[PATCH v3 03/33] swim: Enable the drive when probing

[Finn Thain <fthain@linux-m68k.org>]

According to the ISM spec, the MOTON bit "causes the Enable 1 and Enable 2
signals to be turned on to the drive." It doesn't actually turn on the
motor. When selecting a drive, enable MOTON. Disable it upon eject or
release. This fixes detection of the Sony FDHD drive.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Fixes: 8852ecd97488 ("m68k: mac - Add SWIM floppy support")
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
 drivers/block/swim.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 4721e073a874..4ddb87977fe1 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -154,8 +154,9 @@ struct iwm {
 /*----------------------------------------------------------------------------*/
 
 enum drive_location {
-	INTERNAL_DRIVE = 0x02,
-	EXTERNAL_DRIVE = 0x04,
+	NO_DRIVE = 0,
+	INTERNAL_DRIVE = BIT(1),
+	EXTERNAL_DRIVE = BIT(2),
 };
 
 enum media_type {
@@ -311,9 +312,15 @@ static inline void swim_drive(struct swim __iomem *base,
 	if (location == INTERNAL_DRIVE) {
 		swim_write(base, mode0, EXTERNAL_DRIVE); /* clear drive 1 bit */
 		swim_write(base, mode1, INTERNAL_DRIVE); /* set drive 0 bit */
+		swim_write(base, mode1, MOTON);
 	} else if (location == EXTERNAL_DRIVE) {
 		swim_write(base, mode0, INTERNAL_DRIVE); /* clear drive 0 bit */
 		swim_write(base, mode1, EXTERNAL_DRIVE); /* set drive 1 bit */
+		swim_write(base, mode1, MOTON);
+	} else {
+		swim_write(base, mode0, INTERNAL_DRIVE);
+		swim_write(base, mode0, EXTERNAL_DRIVE);
+		swim_write(base, mode0, MOTON);
 	}
 }
 
@@ -447,6 +454,7 @@ static int floppy_eject(struct floppy_state *fs)
 	swim_drive(base, fs->location);
 	swim_motor(base, OFF);
 	swim_eject(base);
+	swim_drive(base, NO_DRIVE);
 
 	fs->disk_in = 0;
 	fs->ejected = 1;
@@ -652,8 +660,10 @@ static int floppy_open(struct gendisk *disk, blk_mode_t mode)
 	else if (fs->ref_count > 0)
 		--fs->ref_count;
 
-	if (fs->ref_count == 0)
+	if (fs->ref_count == 0) {
 		swim_motor(base, OFF);
+		swim_drive(base, NO_DRIVE);
+	}
 	return err;
 }
 
@@ -682,6 +692,7 @@ static void floppy_release(struct gendisk *disk)
 	if (fs->ref_count == 0) {
 		swim_drive(base, fs->location);
 		swim_motor(base, OFF);
+		swim_drive(base, NO_DRIVE);
 	}
 	mutex_unlock(&swim_mutex);
 }
@@ -804,6 +815,7 @@ static int swim_floppy_init(struct swim_priv *swd)
 	if (swim_readbit(base, DRIVE_PRESENT) &&
 	    !swim_readbit(base, ONEMEG_DRIVE))
 		swim_add_floppy(swd, EXTERNAL_DRIVE);
+	swim_drive(base, NO_DRIVE);
 
 	/* register floppy drives */
 
-- 
2.52.0