[PATCH] staging: comedi: ni_labpc: fix VIRT_TO_BUS dependency

From: Ian Abbott
Date: Mon May 13 2013 - 07:02:49 EST


The "ni_labpc" module acts as a low-level comedi driver for various
Nattional Instruments Lab-PC ISA cards if `CONFIG_NI_LABPC_ISA` is
enabled, and also as a common module depended on by the "ni_labpc_cs"
and "ni_labpc_pci" modules. For ISA cards, it optionally supports the
use of an ISA DMA channel if `CONFIG_ISA_DMA_API` is enabled, using
conditionally compiled code. This conditionally compiled code also
relies on `virt_to_bus()`, which only exists if `CONFIG_VIRT_TO_BUS` is
enabled. Therefore, support for ISA DMA should only be compiled in if
both `CONFIG_ISA_DMA_API` and `CONFIG_VIRT_TO_BUS` are defined,
otherwise the "ni_labpc" module fails to compile on kernels that enable
`CONFIG_ISA_DMA_API` but not `CONFIG_VIRT_TO_BUS`.

Conditionally define a new macro `NI_LABPC_ISA_DMA` iff both
`CONFIG_ISA_DMA_API` and `CONFIG_VIRT_TO_BUS` are defined, and change
the conditional compilation tests to use the new macro instead of
`CONFIG_ISA_DMA_API`.

Also, in the "Kconfig", remove the `VIRT_TO_BUS` dependency from the
`COMEDI_NI_LABPC_ISA` option since the dependency is now checked at
compile time.

Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/Kconfig | 1 -
drivers/staging/comedi/drivers/ni_labpc.c | 18 +++++++++++-------
2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig
index 7871579..c55a79d 100644
--- a/drivers/staging/comedi/Kconfig
+++ b/drivers/staging/comedi/Kconfig
@@ -487,7 +487,6 @@ config COMEDI_NI_ATMIO16D
config COMEDI_NI_LABPC_ISA
tristate "NI Lab-PC and compatibles ISA support"
select COMEDI_NI_LABPC
- depends on VIRT_TO_BUS
---help---
Enable support for National Instruments Lab-PC and compatibles
Lab-PC-1200, Lab-PC-1200AI, Lab-PC+.
diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 3d978f3..5078be7 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -75,6 +75,10 @@
#include "comedi_fc.h"
#include "ni_labpc.h"

+#if defined(CONFIG_ISA_DMA_API) && defined(CONFIG_VIRT_TO_BUS)
+#define NI_LABPC_ISA_DMA
+#endif
+
/*
* Register map (all registers are 8-bit)
*/
@@ -465,7 +469,7 @@ static int labpc_ai_insn_read(struct comedi_device *dev,
return insn->n;
}

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
/* utility function that suggests a dma transfer size in bytes */
static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
{
@@ -883,7 +887,7 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
return ret;
}

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
/* figure out what method we will use to transfer data */
if (devpriv->dma_chan && /* need a dma channel allocated */
/*
@@ -966,7 +970,7 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)

labpc_clear_adc_fifo(dev);

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
/* set up dma transfer */
if (xfer == isa_dma_transfer) {
unsigned long irq_flags;
@@ -1041,7 +1045,7 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
return 0;
}

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
static void labpc_drain_dma(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
@@ -1145,7 +1149,7 @@ 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
+#ifdef NI_LABPC_ISA_DMA
struct labpc_private *devpriv = dev->private;

if (devpriv->current_transfer == isa_dma_transfer)
@@ -1195,7 +1199,7 @@ static irqreturn_t labpc_interrupt(int irq, void *d)
return IRQ_HANDLED;
}

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
if (devpriv->current_transfer == isa_dma_transfer) {
/*
* if a dma terminal count of external stop trigger
@@ -1731,7 +1735,7 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it)
if (ret)
return ret;

-#ifdef CONFIG_ISA_DMA_API
+#ifdef NI_LABPC_ISA_DMA
if (dev->irq && (dma_chan == 1 || dma_chan == 3)) {
devpriv->dma_buffer = kmalloc(dma_buffer_size,
GFP_KERNEL | GFP_DMA);
--
1.8.1.5

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