/*
 * dec_esp.c: Driver for SCSI chips on IOASIC based TURBOchannel DECstations
 *            and TURBOchannel PMAZ-A cards
 *
 * TURBOchannel changes by Harald Koerfgen
 * PMAZ-A support by David Airlie
 *
 * based on jazz_esp.c:
 * Copyright (C) 1997 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
 *
 * jazz_esp is based on David S. Miller's ESP driver and cyber_esp
 *
 * 20000819 - Small PMAZ-AA fixes by Florian Lohoff <flo@rfc822.org>
 *            Be warned the PMAZ-AA works currently as a single card.
 *            Dont try to put multiple cards in one machine - They are
 *            both detected but it may crash under high load garbling your
 *            data.
 * 20001005	- Initialization fixes for 2.4.0-test9
 * 			  Florian Lohoff <flo@rfc822.org>
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blk.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>

#include "scsi.h"
#include "hosts.h"
#include "NCR53C9x.h"
#include "dec_esp.h"

#include <asm/irq.h>
#include <asm/jazz.h>
#include <asm/jazzdma.h>
#include <asm/dma.h>

#include <asm/pgtable.h>

#include <asm/dec/tc.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/ioasic_ints.h>
#include <asm/dec/machtype.h>

/*
 * Once upon a time the pmaz code used to be working but
 * it hasn't been maintained for quite some time.
 * It isn't working anymore but I'll leave here as a
 * starting point. #define this an be prepared for tons
 * of warnings and errors :)
 */
static int  dma_bytes_sent(struct NCR_ESP *esp, int fifo_count);
static void dma_drain(struct NCR_ESP *esp);
static int  dma_can_transfer(struct NCR_ESP *esp, Scsi_Cmnd * sp);
static void dma_dump_state(struct NCR_ESP *esp);
static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length);
static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length);
static void dma_ints_off(struct NCR_ESP *esp);
static void dma_ints_on(struct NCR_ESP *esp);
static int  dma_irq_p(struct NCR_ESP *esp);
static int  dma_ports_p(struct NCR_ESP *esp);
static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write);
static void dma_mmu_get_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd * sp);
static void dma_mmu_get_scsi_sgl(struct NCR_ESP *esp, Scsi_Cmnd * sp);
static void dma_advance_sg(Scsi_Cmnd * sp);

static void pmaz_dma_drain(struct NCR_ESP *esp);
static void pmaz_dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length);
static void pmaz_dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length);
static void pmaz_dma_ints_off(struct NCR_ESP *esp);
static void pmaz_dma_ints_on(struct NCR_ESP *esp);
static void pmaz_dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write);
static void pmaz_dma_mmu_get_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd * sp);

#define TC_ESP_RAM_SIZE 0x20000
#define ESP_TGT_DMA_SIZE ((TC_ESP_RAM_SIZE/7) & ~(sizeof(int)-1))
#define ESP_NCMD 7

#define TC_ESP_DMAR_MASK  0x1ffff
#define TC_ESP_DMAR_WRITE 0x80000000
#define TC_ESP_DMA_ADDR(x) ((unsigned)(x) & TC_ESP_DMAR_MASK)

__u32 esp_virt_buffer;
int scsi_current_length;

volatile unsigned char cmd_buffer[16];
volatile unsigned char pmaz_cmd_buffer[16];
				/* This is where all commands are put
				 * before they are trasfered to the ESP chip
				 * via PIO.
				 */

volatile unsigned long *scsi_dma_ptr;
volatile unsigned long *scsi_next_ptr;
volatile unsigned long *scsi_scr;
volatile unsigned long *ioasic_ssr;
volatile unsigned long *scsi_sdr0;
volatile unsigned long *scsi_sdr1;

static void scsi_dma_int(int, void *, struct pt_regs *);

static Scsi_Host_Template driver_template = SCSI_DEC_ESP;

#include "scsi_module.c"

/***************************************************************** Detection */
int dec_esp_detect(Scsi_Host_Template * tpnt)
{
	struct NCR_ESP *esp;
	struct ConfigDev *esp_dev;
	int slot;
	unsigned long mem_start;

	if (IOASIC) {
		esp_dev = 0;
		esp = esp_allocate(tpnt, (void *) esp_dev);
	
		scsi_dma_ptr = (unsigned long *) (system_base + IOCTL + SCSI_DMA_P);
		scsi_next_ptr = (unsigned long *) (system_base + IOCTL + SCSI_DMA_BP);
		scsi_scr = (unsigned long *) (system_base + IOCTL + SCSI_SCR);
		ioasic_ssr = (unsigned long *) (system_base + IOCTL + SSR);
		scsi_sdr0 = (unsigned long *) (system_base + IOCTL + SCSI_SDR0);
		scsi_sdr1 = (unsigned long *) (system_base + IOCTL + SCSI_SDR1);

		/* Do command transfer with programmed I/O */
		esp->do_pio_cmds = 1;
	
		/* Required functions */
		esp->dma_bytes_sent = &dma_bytes_sent;
		esp->dma_can_transfer = &dma_can_transfer;
		esp->dma_dump_state = &dma_dump_state;
		esp->dma_init_read = &dma_init_read;
		esp->dma_init_write = &dma_init_write;
		esp->dma_ints_off = &dma_ints_off;
		esp->dma_ints_on = &dma_ints_on;
		esp->dma_irq_p = &dma_irq_p;
		esp->dma_ports_p = &dma_ports_p;
		esp->dma_setup = &dma_setup;

		/* Optional functions */
		esp->dma_barrier = 0;
		esp->dma_drain = &dma_drain;
		esp->dma_invalidate = 0;
		esp->dma_irq_entry = 0;
		esp->dma_irq_exit = 0;
		esp->dma_poll = 0;
		esp->dma_reset = 0;
		esp->dma_led_off = 0;
		esp->dma_led_on = 0;
		
		/* virtual DMA functions */
		esp->dma_mmu_get_scsi_one = &dma_mmu_get_scsi_one;
		esp->dma_mmu_get_scsi_sgl = &dma_mmu_get_scsi_sgl;
		esp->dma_mmu_release_scsi_one = 0;
		esp->dma_mmu_release_scsi_sgl = 0;
		esp->dma_advance_sg = &dma_advance_sg;


		/* SCSI chip speed */
		esp->cfreq = 25000000;

		/*
		 * we don't give the address of DMA channel, but the number
		 * of DMA channel, so we can use the jazz DMA functions
		 *
		 */
		esp->dregs = JAZZ_SCSI_DMA;
	
		/* ESP register base */
		esp->eregs = (struct ESP_regs *) (system_base + SCSI);
	
		/* Set the command buffer */
		esp->esp_command = (volatile unsigned char *) cmd_buffer;
	
		/* get virtual dma address for command buffer */
		esp->esp_command_dvma = (__u32) KSEG1ADDR((volatile unsigned char *) cmd_buffer);
	
		esp->irq = SCSI_INT;

		esp->scsi_id = 7;
		
		/* Check for differential SCSI-bus */
		esp->diff = 0;

		esp_initialize(esp);

		if (request_irq(esp->irq, esp_intr, SA_INTERRUPT, 
				"NCR 53C94 SCSI", NULL))
			goto err_dealloc;
		if (request_irq(SCSI_DMA_INT, scsi_dma_int, SA_INTERRUPT, 
				"JUNKIO SCSI DMA", NULL))
			goto err_free_irq;
 			
	}

	if (TURBOCHANNEL) {
		while ((slot = search_tc_card("PMAZ-AA")) >= 0) {
			claim_tc_card(slot);

			esp_dev = 0;
			esp = esp_allocate(tpnt, (void *) esp_dev);

			mem_start = get_tc_base_addr(slot);

			/* Store base addr into esp struct */
			esp->slot = mem_start;

			esp->dregs = 0;
			esp->eregs = (struct ESP_regs *) (mem_start + DEC_SCSI_SREG);
			esp->do_pio_cmds = 1;

			/* Set the command buffer */
			esp->esp_command = (volatile unsigned char *) pmaz_cmd_buffer;

			/* get virtual dma address for command buffer */
			esp->esp_command_dvma = (__u32) KSEG0ADDR((volatile unsigned char *) pmaz_cmd_buffer);

			esp->cfreq = get_tc_speed();

			esp->irq = get_tc_irq_nr(slot);

			/* Required functions */
			esp->dma_bytes_sent = &dma_bytes_sent;
			esp->dma_can_transfer = &dma_can_transfer;
			esp->dma_dump_state = &dma_dump_state;
			esp->dma_init_read = &pmaz_dma_init_read;
			esp->dma_init_write = &pmaz_dma_init_write;
			esp->dma_ints_off = &pmaz_dma_ints_off;
			esp->dma_ints_on = &pmaz_dma_ints_on;
			esp->dma_irq_p = &dma_irq_p;
			esp->dma_ports_p = &dma_ports_p;
			esp->dma_setup = &pmaz_dma_setup;

			/* Optional functions */
			esp->dma_barrier = 0;
			esp->dma_drain = &pmaz_dma_drain;
			esp->dma_invalidate = 0;
			esp->dma_irq_entry = 0;
			esp->dma_irq_exit = 0;
			esp->dma_poll = 0;
			esp->dma_reset = 0;
			esp->dma_led_off = 0;
			esp->dma_led_on = 0;

			esp->dma_mmu_get_scsi_one = pmaz_dma_mmu_get_scsi_one;
			esp->dma_mmu_get_scsi_sgl = 0;
			esp->dma_mmu_release_scsi_one = 0;
			esp->dma_mmu_release_scsi_sgl = 0;
			esp->dma_advance_sg = 0;

 			if (request_irq(esp->irq, esp_intr, SA_INTERRUPT, 
 					 "PMAZ_AA", NULL)) {
 				esp_deallocate(esp);
 				release_tc_card(slot);
 				continue;
 			}
			esp->scsi_id = 7;
			esp->diff = 0;
			esp_initialize(esp);
		}
	}

	if(nesps) {
		printk("ESP: Total of %d ESP hosts found, %d actually in use.\n", nesps, esps_in_use);
		esps_running = esps_in_use;
		return esps_in_use;
	}
	return 0;

 err_free_irq:
	free_irq(esp->irq, esp_intr);
 err_dealloc:
	esp_deallocate(esp);
	return 0;
}

/************************************************************* DMA Functions */
static void scsi_dma_int(int irq, void *dev_id, struct pt_regs *regs)
{
	extern volatile unsigned int *isr;
	unsigned int dummy;

	if (*isr & SCSI_PTR_LOADED) {
		/* next page */
		*scsi_next_ptr = ((*scsi_dma_ptr + PAGE_SIZE) & PAGE_MASK) << 3;
		*isr &= ~SCSI_PTR_LOADED;
	} else {
		if (*isr & SCSI_PAGOVRRUN)
			*isr &= ~SCSI_PAGOVRRUN;
		if (*isr & SCSI_DMA_MEMRDERR) {
			printk("Got unexpected SCSI DMA Interrupt! < ");
			printk("SCSI_DMA_MEMRDERR ");
		printk(">\n");
			*isr &= ~SCSI_DMA_MEMRDERR;
		}
	}

	/*
	 * This routine will only work on IOASIC machines
	 * so we can avoid an indirect function call here
	 * and flush the writeback buffer the fast way
	 */
	dummy = *isr;
	dummy = *isr;
}

static int dma_bytes_sent(struct NCR_ESP *esp, int fifo_count)
{
    return fifo_count;
}

static void dma_drain(struct NCR_ESP *esp)
{
	unsigned long nw = *scsi_scr;
	unsigned short *p = KSEG1ADDR((unsigned short *) ((*scsi_dma_ptr) >> 3));

    /*
	 * Is there something in the dma buffers left?
     */
	if (nw) {
		switch (nw) {
		case 1:
			*p = (unsigned short) *scsi_sdr0;
			break;
		case 2:
			*p++ = (unsigned short) (*scsi_sdr0);
			*p = (unsigned short) ((*scsi_sdr0) >> 16);
			break;
		case 3:
			*p++ = (unsigned short) (*scsi_sdr0);
			*p++ = (unsigned short) ((*scsi_sdr0) >> 16);
			*p = (unsigned short) (*scsi_sdr1);
			break;
		default:
			printk("Strange: %d words in dma buffer left\n", (int) nw);
			break;
		}
	}
}

static int dma_can_transfer(struct NCR_ESP *esp, Scsi_Cmnd * sp)
{
	return sp->SCp.this_residual;;
}

static void dma_dump_state(struct NCR_ESP *esp)
{
/*
    ESPLOG(("esp%d: dma -- enable <%08x> residue <%08x\n",
	    esp->esp_id, vdma_get_enable((int)esp->dregs), vdma_get_resdiue((int)esp->dregs)));
 */
}

static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length)
{
	extern volatile unsigned int *isr;
	unsigned int dummy;

	if (vaddress & 3)
		panic("dec_efs.c: unable to handle partial word transfers, yet...");

	dma_cache_wback_inv((unsigned long) phys_to_virt(vaddress), length);

	*ioasic_ssr &= ~SCSI_DMA_EN;
	*scsi_scr = 0;
	*scsi_dma_ptr = vaddress << 3;

	/* prepare for next page */
	*scsi_next_ptr = ((vaddress + PAGE_SIZE) & PAGE_MASK) << 3;
	*ioasic_ssr |= (SCSI_DMA_DIR | SCSI_DMA_EN);

	/*
	 * see above
	 */
	dummy = *isr;
	dummy = *isr;
}

static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length)
{
	extern volatile unsigned int *isr;
	unsigned int dummy;

	if (vaddress & 3)
		panic("dec_efs.c: unable to handle partial word transfers, yet...");

	dma_cache_wback_inv((unsigned long) phys_to_virt(vaddress), length);

	*ioasic_ssr &= ~(SCSI_DMA_DIR | SCSI_DMA_EN);
	*scsi_scr = 0;
	*scsi_dma_ptr = vaddress << 3;

	/* prepare for next page */
	*scsi_next_ptr = ((vaddress + PAGE_SIZE) & PAGE_MASK) << 3;
	*ioasic_ssr |= SCSI_DMA_EN;

	/*
	 * see above
	 */
	dummy = *isr;
	dummy = *isr;
}

static void dma_ints_off(struct NCR_ESP *esp)
{
	disable_irq(SCSI_DMA_INT);
}

static void dma_ints_on(struct NCR_ESP *esp)
{
	enable_irq(SCSI_DMA_INT);
}

static int dma_irq_p(struct NCR_ESP *esp)
{
    return (esp->eregs->esp_status & ESP_STAT_INTR);
}

static int dma_ports_p(struct NCR_ESP *esp)
{
/*
 * FIXME: what's this good for?
 */
	return 1;
}

static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write)
{
    /*
     * On the Sparc, DMA_ST_WRITE means "move data from device to memory"
     * so when (write) is true, it actually means READ!
     */
	if (write) {
	dma_init_read(esp, addr, count);
    } else {
	dma_init_write(esp, addr, count);
    }
}

/*
 * These aren't used yet
 */
static void dma_mmu_get_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd * sp)
{
	sp->SCp.have_data_in = PHYSADDR(sp->SCp.buffer);
	sp->SCp.ptr = (char *) ((unsigned long) sp->SCp.have_data_in);
}

static void dma_mmu_get_scsi_sgl(struct NCR_ESP *esp, Scsi_Cmnd * sp)
{
    int sz = sp->SCp.buffers_residual;
    struct mmu_sglist *sg = (struct mmu_sglist *) sp->SCp.buffer;

    while (sz >= 0) {
		sg[sz].dvma_addr = PHYSADDR(sg[sz].addr);
	sz--;
    }
	sp->SCp.ptr = (char *) ((unsigned long) sp->SCp.buffer->dvma_address);
}

static void dma_advance_sg(Scsi_Cmnd * sp)
{
	sp->SCp.ptr = (char *) ((unsigned long) sp->SCp.buffer->dvma_address);
}

static void pmaz_dma_drain(struct NCR_ESP *esp)
{
	memcpy((void *) (KSEG0ADDR(esp_virt_buffer)),
		(void *) ( esp->slot + DEC_SCSI_SRAM + ESP_TGT_DMA_SIZE),
		scsi_current_length);
}

static void pmaz_dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length)
{
	volatile int *dmareg = (volatile int *) (esp->slot + DEC_SCSI_DMAREG);

	if (length > ESP_TGT_DMA_SIZE)
		length = ESP_TGT_DMA_SIZE;

	*dmareg = TC_ESP_DMA_ADDR(esp->slot + DEC_SCSI_SRAM + ESP_TGT_DMA_SIZE);

	esp_virt_buffer = vaddress;
	scsi_current_length = length;
}

static void pmaz_dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length)
{
	volatile int *dmareg = (volatile int *) ( esp->slot + DEC_SCSI_DMAREG );

	memcpy((void *) (esp->slot + DEC_SCSI_SRAM + ESP_TGT_DMA_SIZE),
			KSEG0ADDR((void *) vaddress), length);

	*dmareg = TC_ESP_DMAR_WRITE | 
		TC_ESP_DMA_ADDR(esp->slot + DEC_SCSI_SRAM + ESP_TGT_DMA_SIZE);

}

static void pmaz_dma_ints_off(struct NCR_ESP *esp)
{
}

static void pmaz_dma_ints_on(struct NCR_ESP *esp)
{
}

static void pmaz_dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write)
{
	/*
	 * On the Sparc, DMA_ST_WRITE means "move data from device to memory"
	 * so when (write) is true, it actually means READ!
	 */
	if (write) {
		pmaz_dma_init_read(esp, addr, count);
	} else {
		pmaz_dma_init_write(esp, addr, count);
	}
}

static void pmaz_dma_mmu_get_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd * sp)
{
	sp->SCp.have_data_in = (int) sp->SCp.ptr =
	    (char *) KSEG0ADDR((sp->request_buffer));
}