[PATCH 04/12] m68k/mac: Place ISM IOP in bypass mode
From: Finn Thain
Date: Sat Mar 31 2018 - 21:41:21 EST
Some Mac models have an IOP for offloading floppy disk IO. Linux once
had a driver for that but it got removed in commit b21a323710e7
("[PATCH] remove the broken BLK_DEV_SWIM_IOP driver").
Put the ISM IOP into bypass mode so that the existing 'swim_mod' driver
can access the controller directly. Use the appropriate macros for the
flag bits.
Cc: Laurent Vivier <lvivier@xxxxxxxxxx>
Tested-by: Stan Johnson <userm57@xxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/mac/iop.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c
index 9bfa17015768..7864dcca5891 100644
--- a/arch/m68k/mac/iop.c
+++ b/arch/m68k/mac/iop.c
@@ -234,6 +234,7 @@ static struct iop_msg *iop_get_unused_msg(void)
* is to find and initialize the IOPs early in the boot sequence, so that
* the serial IOP can be placed into bypass mode _before_ we try to
* initialize the serial console.
+ * The ISM IOP is put into bypass mode for compatibility with the swim driver.
*/
void __init iop_preinit(void)
@@ -244,7 +245,8 @@ void __init iop_preinit(void)
} else {
iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA;
}
- iop_base[IOP_NUM_SCC]->status_ctrl = 0x87;
+ iop_base[IOP_NUM_SCC]->status_ctrl = IOP_BYPASS | IOP_AUTOINC |
+ IOP_RUN | IOP_DMAINACTIVE;
iop_scc_present = 1;
} else {
iop_base[IOP_NUM_SCC] = NULL;
@@ -256,7 +258,8 @@ void __init iop_preinit(void)
} else {
iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA;
}
- iop_base[IOP_NUM_ISM]->status_ctrl = 0;
+ iop_base[IOP_NUM_ISM]->status_ctrl = IOP_BYPASS | IOP_AUTOINC |
+ IOP_RUN | IOP_DMAINACTIVE;
iop_ism_present = 1;
} else {
iop_base[IOP_NUM_ISM] = NULL;
--
2.16.1