[PATCH 32/46] comedi: pcl711: Add sanity checks for I/O base address

[Ian Abbott]

The "pcl711" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of an
Advantech PCL-711 series board or an Adlink ACL-8112 series board.  It
currently allows any base address to be configured but the hardware only
supports base addresses (configured by on-board DIP switches) in the
range 0 to 0x3F0 (for PCL-711) or 0x200 to 0x3F0 (for ACL-8112) on
16-byte boundaries.

Store the minimum supported I/O base address in the static board
information array elements, and add a sanity check to ensure the device
is not configured at an unsupported base address.

Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
 drivers/comedi/drivers/pcl711.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/pcl711.c b/drivers/comedi/drivers/pcl711.c
index 0cf3917defe7..5d2c4b2aa3bb 100644
--- a/drivers/comedi/drivers/pcl711.c
+++ b/drivers/comedi/drivers/pcl711.c
@@ -112,6 +112,7 @@ struct pcl711_board {
 	int n_aichan;
 	int n_aochan;
 	int maxirq;
+	unsigned int min_io_start;
 	const struct comedi_lrange *ai_range_type;
 };
 
@@ -132,12 +133,14 @@ static const struct pcl711_board boardtypes[] = {
 		.n_aichan	= 16,
 		.n_aochan	= 2,
 		.maxirq		= 15,
+		.min_io_start	= 0x200,
 		.ai_range_type	= &range_acl8112hg_ai,
 	}, {
 		.name		= "acl8112dg",
 		.n_aichan	= 16,
 		.n_aochan	= 2,
 		.maxirq		= 15,
+		.min_io_start	= 0x200,
 		.ai_range_type	= &range_acl8112dg_ai,
 	},
 };
@@ -418,7 +421,8 @@ static int pcl711_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	struct comedi_subdevice *s;
 	int ret;
 
-	ret = comedi_request_region(dev, it->options[0], 0x10);
+	ret = comedi_check_request_region(dev, it->options[0], 0x10,
+					  board->min_io_start, 0x3ff, 16);
 	if (ret)
 		return ret;
 
-- 
2.51.0