/*
   *  linux/drivers/acorn/scsi/powertec.c
   *
   *  Copyright (C) 1997-2005 Russell King
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #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/delay.h>
  #include <linux/interrupt.h>
  #include <linux/init.h>
  #include <linux/dma-mapping.h>
  
  #include <asm/dma.h>
  #include <asm/ecard.h>
  #include <asm/io.h>
  #include <asm/pgtable.h>
  
  #include "../scsi.h"
  #include <scsi/scsi_host.h>
  #include "fas216.h"
  #include "scsi.h"
  
  #include <scsi/scsicam.h>
  
  #define POWERTEC_FAS216_OFFSET	0x3000
  #define POWERTEC_FAS216_SHIFT	6
  
  #define POWERTEC_INTR_STATUS	0x2000
  #define POWERTEC_INTR_BIT	0x80
  
  #define POWERTEC_RESET_CONTROL	0x1018
  #define POWERTEC_RESET_BIT	1
  
  #define POWERTEC_TERM_CONTROL	0x2018
  #define POWERTEC_TERM_ENABLE	1
  
  #define POWERTEC_INTR_CONTROL	0x101c
  #define POWERTEC_INTR_ENABLE	1
  #define POWERTEC_INTR_DISABLE	0
  
  #define VERSION	"1.10 (19/01/2003 2.5.59)"
  
  /*
   * Use term=0,1,0,0,0 to turn terminators on/off.
   * One entry per slot.
   */
  static int term[MAX_ECARDS] = { 1, 1, 1, 1, 1, 1, 1, 1 };
  
  #define NR_SG	256
  
  struct powertec_info {
  	FAS216_Info		info;
  	struct expansion_card	*ec;
  	void __iomem		*base;
  	unsigned int		term_ctl;
  	struct scatterlist	sg[NR_SG];
  };
  
  /* Prototype: void powertecscsi_irqenable(ec, irqnr)
   * Purpose  : Enable interrupts on Powertec SCSI card
   * Params   : ec    - expansion card structure
   *          : irqnr - interrupt number
   */
  static void
  powertecscsi_irqenable(struct expansion_card *ec, int irqnr)
  {
  	struct powertec_info *info = ec->irq_data;
  	writeb(POWERTEC_INTR_ENABLE, info->base + POWERTEC_INTR_CONTROL);
  }
  
  /* Prototype: void powertecscsi_irqdisable(ec, irqnr)
   * Purpose  : Disable interrupts on Powertec SCSI card
   * Params   : ec    - expansion card structure
   *          : irqnr - interrupt number
   */
  static void
  powertecscsi_irqdisable(struct expansion_card *ec, int irqnr)
  {
  	struct powertec_info *info = ec->irq_data;
  	writeb(POWERTEC_INTR_DISABLE, info->base + POWERTEC_INTR_CONTROL);
  }
  
  static const expansioncard_ops_t powertecscsi_ops = {
  	.irqenable	= powertecscsi_irqenable,
  	.irqdisable	= powertecscsi_irqdisable,
  };
  
  /* Prototype: void powertecscsi_terminator_ctl(host, on_off)
   * Purpose  : Turn the Powertec SCSI terminators on or off
   * Params   : host   - card to turn on/off
   *          : on_off - !0 to turn on, 0 to turn off
   */
  static void
  powertecscsi_terminator_ctl(struct Scsi_Host *host, int on_off)
  {
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  
  	info->term_ctl = on_off ? POWERTEC_TERM_ENABLE : 0;
  	writeb(info->term_ctl, info->base + POWERTEC_TERM_CONTROL);
  }
  
  /* Prototype: void powertecscsi_intr(irq, *dev_id, *regs)
   * Purpose  : handle interrupts from Powertec SCSI card
   * Params   : irq    - interrupt number
   *	      dev_id - user-defined (Scsi_Host structure)
   */
  static irqreturn_t powertecscsi_intr(int irq, void *dev_id)
  {
  	struct powertec_info *info = dev_id;
  
  	return fas216_intr(&info->info);
  }
  
  /* Prototype: fasdmatype_t powertecscsi_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  : type of transfer to be performed
   */
  static fasdmatype_t
  powertecscsi_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,
  		       fasdmadir_t direction, fasdmatype_t min_type)
  {
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  	struct device *dev = scsi_get_device(host);
  	int dmach = info->info.scsi.dma;
  
  	if (info->info.ifcfg.capabilities & FASCAP_DMA &&
  	    min_type == fasdma_real_all) {
  		int bufs, map_dir, dma_dir;
  
  		bufs = copy_SCp_to_sg(&info->sg[0], SCp, NR_SG);
  
  		if (direction == DMA_OUT)
  			map_dir = DMA_TO_DEVICE,
  			dma_dir = DMA_MODE_WRITE;
  		else
  			map_dir = DMA_FROM_DEVICE,
  			dma_dir = DMA_MODE_READ;
  
  		dma_map_sg(dev, info->sg, bufs, map_dir);
  
  		disable_dma(dmach);
  		set_dma_sg(dmach, info->sg, bufs);
  		set_dma_mode(dmach, dma_dir);
  		enable_dma(dmach);
  		return fasdma_real_all;
  	}
  
  	/*
  	 * If we're not doing DMA,
  	 *  we'll do slow PIO
  	 */
  	return fasdma_pio;
  }
  
  /* Prototype: int powertecscsi_dma_stop(host, SCpnt)
   * Purpose  : stops DMA/PIO
   * Params   : host  - host
   *	      SCpnt - command
   */
  static void
  powertecscsi_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)
  {
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  	if (info->info.scsi.dma != NO_DMA)
  		disable_dma(info->info.scsi.dma);
  }
  
  /* Prototype: const char *powertecscsi_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.
   */
  const char *powertecscsi_info(struct Scsi_Host *host)
  {
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  	static char string[150];
  
  	sprintf(string, "%s (%s) in slot %d v%s terminators o%s",
  		host->hostt->name, info->info.scsi.type, info->ec->slot_no,
  		VERSION, info->term_ctl ? "n" : "ff");
  
  	return string;
  }
  
  /* Prototype: int powertecscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
   * Purpose  : Set a driver specific function
   * Params   : host   - host to setup
   *          : buffer - buffer containing string describing operation
   *          : length - length of string
   * Returns  : -EINVAL, or 0
   */
  static int
  powertecscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
  {
  	int ret = length;
  
  	if (length >= 12 && strncmp(buffer, "POWERTECSCSI", 12) == 0) {
  		buffer += 12;
  		length -= 12;
  
  		if (length >= 5 && strncmp(buffer, "term=", 5) == 0) {
  			if (buffer[5] == '1')
  				powertecscsi_terminator_ctl(host, 1);
  			else if (buffer[5] == '0')
  				powertecscsi_terminator_ctl(host, 0);
  			else
  				ret = -EINVAL;
  		} else
  			ret = -EINVAL;
  	} else
  		ret = -EINVAL;
  
  	return ret;
  }
  
  /* Prototype: int powertecscsi_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
   *	      inout   - 0 for reading, 1 for writing.
   * Returns  : length of data written to buffer.
   */
  static int powertecscsi_show_info(struct seq_file *m, struct Scsi_Host *host)
  {
  	struct powertec_info *info;
  
  	info = (struct powertec_info *)host->hostdata;
  
  	seq_printf(m, "PowerTec SCSI driver v%s
  ", VERSION);
  	fas216_print_host(&info->info, m);
  	seq_printf(m, "Term    : o%s
  ",
  			info->term_ctl ? "n" : "ff");
  
  	fas216_print_stats(&info->info, m);
  	fas216_print_devices(&info->info, m);
  	return 0;
  }
  
  static ssize_t powertecscsi_show_term(struct device *dev, struct device_attribute *attr, char *buf)
  {
  	struct expansion_card *ec = ECARD_DEV(dev);
  	struct Scsi_Host *host = ecard_get_drvdata(ec);
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  
  	return sprintf(buf, "%d
  ", info->term_ctl ? 1 : 0);
  }
  
  static ssize_t
  powertecscsi_store_term(struct device *dev, struct device_attribute *attr, const char *buf, size_t len)
  {
  	struct expansion_card *ec = ECARD_DEV(dev);
  	struct Scsi_Host *host = ecard_get_drvdata(ec);
  
  	if (len > 1)
  		powertecscsi_terminator_ctl(host, buf[0] != '0');
  
  	return len;
  }
  
  static DEVICE_ATTR(bus_term, S_IRUGO | S_IWUSR,
  		   powertecscsi_show_term, powertecscsi_store_term);
  
  static struct scsi_host_template powertecscsi_template = {
  	.module				= THIS_MODULE,
  	.show_info			= powertecscsi_show_info,
  	.write_info			= powertecscsi_set_proc_info,
  	.name				= "PowerTec SCSI",
  	.info				= powertecscsi_info,
  	.queuecommand			= fas216_queue_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			= 8,
  	.this_id			= 7,
  	.sg_tablesize			= SCSI_MAX_SG_CHAIN_SEGMENTS,
  	.dma_boundary			= IOMD_DMA_BOUNDARY,
  	.cmd_per_lun			= 2,
  	.use_clustering			= ENABLE_CLUSTERING,
  	.proc_name			= "powertec",
  };
  
  static int powertecscsi_probe(struct expansion_card *ec,
  			      const struct ecard_id *id)
  {
  	struct Scsi_Host *host;
  	struct powertec_info *info;
  	void __iomem *base;
  	int ret;
  
  	ret = ecard_request_resources(ec);
  	if (ret)
  		goto out;
  
  	base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
  	if (!base) {
  		ret = -ENOMEM;
  		goto out_region;
  	}
  
  	host = scsi_host_alloc(&powertecscsi_template,
  			       sizeof (struct powertec_info));
  	if (!host) {
  		ret = -ENOMEM;
  		goto out_region;
  	}
  
  	ecard_set_drvdata(ec, host);
  
  	info = (struct powertec_info *)host->hostdata;
  	info->base = base;
  	powertecscsi_terminator_ctl(host, term[ec->slot_no]);
  
  	info->ec = ec;
  	info->info.scsi.io_base		= base + POWERTEC_FAS216_OFFSET;
  	info->info.scsi.io_shift	= POWERTEC_FAS216_SHIFT;
  	info->info.scsi.irq		= ec->irq;
  	info->info.scsi.dma		= ec->dma;
  	info->info.ifcfg.clockrate	= 40; /* MHz */
  	info->info.ifcfg.select_timeout	= 255;
  	info->info.ifcfg.asyncperiod	= 200; /* ns */
  	info->info.ifcfg.sync_max_depth	= 7;
  	info->info.ifcfg.cntl3		= CNTL3_BS8 | CNTL3_FASTSCSI | CNTL3_FASTCLK;
  	info->info.ifcfg.disconnect_ok	= 1;
  	info->info.ifcfg.wide_max_size	= 0;
  	info->info.ifcfg.capabilities	= 0;
  	info->info.dma.setup		= powertecscsi_dma_setup;
  	info->info.dma.pseudo		= NULL;
  	info->info.dma.stop		= powertecscsi_dma_stop;
  
  	ec->irqaddr	= base + POWERTEC_INTR_STATUS;
  	ec->irqmask	= POWERTEC_INTR_BIT;
  
  	ecard_setirq(ec, &powertecscsi_ops, info);
  
  	device_create_file(&ec->dev, &dev_attr_bus_term);
  
  	ret = fas216_init(host);
  	if (ret)
  		goto out_free;
  
  	ret = request_irq(ec->irq, powertecscsi_intr,
  			  IRQF_DISABLED, "powertec", info);
  	if (ret) {
  		printk("scsi%d: IRQ%d not free: %d
  ",
  		       host->host_no, ec->irq, ret);
  		goto out_release;
  	}
  
  	if (info->info.scsi.dma != NO_DMA) {
  		if (request_dma(info->info.scsi.dma, "powertec")) {
  			printk("scsi%d: DMA%d not free, using PIO
  ",
  			       host->host_no, info->info.scsi.dma);
  			info->info.scsi.dma = NO_DMA;
  		} else {
  			set_dma_speed(info->info.scsi.dma, 180);
  			info->info.ifcfg.capabilities |= FASCAP_DMA;
  		}
  	}
  
  	ret = fas216_add(host, &ec->dev);
  	if (ret == 0)
  		goto out;
  
  	if (info->info.scsi.dma != NO_DMA)
  		free_dma(info->info.scsi.dma);
  	free_irq(ec->irq, host);
  
   out_release:
  	fas216_release(host);
  
   out_free:
  	device_remove_file(&ec->dev, &dev_attr_bus_term);
  	scsi_host_put(host);
  
   out_region:
  	ecard_release_resources(ec);
  
   out:
  	return ret;
  }
  
  static void powertecscsi_remove(struct expansion_card *ec)
  {
  	struct Scsi_Host *host = ecard_get_drvdata(ec);
  	struct powertec_info *info = (struct powertec_info *)host->hostdata;
  
  	ecard_set_drvdata(ec, NULL);
  	fas216_remove(host);
  
  	device_remove_file(&ec->dev, &dev_attr_bus_term);
  
  	if (info->info.scsi.dma != NO_DMA)
  		free_dma(info->info.scsi.dma);
  	free_irq(ec->irq, info);
  
  	fas216_release(host);
  	scsi_host_put(host);
  	ecard_release_resources(ec);
  }
  
  static const struct ecard_id powertecscsi_cids[] = {
  	{ MANU_ALSYSTEMS, PROD_ALSYS_SCSIATAPI },
  	{ 0xffff, 0xffff },
  };
  
  static struct ecard_driver powertecscsi_driver = {
  	.probe		= powertecscsi_probe,
  	.remove		= powertecscsi_remove,
  	.id_table	= powertecscsi_cids,
  	.drv = {
  		.name		= "powertecscsi",
  	},
  };
  
  static int __init powertecscsi_init(void)
  {
  	return ecard_register_driver(&powertecscsi_driver);
  }
  
  static void __exit powertecscsi_exit(void)
  {
  	ecard_remove_driver(&powertecscsi_driver);
  }
  
  module_init(powertecscsi_init);
  module_exit(powertecscsi_exit);
  
  MODULE_AUTHOR("Russell King");
  MODULE_DESCRIPTION("Powertec SCSI driver");
  module_param_array(term, int, NULL, 0);
  MODULE_PARM_DESC(term, "SCSI bus termination");
  MODULE_LICENSE("GPL");