/*

   * linux/drivers/scsi/arm/arxescsi.c

   *
   * Copyright (C) 1997-2000 Russell King, Stefan Hanske
   *
   * This driver is based on experimentation.  Hence, it may have made
   * assumptions about the particular card that I have available, and
   * may not be reliable!
   *
   * Changelog:
   *  30-08-1997	RMK	0.0.0	Created, READONLY version as cumana_2.c
   *  22-01-1998	RMK	0.0.1	Updated to 2.1.80
   *  15-04-1998	RMK	0.0.1	Only do PIO if FAS216 will allow it.
   *  11-06-1998 	SH	0.0.2   Changed to support ARXE 16-bit SCSI card
   *				enabled writing
   *  01-01-2000	SH	0.1.0   Added *real* pseudo dma writing
   *				(arxescsi_pseudo_dma_write)
   *  02-04-2000	RMK	0.1.1	Updated for new error handling code.
   *  22-10-2000  SH		Updated for new registering scheme.
   */
  #include <linux/module.h>
  #include <linux/blkdev.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/ioport.h>

  #include <linux/proc_fs.h>
  #include <linux/unistd.h>
  #include <linux/stat.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  
  #include <asm/dma.h>
  #include <asm/io.h>

  #include <asm/ecard.h>
  
  #include "../scsi.h"
  #include <scsi/scsi_host.h>
  #include "fas216.h"
  
  struct arxescsi_info {
  	FAS216_Info		info;
  	struct expansion_card	*ec;
  	void __iomem		*base;
  };
  
  #define DMADATA_OFFSET	(0x200)
  
  #define DMASTAT_OFFSET	(0x600)
  #define DMASTAT_DRQ	(1 << 0)
  
  #define CSTATUS_IRQ	(1 << 0)
  
  #define VERSION "1.10 (23/01/2003 2.5.57)"
  
  /*
   * Function: int arxescsi_dma_setup(host, SCpnt, direction, min_type)
   * Purpose : initialises DMA/PIO
   * Params  : host      - host
   *	     SCpnt     - command
   *	     direction - DMA on to/off of card
   *	     min_type  - minimum DMA support that we must have for this transfer
   * Returns : 0 if we should not set CMD_WITHDMA for transfer info command
   */
  static fasdmatype_t

  arxescsi_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,

  		       fasdmadir_t direction, fasdmatype_t min_type)
  {
  	/*
  	 * We don't do real DMA
  	 */
  	return fasdma_pseudo;
  }
  
  static void arxescsi_pseudo_dma_write(unsigned char *addr, void __iomem *base)
  {
         __asm__ __volatile__(
         "               stmdb   sp!, {r0-r12}
  "
         "               mov     r3, %0
  "
         "               mov     r1, %1
  "
         "               add     r2, r1, #512
  "
         "               mov     r4, #256
  "
         ".loop_1:       ldmia   r3!, {r6, r8, r10, r12}
  "
         "               mov     r5, r6, lsl #16
  "
         "               mov     r7, r8, lsl #16
  "
         ".loop_2:       ldrb    r0, [r1, #1536]
  "
         "               tst     r0, #1
  "
         "               beq     .loop_2
  "
         "               stmia   r2, {r5-r8}
  \t"
         "               mov     r9, r10, lsl #16
  "
         "               mov     r11, r12, lsl #16
  "
         ".loop_3:       ldrb    r0, [r1, #1536]
  "
         "               tst     r0, #1
  "
         "               beq     .loop_3
  "
         "               stmia   r2, {r9-r12}
  "
         "               subs    r4, r4, #16
  "
         "               bne     .loop_1
  "
         "               ldmia   sp!, {r0-r12}
  "
         :
         : "r" (addr), "r" (base));
  }
  
  /*
   * Function: int arxescsi_dma_pseudo(host, SCpnt, direction, transfer)
   * Purpose : handles pseudo DMA
   * Params  : host      - host
   *	     SCpnt     - command
   *	     direction - DMA on to/off of card
   *	     transfer  - minimum number of bytes we expect to transfer
   */
  static void

  arxescsi_dma_pseudo(struct Scsi_Host *host, struct scsi_pointer *SCp,

  		    fasdmadir_t direction, int transfer)
  {
  	struct arxescsi_info *info = (struct arxescsi_info *)host->hostdata;
  	unsigned int length, error = 0;
  	void __iomem *base = info->info.scsi.io_base;
  	unsigned char *addr;
  
  	length = SCp->this_residual;
  	addr = SCp->ptr;
  
  	if (direction == DMA_OUT) {
  		unsigned int word;
  		while (length > 256) {
  			if (readb(base + 0x80) & STAT_INT) {
  				error = 1;
  				break;
  			}
  			arxescsi_pseudo_dma_write(addr, base);
  			addr += 256;
  			length -= 256;
  		}
  
  		if (!error)
  			while (length > 0) {
  				if (readb(base + 0x80) & STAT_INT)
  					break;
  	 
  				if (!(readb(base + DMASTAT_OFFSET) & DMASTAT_DRQ))
  					continue;
  
  				word = *addr | *(addr + 1) << 8;
  
  				writew(word, base + DMADATA_OFFSET);
  				if (length > 1) {
  					addr += 2;
  					length -= 2;
  				} else {
  					addr += 1;
  					length -= 1;
  				}
  			}
  	}
  	else {
  		if (transfer && (transfer & 255)) {
  			while (length >= 256) {
  				if (readb(base + 0x80) & STAT_INT) {
  					error = 1;
  					break;
  				}
  	    
  				if (!(readb(base + DMASTAT_OFFSET) & DMASTAT_DRQ))
  					continue;
  
  				readsw(base + DMADATA_OFFSET, addr, 256 >> 1);
  				addr += 256;
  				length -= 256;
  			}
  		}
  
  		if (!(error))
  			while (length > 0) {
  				unsigned long word;
  
  				if (readb(base + 0x80) & STAT_INT)
  					break;
  
  				if (!(readb(base + DMASTAT_OFFSET) & DMASTAT_DRQ))
  					continue;
  
  				word = readw(base + DMADATA_OFFSET);
  				*addr++ = word;
  				if (--length > 0) {
  					*addr++ = word >> 8;
  					length --;
  				}
  			}
  	}
  }
  
  /*
   * Function: int arxescsi_dma_stop(host, SCpnt)
   * Purpose : stops DMA/PIO
   * Params  : host  - host
   *	     SCpnt - command
   */

  static void arxescsi_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)

  {
  	/*
  	 * no DMA to stop
  	 */
  }
  
  /*
   * Function: const char *arxescsi_info(struct Scsi_Host * host)
   * Purpose : returns a descriptive string about this interface,
   * Params  : host - driver host structure to return info for.
   * Returns : pointer to a static buffer containing null terminated string.
   */
  static const char *arxescsi_info(struct Scsi_Host *host)
  {
  	struct arxescsi_info *info = (struct arxescsi_info *)host->hostdata;
  	static char string[150];
  
  	sprintf(string, "%s (%s) in slot %d v%s",
  		host->hostt->name, info->info.scsi.type, info->ec->slot_no,
  		VERSION);
  
  	return string;
  }
  
  /*
   * Function: int arxescsi_proc_info(char *buffer, char **start, off_t offset,
   *					 int length, int host_no, int inout)
   * Purpose : Return information about the driver to a user process accessing
   *	     the /proc filesystem.
   * Params  : buffer - a buffer to write information to
   *	     start  - a pointer into this buffer set by this routine to the start
   *		      of the required information.

   *	     offset - offset into information that we have read up to.

   *	     length - length of buffer
   *	     host_no - host number to return information for
   *	     inout  - 0 for reading, 1 for writing.
   * Returns : length of data written to buffer.
   */
  static int
  arxescsi_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length,
  		   int inout)
  {
  	struct arxescsi_info *info;
  	char *p = buffer;
  	int pos;
  
  	info = (struct arxescsi_info *)host->hostdata;
  	if (inout == 1)
  		return -EINVAL;
  
  	p += sprintf(p, "ARXE 16-bit SCSI driver v%s
  ", VERSION);
  	p += fas216_print_host(&info->info, p);
  	p += fas216_print_stats(&info->info, p);
  	p += fas216_print_devices(&info->info, p);
  
  	*start = buffer + offset;
  	pos = p - buffer - offset;
  	if (pos > length)
  		pos = length;
  
  	return pos;
  }

  static struct scsi_host_template arxescsi_template = {

  	.proc_info			= arxescsi_proc_info,
  	.name				= "ARXE SCSI card",
  	.info				= arxescsi_info,
  	.queuecommand			= fas216_noqueue_command,
  	.eh_host_reset_handler		= fas216_eh_host_reset,
  	.eh_bus_reset_handler		= fas216_eh_bus_reset,
  	.eh_device_reset_handler	= fas216_eh_device_reset,
  	.eh_abort_handler		= fas216_eh_abort,
  	.can_queue			= 0,
  	.this_id			= 7,
  	.sg_tablesize			= SG_ALL,
  	.cmd_per_lun			= 1,
  	.use_clustering			= DISABLE_CLUSTERING,
  	.proc_name			= "arxescsi",
  };
  
  static int __devinit
  arxescsi_probe(struct expansion_card *ec, const struct ecard_id *id)
  {
  	struct Scsi_Host *host;
  	struct arxescsi_info *info;

  	void __iomem *base;
  	int ret;
  
  	ret = ecard_request_resources(ec);
  	if (ret)
  		goto out;

  	base = ecardm_iomap(ec, ECARD_RES_MEMC, 0, 0);

  	if (!base) {
  		ret = -ENOMEM;
  		goto out_region;
  	}
  
  	host = scsi_host_alloc(&arxescsi_template, sizeof(struct arxescsi_info));
  	if (!host) {
  		ret = -ENOMEM;

  		goto out_region;

  	}
  
  	info = (struct arxescsi_info *)host->hostdata;
  	info->ec = ec;
  	info->base = base;
  
  	info->info.scsi.io_base		= base + 0x2000;
  	info->info.scsi.irq		= NO_IRQ;
  	info->info.scsi.dma		= NO_DMA;
  	info->info.scsi.io_shift	= 5;
  	info->info.ifcfg.clockrate	= 24; /* MHz */
  	info->info.ifcfg.select_timeout = 255;
  	info->info.ifcfg.asyncperiod	= 200; /* ns */
  	info->info.ifcfg.sync_max_depth	= 0;
  	info->info.ifcfg.cntl3		= CNTL3_FASTSCSI | CNTL3_FASTCLK;
  	info->info.ifcfg.disconnect_ok	= 0;
  	info->info.ifcfg.wide_max_size	= 0;
  	info->info.ifcfg.capabilities	= FASCAP_PSEUDODMA;
  	info->info.dma.setup		= arxescsi_dma_setup;
  	info->info.dma.pseudo		= arxescsi_dma_pseudo;
  	info->info.dma.stop		= arxescsi_dma_stop;
  		
  	ec->irqaddr = base;
  	ec->irqmask = CSTATUS_IRQ;
  
  	ret = fas216_init(host);
  	if (ret)
  		goto out_unregister;
  
  	ret = fas216_add(host, &ec->dev);
  	if (ret == 0)
  		goto out;
  
  	fas216_release(host);
   out_unregister:
  	scsi_host_put(host);

   out_region:
  	ecard_release_resources(ec);
   out:
  	return ret;
  }
  
  static void __devexit arxescsi_remove(struct expansion_card *ec)
  {
  	struct Scsi_Host *host = ecard_get_drvdata(ec);

  
  	ecard_set_drvdata(ec, NULL);
  	fas216_remove(host);

  	fas216_release(host);
  	scsi_host_put(host);
  	ecard_release_resources(ec);
  }
  
  static const struct ecard_id arxescsi_cids[] = {
  	{ MANU_ARXE, PROD_ARXE_SCSI },
  	{ 0xffff, 0xffff },
  };
  
  static struct ecard_driver arxescsi_driver = {
  	.probe		= arxescsi_probe,
  	.remove		= __devexit_p(arxescsi_remove),
  	.id_table	= arxescsi_cids,
  	.drv = {
  		.name		= "arxescsi",
  	},
  };
  
  static int __init init_arxe_scsi_driver(void)
  {
  	return ecard_register_driver(&arxescsi_driver);
  }
  
  static void __exit exit_arxe_scsi_driver(void)
  {
  	ecard_remove_driver(&arxescsi_driver);
  }
  
  module_init(init_arxe_scsi_driver);
  module_exit(exit_arxe_scsi_driver);
  
  MODULE_AUTHOR("Stefan Hanske");
  MODULE_DESCRIPTION("ARXESCSI driver for Acorn machines");
  MODULE_LICENSE("GPL");