ecard.c

linux-2.6.15.6

/*
 *  linux/arch/arm26/kernel/ecard.c
 *
 *  Copyright 1995-2001 Russell King
 *  Copyright 2003 Ian Molton
 *
 * 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.
 *
 *  Find all installed expansion cards, and handle interrupts from them.
 *
 *  Created from information from Acorns RiscOS3 PRMs
 *  15-Jun-2003 IM      Modified from ARM32 (RiscPC capable) version
 *  10-Jan-1999	RMK	Run loaders in a simulated RISC OS environment.
 *  06-May-1997	RMK	Added blacklist for cards whose loader doesn't work.
 *  12-Sep-1997	RMK	Created new handling of interrupt enables/disables
 *			- cards can now register their own routine to control
 *			interrupts (recommended).
 *  29-Sep-1997	RMK	Expansion card interrupt hardware not being re-enabled
 *			on reset from Linux. (Caused cards not to respond
 *			under RiscOS without hard reset).
 *
 */
#define ECARD_C

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/device.h>
#include <linux/init.h>

#include <asm/dma.h>
#include <asm/ecard.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/irqchip.h>
#include <asm/tlbflush.h>

enum req {
	req_readbytes,
	req_reset
};

struct ecard_request {
	enum req	req;
	ecard_t		*ec;
	unsigned int	address;
	unsigned int	length;
	unsigned int	use_loader;
	void		*buffer;
};

struct expcard_blacklist {
	unsigned short	 manufacturer;
	unsigned short	 product;
	const char	*type;
};

static ecard_t *cards;
static ecard_t *slot_to_expcard[MAX_ECARDS];
static unsigned int ectcr;

/* List of descriptions of cards which don't have an extended
 * identification, or chunk directories containing a description.
 */
static struct expcard_blacklist __initdata blacklist[] = {
	{ MANU_ACORN, PROD_ACORN_ETHER1, "Acorn Ether1" }
};

asmlinkage extern int
ecard_loader_reset(volatile unsigned char *pa, loader_t loader);
asmlinkage extern int
ecard_loader_read(int off, volatile unsigned char *pa, loader_t loader);

static const struct ecard_id *
ecard_match_device(const struct ecard_id *ids, struct expansion_card *ec);

static inline unsigned short
ecard_getu16(unsigned char *v)
{
	return v[0] | v[1] << 8;
}

static inline signed long
ecard_gets24(unsigned char *v)
{
	return v[0] | v[1] << 8 | v[2] << 16 | ((v[2] & 0x80) ? 0xff000000 : 0);
}

static inline ecard_t *
slot_to_ecard(unsigned int slot)
{
	return slot < MAX_ECARDS ? slot_to_expcard[slot] : NULL;
}

/* ===================== Expansion card daemon ======================== */
/*
 * Since the loader programs on the expansion cards need to be run
 * in a specific environment, create a separate task with this
 * environment up, and pass requests to this task as and when we
 * need to.
 *
 * This should allow 99% of loaders to be called from Linux.
 *
 * From a security standpoint, we trust the card vendors.  This
 * may be a misplaced trust.
 */
#define BUS_ADDR(x) ((((unsigned long)(x)) << 2) + IO_BASE)
#define POD_INT_ADDR(x)	((volatile unsigned char *)\
			 ((BUS_ADDR((x)) - IO_BASE) + IO_START))

static inline void ecard_task_reset(struct ecard_request *req)
{
	struct expansion_card *ec = req->ec;
	if (ec->loader)
		ecard_loader_reset(POD_INT_ADDR(ec->podaddr), ec->loader);
}

static void
ecard_task_readbytes(struct ecard_request *req)
{
	unsigned char *buf = (unsigned char *)req->buffer;
	volatile unsigned char *base_addr =
		(volatile unsigned char *)POD_INT_ADDR(req->ec->podaddr);
	unsigned int len = req->length;
	unsigned int off = req->address;

	if (!req->use_loader || !req->ec->loader) {
		off *= 4;
		while (len--) {
			*buf++ = base_addr[off];
			off += 4;
		}
	} else {
		while(len--) {
			/*
			 * The following is required by some
			 * expansion card loader programs.
			 */
			*(unsigned long *)0x108 = 0;
			*buf++ = ecard_loader_read(off++, base_addr,
						   req->ec->loader);
		}
	}
}

static void ecard_do_request(struct ecard_request *req)
{
	switch (req->req) {
	case req_readbytes:
		ecard_task_readbytes(req);
		break;

	case req_reset:
		ecard_task_reset(req);
		break;
	}
}

/*
 * On 26-bit processors, we don't need the kcardd thread to access the
 * expansion card loaders.  We do it directly.
 */
#define ecard_call(req)	ecard_do_request(req)

/* ======================= Mid-level card control ===================== */

static void
ecard_readbytes(void *addr, ecard_t *ec, int off, int len, int useld)
{
	struct ecard_request req;

	req.req		= req_readbytes;
	req.ec		= ec;
	req.address	= off;
	req.length	= len;
	req.use_loader	= useld;
	req.buffer	= addr;

	ecard_call(&req);
}

int ecard_readchunk(struct in_chunk_dir *cd, ecard_t *ec, int id, int num)
{
	struct ex_chunk_dir excd;
	int index = 16;
	int useld = 0;

	if (!ec->cid.cd)
		return 0;

	while(1) {
		ecard_readbytes(&excd, ec, index, 8, useld);
		index += 8;
		if (c_id(&excd) == 0) {
			if (!useld && ec->loader) {
				useld = 1;
				index = 0;
				continue;
			}
			return 0;
		}
		if (c_id(&excd) == 0xf0) { /* link */
			index = c_start(&excd);
			continue;
		}
		if (c_id(&excd) == 0x80) { /* loader */
			if (!ec->loader) {
				ec->loader = (loader_t)kmalloc(c_len(&excd),
							       GFP_KERNEL);
				if (ec->loader)
					ecard_readbytes(ec->loader, ec,
							(int)c_start(&excd),
							c_len(&excd), useld);
				else
					return 0;
			}
			continue;
		}
		if (c_id(&excd) == id && num-- == 0)
			break;
	}

	if (c_id(&excd) & 0x80) {
		switch (c_id(&excd) & 0x70) {
		case 0x70:
			ecard_readbytes((unsigned char *)excd.d.string, ec,
					(int)c_start(&excd), c_len(&excd),
					useld);
			break;
		case 0x00:
			break;
		}
	}
	cd->start_offset = c_start(&excd);
	memcpy(cd->d.string, excd.d.string, 256);
	return 1;
}

/* ======================= Interrupt control ============================ */

static void ecard_def_irq_enable(ecard_t *ec, int irqnr)
{
}

static void ecard_def_irq_disable(ecard_t *ec, int irqnr)
{
}

static int ecard_def_irq_pending(ecard_t *ec)
{
	return !ec->irqmask || ec->irqaddr[0] & ec->irqmask;
}

static void ecard_def_fiq_enable(ecard_t *ec, int fiqnr)
{
	panic("ecard_def_fiq_enable called - impossible");
}

static void ecard_def_fiq_disable(ecard_t *ec, int fiqnr)
{
	panic("ecard_def_fiq_disable called - impossible");
}

static int ecard_def_fiq_pending(ecard_t *ec)
{
	return !ec->fiqmask || ec->fiqaddr[0] & ec->fiqmask;
}

static expansioncard_ops_t ecard_default_ops = {
	ecard_def_irq_enable,
	ecard_def_irq_disable,
	ecard_def_irq_pending,
	ecard_def_fiq_enable,
	ecard_def_fiq_disable,
	ecard_def_fiq_pending
};

/*
 * Enable and disable interrupts from expansion cards.
 * (interrupts are disabled for these functions).
 *
 * They are not meant to be called directly, but via enable/disable_irq.
 */
static void ecard_irq_unmask(unsigned int irqnr)
{
	ecard_t *ec = slot_to_ecard(irqnr - 32);

	if (ec) {
		if (!ec->ops)
			ec->ops = &ecard_default_ops;

		if (ec->claimed && ec->ops->irqenable)
			ec->ops->irqenable(ec, irqnr);
		else
			printk(KERN_ERR "ecard: rejecting request to "
				"enable IRQs for %d\n", irqnr);
	}
}

static void ecard_irq_mask(unsigned int irqnr)
{
	ecard_t *ec = slot_to_ecard(irqnr - 32);

	if (ec) {
		if (!ec->ops)
			ec->ops = &ecard_default_ops;

		if (ec->ops && ec->ops->irqdisable)
			ec->ops->irqdisable(ec, irqnr);
	}
}

static struct irqchip ecard_chip = {
	.ack	= ecard_irq_mask,
	.mask	= ecard_irq_mask,
	.unmask = ecard_irq_unmask,
};

void ecard_enablefiq(unsigned int fiqnr)
{
	ecard_t *ec = slot_to_ecard(fiqnr);

	if (ec) {
		if (!ec->ops)
			ec->ops = &ecard_default_ops;

		if (ec->claimed && ec->ops->fiqenable)
			ec->ops->fiqenable(ec, fiqnr);
		else
			printk(KERN_ERR "ecard: rejecting request to "
				"enable FIQs for %d\n", fiqnr);
	}
}

void ecard_disablefiq(unsigned int fiqnr)
{
	ecard_t *ec = slot_to_ecard(fiqnr);

	if (ec) {
		if (!ec->ops)
			ec->ops = &ecard_default_ops;

		if (ec->ops->fiqdisable)
			ec->ops->fiqdisable(ec, fiqnr);
	}
}

static void
ecard_dump_irq_state(ecard_t *ec)
{
	printk("  %d: %sclaimed, ",
	       ec->slot_no,
	       ec->claimed ? "" : "not ");

	if (ec->ops && ec->ops->irqpending &&
	    ec->ops != &ecard_default_ops)
		printk("irq %spending\n",
		       ec->ops->irqpending(ec) ? "" : "not ");
	else
		printk("irqaddr %p, mask = %02X, status = %02X\n",
		       ec->irqaddr, ec->irqmask, *ec->irqaddr);
}

static void ecard_check_lockup(struct irqdesc *desc)
{
	static int last, lockup;
	ecard_t *ec;

	/*
	 * If the timer interrupt has not run since the last million
	 * unrecognised expansion card interrupts, then there is
	 * something seriously wrong.  Disable the expansion card
	 * interrupts so at least we can continue.
	 *
	 * Maybe we ought to start a timer to re-enable them some time
	 * later?
	 */
	if (last == jiffies) {
		lockup += 1;
		if (lockup > 1000000) {
			printk(KERN_ERR "\nInterrupt lockup detected - "
			       "disabling all expansion card interrupts\n");

			desc->chip->mask(IRQ_EXPANSIONCARD);

			printk("Expansion card IRQ state:\n");

			for (ec = cards; ec; ec = ec->next)
				ecard_dump_irq_state(ec);
		}
	} else
		lockup = 0;

	/*
	 * If we did not recognise the source of this interrupt,
	 * warn the user, but don't flood the user with these messages.
	 */
	if (!last || time_after(jiffies, (unsigned long)(last + 5*HZ))) {
		last = jiffies;
		printk(KERN_WARNING "Unrecognised interrupt from backplane\n");
	}
}

static void
ecard_irq_handler(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
{
	ecard_t *ec;
	int called = 0;

	desc->chip->mask(irq);
	for (ec = cards; ec; ec = ec->next) {
		int pending;

		if (!ec->claimed || ec->irq == NO_IRQ)
			continue;