icside.c

来自「linux 内核源代码」· C语言 代码 · 共 747 行 · 第 1/2 页

/*
 * linux/drivers/ide/arm/icside.c
 *
 * Copyright (c) 1996-2004 Russell King.
 *
 * Please note that this platform does not support 32-bit IDE IO.
 */

#include <linux/string.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/ide.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/scatterlist.h>
#include <linux/io.h>

#include <asm/dma.h>
#include <asm/ecard.h>

#define ICS_IDENT_OFFSET		0x2280

#define ICS_ARCIN_V5_INTRSTAT		0x0000
#define ICS_ARCIN_V5_INTROFFSET		0x0004
#define ICS_ARCIN_V5_IDEOFFSET		0x2800
#define ICS_ARCIN_V5_IDEALTOFFSET	0x2b80
#define ICS_ARCIN_V5_IDESTEPPING	6

#define ICS_ARCIN_V6_IDEOFFSET_1	0x2000
#define ICS_ARCIN_V6_INTROFFSET_1	0x2200
#define ICS_ARCIN_V6_INTRSTAT_1		0x2290
#define ICS_ARCIN_V6_IDEALTOFFSET_1	0x2380
#define ICS_ARCIN_V6_IDEOFFSET_2	0x3000
#define ICS_ARCIN_V6_INTROFFSET_2	0x3200
#define ICS_ARCIN_V6_INTRSTAT_2		0x3290
#define ICS_ARCIN_V6_IDEALTOFFSET_2	0x3380
#define ICS_ARCIN_V6_IDESTEPPING	6

struct cardinfo {
	unsigned int dataoffset;
	unsigned int ctrloffset;
	unsigned int stepping;
};

static struct cardinfo icside_cardinfo_v5 = {
	.dataoffset	= ICS_ARCIN_V5_IDEOFFSET,
	.ctrloffset	= ICS_ARCIN_V5_IDEALTOFFSET,
	.stepping	= ICS_ARCIN_V5_IDESTEPPING,
};

static struct cardinfo icside_cardinfo_v6_1 = {
	.dataoffset	= ICS_ARCIN_V6_IDEOFFSET_1,
	.ctrloffset	= ICS_ARCIN_V6_IDEALTOFFSET_1,
	.stepping	= ICS_ARCIN_V6_IDESTEPPING,
};

static struct cardinfo icside_cardinfo_v6_2 = {
	.dataoffset	= ICS_ARCIN_V6_IDEOFFSET_2,
	.ctrloffset	= ICS_ARCIN_V6_IDEALTOFFSET_2,
	.stepping	= ICS_ARCIN_V6_IDESTEPPING,
};

struct icside_state {
	unsigned int channel;
	unsigned int enabled;
	void __iomem *irq_port;
	void __iomem *ioc_base;
	unsigned int type;
	/* parent device... until the IDE core gets one of its own */
	struct device *dev;
	ide_hwif_t *hwif[2];
};

#define ICS_TYPE_A3IN	0
#define ICS_TYPE_A3USER	1
#define ICS_TYPE_V6	3
#define ICS_TYPE_V5	15
#define ICS_TYPE_NOTYPE	((unsigned int)-1)

/* ---------------- Version 5 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
	struct icside_state *state = ec->irq_data;

	writeb(0, state->irq_port + ICS_ARCIN_V5_INTROFFSET);
}

/* Prototype: icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v5 (struct expansion_card *ec, int irqnr)
{
	struct icside_state *state = ec->irq_data;

	readb(state->irq_port + ICS_ARCIN_V5_INTROFFSET);
}

static const expansioncard_ops_t icside_ops_arcin_v5 = {
	.irqenable	= icside_irqenable_arcin_v5,
	.irqdisable	= icside_irqdisable_arcin_v5,
};


/* ---------------- Version 6 PCB Support Functions --------------------- */
/* Prototype: icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : enable interrupts from card
 */
static void icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
	struct icside_state *state = ec->irq_data;
	void __iomem *base = state->irq_port;

	state->enabled = 1;

	switch (state->channel) {
	case 0:
		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);
		readb(base + ICS_ARCIN_V6_INTROFFSET_2);
		break;
	case 1:
		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);
		readb(base + ICS_ARCIN_V6_INTROFFSET_1);
		break;
	}
}

/* Prototype: icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
 * Purpose  : disable interrupts from card
 */
static void icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
{
	struct icside_state *state = ec->irq_data;

	state->enabled = 0;

	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
}

/* Prototype: icside_irqprobe(struct expansion_card *ec)
 * Purpose  : detect an active interrupt from card
 */
static int icside_irqpending_arcin_v6(struct expansion_card *ec)
{
	struct icside_state *state = ec->irq_data;

	return readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_1) & 1 ||
	       readb(state->irq_port + ICS_ARCIN_V6_INTRSTAT_2) & 1;
}

static const expansioncard_ops_t icside_ops_arcin_v6 = {
	.irqenable	= icside_irqenable_arcin_v6,
	.irqdisable	= icside_irqdisable_arcin_v6,
	.irqpending	= icside_irqpending_arcin_v6,
};

/*
 * Handle routing of interrupts.  This is called before
 * we write the command to the drive.
 */
static void icside_maskproc(ide_drive_t *drive, int mask)
{
	ide_hwif_t *hwif = HWIF(drive);
	struct icside_state *state = hwif->hwif_data;
	unsigned long flags;

	local_irq_save(flags);

	state->channel = hwif->channel;

	if (state->enabled && !mask) {
		switch (hwif->channel) {
		case 0:
			writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
			readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
			break;
		case 1:
			writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
			readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
			break;
		}
	} else {
		readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);
		readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);
	}

	local_irq_restore(flags);
}

#ifdef CONFIG_BLK_DEV_IDEDMA_ICS
/*
 * SG-DMA support.
 *
 * Similar to the BM-DMA, but we use the RiscPCs IOMD DMA controllers.
 * There is only one DMA controller per card, which means that only
 * one drive can be accessed at one time.  NOTE! We do not enforce that
 * here, but we rely on the main IDE driver spotting that both
 * interfaces use the same IRQ, which should guarantee this.
 */

static void icside_build_sglist(ide_drive_t *drive, struct request *rq)
{
	ide_hwif_t *hwif = drive->hwif;
	struct icside_state *state = hwif->hwif_data;
	struct scatterlist *sg = hwif->sg_table;

	ide_map_sg(drive, rq);

	if (rq_data_dir(rq) == READ)
		hwif->sg_dma_direction = DMA_FROM_DEVICE;
	else
		hwif->sg_dma_direction = DMA_TO_DEVICE;

	hwif->sg_nents = dma_map_sg(state->dev, sg, hwif->sg_nents,
				    hwif->sg_dma_direction);
}

/*
 * Configure the IOMD to give the appropriate timings for the transfer
 * mode being requested.  We take the advice of the ATA standards, and
 * calculate the cycle time based on the transfer mode, and the EIDE
 * MW DMA specs that the drive provides in the IDENTIFY command.
 *
 * We have the following IOMD DMA modes to choose from:
 *
 *	Type	Active		Recovery	Cycle
 *	A	250 (250)	312 (550)	562 (800)
 *	B	187		250		437
 *	C	125 (125)	125 (375)	250 (500)
 *	D	62		125		187
 *
 * (figures in brackets are actual measured timings)
 *
 * However, we also need to take care of the read/write active and
 * recovery timings:
 *
 *			Read	Write
 *  	Mode	Active	-- Recovery --	Cycle	IOMD type
 *	MW0	215	50	215	480	A
 *	MW1	80	50	50	150	C
 *	MW2	70	25	25	120	C
 */
static void icside_set_dma_mode(ide_drive_t *drive, const u8 xfer_mode)
{
	int cycle_time, use_dma_info = 0;

	switch (xfer_mode) {
	case XFER_MW_DMA_2:
		cycle_time = 250;
		use_dma_info = 1;
		break;

	case XFER_MW_DMA_1:
		cycle_time = 250;
		use_dma_info = 1;
		break;

	case XFER_MW_DMA_0:
		cycle_time = 480;
		break;

	case XFER_SW_DMA_2:
	case XFER_SW_DMA_1:
	case XFER_SW_DMA_0:
		cycle_time = 480;
		break;
	default:
		return;
	}

	/*
	 * If we're going to be doing MW_DMA_1 or MW_DMA_2, we should
	 * take care to note the values in the ID...
	 */
	if (use_dma_info && drive->id->eide_dma_time > cycle_time)
		cycle_time = drive->id->eide_dma_time;

	drive->drive_data = cycle_time;

	printk("%s: %s selected (peak %dMB/s)\n", drive->name,
		ide_xfer_verbose(xfer_mode), 2000 / drive->drive_data);
}

static void icside_dma_host_off(ide_drive_t *drive)
{
}

static void icside_dma_off_quietly(ide_drive_t *drive)
{
	drive->using_dma = 0;
}

static void icside_dma_host_on(ide_drive_t *drive)
{
}

static int icside_dma_on(ide_drive_t *drive)
{
	drive->using_dma = 1;

	return 0;
}

static int icside_dma_end(ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	struct icside_state *state = hwif->hwif_data;

	drive->waiting_for_dma = 0;

	disable_dma(ECARD_DEV(state->dev)->dma);

	/* Teardown mappings after DMA has completed. */
	dma_unmap_sg(state->dev, hwif->sg_table, hwif->sg_nents,
		     hwif->sg_dma_direction);

	return get_dma_residue(ECARD_DEV(state->dev)->dma) != 0;
}

static void icside_dma_start(ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	struct icside_state *state = hwif->hwif_data;

	/* We can not enable DMA on both channels simultaneously. */
	BUG_ON(dma_channel_active(ECARD_DEV(state->dev)->dma));
	enable_dma(ECARD_DEV(state->dev)->dma);
}

static int icside_dma_setup(ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	struct icside_state *state = hwif->hwif_data;
	struct request *rq = hwif->hwgroup->rq;
	unsigned int dma_mode;

	if (rq_data_dir(rq))
		dma_mode = DMA_MODE_WRITE;
	else
		dma_mode = DMA_MODE_READ;

	/*
	 * We can not enable DMA on both channels.
	 */
	BUG_ON(dma_channel_active(ECARD_DEV(state->dev)->dma));

	icside_build_sglist(drive, rq);

	/*
	 * Ensure that we have the right interrupt routed.
	 */
	icside_maskproc(drive, 0);

	/*
	 * Route the DMA signals to the correct interface.
	 */
	writeb(hwif->select_data, hwif->config_data);

	/*
	 * Select the correct timing for this drive.
	 */
	set_dma_speed(ECARD_DEV(state->dev)->dma, drive->drive_data);

	/*
	 * Tell the DMA engine about the SG table and
	 * data direction.