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authorH Hartley Sweeten <hsweeten@visionengravers.com>2015-06-18 10:54:49 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-06-18 21:19:02 -0700
commit06ad6bd8698c1202423ead5a9e85564134382065 (patch)
treeb13165e7f54071457e70598b59fd902238f8daff /drivers/staging
parent4f3aa186d325f469c142ce8c804548e2b2f18a9d (diff)
staging: comedi: das1800: cleanup das1800_probe()
Make this function return a pointer to the boardinfo instead of an index. Since it's not typical, add a comment to clarify why this legacy driver does a probe. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
-rw-r--r--drivers/staging/comedi/drivers/das1800.c44
1 files changed, 23 insertions, 21 deletions
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 53baf37cd21a..a7471bb7c39b 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -1216,62 +1216,67 @@ static void das1800_free_dma(struct comedi_device *dev)
comedi_isadma_free(devpriv->dma);
}
-static int das1800_probe(struct comedi_device *dev)
+static const struct das1800_board *das1800_probe(struct comedi_device *dev)
{
const struct das1800_board *board = dev->board_ptr;
- int index;
+ int index = board ? board - das1800_boards : -EINVAL;
int id;
- /* calc the offset to the boardinfo that was found by the core */
- index = board - das1800_boards;
-
- /* verify that the board id matches the boardinfo */
+ /*
+ * The dev->board_ptr will be set by comedi_device_attach() if the
+ * board name provided by the user matches a board->name in this
+ * driver. If so, this function sanity checks the id to verify that
+ * the board is correct.
+ *
+ * If the dev->board_ptr is not set, the user is trying to attach
+ * an unspecified board to this driver. In this case the id is used
+ * to 'probe' for the correct dev->board_ptr.
+ */
id = (inb(dev->iobase + DAS1800_DIGITAL) >> 4) & 0xf;
switch (id) {
case 0x3:
if (index == das1801st_da || index == das1802st_da ||
index == das1701st_da || index == das1702st_da)
- return index;
+ return board;
index = das1801st;
break;
case 0x4:
if (index == das1802hr_da || index == das1702hr_da)
- return index;
+ return board;
index = das1802hr;
break;
case 0x5:
if (index == das1801ao || index == das1802ao ||
index == das1701ao || index == das1702ao)
- return index;
+ return board;
index = das1801ao;
break;
case 0x6:
if (index == das1802hr || index == das1702hr)
- return index;
+ return board;
index = das1802hr;
break;
case 0x7:
if (index == das1801st || index == das1802st ||
index == das1701st || index == das1702st)
- return index;
+ return board;
index = das1801st;
break;
case 0x8:
if (index == das1801hc || index == das1802hc)
- return index;
+ return board;
index = das1801hc;
- break;
default:
dev_err(dev->class_dev,
"Board model: probe returned 0x%x (unknown, please report)\n",
id);
- break;
+ return NULL;
}
dev_err(dev->class_dev,
"Board model (probed, not recommended): %s series\n",
das1800_boards[index].name);
- return index;
+ return &das1800_boards[index];
}
static int das1800_attach(struct comedi_device *dev,
@@ -1281,7 +1286,6 @@ static int das1800_attach(struct comedi_device *dev,
struct das1800_private *devpriv;
struct comedi_subdevice *s;
unsigned int irq = it->options[1];
- int board;
int ret;
devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
@@ -1292,14 +1296,12 @@ static int das1800_attach(struct comedi_device *dev,
if (ret)
return ret;
- board = das1800_probe(dev);
- if (board < 0) {
+ thisboard = das1800_probe(dev);
+ if (!thisboard) {
dev_err(dev->class_dev, "unable to determine board type\n");
return -ENODEV;
}
-
- dev->board_ptr = das1800_boards + board;
- thisboard = dev->board_ptr;
+ dev->board_ptr = thisboard;
dev->board_name = thisboard->name;
/* if it is an 'ao' board with fancy analog out then we need extra io ports */