ps2esdi.c

Linux块设备驱动源码

	/* BA */
	printk("%s: DMA arbitration level : %d\n",
	       DEVICE_NAME, dma_arb_level);

	LITE_ON;
	current_int_handler = ps2esdi_initial_reset_int_handler;
	reset_ctrl();
	reset_status = 0;
	reset_start = jiffies;
	while (!reset_status) {
		init_timer(&esdi_timer);
		esdi_timer.expires = jiffies + HZ;
		esdi_timer.data = 0;
		add_timer(&esdi_timer);
		sleep_on(&ps2esdi_int);
	}
	reset_end = jiffies;
	LITE_OFF;
	printk("%s: reset interrupt after %d jiffies,  %u.%02u secs\n",
	       DEVICE_NAME, reset_end - reset_start, (reset_end - reset_start) / HZ,
	       (reset_end - reset_start) % HZ);


	/* Integrated ESDI Disk and Controller has only one drive! */
	if (adapterID == INTG_ESDI_ID) {/* if not "normal" PS2 ESDI adapter */
		ps2esdi_drives = 1;	/* then we have only one physical disk! */		intg_esdi = 1;
	}



	/* finally this part sets up some global data structures etc. */

	ps2esdi_get_device_cfg();

	/* some annoyance in the above routine returns TWO drives?
	 Is something else happining in the background?
	 Regaurdless we fix the # of drives again. AJK */
	/* Integrated ESDI Disk and Controller has only one drive! */
	if (adapterID == INTG_ESDI_ID)	/* if not "normal" PS2 ESDI adapter */
		ps2esdi_drives = 1;	/* Not three or two, ONE DAMNIT! */

	current_int_handler = ps2esdi_normal_interrupt_handler;

	if (request_dma(dma_arb_level, "ed") !=0) {
		printk(KERN_WARNING "PS2ESDI: Can't request dma-channel %d\n"
			,(int) dma_arb_level);
		error = -EBUSY;
		goto err_out3;
	}
	blk_queue_max_sectors(ps2esdi_queue, 128);

	error = -ENOMEM;
	for (i = 0; i < ps2esdi_drives; i++) {
		struct gendisk *disk = alloc_disk(64);
		if (!disk)
			goto err_out4;
		disk->major = PS2ESDI_MAJOR;
		disk->first_minor = i<<6;
		sprintf(disk->disk_name, "ed%c", 'a'+i);
		sprintf(disk->devfs_name, "ed/target%d", i);
		disk->fops = &ps2esdi_fops;
		ps2esdi_gendisk[i] = disk;
	}

	for (i = 0; i < ps2esdi_drives; i++) {
		struct gendisk *disk = ps2esdi_gendisk[i];
		set_capacity(disk, ps2esdi_info[i].head * ps2esdi_info[i].sect *
				ps2esdi_info[i].cyl);
		disk->queue = ps2esdi_queue;
		disk->private_data = &ps2esdi_info[i];
		add_disk(disk);
	}
	return 0;
err_out4:
	while (i--)
		put_disk(ps2esdi_gendisk[i]);
err_out3:
	release_region(io_base, 4);
err_out2:
	free_irq(PS2ESDI_IRQ, &ps2esdi_gendisk);
err_out1:
	if(ps2esdi_slot) {
		mca_mark_as_unused(ps2esdi_slot);
		mca_set_adapter_procfn(ps2esdi_slot, NULL, NULL);
	}
	return error;
}

static void __init ps2esdi_get_device_cfg(void)
{
	u_short cmd_blk[TYPE_0_CMD_BLK_LENGTH];

	/*BA */ printk("%s: Drive 0\n", DEVICE_NAME);
	current_int_handler = ps2esdi_geometry_int_handler;
	cmd_blk[0] = CMD_GET_DEV_CONFIG | 0x600;
	cmd_blk[1] = 0;
	no_int_yet = TRUE;
	ps2esdi_out_cmd_blk(cmd_blk);
	if (no_int_yet)
		sleep_on(&ps2esdi_int);

	if (ps2esdi_drives > 1) {
		printk("%s: Drive 1\n", DEVICE_NAME);	/*BA */
		cmd_blk[0] = CMD_GET_DEV_CONFIG | (1 << 5) | 0x600;
		cmd_blk[1] = 0;
		no_int_yet = TRUE;
		ps2esdi_out_cmd_blk(cmd_blk);
		if (no_int_yet)
			sleep_on(&ps2esdi_int);
	}			/* if second physical drive is present */
	return;
}

/* strategy routine that handles most of the IO requests */
static void do_ps2esdi_request(request_queue_t * q)
{
	struct request *req;
	/* since, this routine is called with interrupts cleared - they 
	   must be before it finishes  */

	req = elv_next_request(q);
	if (!req)
		return;

#if 0
	printk("%s:got request. device : %s command : %d  sector : %ld count : %ld, buffer: %p\n",
	       DEVICE_NAME,
	       req->rq_disk->disk_name,
	       req->cmd, req->sector,
	       req->current_nr_sectors, req->buffer);
#endif

	/* check for above 16Mb dmas */
	if (isa_virt_to_bus(req->buffer + req->current_nr_sectors * 512) > 16 * MB) {
		printk("%s: DMA above 16MB not supported\n", DEVICE_NAME);
		end_request(req, FAIL);
		return;
	}

	if (req->sector+req->current_nr_sectors > get_capacity(req->rq_disk)) {
		printk("Grrr. error. ps2esdi_drives: %d, %llu %llu\n",
		    ps2esdi_drives, req->sector,
		    (unsigned long long)get_capacity(req->rq_disk));
		end_request(req, FAIL);
		return;
	}

	switch (rq_data_dir(req)) {
	case READ:
		ps2esdi_readwrite(READ, req);
		break;
	case WRITE:
		ps2esdi_readwrite(WRITE, req);
		break;
	default:
		printk("%s: Unknown command\n", req->rq_disk->disk_name);
		end_request(req, FAIL);
		break;
	}		/* handle different commands */
}				/* main strategy routine */

/* resets the ESDI adapter */
static void reset_ctrl(void)
{

	u_long expire;
	u_short status;

	/* enable interrupts on the controller */
	status = inb(ESDI_INTRPT);
	outb((status & 0xe0) | ATT_EOI, ESDI_ATTN);	/* to be sure we don't have
							   any interrupt pending... */
	outb_p(CTRL_ENABLE_INTR, ESDI_CONTROL);

	/* read the ESDI status port - if the controller is not busy,
	   simply do a soft reset (fast) - otherwise we'll have to do a
	   hard (slow) reset.  */
	if (!(inb_p(ESDI_STATUS) & STATUS_BUSY)) {
		/*BA */ printk("%s: soft reset...\n", DEVICE_NAME);
		outb_p(CTRL_SOFT_RESET, ESDI_ATTN);
	}
	/* soft reset */ 
	else {
		/*BA */
		printk("%s: hard reset...\n", DEVICE_NAME);
		outb_p(CTRL_HARD_RESET, ESDI_CONTROL);
		expire = jiffies + 2*HZ;
		while (time_before(jiffies, expire));
		outb_p(1, ESDI_CONTROL);
	}			/* hard reset */


}				/* reset the controller */

/* called by the strategy routine to handle read and write requests */
static void ps2esdi_readwrite(int cmd, struct request *req)
{
	struct ps2esdi_i_struct *p = req->rq_disk->private_data;
	unsigned block = req->sector;
	unsigned count = req->current_nr_sectors;
	int drive = p - ps2esdi_info;
	u_short track, head, cylinder, sector;
	u_short cmd_blk[TYPE_1_CMD_BLK_LENGTH];

	/* do some relevant arithmatic */
	track = block / p->sect;
	head = track % p->head;
	cylinder = track / p->head;
	sector = block % p->sect;

#if 0
	printk("%s: cyl=%d head=%d sect=%d\n", DEVICE_NAME, cylinder, head, sector);
#endif
	/* call the routine that actually fills out a command block */
	ps2esdi_fill_cmd_block
	    (cmd_blk,
	     (cmd == READ) ? CMD_READ : CMD_WRITE,
	     cylinder, head, sector, count, drive);

	/* send the command block to the controller */
	current_req = req;
	spin_unlock_irq(&ps2esdi_lock);
	if (ps2esdi_out_cmd_blk(cmd_blk)) {
		spin_lock_irq(&ps2esdi_lock);
		printk("%s: Controller failed\n", DEVICE_NAME);
		if ((++req->errors) >= MAX_RETRIES)
			end_request(req, FAIL);
	}
	/* check for failure to put out the command block */ 
	else {
		spin_lock_irq(&ps2esdi_lock);
#if 0
		printk("%s: waiting for xfer\n", DEVICE_NAME);
#endif
		/* turn disk lights on */
		LITE_ON;
	}

}				/* ps2esdi_readwrite */

/* fill out the command block */
static void ps2esdi_fill_cmd_block(u_short * cmd_blk, u_short cmd,
 u_short cyl, u_short head, u_short sector, u_short length, u_char drive)
{

	cmd_blk[0] = (drive << 5) | cmd;
	cmd_blk[1] = length;
	cmd_blk[2] = ((cyl & 0x1f) << 11) | (head << 5) | sector;
	cmd_blk[3] = (cyl & 0x3E0) >> 5;

}				/* fill out the command block */

/* write a command block to the controller */
static int ps2esdi_out_cmd_blk(u_short * cmd_blk)
{

	int i;
	unsigned long jif;
	u_char status;

	/* enable interrupts */
	outb(CTRL_ENABLE_INTR, ESDI_CONTROL);

	/* do not write to the controller, if it is busy */
	for (jif = jiffies + ESDI_STAT_TIMEOUT;
		time_after(jif, jiffies) &&
			(inb(ESDI_STATUS) & STATUS_BUSY); )
		;

#if 0
	printk("%s: i(1)=%ld\n", DEVICE_NAME, jif);
#endif

	/* if device is still busy - then just time out */
	if (inb(ESDI_STATUS) & STATUS_BUSY) {
		printk("%s: ps2esdi_out_cmd timed out (1)\n", DEVICE_NAME);
		return ERROR;
	}			/* timeout ??? */
	/* Set up the attention register in the controller */
	outb(((*cmd_blk) & 0xE0) | 1, ESDI_ATTN);

#if 0
	printk("%s: sending %d words to controller\n", DEVICE_NAME, (((*cmd_blk) >> 14) + 1) << 1);
#endif

	/* one by one send each word out */
	for (i = (((*cmd_blk) >> 14) + 1) << 1; i; i--) {
		status = inb(ESDI_STATUS);
		for (jif = jiffies + ESDI_STAT_TIMEOUT;
		     time_after(jif, jiffies) && (status & STATUS_BUSY) &&
		   (status & STATUS_CMD_INF); status = inb(ESDI_STATUS));
		if ((status & (STATUS_BUSY | STATUS_CMD_INF)) == STATUS_BUSY) {
#if 0
			printk("%s: sending %04X\n", DEVICE_NAME, *cmd_blk);
#endif
			outw(*cmd_blk++, ESDI_CMD_INT);
		} else {
			printk("%s: ps2esdi_out_cmd timed out while sending command (status=%02X)\n",
			       DEVICE_NAME, status);
			return ERROR;
		}
	}			/* send all words out */
	return OK;
}				/* send out the commands */


/* prepare for dma - do all the necessary setup */
static void ps2esdi_prep_dma(char *buffer, u_short length, u_char dma_xmode)
{
	unsigned long flags = claim_dma_lock();

	mca_disable_dma(dma_arb_level);

	mca_set_dma_addr(dma_arb_level, isa_virt_to_bus(buffer));

	mca_set_dma_count(dma_arb_level, length * 512 / 2);

	mca_set_dma_mode(dma_arb_level, dma_xmode);

	mca_enable_dma(dma_arb_level);

	release_dma_lock(flags);

}				/* prepare for dma */



static irqreturn_t ps2esdi_interrupt_handler(int irq, void *dev_id,
				      struct pt_regs *regs)
{
	u_int int_ret_code;

	if (inb(ESDI_STATUS) & STATUS_INTR) {
		int_ret_code = inb(ESDI_INTRPT);
		if (current_int_handler) {
			/* Disable adapter interrupts till processing is finished */
			outb(CTRL_DISABLE_INTR, ESDI_CONTROL);
			current_int_handler(int_ret_code);
		} else
			printk("%s: help ! No interrupt handler.\n", DEVICE_NAME);
	} else {
		return IRQ_NONE;
	}
	return IRQ_HANDLED;
}

static void ps2esdi_initial_reset_int_handler(u_int int_ret_code)
{

	switch (int_ret_code & 0xf) {
	case INT_RESET:
		/*BA */
		printk("%s: initial reset completed.\n", DEVICE_NAME);
		outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
		wake_up(&ps2esdi_int);
		break;
	case INT_ATTN_ERROR:
		printk("%s: Attention error. interrupt status : %02X\n", DEVICE_NAME,
		       int_ret_code);
		printk("%s: status: %02x\n", DEVICE_NAME, inb(ESDI_STATUS));
		break;
	default:
		printk("%s: initial reset handler received interrupt: %02X\n",
		       DEVICE_NAME, int_ret_code);