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>
This commit is contained in:
H Hartley Sweeten 2015-06-18 10:54:49 -07:00 committed by Greg Kroah-Hartman
parent 4f3aa186d3
commit 06ad6bd869

View File

@ -1216,62 +1216,67 @@ static void das1800_free_dma(struct comedi_device *dev)
comedi_isadma_free(devpriv->dma); 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; const struct das1800_board *board = dev->board_ptr;
int index; int index = board ? board - das1800_boards : -EINVAL;
int id; int id;
/* calc the offset to the boardinfo that was found by the core */ /*
index = board - das1800_boards; * 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
/* verify that the board id matches the boardinfo */ * 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; id = (inb(dev->iobase + DAS1800_DIGITAL) >> 4) & 0xf;
switch (id) { switch (id) {
case 0x3: case 0x3:
if (index == das1801st_da || index == das1802st_da || if (index == das1801st_da || index == das1802st_da ||
index == das1701st_da || index == das1702st_da) index == das1701st_da || index == das1702st_da)
return index; return board;
index = das1801st; index = das1801st;
break; break;
case 0x4: case 0x4:
if (index == das1802hr_da || index == das1702hr_da) if (index == das1802hr_da || index == das1702hr_da)
return index; return board;
index = das1802hr; index = das1802hr;
break; break;
case 0x5: case 0x5:
if (index == das1801ao || index == das1802ao || if (index == das1801ao || index == das1802ao ||
index == das1701ao || index == das1702ao) index == das1701ao || index == das1702ao)
return index; return board;
index = das1801ao; index = das1801ao;
break; break;
case 0x6: case 0x6:
if (index == das1802hr || index == das1702hr) if (index == das1802hr || index == das1702hr)
return index; return board;
index = das1802hr; index = das1802hr;
break; break;
case 0x7: case 0x7:
if (index == das1801st || index == das1802st || if (index == das1801st || index == das1802st ||
index == das1701st || index == das1702st) index == das1701st || index == das1702st)
return index; return board;
index = das1801st; index = das1801st;
break; break;
case 0x8: case 0x8:
if (index == das1801hc || index == das1802hc) if (index == das1801hc || index == das1802hc)
return index; return board;
index = das1801hc; index = das1801hc;
break;
default: default:
dev_err(dev->class_dev, dev_err(dev->class_dev,
"Board model: probe returned 0x%x (unknown, please report)\n", "Board model: probe returned 0x%x (unknown, please report)\n",
id); id);
break; return NULL;
} }
dev_err(dev->class_dev, dev_err(dev->class_dev,
"Board model (probed, not recommended): %s series\n", "Board model (probed, not recommended): %s series\n",
das1800_boards[index].name); das1800_boards[index].name);
return index; return &das1800_boards[index];
} }
static int das1800_attach(struct comedi_device *dev, 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 das1800_private *devpriv;
struct comedi_subdevice *s; struct comedi_subdevice *s;
unsigned int irq = it->options[1]; unsigned int irq = it->options[1];
int board;
int ret; int ret;
devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv)); devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
@ -1292,14 +1296,12 @@ static int das1800_attach(struct comedi_device *dev,
if (ret) if (ret)
return ret; return ret;
board = das1800_probe(dev); thisboard = das1800_probe(dev);
if (board < 0) { if (!thisboard) {
dev_err(dev->class_dev, "unable to determine board type\n"); dev_err(dev->class_dev, "unable to determine board type\n");
return -ENODEV; return -ENODEV;
} }
dev->board_ptr = thisboard;
dev->board_ptr = das1800_boards + board;
thisboard = dev->board_ptr;
dev->board_name = thisboard->name; dev->board_name = thisboard->name;
/* if it is an 'ao' board with fancy analog out then we need extra io ports */ /* if it is an 'ao' board with fancy analog out then we need extra io ports */