[PATCH 00/12] staging: comedi: ni_labpc: split out ISA DMA support

[PATCH 00/12] staging: comedi: ni_labpc: split out ISA DMA support

[Ian Abbott]

The "ni_labpc" module is a common module for the "ni_labpc_cs" and
"ni_labpc_pci" modules.  It is also a comedi driver for National
Instruments Lab-PC ISA boards if the `COMEDI_NI_LABPC_ISA` option is
enabled.  In that case, the module may include code
to handle ISA DMA transfers if the `ISA_DMA_API` and `VIRT_TO_BUS`
options are also enabled.

Move the ISA DMA handling code into a new module "ni_labpc_isadma" which
is only built if the `COMEDI_NI_LABPC_ISA`, `ISA_DMA_API` and
`VIRT_TO_BUS` options are enabled.  This allows a bunch of `#ifdef`s to
be removed.

01) staging: comedi: ni_labpc: fix possible double-free of dma_buffer
02) staging: comedi: ni_labpc: don't clear cmd3 bits explicitly in
    labpc_ai_cmd()
03) staging: comedi: ni_labpc_isadma: new module for ISA DMA support
04) staging: comedi: ni_labpc: migrate DMA channel init & free
05) staging: comedi: ni_labpc_isadma: add labpc_have_dma_chan()
06) staging: comedi: ni_labpc: use labpc_have_dma_chan()
07) staging: comedi: ni_labpc: move register defs to new file
08) staging: comedi: ni_labpc: migrate DMA transfer set-up
09) staging: comedi: ni_labpc: migrate labpc_drain_dma()
10) staging: comedi: ni_labpc: migrate DMA status handling
11) staging: comedi: ni_labpc: tidy up after DMA code migration
12) staging: comedi: COMEDI_NI_LABPC_ISA no longer depends on
    VIRT_TO_BUS

 drivers/staging/comedi/Kconfig                   |   5 +-
 drivers/staging/comedi/drivers/Makefile          |   1 +
 drivers/staging/comedi/drivers/ni_labpc.c        | 279 ++---------------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 226 ++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h |  57 +++++
 drivers/staging/comedi/drivers/ni_labpc_regs.h   |  75 ++++++
 6 files changed, 387 insertions(+), 256 deletions(-)
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[PATCH 01/12] staging: comedi: ni_labpc: fix possible double-free of dma_buffer

[Ian Abbott]

If `labpc_attach()` allocates memory for `devpriv->dma_buffer` but fails
to request a DMA channel, it frees `devpriv->dma_buffer` but leaves the
pointer set.  Later, `labpc_detach()` frees `devpriv->dma_buffer` again,
which means it has been freed twice in this case.

Fix it by only setting `devpriv->dma_buffer` in `labpc_attach()` if the
DMA channel was requested successfully.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index f161e70..0783d65 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -1712,13 +1712,15 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 
 #ifdef CONFIG_ISA_DMA_API
 	if (dev->irq && (dma_chan == 1 || dma_chan == 3)) {
-		devpriv->dma_buffer = kmalloc(dma_buffer_size,
-					      GFP_KERNEL | GFP_DMA);
-		if (devpriv->dma_buffer) {
+		void *dma_buffer = kmalloc(dma_buffer_size,
+					   GFP_KERNEL | GFP_DMA);
+
+		if (dma_buffer) {
 			ret = request_dma(dma_chan, dev->board_name);
 			if (ret == 0) {
 				unsigned long dma_flags;
 
+				devpriv->dma_buffer = dma_buffer;
 				devpriv->dma_chan = dma_chan;
 				devpriv->dma_addr =
 					virt_to_bus(devpriv->dma_buffer);
@@ -1728,7 +1730,7 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 				set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);
 				release_dma_lock(dma_flags);
 			} else {
-				kfree(devpriv->dma_buffer);
+				kfree(dma_buffer);
 			}
 		}
 	}
-- 
1.8.2.1

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[PATCH 02/12] staging: comedi: ni_labpc: don't clear cmd3 bits explicitly in labpc_ai_cmd()

[Ian Abbott]

`labpc_ai_cmd()` calls `labpc_cancel()` which already sets
`devpriv->cmd3` to 0.  Remove the lines from `labpc_ai_cmd()` that clear
specific bits in `devpriv->cmd3` explicitly as they have no effect.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 0783d65..7dec029 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -975,8 +975,7 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 		release_dma_lock(irq_flags);
 		/*  enable board's dma */
 		devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
-	} else
-		devpriv->cmd3 &= ~(CMD3_DMAEN | CMD3_DMATCINTEN);
+	}
 #endif
 
 	/*  enable error interrupts */
@@ -984,8 +983,6 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	/*  enable fifo not empty interrupt? */
 	if (xfer == fifo_not_empty_transfer)
 		devpriv->cmd3 |= CMD3_FIFOINTEN;
-	else
-		devpriv->cmd3 &= ~CMD3_FIFOINTEN;
 	devpriv->write_byte(devpriv->cmd3, dev->iobase + CMD3_REG);
 
 	/*  setup any external triggering/pacing (cmd4 register) */
-- 
1.8.2.1

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[PATCH 03/12] staging: comedi: ni_labpc_isadma: new module for ISA DMA support

[Ian Abbott]

It's just an empty module at the moment, selected by COMEDI_NI_LABPC_ISA
&& ISA_DMA_API && VIRT_TO_BUS, but will be populated by later patches to
migrate ISA DMA support for NI Lab-PC cards out of the "ni_labpc"
module.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/Kconfig                   |  4 +++
 drivers/staging/comedi/drivers/Makefile          |  1 +
 drivers/staging/comedi/drivers/ni_labpc.c        |  1 +
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 37 ++++++++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h | 16 ++++++++++
 5 files changed, 59 insertions(+)
 create mode 100644 drivers/staging/comedi/drivers/ni_labpc_isadma.c
 create mode 100644 drivers/staging/comedi/drivers/ni_labpc_isadma.h

diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig
index 8c8a551..faecf67 100644
--- a/drivers/staging/comedi/Kconfig
+++ b/drivers/staging/comedi/Kconfig
@@ -473,6 +473,7 @@ config COMEDI_NI_ATMIO16D
 config COMEDI_NI_LABPC_ISA
 	tristate "NI Lab-PC and compatibles ISA support"
 	select COMEDI_NI_LABPC
+	select COMEDI_NI_LABPC_ISADMA if ISA_DMA_API && VIRT_TO_BUS
 	depends on VIRT_TO_BUS
 	---help---
 	  Enable support for National Instruments Lab-PC and compatibles
@@ -1262,6 +1263,9 @@ config COMEDI_NI_LABPC
 	select COMEDI_8255
 	select COMEDI_FC
 
+config COMEDI_NI_LABPC_ISADMA
+	tristate
+
 config COMEDI_NI_TIO
 	tristate
 
diff --git a/drivers/staging/comedi/drivers/Makefile b/drivers/staging/comedi/drivers/Makefile
index dbb93e3..3fdca81 100644
--- a/drivers/staging/comedi/drivers/Makefile
+++ b/drivers/staging/comedi/drivers/Makefile
@@ -132,6 +132,7 @@ obj-$(CONFIG_COMEDI_MITE)		+= mite.o
 obj-$(CONFIG_COMEDI_NI_TIO)		+= ni_tio.o
 obj-$(CONFIG_COMEDI_NI_TIOCMD)		+= ni_tiocmd.o
 obj-$(CONFIG_COMEDI_NI_LABPC)		+= ni_labpc.o
+obj-$(CONFIG_COMEDI_NI_LABPC_ISADMA)	+= ni_labpc_isadma.o
 
 obj-$(CONFIG_COMEDI_8255)		+= 8255.o
 obj-$(CONFIG_COMEDI_AMPLC_DIO200)	+= amplc_dio200_common.o
diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 7dec029..41f1674 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -70,6 +70,7 @@
 #include "8255.h"
 #include "comedi_fc.h"
 #include "ni_labpc.h"
+#include "ni_labpc_isadma.h"
 
 /*
  * Register map (all registers are 8-bit)
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
new file mode 100644
index 0000000..586ea54
--- /dev/null
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -0,0 +1,37 @@
+/*
+ * comedi/drivers/ni_labpc_isadma.c
+ * ISA DMA support for National Instruments Lab-PC series boards and
+ * compatibles.
+ *
+ * Extracted from ni_labpc.c:
+ * Copyright (C) 2001-2003 Frank Mori Hess <fmhess@users.sourceforge.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+
+#include "ni_labpc_isadma.h"
+
+static int __init ni_labpc_isadma_init_module(void)
+{
+	return 0;
+}
+module_init(ni_labpc_isadma_init_module);
+
+static void __exit ni_labpc_isadma_cleanup_module(void)
+{
+}
+module_exit(ni_labpc_isadma_cleanup_module);
+
+MODULE_AUTHOR("Comedi http://www.comedi.org");
+MODULE_DESCRIPTION("Comedi NI Lab-PC ISA DMA support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
new file mode 100644
index 0000000..ac644f0
--- /dev/null
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -0,0 +1,16 @@
+/*
+ * ni_labpc ISA DMA support.
+*/
+
+#ifndef _NI_LABPC_ISADMA_H
+#define _NI_LABPC_ISADMA_H
+
+#define NI_LABPC_HAVE_ISA_DMA	IS_ENABLED(CONFIG_COMEDI_NI_LABPC_ISADMA)
+
+#if NI_LABPC_HAVE_ISA_DMA
+
+#else
+
+#endif
+
+#endif /* _NI_LABPC_ISADMA_H */
-- 
1.8.2.1

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[PATCH 04/12] staging: comedi: ni_labpc: migrate DMA channel init & free

[Ian Abbott]

Migrate the code for requesting an ISA DMA channel and a DMA buffer, and
the code for freeing them into two new functions in the
"ni_labpc_isadma" module: `labpc_init_dma_chan()` and
`labpc_free_dma_chan()`.  Dummy inline functions are provided in
"ni_labpc_isadma.h" if the "ni_labpc_isadma" module is not being built.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c        | 35 +++------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 54 ++++++++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h | 13 ++++++
 3 files changed, 72 insertions(+), 30 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 41f1674..301b532 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -1708,31 +1708,8 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	if (ret)
 		return ret;
 
-#ifdef CONFIG_ISA_DMA_API
-	if (dev->irq && (dma_chan == 1 || dma_chan == 3)) {
-		void *dma_buffer = kmalloc(dma_buffer_size,
-					   GFP_KERNEL | GFP_DMA);
-
-		if (dma_buffer) {
-			ret = request_dma(dma_chan, dev->board_name);
-			if (ret == 0) {
-				unsigned long dma_flags;
-
-				devpriv->dma_buffer = dma_buffer;
-				devpriv->dma_chan = dma_chan;
-				devpriv->dma_addr =
-					virt_to_bus(devpriv->dma_buffer);
-
-				dma_flags = claim_dma_lock();
-				disable_dma(devpriv->dma_chan);
-				set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);
-				release_dma_lock(dma_flags);
-			} else {
-				kfree(dma_buffer);
-			}
-		}
-	}
-#endif
+	if (dev->irq)
+		labpc_init_dma_chan(dev, dma_chan);
 
 	return 0;
 }
@@ -1741,11 +1718,9 @@ static void labpc_detach(struct comedi_device *dev)
 {
 	struct labpc_private *devpriv = dev->private;
 
-	if (devpriv) {
-		kfree(devpriv->dma_buffer);
-		if (devpriv->dma_chan)
-			free_dma(devpriv->dma_chan);
-	}
+	if (devpriv)
+		labpc_free_dma_chan(dev);
+
 	comedi_legacy_detach(dev);
 }
 
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index 586ea54..e6c8437 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -18,9 +18,63 @@
  */
 
 #include <linux/module.h>
+#include <linux/slab.h>
+#include "../comedidev.h"
 
+#include <asm/dma.h>
+
+#include "ni_labpc.h"
 #include "ni_labpc_isadma.h"
 
+/* size in bytes of dma buffer */
+static const int dma_buffer_size = 0xff00;
+
+int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
+{
+	struct labpc_private *devpriv = dev->private;
+	void *dma_buffer;
+	unsigned long dma_flags;
+	int ret;
+
+	if (dma_chan != 1 && dma_chan != 3)
+		return -EINVAL;
+
+	dma_buffer = kmalloc(dma_buffer_size, GFP_KERNEL | GFP_DMA);
+	if (!dma_buffer)
+		return -ENOMEM;
+
+	ret = request_dma(dma_chan, dev->board_name);
+	if (ret) {
+		kfree(dma_buffer);
+		return ret;
+	}
+
+	devpriv->dma_buffer = dma_buffer;
+	devpriv->dma_chan = dma_chan;
+	devpriv->dma_addr = virt_to_bus(devpriv->dma_buffer);
+
+	dma_flags = claim_dma_lock();
+	disable_dma(devpriv->dma_chan);
+	set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);
+	release_dma_lock(dma_flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(labpc_init_dma_chan);
+
+void labpc_free_dma_chan(struct comedi_device *dev)
+{
+	struct labpc_private *devpriv = dev->private;
+
+	kfree(devpriv->dma_buffer);
+	devpriv->dma_buffer = NULL;
+	if (devpriv->dma_chan) {
+		free_dma(devpriv->dma_chan);
+		devpriv->dma_chan = 0;
+	}
+}
+EXPORT_SYMBOL_GPL(labpc_free_dma_chan);
+
 static int __init ni_labpc_isadma_init_module(void)
 {
 	return 0;
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index ac644f0..144f4ba 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -9,8 +9,21 @@
 
 #if NI_LABPC_HAVE_ISA_DMA
 
+int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
+void labpc_free_dma_chan(struct comedi_device *dev);
+
 #else
 
+static inline int labpc_init_dma_chan(struct comedi_device *dev,
+				      unsigned int dma_chan)
+{
+	return -ENOTSUPP;
+}
+
+static inline void labpc_free_dma_chan(struct comedi_device *dev)
+{
+}
+
 #endif
 
 #endif /* _NI_LABPC_ISADMA_H */
-- 
1.8.2.1

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[PATCH 05/12] staging: comedi: ni_labpc_isadma: add labpc_have_dma_chan()

[Ian Abbott]

Add a static inline function to "ni_labpc_isadma.h" to test if a DMA
channel has been set-up, in which case `devpriv->dma_chan` will be
non-zero (where `devpriv` point to the private data for the comedi
device).  If the "ni_labpc_isadma" module is not being built, don't
bother checking `devpriv->dma_chan`; just return `false` as this may
help the compiler to optimize out some unreachable code.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc_isadma.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index 144f4ba..3b022ea 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -9,11 +9,23 @@
 
 #if NI_LABPC_HAVE_ISA_DMA
 
+static inline bool labpc_have_dma_chan(struct comedi_device *dev)
+{
+	struct labpc_private *devpriv = dev->private;
+
+	return (bool)devpriv->dma_chan;
+}
+
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
 void labpc_free_dma_chan(struct comedi_device *dev);
 
 #else
 
+static inline bool labpc_have_dma_chan(struct comedi_device *dev)
+{
+	return false;
+}
+
 static inline int labpc_init_dma_chan(struct comedi_device *dev,
 				      unsigned int dma_chan)
 {
-- 
1.8.2.1

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[PATCH 06/12] staging: comedi: ni_labpc: use labpc_have_dma_chan()

[Ian Abbott]

Call the new static inline function `labpc_have_dma_chan()` from
`labpc_ai_cmd()` to check if the ISA DMA channel has been initialized,
tidying up the surrounding code and removing an `#ifdef`.  If the
"ni_labpc_isadma" module is not being built, `labpc_have_dma_chan()`
doesn't bother checking the DMA channel and just returns `false`,
allowing the compiler to optimize out a small amount of code.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 301b532..25d8ae3 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -870,25 +870,20 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 		return ret;
 	}
 
-#ifdef CONFIG_ISA_DMA_API
-	/*  figure out what method we will use to transfer data */
-	if (devpriv->dma_chan &&	/*  need a dma channel allocated */
-		/*
-		 * dma unsafe at RT priority,
-		 * and too much setup time for TRIG_WAKE_EOS for
-		 */
-	    (cmd->flags & (TRIG_WAKE_EOS | TRIG_RT)) == 0) {
+	/* figure out what method we will use to transfer data */
+	if (labpc_have_dma_chan(dev) &&
+	    /* dma unsafe at RT priority,
+	     * and too much setup time for TRIG_WAKE_EOS */
+	    (cmd->flags & (TRIG_WAKE_EOS | TRIG_RT)) == 0)
 		xfer = isa_dma_transfer;
-		/* pc-plus has no fifo-half full interrupt */
-	} else
-#endif
-	if (board->is_labpc1200 &&
-		   /*  wake-end-of-scan should interrupt on fifo not empty */
-		   (cmd->flags & TRIG_WAKE_EOS) == 0 &&
-		   /*  make sure we are taking more than just a few points */
-		   (cmd->stop_src != TRIG_COUNT || devpriv->count > 256)) {
+	else if (/* pc-plus has no fifo-half full interrupt */
+		 board->is_labpc1200 &&
+		 /* wake-end-of-scan should interrupt on fifo not empty */
+		 (cmd->flags & TRIG_WAKE_EOS) == 0 &&
+		 /* make sure we are taking more than just a few points */
+		 (cmd->stop_src != TRIG_COUNT || devpriv->count > 256))
 		xfer = fifo_half_full_transfer;
-	} else
+	else
 		xfer = fifo_not_empty_transfer;
 	devpriv->current_transfer = xfer;
 
-- 
1.8.2.1

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[PATCH 07/12] staging: comedi: ni_labpc: move register defs to new file

[Ian Abbott]

The new "ni_labpc_isadma" module will need to access some register
definitions from "ni_labpc.c", which is not part of the module's source.
Move all the register definitions into a new, common header file
"ni_labpc_regs.h".

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c        | 68 +--------------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c |  1 +
 drivers/staging/comedi/drivers/ni_labpc_regs.h   | 75 ++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 67 deletions(-)
 create mode 100644 drivers/staging/comedi/drivers/ni_labpc_regs.h

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 25d8ae3..c0ab71e 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -70,75 +70,9 @@
 #include "8255.h"
 #include "comedi_fc.h"
 #include "ni_labpc.h"
+#include "ni_labpc_regs.h"
 #include "ni_labpc_isadma.h"
 
-/*
- * Register map (all registers are 8-bit)
- */
-#define STAT1_REG		0x00	/* R: Status 1 reg */
-#define STAT1_DAVAIL		(1 << 0)
-#define STAT1_OVERRUN		(1 << 1)
-#define STAT1_OVERFLOW		(1 << 2)
-#define STAT1_CNTINT		(1 << 3)
-#define STAT1_GATA0		(1 << 5)
-#define STAT1_EXTGATA0		(1 << 6)
-#define CMD1_REG		0x00	/* W: Command 1 reg */
-#define CMD1_MA(x)		(((x) & 0x7) << 0)
-#define CMD1_TWOSCMP		(1 << 3)
-#define CMD1_GAIN(x)		(((x) & 0x7) << 4)
-#define CMD1_SCANEN		(1 << 7)
-#define CMD2_REG		0x01	/* W: Command 2 reg */
-#define CMD2_PRETRIG		(1 << 0)
-#define CMD2_HWTRIG		(1 << 1)
-#define CMD2_SWTRIG		(1 << 2)
-#define CMD2_TBSEL		(1 << 3)
-#define CMD2_2SDAC0		(1 << 4)
-#define CMD2_2SDAC1		(1 << 5)
-#define CMD2_LDAC(x)		(1 << (6 + (x)))
-#define CMD3_REG		0x02	/* W: Command 3 reg */
-#define CMD3_DMAEN		(1 << 0)
-#define CMD3_DIOINTEN		(1 << 1)
-#define CMD3_DMATCINTEN		(1 << 2)
-#define CMD3_CNTINTEN		(1 << 3)
-#define CMD3_ERRINTEN		(1 << 4)
-#define CMD3_FIFOINTEN		(1 << 5)
-#define ADC_START_CONVERT_REG	0x03	/* W: Start Convert reg */
-#define DAC_LSB_REG(x)		(0x04 + 2 * (x)) /* W: DAC0/1 LSB reg */
-#define DAC_MSB_REG(x)		(0x05 + 2 * (x)) /* W: DAC0/1 MSB reg */
-#define ADC_FIFO_CLEAR_REG	0x08	/* W: A/D FIFO Clear reg */
-#define ADC_FIFO_REG		0x0a	/* R: A/D FIFO reg */
-#define DMATC_CLEAR_REG		0x0a	/* W: DMA Interrupt Clear reg */
-#define TIMER_CLEAR_REG		0x0c	/* W: Timer Interrupt Clear reg */
-#define CMD6_REG		0x0e	/* W: Command 6 reg */
-#define CMD6_NRSE		(1 << 0)
-#define CMD6_ADCUNI		(1 << 1)
-#define CMD6_DACUNI(x)		(1 << (2 + (x)))
-#define CMD6_HFINTEN		(1 << 5)
-#define CMD6_DQINTEN		(1 << 6)
-#define CMD6_SCANUP		(1 << 7)
-#define CMD4_REG		0x0f	/* W: Command 3 reg */
-#define CMD4_INTSCAN		(1 << 0)
-#define CMD4_EOIRCV		(1 << 1)
-#define CMD4_ECLKDRV		(1 << 2)
-#define CMD4_SEDIFF		(1 << 3)
-#define CMD4_ECLKRCV		(1 << 4)
-#define DIO_BASE_REG		0x10	/* R/W: 8255 DIO base reg */
-#define COUNTER_A_BASE_REG	0x14	/* R/W: 8253 Counter A base reg */
-#define COUNTER_B_BASE_REG	0x18	/* R/W: 8253 Counter B base reg */
-#define CMD5_REG		0x1c	/* W: Command 5 reg */
-#define CMD5_WRTPRT		(1 << 2)
-#define CMD5_DITHEREN		(1 << 3)
-#define CMD5_CALDACLD		(1 << 4)
-#define CMD5_SCLK		(1 << 5)
-#define CMD5_SDATA		(1 << 6)
-#define CMD5_EEPROMCS		(1 << 7)
-#define STAT2_REG		0x1d	/* R: Status 2 reg */
-#define STAT2_PROMOUT		(1 << 0)
-#define STAT2_OUTA1		(1 << 1)
-#define STAT2_FIFONHF		(1 << 2)
-#define INTERVAL_COUNT_REG	0x1e	/* W: Interval Counter Data reg */
-#define INTERVAL_STROBE_REG	0x1f	/* W: Interval Counter Strobe reg */
-
 #define LABPC_SIZE		0x20	/* size of ISA io region */
 #define LABPC_TIMER_BASE	500	/* 2 MHz master clock */
 #define LABPC_ADC_TIMEOUT	1000
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index e6c8437..a052974 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -24,6 +24,7 @@
 #include <asm/dma.h>
 
 #include "ni_labpc.h"
+#include "ni_labpc_regs.h"
 #include "ni_labpc_isadma.h"
 
 /* size in bytes of dma buffer */
diff --git a/drivers/staging/comedi/drivers/ni_labpc_regs.h b/drivers/staging/comedi/drivers/ni_labpc_regs.h
new file mode 100644
index 0000000..2a274a3
--- /dev/null
+++ b/drivers/staging/comedi/drivers/ni_labpc_regs.h
@@ -0,0 +1,75 @@
+/*
+ * ni_labpc register definitions.
+*/
+
+#ifndef _NI_LABPC_REGS_H
+#define _NI_LABPC_REGS_H
+
+/*
+ * Register map (all registers are 8-bit)
+ */
+#define STAT1_REG		0x00	/* R: Status 1 reg */
+#define STAT1_DAVAIL		(1 << 0)
+#define STAT1_OVERRUN		(1 << 1)
+#define STAT1_OVERFLOW		(1 << 2)
+#define STAT1_CNTINT		(1 << 3)
+#define STAT1_GATA0		(1 << 5)
+#define STAT1_EXTGATA0		(1 << 6)
+#define CMD1_REG		0x00	/* W: Command 1 reg */
+#define CMD1_MA(x)		(((x) & 0x7) << 0)
+#define CMD1_TWOSCMP		(1 << 3)
+#define CMD1_GAIN(x)		(((x) & 0x7) << 4)
+#define CMD1_SCANEN		(1 << 7)
+#define CMD2_REG		0x01	/* W: Command 2 reg */
+#define CMD2_PRETRIG		(1 << 0)
+#define CMD2_HWTRIG		(1 << 1)
+#define CMD2_SWTRIG		(1 << 2)
+#define CMD2_TBSEL		(1 << 3)
+#define CMD2_2SDAC0		(1 << 4)
+#define CMD2_2SDAC1		(1 << 5)
+#define CMD2_LDAC(x)		(1 << (6 + (x)))
+#define CMD3_REG		0x02	/* W: Command 3 reg */
+#define CMD3_DMAEN		(1 << 0)
+#define CMD3_DIOINTEN		(1 << 1)
+#define CMD3_DMATCINTEN		(1 << 2)
+#define CMD3_CNTINTEN		(1 << 3)
+#define CMD3_ERRINTEN		(1 << 4)
+#define CMD3_FIFOINTEN		(1 << 5)
+#define ADC_START_CONVERT_REG	0x03	/* W: Start Convert reg */
+#define DAC_LSB_REG(x)		(0x04 + 2 * (x)) /* W: DAC0/1 LSB reg */
+#define DAC_MSB_REG(x)		(0x05 + 2 * (x)) /* W: DAC0/1 MSB reg */
+#define ADC_FIFO_CLEAR_REG	0x08	/* W: A/D FIFO Clear reg */
+#define ADC_FIFO_REG		0x0a	/* R: A/D FIFO reg */
+#define DMATC_CLEAR_REG		0x0a	/* W: DMA Interrupt Clear reg */
+#define TIMER_CLEAR_REG		0x0c	/* W: Timer Interrupt Clear reg */
+#define CMD6_REG		0x0e	/* W: Command 6 reg */
+#define CMD6_NRSE		(1 << 0)
+#define CMD6_ADCUNI		(1 << 1)
+#define CMD6_DACUNI(x)		(1 << (2 + (x)))
+#define CMD6_HFINTEN		(1 << 5)
+#define CMD6_DQINTEN		(1 << 6)
+#define CMD6_SCANUP		(1 << 7)
+#define CMD4_REG		0x0f	/* W: Command 3 reg */
+#define CMD4_INTSCAN		(1 << 0)
+#define CMD4_EOIRCV		(1 << 1)
+#define CMD4_ECLKDRV		(1 << 2)
+#define CMD4_SEDIFF		(1 << 3)
+#define CMD4_ECLKRCV		(1 << 4)
+#define DIO_BASE_REG		0x10	/* R/W: 8255 DIO base reg */
+#define COUNTER_A_BASE_REG	0x14	/* R/W: 8253 Counter A base reg */
+#define COUNTER_B_BASE_REG	0x18	/* R/W: 8253 Counter B base reg */
+#define CMD5_REG		0x1c	/* W: Command 5 reg */
+#define CMD5_WRTPRT		(1 << 2)
+#define CMD5_DITHEREN		(1 << 3)
+#define CMD5_CALDACLD		(1 << 4)
+#define CMD5_SCLK		(1 << 5)
+#define CMD5_SDATA		(1 << 6)
+#define CMD5_EEPROMCS		(1 << 7)
+#define STAT2_REG		0x1d	/* R: Status 2 reg */
+#define STAT2_PROMOUT		(1 << 0)
+#define STAT2_OUTA1		(1 << 1)
+#define STAT2_FIFONHF		(1 << 2)
+#define INTERVAL_COUNT_REG	0x1e	/* W: Interval Counter Data reg */
+#define INTERVAL_STROBE_REG	0x1f	/* W: Interval Counter Strobe reg */
+
+#endif /* _NI_LABPC_REGS_H */
-- 
1.8.2.1

[PATCH 08/12] staging: comedi: ni_labpc: migrate DMA transfer set-up

[Ian Abbott]

Migrate the code for setting up an ISA DMA transfer into a new function
`labpc_setup_dma()` in the "ni_labpc_isadma" module.  Provide a dummy
inline function in "ni_labpc_isadma.h" if the "ni_labpc_isadma" module
is not being built.

The static function `labpc_suggest_transfer_size()` also needs to move
across to the new module.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c        | 53 +-----------------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 51 +++++++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h |  6 +++
 3 files changed, 59 insertions(+), 51 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index c0ab71e..39cdfda 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -386,32 +386,6 @@ static int labpc_ai_insn_read(struct comedi_device *dev,
 	return insn->n;
 }
 
-#ifdef CONFIG_ISA_DMA_API
-/* utility function that suggests a dma transfer size in bytes */
-static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
-{
-	unsigned int size;
-	unsigned int freq;
-
-	if (cmd->convert_src == TRIG_TIMER)
-		freq = 1000000000 / cmd->convert_arg;
-	/* return some default value */
-	else
-		freq = 0xffffffff;
-
-	/* make buffer fill in no more than 1/3 second */
-	size = (freq / 3) * sample_size;
-
-	/* set a minimum and maximum size allowed */
-	if (size > dma_buffer_size)
-		size = dma_buffer_size - dma_buffer_size % sample_size;
-	else if (size < sample_size)
-		size = sample_size;
-
-	return size;
-}
-#endif
-
 static bool labpc_use_continuous_mode(const struct comedi_cmd *cmd,
 				      enum scan_mode mode)
 {
@@ -882,31 +856,8 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	labpc_clear_adc_fifo(dev);
 
-#ifdef CONFIG_ISA_DMA_API
-	/*  set up dma transfer */
-	if (xfer == isa_dma_transfer) {
-		unsigned long irq_flags;
-
-		irq_flags = claim_dma_lock();
-		disable_dma(devpriv->dma_chan);
-		/* clear flip-flop to make sure 2-byte registers for
-		 * count and address get set correctly */
-		clear_dma_ff(devpriv->dma_chan);
-		set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
-		/*  set appropriate size of transfer */
-		devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);
-		if (cmd->stop_src == TRIG_COUNT &&
-		    devpriv->count * sample_size < devpriv->dma_transfer_size) {
-			devpriv->dma_transfer_size =
-			    devpriv->count * sample_size;
-		}
-		set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
-		enable_dma(devpriv->dma_chan);
-		release_dma_lock(irq_flags);
-		/*  enable board's dma */
-		devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
-	}
-#endif
+	if (xfer == isa_dma_transfer)
+		labpc_setup_dma(dev, s);
 
 	/*  enable error interrupts */
 	devpriv->cmd3 |= CMD3_ERRINTEN;
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index a052974..dba2be3 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -29,6 +29,57 @@
 
 /* size in bytes of dma buffer */
 static const int dma_buffer_size = 0xff00;
+/* 2 bytes per sample */
+static const int sample_size = 2;
+
+/* utility function that suggests a dma transfer size in bytes */
+static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
+{
+	unsigned int size;
+	unsigned int freq;
+
+	if (cmd->convert_src == TRIG_TIMER)
+		freq = 1000000000 / cmd->convert_arg;
+	else
+		/* return some default value */
+		freq = 0xffffffff;
+
+	/* make buffer fill in no more than 1/3 second */
+	size = (freq / 3) * sample_size;
+
+	/* set a minimum and maximum size allowed */
+	if (size > dma_buffer_size)
+		size = dma_buffer_size - dma_buffer_size % sample_size;
+	else if (size < sample_size)
+		size = sample_size;
+
+	return size;
+}
+
+void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+	struct labpc_private *devpriv = dev->private;
+	struct comedi_cmd *cmd = &s->async->cmd;
+	unsigned long irq_flags;
+
+	irq_flags = claim_dma_lock();
+	disable_dma(devpriv->dma_chan);
+	/* clear flip-flop to make sure 2-byte registers for
+	 * count and address get set correctly */
+	clear_dma_ff(devpriv->dma_chan);
+	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
+	/* set appropriate size of transfer */
+	devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);
+	if (cmd->stop_src == TRIG_COUNT &&
+	    devpriv->count * sample_size < devpriv->dma_transfer_size)
+		devpriv->dma_transfer_size = devpriv->count * sample_size;
+	set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
+	enable_dma(devpriv->dma_chan);
+	release_dma_lock(irq_flags);
+	/* set CMD3 bits for caller to enable DMA and interrupt */
+	devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
+}
+EXPORT_SYMBOL_GPL(labpc_setup_dma);
 
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
 {
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index 3b022ea..c721f57 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -18,6 +18,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev)
 
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
 void labpc_free_dma_chan(struct comedi_device *dev);
+void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s);
 
 #else
 
@@ -36,6 +37,11 @@ static inline void labpc_free_dma_chan(struct comedi_device *dev)
 {
 }
 
+static inline void labpc_setup_dma(struct comedi_device *dev,
+				   struct comedi_subdevice *s)
+{
+}
+
 #endif
 
 #endif /* _NI_LABPC_ISADMA_H */
-- 
1.8.2.1

[PATCH 09/12] staging: comedi: ni_labpc: migrate labpc_drain_dma()

[Ian Abbott]

Move `labpc_drain_dma()` into the "ni_labpc_isadma" module.  Provide a
dummy inline function in "ni_labpc_isadma.h" if the module is not being
built.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c        | 56 ------------------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 56 ++++++++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h |  5 +++
 3 files changed, 61 insertions(+), 56 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 39cdfda..fc2dfea 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -905,60 +905,6 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 }
 
 #ifdef CONFIG_ISA_DMA_API
-static void labpc_drain_dma(struct comedi_device *dev)
-{
-	struct labpc_private *devpriv = dev->private;
-	struct comedi_subdevice *s = dev->read_subdev;
-	struct comedi_async *async = s->async;
-	int status;
-	unsigned long flags;
-	unsigned int max_points, num_points, residue, leftover;
-	int i;
-
-	status = devpriv->stat1;
-
-	flags = claim_dma_lock();
-	disable_dma(devpriv->dma_chan);
-	/* clear flip-flop to make sure 2-byte registers for
-	 * count and address get set correctly */
-	clear_dma_ff(devpriv->dma_chan);
-
-	/*  figure out how many points to read */
-	max_points = devpriv->dma_transfer_size / sample_size;
-	/* residue is the number of points left to be done on the dma
-	 * transfer.  It should always be zero at this point unless
-	 * the stop_src is set to external triggering.
-	 */
-	residue = get_dma_residue(devpriv->dma_chan) / sample_size;
-	num_points = max_points - residue;
-	if (devpriv->count < num_points && async->cmd.stop_src == TRIG_COUNT)
-		num_points = devpriv->count;
-
-	/*  figure out how many points will be stored next time */
-	leftover = 0;
-	if (async->cmd.stop_src != TRIG_COUNT) {
-		leftover = devpriv->dma_transfer_size / sample_size;
-	} else if (devpriv->count > num_points) {
-		leftover = devpriv->count - num_points;
-		if (leftover > max_points)
-			leftover = max_points;
-	}
-
-	/* write data to comedi buffer */
-	for (i = 0; i < num_points; i++)
-		cfc_write_to_buffer(s, devpriv->dma_buffer[i]);
-
-	if (async->cmd.stop_src == TRIG_COUNT)
-		devpriv->count -= num_points;
-
-	/*  set address and count for next transfer */
-	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
-	set_dma_count(devpriv->dma_chan, leftover * sample_size);
-	release_dma_lock(flags);
-
-	async->events |= COMEDI_CB_BLOCK;
-}
-
 static void handle_isa_dma(struct comedi_device *dev)
 {
 	struct labpc_private *devpriv = dev->private;
@@ -1008,12 +954,10 @@ static int labpc_drain_fifo(struct comedi_device *dev)
  * when acquisition is terminated by stop_src == TRIG_EXT). */
 static void labpc_drain_dregs(struct comedi_device *dev)
 {
-#ifdef CONFIG_ISA_DMA_API
 	struct labpc_private *devpriv = dev->private;
 
 	if (devpriv->current_transfer == isa_dma_transfer)
 		labpc_drain_dma(dev);
-#endif
 
 	labpc_drain_fifo(dev);
 }
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index dba2be3..c4bfecc 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -23,6 +23,7 @@
 
 #include <asm/dma.h>
 
+#include "comedi_fc.h"
 #include "ni_labpc.h"
 #include "ni_labpc_regs.h"
 #include "ni_labpc_isadma.h"
@@ -81,6 +82,61 @@ void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)
 }
 EXPORT_SYMBOL_GPL(labpc_setup_dma);
 
+void labpc_drain_dma(struct comedi_device *dev)
+{
+	struct labpc_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	struct comedi_async *async = s->async;
+	int status;
+	unsigned long flags;
+	unsigned int max_points, num_points, residue, leftover;
+	int i;
+
+	status = devpriv->stat1;
+
+	flags = claim_dma_lock();
+	disable_dma(devpriv->dma_chan);
+	/* clear flip-flop to make sure 2-byte registers for
+	 * count and address get set correctly */
+	clear_dma_ff(devpriv->dma_chan);
+
+	/* figure out how many points to read */
+	max_points = devpriv->dma_transfer_size / sample_size;
+	/* residue is the number of points left to be done on the dma
+	 * transfer.  It should always be zero at this point unless
+	 * the stop_src is set to external triggering.
+	 */
+	residue = get_dma_residue(devpriv->dma_chan) / sample_size;
+	num_points = max_points - residue;
+	if (devpriv->count < num_points && async->cmd.stop_src == TRIG_COUNT)
+		num_points = devpriv->count;
+
+	/* figure out how many points will be stored next time */
+	leftover = 0;
+	if (async->cmd.stop_src != TRIG_COUNT) {
+		leftover = devpriv->dma_transfer_size / sample_size;
+	} else if (devpriv->count > num_points) {
+		leftover = devpriv->count - num_points;
+		if (leftover > max_points)
+			leftover = max_points;
+	}
+
+	/* write data to comedi buffer */
+	for (i = 0; i < num_points; i++)
+		cfc_write_to_buffer(s, devpriv->dma_buffer[i]);
+
+	if (async->cmd.stop_src == TRIG_COUNT)
+		devpriv->count -= num_points;
+
+	/* set address and count for next transfer */
+	set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
+	set_dma_count(devpriv->dma_chan, leftover * sample_size);
+	release_dma_lock(flags);
+
+	async->events |= COMEDI_CB_BLOCK;
+}
+EXPORT_SYMBOL_GPL(labpc_drain_dma);
+
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
 {
 	struct labpc_private *devpriv = dev->private;
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index c721f57..1f322f2 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -19,6 +19,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev)
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
 void labpc_free_dma_chan(struct comedi_device *dev);
 void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s);
+void labpc_drain_dma(struct comedi_device *dev);
 
 #else
 
@@ -42,6 +43,10 @@ static inline void labpc_setup_dma(struct comedi_device *dev,
 {
 }
 
+static inline void labpc_drain_dma(struct comedi_device *dev)
+{
+}
+
 #endif
 
 #endif /* _NI_LABPC_ISADMA_H */
-- 
1.8.2.1

[PATCH 10/12] staging: comedi: ni_labpc: migrate DMA status handling

[Ian Abbott]

Migrate the code for checking and handling the interrupt status handling
for ISA DMA transfers into new a new function
`labpc_handle_dma_status()` in the "ni_labpc_isadma" module.  Provide a
dummy inline function in "ni_labpc_isadma.h" if the "ni_labpc_isadma"
module is not being built.

The static function `handle_isa_dma()` also needs to move across to the
new module.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c        | 29 +++---------------------
 drivers/staging/comedi/drivers/ni_labpc_isadma.c | 27 ++++++++++++++++++++++
 drivers/staging/comedi/drivers/ni_labpc_isadma.h |  5 ++++
 3 files changed, 35 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index fc2dfea..2f6c430e 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -904,20 +904,6 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	return 0;
 }
 
-#ifdef CONFIG_ISA_DMA_API
-static void handle_isa_dma(struct comedi_device *dev)
-{
-	struct labpc_private *devpriv = dev->private;
-
-	labpc_drain_dma(dev);
-
-	enable_dma(devpriv->dma_chan);
-
-	/*  clear dma tc interrupt */
-	devpriv->write_byte(0x1, dev->iobase + DMATC_CLEAR_REG);
-}
-#endif
-
 /* read all available samples from ai fifo */
 static int labpc_drain_fifo(struct comedi_device *dev)
 {
@@ -1002,18 +988,9 @@ static irqreturn_t labpc_interrupt(int irq, void *d)
 		return IRQ_HANDLED;
 	}
 
-#ifdef CONFIG_ISA_DMA_API
-	if (devpriv->current_transfer == isa_dma_transfer) {
-		/*
-		 * if a dma terminal count of external stop trigger
-		 * has occurred
-		 */
-		if (devpriv->stat1 & STAT1_GATA0 ||
-		    (board->is_labpc1200 && devpriv->stat2 & STAT2_OUTA1)) {
-			handle_isa_dma(dev);
-		}
-	} else
-#endif
+	if (devpriv->current_transfer == isa_dma_transfer)
+		labpc_handle_dma_status(dev);
+	else
 		labpc_drain_fifo(dev);
 
 	if (devpriv->stat1 & STAT1_CNTINT) {
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index c4bfecc..2149596 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -137,6 +137,33 @@ void labpc_drain_dma(struct comedi_device *dev)
 }
 EXPORT_SYMBOL_GPL(labpc_drain_dma);
 
+static void handle_isa_dma(struct comedi_device *dev)
+{
+	struct labpc_private *devpriv = dev->private;
+
+	labpc_drain_dma(dev);
+
+	enable_dma(devpriv->dma_chan);
+
+	/* clear dma tc interrupt */
+	devpriv->write_byte(0x1, dev->iobase + DMATC_CLEAR_REG);
+}
+
+void labpc_handle_dma_status(struct comedi_device *dev)
+{
+	const struct labpc_boardinfo *board = comedi_board(dev);
+	struct labpc_private *devpriv = dev->private;
+
+	/*
+	 * if a dma terminal count of external stop trigger
+	 * has occurred
+	 */
+	if (devpriv->stat1 & STAT1_GATA0 ||
+	    (board->is_labpc1200 && devpriv->stat2 & STAT2_OUTA1))
+		handle_isa_dma(dev);
+}
+EXPORT_SYMBOL_GPL(labpc_handle_dma_status);
+
 int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
 {
 	struct labpc_private *devpriv = dev->private;
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index 1f322f2..771af4b 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -20,6 +20,7 @@ int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
 void labpc_free_dma_chan(struct comedi_device *dev);
 void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s);
 void labpc_drain_dma(struct comedi_device *dev);
+void labpc_handle_dma_status(struct comedi_device *dev);
 
 #else
 
@@ -47,6 +48,10 @@ static inline void labpc_drain_dma(struct comedi_device *dev)
 {
 }
 
+static inline void labpc_handle_dma_status(struct comedi_device *dev)
+{
+}
+
 #endif
 
 #endif /* _NI_LABPC_ISADMA_H */
-- 
1.8.2.1

[PATCH 11/12] staging: comedi: ni_labpc: tidy up after DMA code migration

[Ian Abbott]

After migrating the ISA DMA handling code to the "ni_labpc_isadma"
module, get rid of an unneeded `#include` and a couple of unused
static variables.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_labpc.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 2f6c430e..6a35ec0a 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -64,8 +64,6 @@
 
 #include "../comedidev.h"
 
-#include <asm/dma.h>
-
 #include "8253.h"
 #include "8255.h"
 #include "comedi_fc.h"
@@ -174,11 +172,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 };
 #endif
 
-/* size in bytes of dma buffer */
-static const int dma_buffer_size = 0xff00;
-/* 2 bytes per sample */
-static const int sample_size = 2;
-
 static int labpc_counter_load(struct comedi_device *dev,
 			      unsigned long base_address,
 			      unsigned int counter_number,
-- 
1.8.2.1

[PATCH 12/12] staging: comedi: COMEDI_NI_LABPC_ISA no longer depends on VIRT_TO_BUS

[Ian Abbott]

After migrating ISA DMA support from the "ni_labpc" module to the new
"ni_labpc_isadma" module, the `COMEDI_NI_LABPC_ISA` configuration option
no longer depends on `VIRT_TO_BUS`, so remove the dependency.

(The new `COMEDI_NI_LABPC_ISADMA` option does depend on `VIRT_TO_BUS`
but is not configured manually and is only selected automatically if the
`VIRT_TO_BUS` and `ISA_DMA_API` options are set.)

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig
index faecf67..620100b 100644
--- a/drivers/staging/comedi/Kconfig
+++ b/drivers/staging/comedi/Kconfig
@@ -474,7 +474,6 @@ config COMEDI_NI_LABPC_ISA
 	tristate "NI Lab-PC and compatibles ISA support"
 	select COMEDI_NI_LABPC
 	select COMEDI_NI_LABPC_ISADMA if ISA_DMA_API && VIRT_TO_BUS
-	depends on VIRT_TO_BUS
 	---help---
 	  Enable support for National Instruments Lab-PC and compatibles
 	  Lab-PC-1200, Lab-PC-1200AI, Lab-PC+.
-- 
1.8.2.1