ata: pata_parport: add driver (PARIDE replacement)

The pata_parport is a libata-based replacement of the old PARIDE
subsystem - driver for parallel port IDE devices.
It uses the original paride low-level protocol drivers but does not
need the high-level drivers (pd, pcd, pf, pt, pg). The IDE devices
behind parallel port adapters are handled by the ATA layer.

This will allow paride and its high-level drivers to be removed.

Unfortunately, libata drivers cannot sleep so pata_parport claims
parport before activating the ata host and keeps it claimed (and
protocol connected) until the ata host is removed. This means that
no devices can be chained (neither other pata_parport devices nor
a printer).

paride and pata_parport are mutually exclusive because the compiled
protocol drivers are incompatible.

Tested with:
 - Imation SuperDisk LS-120 and HP C4381A (EPAT)
 - Freecom Parallel CD (FRPW)
 - Toshiba Mobile CD-RW 2793008 w/Freecom Parallel Cable rev.903 (FRIQ)
 - Backpack CD-RW 222011 and CD-RW 19350 (BPCK6)

The following bugs in low-level protocol drivers were found and will
be fixed later:

Note: EPP-32 mode is buggy in EPAT - and also in all other protocol
drivers - they don't handle non-multiple-of-4 block transfers
correctly. This causes problems with LS-120 drive.
There is also another bug in EPAT: EPP modes don't work unless a 4-bit
or 8-bit mode is used first (probably some initialization missing?).
Once the device is initialized, EPP works until power cycle.

So after device power on, you have to:
echo "parport0 epat 0" >/sys/bus/pata_parport/new_device
echo pata_parport.0 >/sys/bus/pata_parport/delete_device
echo "parport0 epat 4" >/sys/bus/pata_parport/new_device
(autoprobe will initialize correctly as it tries the slowest modes
first but you'll get the broken EPP-32 mode)

Note: EPP modes are buggy in FRPW, only modes 0 and 1 work.

Signed-off-by: Ondrej Zary <linux@zary.sk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

2 files changed, 29 insertions, 16 deletions

diff --git a/drivers/block/paride/Kconfig b/drivers/block/paride/Kconfig
index a295634597ba..01e4ef3655c1 100644
--- a/drivers/block/paride/Kconfig
+++ b/drivers/block/paride/Kconfig
@@ -92,11 +92,11 @@ config PARIDE_PG
 	  later fully support this driver.
 
 comment "Parallel IDE protocol modules"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 
 config PARIDE_ATEN
 	tristate "ATEN EH-100 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the ATEN EH-100 parallel port IDE
 	  protocol. This protocol is used in some inexpensive low performance
@@ -109,7 +109,7 @@ config PARIDE_ATEN
 
 config PARIDE_BPCK
 	tristate "MicroSolutions backpack (Series 5) protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the Micro Solutions BACKPACK
 	  parallel port Series 5 IDE protocol.  (Most BACKPACK drives made
@@ -127,7 +127,7 @@ config PARIDE_BPCK
 
 config PARIDE_BPCK6
 	tristate "MicroSolutions backpack (Series 6) protocol"
-	depends on PARIDE && !64BIT
+	depends on (PARIDE || PATA_PARPORT) && !64BIT
 	help
 	  This option enables support for the Micro Solutions BACKPACK
 	  parallel port Series 6 IDE protocol.  (Most BACKPACK drives made
@@ -146,7 +146,7 @@ config PARIDE_BPCK6
 
 config PARIDE_COMM
 	tristate "DataStor Commuter protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the Commuter parallel port IDE
 	  protocol from DataStor. If you chose to build PARIDE support
@@ -157,7 +157,7 @@ config PARIDE_COMM
 
 config PARIDE_DSTR
 	tristate "DataStor EP-2000 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the EP-2000 parallel port IDE
 	  protocol from DataStor. If you chose to build PARIDE support
@@ -168,7 +168,7 @@ config PARIDE_DSTR
 
 config PARIDE_FIT2
 	tristate "FIT TD-2000 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the TD-2000 parallel port IDE
 	  protocol from Fidelity International Technology. This is a simple
@@ -181,7 +181,7 @@ config PARIDE_FIT2
 
 config PARIDE_FIT3
 	tristate "FIT TD-3000 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the TD-3000 parallel port IDE
 	  protocol from Fidelity International Technology. This protocol is
@@ -194,7 +194,7 @@ config PARIDE_FIT3
 
 config PARIDE_EPAT
 	tristate "Shuttle EPAT/EPEZ protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the EPAT parallel port IDE protocol.
 	  EPAT is a parallel port IDE adapter manufactured by Shuttle
@@ -216,7 +216,7 @@ config PARIDE_EPATC8
 
 config PARIDE_EPIA
 	tristate "Shuttle EPIA protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the (obsolete) EPIA parallel port
 	  IDE protocol from Shuttle Technology. This adapter can still be
@@ -228,7 +228,7 @@ config PARIDE_EPIA
 
 config PARIDE_FRIQ
 	tristate "Freecom IQ ASIC-2 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for version 2 of the Freecom IQ parallel
 	  port IDE adapter.  This adapter is used by the Maxell Superdisk
@@ -240,7 +240,7 @@ config PARIDE_FRIQ
 
 config PARIDE_FRPW
 	tristate "FreeCom power protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the Freecom power parallel port IDE
 	  protocol. If you chose to build PARIDE support into your kernel, you
@@ -251,7 +251,7 @@ config PARIDE_FRPW
 
 config PARIDE_KBIC
 	tristate "KingByte KBIC-951A/971A protocols"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the KBIC-951A and KBIC-971A parallel
 	  port IDE protocols from KingByte Information Corp. KingByte's
@@ -264,7 +264,7 @@ config PARIDE_KBIC
 
 config PARIDE_KTTI
 	tristate "KT PHd protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the "PHd" parallel port IDE protocol
 	  from KT Technology. This is a simple (low speed) adapter that is
@@ -277,7 +277,7 @@ config PARIDE_KTTI
 
 config PARIDE_ON20
 	tristate "OnSpec 90c20 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the (obsolete) 90c20 parallel port
 	  IDE protocol from OnSpec (often marketed under the ValuStore brand
@@ -289,7 +289,7 @@ config PARIDE_ON20
 
 config PARIDE_ON26
 	tristate "OnSpec 90c26 protocol"
-	depends on PARIDE
+	depends on PARIDE || PATA_PARPORT
 	help
 	  This option enables support for the 90c26 parallel port IDE protocol
 	  from OnSpec Electronics (often marketed under the ValuStore brand
diff --git a/drivers/block/paride/paride.h b/drivers/block/paride/paride.h
index ddb9e589da7f..24dcfadb782d 100644
--- a/drivers/block/paride/paride.h
+++ b/drivers/block/paride/paride.h
@@ -1,3 +1,15 @@
+/*
+ * The low-level protocol modules are used by either paride or pata_parport.
+ * These two are mutually exclusive because the compiled low-level protocol
+ * modules are not compatible.
+ * When PATA_PARPORT is enabled, include pata_parport.h instead of the rest
+ * of this file.
+ */
+
+#if IS_ENABLED(CONFIG_PATA_PARPORT)
+#include <linux/pata_parport.h>
+
+#else
 #ifndef __DRIVERS_PARIDE_H__
 #define __DRIVERS_PARIDE_H__
 
@@ -170,3 +182,4 @@ void pi_unregister_driver(void *);
 
 #endif /* __DRIVERS_PARIDE_H__ */
 /* end of paride.h */
+#endif /* IS_ENABLED(CONFIG_PATA_PARPORT) */