ppc32: Bring back PowerMac swim3 floppy driver into working state

Forward port Paul's latest fixes from 2.4. This driver still need
significant work to fit into the "macio" model properly, among
others.

drivers/block/swim3.c

@@ -24,7 +24,10 @@
 #include <linux/delay.h>
 #include <linux/fd.h>
 #include <linux/ioctl.h>
+#include <linux/blkdev.h>
 #include <linux/devfs_fs_kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
 #include <asm/io.h>
 #include <asm/dbdma.h>
 #include <asm/prom.h>
@@ -144,7 +147,7 @@ struct swim3 {
 #define RELAX		3	/* also eject in progress */
 #define READ_DATA_0	4
 #define TWOMEG_DRIVE	5
-#define SINGLE_SIDED	6
+#define SINGLE_SIDED	6	/* drive or diskette is 4MB type? */
 #define DRIVE_PRESENT	7
 #define DISK_IN		8
 #define WRITE_PROT	9
@@ -184,6 +187,7 @@ struct floppy_state {
 	int	req_sector;	/* sector number ditto */
 	int	scount;		/* # sectors we're transferring at present */
 	int	retries;
+	int	settle_time;
 	int	secpercyl;	/* disk geometry information */
 	int	secpertrack;
 	int	total_secs;
@@ -232,8 +236,9 @@ static void setup_transfer(struct floppy_state *fs);
 static void act(struct floppy_state *fs);
 static void scan_timeout(unsigned long data);
 static void seek_timeout(unsigned long data);
+static void settle_timeout(unsigned long data);
 static void xfer_timeout(unsigned long data);
-static void swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static irqreturn_t swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs);
 /*static void fd_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs);*/
 static int grab_drive(struct floppy_state *fs, enum swim_state state,
 		      int interruptible);
@@ -274,7 +279,6 @@ static void swim3_action(struct floppy_state *fs, int action)
 	udelay(2);
 	out_8(&sw->select, sw->select & ~LSTRB);
 	udelay(1);
-	out_8(&sw->select, RELAX);
 }
 
 static int swim3_readbit(struct floppy_state *fs, int bit)
@@ -283,9 +287,8 @@ static int swim3_readbit(struct floppy_state *fs, int bit)
 	int stat;
 
 	swim3_select(fs, bit);
-	udelay(10);
+	udelay(1);
 	stat = in_8(&sw->status);
-	out_8(&sw->select, RELAX);
 	return (stat & DATA) == 0;
 }
 
@@ -374,13 +377,13 @@ static void set_timeout(struct floppy_state *fs, int nticks,
 static inline void scan_track(struct floppy_state *fs)
 {
 	volatile struct swim3 *sw = fs->swim3;
-	int xx;
 
 	swim3_select(fs, READ_DATA_0);
-	xx = sw->intr;		/* clear SEEN_SECTOR bit */
+	in_8(&sw->intr);		/* clear SEEN_SECTOR bit */
+	in_8(&sw->error);
+	out_8(&sw->intr_enable, SEEN_SECTOR);
 	out_8(&sw->control_bis, DO_ACTION);
 	/* enable intr when track found */
-	out_8(&sw->intr_enable, ERROR_INTR | SEEN_SECTOR);
 	set_timeout(fs, HZ, scan_timeout);	/* enable timeout */
 }
 
@@ -395,12 +398,14 @@ static inline void seek_track(struct floppy_state *fs, int n)
 		swim3_action(fs, SEEK_NEGATIVE);
 		sw->nseek = -n;
 	}
-	fs->expect_cyl = (fs->cur_cyl > 0)? fs->cur_cyl + n: -1;
+	fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
 	swim3_select(fs, STEP);
-	out_8(&sw->control_bis, DO_SEEK);
+	in_8(&sw->error);
 	/* enable intr when seek finished */
-	out_8(&sw->intr_enable, ERROR_INTR | SEEK_DONE);
-	set_timeout(fs, HZ/2, seek_timeout);	/* enable timeout */
+	out_8(&sw->intr_enable, SEEK_DONE);
+	out_8(&sw->control_bis, DO_SEEK);
+	set_timeout(fs, 3*HZ, seek_timeout);	/* enable timeout */
+	fs->settle_time = 0;
 }
 
 static inline void init_dma(struct dbdma_cmd *cp, int cmd,
@@ -448,18 +453,21 @@ static inline void setup_transfer(struct floppy_state *fs)
 	}
 	++cp;
 	out_le16(&cp->command, DBDMA_STOP);
+	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
+	in_8(&sw->error);
+	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
+	if (rq_data_dir(fd_req) == WRITE)
+		out_8(&sw->control_bis, WRITE_SECTORS);
+	in_8(&sw->intr);
 	out_le32(&dr->control, (RUN << 16) | RUN);
-	out_8(&sw->control_bis,
-	      (rq_data_dir(fd_req) == WRITE? WRITE_SECTORS: 0) | DO_ACTION);
 	/* enable intr when transfer complete */
-	out_8(&sw->intr_enable, ERROR_INTR | TRANSFER_DONE);
+	out_8(&sw->intr_enable, TRANSFER_DONE);
+	out_8(&sw->control_bis, DO_ACTION);
 	set_timeout(fs, 2*HZ, xfer_timeout);	/* enable timeout */
 }
 
 static void act(struct floppy_state *fs)
 {
-	volatile struct swim3 *sw = fs->swim3;
-
 	for (;;) {
 		switch (fs->state) {
 		case idle:
@@ -492,20 +500,10 @@ static void act(struct floppy_state *fs)
 			return;
 
 		case settling:
-			/* wait for SEEK_COMPLETE to become true */
-			swim3_select(fs, SEEK_COMPLETE);
-			udelay(10);
-			out_8(&sw->intr_enable, ERROR_INTR | DATA_CHANGED);
-			in_8(&sw->intr);	/* clear DATA_CHANGED */
-			if (in_8(&sw->status) & DATA) {
-				/* seek_complete is not yet true */
-				set_timeout(fs, HZ/2, seek_timeout);
-				return;
-			}
-			out_8(&sw->intr_enable, 0);
-			in_8(&sw->intr);
-			fs->state = locating;
-			break;
+			/* check for SEEK_COMPLETE after 30ms */
+			fs->settle_time = (HZ + 32) / 33;
+			set_timeout(fs, fs->settle_time, settle_timeout);
+			return;
 
 		case do_transfer:
 			if (fs->cur_cyl != fs->req_cyl) {
@@ -537,7 +535,7 @@ static void scan_timeout(unsigned long data)
 	volatile struct swim3 *sw = fs->swim3;
 
 	fs->timeout_pending = 0;
-	out_8(&sw->control_bic, DO_ACTION);
+	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
 	out_8(&sw->select, RELAX);
 	out_8(&sw->intr_enable, 0);
 	fs->cur_cyl = -1;
@@ -557,20 +555,34 @@ static void seek_timeout(unsigned long data)
 	volatile struct swim3 *sw = fs->swim3;
 
 	fs->timeout_pending = 0;
-	if (fs->state == settling) {
-		printk(KERN_ERR "swim3: MSI sel=%x ctrl=%x stat=%x intr=%x ie=%x\n",
-		       sw->select, sw->control, sw->status, sw->intr, sw->intr_enable);
-	}
 	out_8(&sw->control_bic, DO_SEEK);
 	out_8(&sw->select, RELAX);
 	out_8(&sw->intr_enable, 0);
-	if (fs->state == settling && swim3_readbit(fs, SEEK_COMPLETE)) {
-		/* printk(KERN_DEBUG "swim3: missed settling interrupt\n"); */
+	printk(KERN_ERR "swim3: seek timeout\n");
+	end_request(fd_req, 0);
+	fs->state = idle;
+	start_request(fs);
+}
+
+static void settle_timeout(unsigned long data)
+{
+	struct floppy_state *fs = (struct floppy_state *) data;
+	volatile struct swim3 *sw = fs->swim3;
+
+	fs->timeout_pending = 0;
+	if (swim3_readbit(fs, SEEK_COMPLETE)) {
+		out_8(&sw->select, RELAX);
 		fs->state = locating;
 		act(fs);
 		return;
 	}
-	printk(KERN_ERR "swim3: seek timeout\n");
+	out_8(&sw->select, RELAX);
+	if (fs->settle_time < 2*HZ) {
+		++fs->settle_time;
+		set_timeout(fs, 1, settle_timeout);
+		return;
+	}
+	printk(KERN_ERR "swim3: seek settle timeout\n");
 	end_request(fd_req, 0);
 	fs->state = idle;
 	start_request(fs);
@@ -583,9 +595,13 @@ static void xfer_timeout(unsigned long data)
 	struct dbdma_regs *dr = fs->dma;
 	struct dbdma_cmd *cp = fs->dma_cmd;
 	unsigned long s;
+	int n;
 
 	fs->timeout_pending = 0;
 	st_le32(&dr->control, RUN << 16);
+	/* We must wait a bit for dbdma to stop */
+	for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
+		udelay(1);
 	out_8(&sw->intr_enable, 0);
 	out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
 	out_8(&sw->select, RELAX);
@@ -604,7 +620,7 @@ static void xfer_timeout(unsigned long data)
 	start_request(fs);
 }
 
-static void swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
 	struct floppy_state *fs = (struct floppy_state *) dev_id;
 	volatile struct swim3 *sw = fs->swim3;
@@ -613,18 +629,15 @@ static void swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	struct dbdma_regs *dr;
 	struct dbdma_cmd *cp;
 
-	err = in_8(&sw->error);
 	intr = in_8(&sw->intr);
-#if 0
-	printk("swim3 intr state=%d intr=%x err=%x\n", fs->state, intr, err);
-#endif
+	err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
 	if ((intr & ERROR_INTR) && fs->state != do_transfer)
 		printk(KERN_ERR "swim3_interrupt, state=%d, dir=%lx, intr=%x, err=%x\n",
 		       fs->state, rq_data_dir(fd_req), intr, err);
 	switch (fs->state) {
 	case locating:
 		if (intr & SEEN_SECTOR) {
-			out_8(&sw->control_bic, DO_ACTION);
+			out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
 			out_8(&sw->select, RELAX);
 			out_8(&sw->intr_enable, 0);
 			del_timer(&fs->timeout);
@@ -674,19 +687,33 @@ static void swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	case do_transfer:
 		if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
 			break;
-		dr = fs->dma;
-		cp = fs->dma_cmd;
-		/* We must wait a bit for dbdma to complete */
-		for (n=0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
-			udelay(10);
-		DBDMA_DO_STOP(dr);
 		out_8(&sw->intr_enable, 0);
 		out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
 		out_8(&sw->select, RELAX);
 		del_timer(&fs->timeout);
 		fs->timeout_pending = 0;
+		dr = fs->dma;
+		cp = fs->dma_cmd;
 		if (rq_data_dir(fd_req) == WRITE)
 			++cp;
+		/*
+		 * Check that the main data transfer has finished.
+		 * On writing, the swim3 sometimes doesn't use
+		 * up all the bytes of the postamble, so we can still
+		 * see DMA active here.  That doesn't matter as long
+		 * as all the sector data has been transferred.
+		 */
+		if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
+			/* wait a little while for DMA to complete */
+			for (n = 0; n < 100; ++n) {
+				if (cp->xfer_status != 0)
+					break;
+				udelay(1);
+				barrier();
+			}
+		}
+		/* turn off DMA */
+		out_le32(&dr->control, (RUN | PAUSE) << 16);
 		stat = ld_le16(&cp->xfer_status);
 		resid = ld_le16(&cp->res_count);
 		if (intr & ERROR_INTR) {
@@ -742,6 +769,7 @@ static void swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	default:
 		printk(KERN_ERR "swim3: don't know what to do in state %d\n", fs->state);
 	}
+	return IRQ_HANDLED;
 }
 
 /*
@@ -793,16 +821,19 @@ static int fd_eject(struct floppy_state *fs)
 	if (err)
 		return err;
 	swim3_action(fs, EJECT);
-	for (n = 2*HZ; n > 0; --n) {
-		if (swim3_readbit(fs, RELAX))
-			break;
+	for (n = 20; n > 0; --n) {
 		if (signal_pending(current)) {
 			err = -EINTR;
 			break;
 		}
+		swim3_select(fs, RELAX);
 		current->state = TASK_INTERRUPTIBLE;
 		schedule_timeout(1);
+		if (swim3_readbit(fs, DISK_IN) == 0)
+			break;
 	}
+	swim3_select(fs, RELAX);
+	udelay(150);
 	fs->ejected = 1;
 	release_drive(fs);
 	return err;
@@ -847,29 +878,31 @@ static int floppy_open(struct inode *inode, struct file *filp)
 	if (fs->ref_count == 0) {
 		if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
 			return -ENXIO;
-		out_8(&sw->mode, 0x95);
-		out_8(&sw->control_bic, 0xff);
 		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
+		out_8(&sw->control_bic, 0xff);
+		out_8(&sw->mode, 0x95);
 		udelay(10);
 		out_8(&sw->intr_enable, 0);
 		out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
 		swim3_action(fs, MOTOR_ON);
 		fs->write_prot = -1;
 		fs->cur_cyl = -1;
-		for (n = HZ; n > 0; --n) {
-			if (swim3_readbit(fs, SEEK_COMPLETE))
+		for (n = 0; n < 2 * HZ; ++n) {
+			if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
 				break;
 			if (signal_pending(current)) {
 				err = -EINTR;
 				break;
 			}
+			swim3_select(fs, RELAX);
 			current->state = TASK_INTERRUPTIBLE;
 			schedule_timeout(1);
 		}
 		if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
 				 || swim3_readbit(fs, DISK_IN) == 0))
 			err = -ENXIO;
-		swim3_action(fs, 9);
+		swim3_action(fs, SETMFM);
+		swim3_select(fs, RELAX);
 
 	} else if (fs->ref_count == -1 || filp->f_flags & O_EXCL)
 		return -EBUSY;
@@ -892,6 +925,7 @@ static int floppy_open(struct inode *inode, struct file *filp)
 		if (fs->ref_count == 0) {
 			swim3_action(fs, MOTOR_OFF);
 			out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
+			swim3_select(fs, RELAX);
 		}
 		return err;
 	}
@@ -911,6 +945,7 @@ static int floppy_release(struct inode *inode, struct file *filp)
 	if (fs->ref_count > 0 && --fs->ref_count == 0) {
 		swim3_action(fs, MOTOR_OFF);
 		out_8(&sw->control_bic, 0xff);
+		swim3_select(fs, RELAX);
 	}
 	return 0;
 }
@@ -933,15 +968,17 @@ static int floppy_revalidate(struct gendisk *disk)
 	sw = fs->swim3;
 	grab_drive(fs, revalidating, 0);
 	out_8(&sw->intr_enable, 0);
-	out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
-	swim3_action(fs, MOTOR_ON);
+	out_8(&sw->control_bis, DRIVE_ENABLE);
+	swim3_action(fs, MOTOR_ON);	/* necessary? */
 	fs->write_prot = -1;
 	fs->cur_cyl = -1;
+	mdelay(1);
 	for (n = HZ; n > 0; --n) {
 		if (swim3_readbit(fs, SEEK_COMPLETE))
 			break;
 		if (signal_pending(current))
 			break;
+		swim3_select(fs, RELAX);
 		current->state = TASK_INTERRUPTIBLE;
 		schedule_timeout(1);
 	}
@@ -951,17 +988,14 @@ static int floppy_revalidate(struct gendisk *disk)
 		swim3_action(fs, MOTOR_OFF);
 	else {
 		fs->ejected = 0;
-		swim3_action(fs, 9);
+		swim3_action(fs, SETMFM);
 	}
+	swim3_select(fs, RELAX);
 
 	release_drive(fs);
 	return ret;
 }
 
-static void floppy_off(unsigned int nr)
-{
-}
-
 static struct block_device_operations floppy_fops = {
 	.open		= floppy_open,
 	.release	= floppy_release,
@@ -1104,3 +1138,5 @@ static int swim3_add_device(struct device_node *swim)
 	
 	return 0;
 }
+
+module_init(swim3_init)