	/* now we have registered we can safely setup the hardware */
  	out_8(AP_CONTROL_3A, RESET_CREG);
  	out_be16(AP_WRITE_ENABLE, 0x0);
  	out_8(AP_CONTROL_0, NORMAL_MODE);
  	out_8(AP_CONTROL_1, (AD_BLT | DST_EQ_SRC | NORM_CREG1));
  	out_8(AP_CONTROL_2, S_DATA_PLN);
  	out_be16(AP_ROP_1, SWAP(0x3));
  
  	printk("apollo frame buffer alive and kicking !
  ");
  	return err;
  }
  
  static struct platform_driver dnfb_driver = {
  	.probe	= dnfb_probe,
  	.driver	= {
  		.name	= "dnfb",
  	},
  };
  
  static struct platform_device dnfb_device = {
  	.name	= "dnfb",
  };
  
  int __init dnfb_init(void)
  {
  	int ret;
  
  	if (!MACH_IS_APOLLO)
  		return -ENODEV;
  
  	if (fb_get_options("dnfb", NULL))
  		return -ENODEV;
  
  	ret = platform_driver_register(&dnfb_driver);
  
  	if (!ret) {
  		ret = platform_device_register(&dnfb_device);
  		if (ret)
  			platform_driver_unregister(&dnfb_driver);
  	}
  	return ret;
  }
  
  module_init(dnfb_init);
  
  MODULE_LICENSE("GPL");