/*
   * eisa.c - provide support for EISA adapters in PA-RISC machines
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   *
   * Copyright (c) 2001 Matthew Wilcox for Hewlett Packard
   * Copyright (c) 2001 Daniel Engstrom <5116@telia.com>
   *
   * There are two distinct EISA adapters.  Mongoose is found in machines
   * before the 712; then the Wax ASIC is used.  To complicate matters, the
   * Wax ASIC also includes a PS/2 and RS-232 controller, but those are
   * dealt with elsewhere; this file is concerned only with the EISA portions
   * of Wax.
   * 
   * 
   * HINT:
   * -----
   * To allow an ISA card to work properly in the EISA slot you need to
   * set an edge trigger level. This may be done on the palo command line 
   * by adding the kernel parameter "eisa_irq_edge=n,n2,[...]]", with 
   * n and n2 as the irq levels you want to use.
   * 
   * Example: "eisa_irq_edge=10,11" allows ISA cards to operate at 
   * irq levels 10 and 11.
   */
  
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/spinlock.h>
  #include <linux/eisa.h>
  
  #include <asm/byteorder.h>
  #include <asm/io.h>
  #include <asm/hardware.h>
  #include <asm/processor.h>
  #include <asm/parisc-device.h>
  #include <asm/delay.h>
  #include <asm/eisa_bus.h>
  #include <asm/eisa_eeprom.h>
  
  #if 0
  #define EISA_DBG(msg, arg... ) printk(KERN_DEBUG "eisa: " msg , ## arg )
  #else
  #define EISA_DBG(msg, arg... )  
  #endif
  
  #define SNAKES_EEPROM_BASE_ADDR 0xF0810400
  #define MIRAGE_EEPROM_BASE_ADDR 0xF00C0400
  
  static DEFINE_SPINLOCK(eisa_irq_lock);
  
  void __iomem *eisa_eeprom_addr __read_mostly;
  
  /* We can only have one EISA adapter in the system because neither
   * implementation can be flexed.
   */
  static struct eisa_ba {
  	struct pci_hba_data	hba;
  	unsigned long eeprom_addr;
  	struct eisa_root_device root;
  } eisa_dev;
  
  /* Port ops */
  
  static inline unsigned long eisa_permute(unsigned short port)
  {
  	if (port & 0x300) {
  		return 0xfc000000 | ((port & 0xfc00) >> 6)
  			| ((port & 0x3f8) << 9) | (port & 7);
  	} else {
  		return 0xfc000000 | port;
  	}
  }
  
  unsigned char eisa_in8(unsigned short port)
  {
  	if (EISA_bus)
  		return gsc_readb(eisa_permute(port));
  	return 0xff;
  }
  
  unsigned short eisa_in16(unsigned short port)
  {
  	if (EISA_bus)
  		return le16_to_cpu(gsc_readw(eisa_permute(port)));
  	return 0xffff;
  }
  
  unsigned int eisa_in32(unsigned short port)
  {
  	if (EISA_bus)
  		return le32_to_cpu(gsc_readl(eisa_permute(port)));
  	return 0xffffffff;
  }
  
  void eisa_out8(unsigned char data, unsigned short port)
  {
  	if (EISA_bus)
  		gsc_writeb(data, eisa_permute(port));
  }
  
  void eisa_out16(unsigned short data, unsigned short port)
  {
  	if (EISA_bus)	
  		gsc_writew(cpu_to_le16(data), eisa_permute(port));
  }
  
  void eisa_out32(unsigned int data, unsigned short port)
  {
  	if (EISA_bus)
  		gsc_writel(cpu_to_le32(data), eisa_permute(port));
  }
  
  #ifndef CONFIG_PCI
  /* We call these directly without PCI.  See asm/io.h. */
  EXPORT_SYMBOL(eisa_in8);
  EXPORT_SYMBOL(eisa_in16);
  EXPORT_SYMBOL(eisa_in32);
  EXPORT_SYMBOL(eisa_out8);
  EXPORT_SYMBOL(eisa_out16);
  EXPORT_SYMBOL(eisa_out32);
  #endif
  
  /* Interrupt handling */
  
  /* cached interrupt mask registers */
  static int master_mask;
  static int slave_mask;
  
  /* the trig level can be set with the
   * eisa_irq_edge=n,n,n commandline parameter 
   * We should really read this from the EEPROM 
   * in the furure. 
   */
  /* irq 13,8,2,1,0 must be edge */
  static unsigned int eisa_irq_level __read_mostly; /* default to edge triggered */
  
  
  /* called by free irq */
  static void eisa_mask_irq(struct irq_data *d)
  {
  	unsigned int irq = d->irq;
  	unsigned long flags;
  
  	EISA_DBG("disable irq %d
  ", irq);
  	/* just mask for now */
  	spin_lock_irqsave(&eisa_irq_lock, flags);
          if (irq & 8) {
  		slave_mask |= (1 << (irq&7));
  		eisa_out8(slave_mask, 0xa1);
  	} else {
  		master_mask |= (1 << (irq&7));
  		eisa_out8(master_mask, 0x21);
  	}
  	spin_unlock_irqrestore(&eisa_irq_lock, flags);
  	EISA_DBG("pic0 mask %02x
  ", eisa_in8(0x21));
  	EISA_DBG("pic1 mask %02x
  ", eisa_in8(0xa1));
  }
  
  /* called by request irq */
  static void eisa_unmask_irq(struct irq_data *d)
  {
  	unsigned int irq = d->irq;
  	unsigned long flags;
  	EISA_DBG("enable irq %d
  ", irq);
  		
  	spin_lock_irqsave(&eisa_irq_lock, flags);
          if (irq & 8) {
  		slave_mask &= ~(1 << (irq&7));
  		eisa_out8(slave_mask, 0xa1);
  	} else {
  		master_mask &= ~(1 << (irq&7));
  		eisa_out8(master_mask, 0x21);
  	}
  	spin_unlock_irqrestore(&eisa_irq_lock, flags);
  	EISA_DBG("pic0 mask %02x
  ", eisa_in8(0x21));
  	EISA_DBG("pic1 mask %02x
  ", eisa_in8(0xa1));
  }
  
  static struct irq_chip eisa_interrupt_type = {
  	.name		=	"EISA",
  	.irq_unmask	=	eisa_unmask_irq,
  	.irq_mask	=	eisa_mask_irq,
  };
  
  static irqreturn_t eisa_irq(int wax_irq, void *intr_dev)
  {
  	int irq = gsc_readb(0xfc01f000); /* EISA supports 16 irqs */
  	unsigned long flags;
          
  	spin_lock_irqsave(&eisa_irq_lock, flags);
  	/* read IRR command */
  	eisa_out8(0x0a, 0x20);
  	eisa_out8(0x0a, 0xa0);
  
  	EISA_DBG("irq IAR %02x 8259-1 irr %02x 8259-2 irr %02x
  ",
  		   irq, eisa_in8(0x20), eisa_in8(0xa0));
     
  	/* read ISR command */
  	eisa_out8(0x0a, 0x20);
  	eisa_out8(0x0a, 0xa0);
  	EISA_DBG("irq 8259-1 isr %02x imr %02x 8259-2 isr %02x imr %02x
  ",
  		 eisa_in8(0x20), eisa_in8(0x21), eisa_in8(0xa0), eisa_in8(0xa1));
  	
  	irq &= 0xf;
  	
  	/* mask irq and write eoi */
  	if (irq & 8) {
  		slave_mask |= (1 << (irq&7));
  		eisa_out8(slave_mask, 0xa1);
  		eisa_out8(0x60 | (irq&7),0xa0);/* 'Specific EOI' to slave */
  		eisa_out8(0x62,0x20);	/* 'Specific EOI' to master-IRQ2 */
  		
  	} else {
  		master_mask |= (1 << (irq&7));
  		eisa_out8(master_mask, 0x21);
  		eisa_out8(0x60|irq,0x20);	/* 'Specific EOI' to master */
  	}
  	spin_unlock_irqrestore(&eisa_irq_lock, flags);
  
  	generic_handle_irq(irq);
     
  	spin_lock_irqsave(&eisa_irq_lock, flags);
  	/* unmask */
          if (irq & 8) {
  		slave_mask &= ~(1 << (irq&7));
  		eisa_out8(slave_mask, 0xa1);
  	} else {
  		master_mask &= ~(1 << (irq&7));
  		eisa_out8(master_mask, 0x21);
  	}
  	spin_unlock_irqrestore(&eisa_irq_lock, flags);
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t dummy_irq2_handler(int _, void *dev)
  {
  	printk(KERN_ALERT "eisa: uhh, irq2?
  ");
  	return IRQ_HANDLED;
  }
  
  static struct irqaction irq2_action = {
  	.handler = dummy_irq2_handler,
  	.name = "cascade",
  };
  
  static void init_eisa_pic(void)
  {
  	unsigned long flags;
  	
  	spin_lock_irqsave(&eisa_irq_lock, flags);
  
  	eisa_out8(0xff, 0x21); /* mask during init */
  	eisa_out8(0xff, 0xa1); /* mask during init */
  	
  	/* master pic */
  	eisa_out8(0x11,0x20); /* ICW1 */   
  	eisa_out8(0x00,0x21); /* ICW2 */   
  	eisa_out8(0x04,0x21); /* ICW3 */   
  	eisa_out8(0x01,0x21); /* ICW4 */   
  	eisa_out8(0x40,0x20); /* OCW2 */   
  	
  	/* slave pic */
  	eisa_out8(0x11,0xa0); /* ICW1 */   
  	eisa_out8(0x08,0xa1); /* ICW2 */   
          eisa_out8(0x02,0xa1); /* ICW3 */   
  	eisa_out8(0x01,0xa1); /* ICW4 */   
  	eisa_out8(0x40,0xa0); /* OCW2 */   
          
  	udelay(100);
  	
  	slave_mask = 0xff; 
  	master_mask = 0xfb; 
  	eisa_out8(slave_mask, 0xa1); /* OCW1 */
  	eisa_out8(master_mask, 0x21); /* OCW1 */
  	
  	/* setup trig level */
  	EISA_DBG("EISA edge/level %04x
  ", eisa_irq_level);
  	
  	eisa_out8(eisa_irq_level&0xff, 0x4d0); /* Set all irq's to edge  */
  	eisa_out8((eisa_irq_level >> 8) & 0xff, 0x4d1); 
  	
  	EISA_DBG("pic0 mask %02x
  ", eisa_in8(0x21));
  	EISA_DBG("pic1 mask %02x
  ", eisa_in8(0xa1));
  	EISA_DBG("pic0 edge/level %02x
  ", eisa_in8(0x4d0));
  	EISA_DBG("pic1 edge/level %02x
  ", eisa_in8(0x4d1));
  	
  	spin_unlock_irqrestore(&eisa_irq_lock, flags);
  }
  
  /* Device initialisation */
  
  #define is_mongoose(dev) (dev->id.sversion == 0x00076)
  
  static int __init eisa_probe(struct parisc_device *dev)
  {
  	int i, result;
  
  	char *name = is_mongoose(dev) ? "Mongoose" : "Wax";
  
  	printk(KERN_INFO "%s EISA Adapter found at 0x%08lx
  ", 
  		name, (unsigned long)dev->hpa.start);
  
  	eisa_dev.hba.dev = dev;
  	eisa_dev.hba.iommu = ccio_get_iommu(dev);
  
  	eisa_dev.hba.lmmio_space.name = "EISA";
  	eisa_dev.hba.lmmio_space.start = F_EXTEND(0xfc000000);
  	eisa_dev.hba.lmmio_space.end = F_EXTEND(0xffbfffff);
  	eisa_dev.hba.lmmio_space.flags = IORESOURCE_MEM;
  	result = ccio_request_resource(dev, &eisa_dev.hba.lmmio_space);
  	if (result < 0) {
  		printk(KERN_ERR "EISA: failed to claim EISA Bus address space!
  ");
  		return result;
  	}
  	eisa_dev.hba.io_space.name = "EISA";
  	eisa_dev.hba.io_space.start = 0;
  	eisa_dev.hba.io_space.end = 0xffff;
  	eisa_dev.hba.lmmio_space.flags = IORESOURCE_IO;
  	result = request_resource(&ioport_resource, &eisa_dev.hba.io_space);
  	if (result < 0) {
  		printk(KERN_ERR "EISA: failed to claim EISA Bus port space!
  ");
  		return result;
  	}
  	pcibios_register_hba(&eisa_dev.hba);
  
  	result = request_irq(dev->irq, eisa_irq, IRQF_SHARED, "EISA", &eisa_dev);
  	if (result) {
  		printk(KERN_ERR "EISA: request_irq failed!
  ");
  		return result;
  	}
  	
  	/* Reserve IRQ2 */
  	setup_irq(2, &irq2_action);
  	for (i = 0; i < 16; i++) {
  		irq_set_chip_and_handler(i, &eisa_interrupt_type,
  					 handle_simple_irq);
  	}
  	
  	EISA_bus = 1;
  
  	if (dev->num_addrs) {
  		/* newer firmware hand out the eeprom address */
  		eisa_dev.eeprom_addr = dev->addr[0];
  	} else {
  		/* old firmware, need to figure out the box */
  		if (is_mongoose(dev)) {
  			eisa_dev.eeprom_addr = SNAKES_EEPROM_BASE_ADDR;
  		} else {
  			eisa_dev.eeprom_addr = MIRAGE_EEPROM_BASE_ADDR;
  		}
  	}
  	eisa_eeprom_addr = ioremap_nocache(eisa_dev.eeprom_addr, HPEE_MAX_LENGTH);
  	result = eisa_enumerator(eisa_dev.eeprom_addr, &eisa_dev.hba.io_space,
  			&eisa_dev.hba.lmmio_space);
  	init_eisa_pic();
  
  	if (result >= 0) {
  		/* FIXME : Don't enumerate the bus twice. */
  		eisa_dev.root.dev = &dev->dev;
  		dev_set_drvdata(&dev->dev, &eisa_dev.root);
  		eisa_dev.root.bus_base_addr = 0;
  		eisa_dev.root.res = &eisa_dev.hba.io_space;
  		eisa_dev.root.slots = result;
  		eisa_dev.root.dma_mask = 0xffffffff; /* wild guess */
  		if (eisa_root_register (&eisa_dev.root)) {
  			printk(KERN_ERR "EISA: Failed to register EISA root
  ");
  			return -1;
  		}
  	}
  	
  	return 0;
  }
  
  static const struct parisc_device_id eisa_tbl[] = {
  	{ HPHW_BA, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00076 }, /* Mongoose */
  	{ HPHW_BA, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00090 }, /* Wax EISA */
  	{ 0, }
  };
  
  MODULE_DEVICE_TABLE(parisc, eisa_tbl);
  
  static struct parisc_driver eisa_driver = {
  	.name =		"eisa_ba",
  	.id_table =	eisa_tbl,
  	.probe =	eisa_probe,
  };
  
  void __init eisa_init(void)
  {
  	register_parisc_driver(&eisa_driver);
  }
  
  
  static unsigned int eisa_irq_configured;
  void eisa_make_irq_level(int num)
  {
  	if (eisa_irq_configured& (1<<num)) {
  		printk(KERN_WARNING
  		       "IRQ %d polarity configured twice (last to level)
  ", 
  		       num);
  	}
  	eisa_irq_level |= (1<<num); /* set the corresponding bit */
  	eisa_irq_configured |= (1<<num); /* set the corresponding bit */
  }
  
  void eisa_make_irq_edge(int num)
  {
  	if (eisa_irq_configured& (1<<num)) {
  		printk(KERN_WARNING 
  		       "IRQ %d polarity configured twice (last to edge)
  ",
  		       num);
  	}
  	eisa_irq_level &= ~(1<<num); /* clear the corresponding bit */
  	eisa_irq_configured |= (1<<num); /* set the corresponding bit */
  }
  
  static int __init eisa_irq_setup(char *str)
  {
  	char *cur = str;
  	int val;
  
  	EISA_DBG("IRQ setup
  ");
  	while (cur != NULL) {
  		char *pe;
  		
  		val = (int) simple_strtoul(cur, &pe, 0);
  		if (val > 15 || val < 0) {
  			printk(KERN_ERR "eisa: EISA irq value are 0-15
  ");
  			continue;
  		}
  		if (val == 2) { 
  			val = 9;
  		}
  		eisa_make_irq_edge(val); /* clear the corresponding bit */
  		EISA_DBG("setting IRQ %d to edge-triggered mode
  ", val);
  		
  		if ((cur = strchr(cur, ','))) {
  			cur++;
  		} else {
  			break;
  		}
  	}
  	return 1;
  }
  
  __setup("eisa_irq_edge=", eisa_irq_setup);