path: root/arch/arm/mach-rpc/ecard.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/arch/arm/kernel/ecard.c
 *
 *  Copyright 1995-2001 Russell King
 *
 *  Find all installed expansion cards, and handle interrupts from them.
 *
 *  Created from information from Acorns RiscOS3 PRMs
 *
 *  08-Dec-1996	RMK	Added code for the 9'th expansion card - the ether
 *			podule slot.
 *  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).
 *  15-Feb-1998	RMK	Added DMA support
 *  12-Sep-1998	RMK	Added EASI support
 *  10-Jan-1999	RMK	Run loaders in a simulated RISC OS environment.
 *  17-Apr-1999	RMK	Support for EASI Type C cycles.
 */
#define ECARD_C

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/reboot.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/irq.h>
#include <linux/io.h>

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

#include "ecard.h"

struct ecard_request {
	void		(*fn)(struct ecard_request *);
	ecard_t		*ec;
	unsigned int	address;
	unsigned int	length;
	unsigned int	use_loader;
	void		*buffer;
	struct completion *complete;
};

struct expcard_quirklist {
	unsigned short	 manufacturer;
	unsigned short	 product;
	const char	*type;
	void (*init)(ecard_t *ec);
};

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

static void atomwide_3p_quirk(ecard_t *ec);

/* List of descriptions of cards which don't have an extended
 * identification, or chunk directories containing a description.
 */
static struct expcard_quirklist quirklist[] __initdata = {
	{ MANU_ACORN, PROD_ACORN_ETHER1, "Acorn Ether1" },
	{ MANU_ATOMWIDE, PROD_ATOMWIDE_3PSERIAL, NULL, atomwide_3p_quirk },
};

asmlinkage extern int
ecard_loader_reset(unsigned long base, loader_t loader);
asmlinkage extern int
ecard_loader_read(int off, unsigned long base, loader_t loader);

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.
 */
static void ecard_task_reset(struct ecard_request *req)
{
	struct expansion_card *ec = req->ec;
	struct resource *res;

	res = ec->slot_no == 8
		? &ec->resource[ECARD_RES_MEMC]
		: ec->easi
		  ? &ec->resource[ECARD_RES_EASI]
		  : &ec->resource[ECARD_RES_IOCSYNC];

	ecard_loader_reset(res->start, ec->loader);
}

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

	if (ec->slot_no == 8) {
		void __iomem *base = (void __iomem *)
				ec->resource[ECARD_RES_MEMC].start;

		/*
		 * The card maintains an index which increments the address
		 * into a 4096-byte page on each access.  We need to keep
		 * track of the counter.
		 */
		static unsigned int index;
		unsigned int page;

		page = (off >> 12) * 4;
		if (page > 256 * 4)
			return;

		off &= 4095;

		/*