ioc3.c

linux 内核源代码

/*
 * SGI IOC3 master driver and IRQ demuxer
 *
 * Copyright (c) 2005 Stanislaw Skowronek <[e-mail]>
 * Heavily based on similar work by:
 *   Brent Casavant <[e-mail]> - IOC4 master driver
 *   Pat Gefre <[e-mail]> - IOC3 serial port IRQ demuxer
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/ioc3.h>
#include <linux/rwsem.h>

#define IOC3_PCI_SIZE 0x100000

static LIST_HEAD(ioc3_devices);
static int ioc3_counter;
static DECLARE_RWSEM(ioc3_devices_rwsem);

static struct ioc3_submodule *ioc3_submodules[IOC3_MAX_SUBMODULES];
static struct ioc3_submodule *ioc3_ethernet;
static DEFINE_RWLOCK(ioc3_submodules_lock);

/* NIC probing code */

#define GPCR_MLAN_EN    0x00200000      /* enable MCR to pin 8 */

static inline unsigned mcr_pack(unsigned pulse, unsigned sample)
{
	return (pulse << 10) | (sample << 2);
}

static int nic_wait(struct ioc3_driver_data *idd)
{
	unsigned mcr;

        do {
                mcr = readl(&idd->vma->mcr);
        } while (!(mcr & 2));

        return mcr & 1;
}

static int nic_reset(struct ioc3_driver_data *idd)
{
        int presence;
	unsigned long flags;

	local_irq_save(flags);
	writel(mcr_pack(500, 65), &idd->vma->mcr);
	presence = nic_wait(idd);
	local_irq_restore(flags);

	udelay(500);

        return presence;
}

static int nic_read_bit(struct ioc3_driver_data *idd)
{
	int result;
	unsigned long flags;

	local_irq_save(flags);
	writel(mcr_pack(6, 13), &idd->vma->mcr);
	result = nic_wait(idd);
	local_irq_restore(flags);

	udelay(500);

	return result;
}

static void nic_write_bit(struct ioc3_driver_data *idd, int bit)
{
	if (bit)
		writel(mcr_pack(6, 110), &idd->vma->mcr);
	else
		writel(mcr_pack(80, 30), &idd->vma->mcr);

	nic_wait(idd);
}

static unsigned nic_read_byte(struct ioc3_driver_data *idd)
{
	unsigned result = 0;
	int i;

	for (i = 0; i < 8; i++)
		result = (result >> 1) | (nic_read_bit(idd) << 7);

	return result;
}

static void nic_write_byte(struct ioc3_driver_data *idd, int byte)
{
	int i, bit;

	for (i = 8; i; i--) {
		bit = byte & 1;
		byte >>= 1;

		nic_write_bit(idd, bit);
	}
}

static unsigned long
nic_find(struct ioc3_driver_data *idd, int *last, unsigned long addr)
{
	int a, b, index, disc;

	nic_reset(idd);

	/* Search ROM.  */
	nic_write_byte(idd, 0xF0);

	/* Algorithm from ``Book of iButton Standards''.  */
	for (index = 0, disc = 0; index < 64; index++) {
		a = nic_read_bit(idd);
		b = nic_read_bit(idd);

		if (a && b) {
			printk(KERN_WARNING "IOC3 NIC search failed.\n");
			*last = 0;
			return 0;
		}

		if (!a && !b) {
			if (index == *last) {
				addr |= 1UL << index;
			} else if (index > *last) {
				addr &= ~(1UL << index);
				disc = index;
			} else if ((addr & (1UL << index)) == 0)
				disc = index;
			nic_write_bit(idd, (addr>>index)&1);
			continue;
		} else {
			if (a)
				addr |= 1UL << index;
			else
				addr &= ~(1UL << index);
			nic_write_bit(idd, a);
			continue;
		}
	}
	*last = disc;
	return addr;
}

static void nic_addr(struct ioc3_driver_data *idd, unsigned long addr)
{
	int index;

	nic_reset(idd);
	nic_write_byte(idd, 0xF0);
	for (index = 0; index < 64; index++) {
		nic_read_bit(idd);
		nic_read_bit(idd);
		nic_write_bit(idd, (addr>>index)&1);
	}
}

static void crc16_byte(unsigned int *crc, unsigned char db)
{
	int i;

	for(i=0;i<8;i++) {
		*crc <<= 1;
		if((db^(*crc>>16)) & 1)
			*crc ^= 0x8005;
		db >>= 1;
	}
	*crc &= 0xFFFF;
}

static unsigned int crc16_area(unsigned char *dbs, int size, unsigned int crc)
{
	while(size--)
		crc16_byte(&crc, *(dbs++));
	return crc;
}

static void crc8_byte(unsigned int *crc, unsigned char db)
{
	int i,f;

	for(i=0;i<8;i++) {
		f = (*crc ^ db) & 1;
		*crc >>= 1;
		db >>= 1;
		if(f)
			*crc ^= 0x8c;
	}
	*crc &= 0xff;
}

static unsigned int crc8_addr(unsigned long addr)
{
	int i;
	unsigned int crc = 0x00;

	for(i=0;i<8;i++)
		crc8_byte(&crc, addr>>(i<<3));
	return crc;
}

static void
read_redir_page(struct ioc3_driver_data *idd, unsigned long addr, int page,
			unsigned char *redir, unsigned char *data)
{
	int loops = 16, i;

	while(redir[page] != 0xFF) {
		page = redir[page]^0xFF;
		loops--;
		if(loops<0) {
			printk(KERN_ERR "IOC3: NIC circular redirection\n");
			return;
		}
	}
	loops = 3;
	while(loops>0) {
		nic_addr(idd, addr);
		nic_write_byte(idd, 0xF0);
		nic_write_byte(idd, (page << 5) & 0xE0);
		nic_write_byte(idd, (page >> 3) & 0x1F);
		for(i=0;i<0x20;i++)
			data[i] = nic_read_byte(idd);
		if(crc16_area(data, 0x20, 0x0000) == 0x800d)
			return;
		loops--;
	}
	printk(KERN_ERR "IOC3: CRC error in data page\n");
	for(i=0;i<0x20;i++)
		data[i] = 0x00;
}

static void
read_redir_map(struct ioc3_driver_data *idd, unsigned long addr,
					 unsigned char *redir)
{
	int i,j,loops = 3,crc_ok;
	unsigned int crc;

	while(loops>0) {
		crc_ok = 1;
		nic_addr(idd, addr);
		nic_write_byte(idd, 0xAA);
		nic_write_byte(idd, 0x00);
		nic_write_byte(idd, 0x01);
		for(i=0;i<64;i+=8) {
			for(j=0;j<8;j++)
				redir[i+j] = nic_read_byte(idd);
			crc = crc16_area(redir+i, 8, (i==0)?0x8707:0x0000);
			crc16_byte(&crc, nic_read_byte(idd));
			crc16_byte(&crc, nic_read_byte(idd));
			if(crc != 0x800d)
				crc_ok = 0;
		}
		if(crc_ok)
			return;
		loops--;
	}
	printk(KERN_ERR "IOC3: CRC error in redirection page\n");
	for(i=0;i<64;i++)
		redir[i] = 0xFF;
}

static void read_nic(struct ioc3_driver_data *idd, unsigned long addr)
{
	unsigned char redir[64];
	unsigned char data[64],part[32];
	int i,j;

	/* read redirections */
	read_redir_map(idd, addr, redir);
	/* read data pages */
	read_redir_page(idd, addr, 0, redir, data);
	read_redir_page(idd, addr, 1, redir, data+32);
	/* assemble the part # */
	j=0;
	for(i=0;i<19;i++)
		if(data[i+11] != ' ')
			part[j++] = data[i+11];
	for(i=0;i<6;i++)
		if(data[i+32] != ' ')
			part[j++] = data[i+32];
	part[j] = 0;
	/* skip Octane power supplies */
	if(!strncmp(part, "060-0035-", 9))
		return;
	if(!strncmp(part, "060-0038-", 9))
		return;
	strcpy(idd->nic_part, part);
	/* assemble the serial # */
	j=0;
	for(i=0;i<10;i++)
		if(data[i+1] != ' ')
			idd->nic_serial[j++] = data[i+1];
	idd->nic_serial[j] = 0;
}

static void read_mac(struct ioc3_driver_data *idd, unsigned long addr)
{
	int i, loops = 3;
	unsigned char data[13];

	while(loops>0) {
		nic_addr(idd, addr);
		nic_write_byte(idd, 0xF0);
		nic_write_byte(idd, 0x00);
		nic_write_byte(idd, 0x00);
		nic_read_byte(idd);
		for(i=0;i<13;i++)
			data[i] = nic_read_byte(idd);
		if(crc16_area(data, 13, 0x0000) == 0x800d) {
			for(i=10;i>4;i--)
				idd->nic_mac[10-i] = data[i];
			return;
		}
		loops--;
	}
	printk(KERN_ERR "IOC3: CRC error in MAC address\n");
	for(i=0;i<6;i++)
		idd->nic_mac[i] = 0x00;
}

static void probe_nic(struct ioc3_driver_data *idd)
{
        int save = 0, loops = 3;
        unsigned long first, addr;

        writel(GPCR_MLAN_EN, &idd->vma->gpcr_s);

        while(loops>0) {
                idd->nic_part[0] = 0;
                idd->nic_serial[0] = 0;
                addr = first = nic_find(idd, &save, 0);
                if(!first)
                        return;
                while(1) {
                        if(crc8_addr(addr))
                                break;
                        else {
                                switch(addr & 0xFF) {
                                case 0x0B:
                                        read_nic(idd, addr);
                                        break;
                                case 0x09:
                                case 0x89:
                                case 0x91:
                                        read_mac(idd, addr);
                                        break;
                                }
                        }
                        addr = nic_find(idd, &save, addr);
                        if(addr == first)
                                return;
                }
                loops--;
        }
        printk(KERN_ERR "IOC3: CRC error in NIC address\n");
}

/* Interrupts */

static void write_ireg(struct ioc3_driver_data *idd, uint32_t val, int which)
{
	unsigned long flags;

	spin_lock_irqsave(&idd->ir_lock, flags);
	switch (which) {
	case IOC3_W_IES:
		writel(val, &idd->vma->sio_ies);
		break;
	case IOC3_W_IEC:
		writel(val, &idd->vma->sio_iec);
		break;
	}
	spin_unlock_irqrestore(&idd->ir_lock, flags);
}
static inline uint32_t get_pending_intrs(struct ioc3_driver_data *idd)
{
	unsigned long flag;
	uint32_t intrs = 0;

	spin_lock_irqsave(&idd->ir_lock, flag);
	intrs = readl(&idd->vma->sio_ir);
	intrs &= readl(&idd->vma->sio_ies);
	spin_unlock_irqrestore(&idd->ir_lock, flag);
	return intrs;
}

static irqreturn_t ioc3_intr_io(int irq, void *arg)
{
	unsigned long flags;
	struct ioc3_driver_data *idd = arg;
	int handled = 1, id;
	unsigned int pending;

	read_lock_irqsave(&ioc3_submodules_lock, flags);

	if(idd->dual_irq && readb(&idd->vma->eisr)) {
		/* send Ethernet IRQ to the driver */
		if(ioc3_ethernet && idd->active[ioc3_ethernet->id] &&
						ioc3_ethernet->intr) {
			handled = handled && !ioc3_ethernet->intr(ioc3_ethernet,
							idd, 0);
		}
	}
	pending = get_pending_intrs(idd);	/* look at the IO IRQs */

	for(id=0;id<IOC3_MAX_SUBMODULES;id++) {
		if(idd->active[id] && ioc3_submodules[id]
				&& (pending & ioc3_submodules[id]->irq_mask)