If a DIO subdevice has more than 32 channels, its 'insn_bits' handler is
supposed to take account of the base channel from
`CR_CHAN(insn->chanspec)`. (The comedi core will adjust the base
channel to 0 and shift the mask and data to compensate if the subdevice
has less than or equal to 32 channels.) The "comedi_bond" driver
currently ignores the base channel and assumes it is 0.
Replace `comedi_dio_bitfield()` in the "kcomedilib" module with
`comedi_dio_bitfield2()` that takes account of the base channel, and
rewrite the "comedi_bond" driver's 'insn_bits' handler
(`bonding_dio_insn_bits()`) to take account of the base channel and use
the new function.
No other modules use `comedi_dio_bitfield()` so it is safe to replace it
with `comedi_dio_bitfield2()`. The name follows that of the equivalent
function in the user-space comedilib. If the base channel is non-zero
and the subdevice has less than or equal to 32 channels it needs to
adjust things in the same way as the comedi core (same as `parse_insn()`
in "comedi_fops.c") due to most drivers ignoring the base channel.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/comedilib.h | 5 +-
drivers/staging/comedi/drivers/comedi_bond.c | 87 ++++++++++++----------
.../staging/comedi/kcomedilib/kcomedilib_main.c | 37 +++++++--
3 files changed, 83 insertions(+), 46 deletions(-)
diff --git a/drivers/staging/comedi/comedilib.h b/drivers/staging/comedi/comedilib.h
index 47b1640..56baf85 100644
--- a/drivers/staging/comedi/comedilib.h
+++ b/drivers/staging/comedi/comedilib.h
@@ -25,8 +25,9 @@ int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
unsigned int chan, unsigned int *io);
int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
unsigned int chan, unsigned int io);
-int comedi_dio_bitfield(struct comedi_device *dev, unsigned int subdev,
- unsigned int mask, unsigned int *bits);
+int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
+ unsigned int mask, unsigned int *bits,
+ unsigned int base_channel);
int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
unsigned int subd);
int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice);
diff --git a/drivers/staging/comedi/drivers/comedi_bond.c b/drivers/staging/comedi/drivers/comedi_bond.c
index a1c51a2..8e2696c 100644
--- a/drivers/staging/comedi/drivers/comedi_bond.c
+++ b/drivers/staging/comedi/drivers/comedi_bond.c
@@ -73,48 +73,59 @@ static int bonding_dio_insn_bits(struct comedi_device *dev,
struct comedi_insn *insn, unsigned int *data)
{
struct comedi_bond_private *devpriv = dev->private;
-#define LSAMPL_BITS (sizeof(unsigned int)*8)
- unsigned nchans = LSAMPL_BITS, num_done = 0, i;
+ unsigned int n_left, n_done, base_chan;
+ unsigned int write_mask, data_bits;
+ struct bonded_device **devs;
- if (devpriv->nchans < nchans)
- nchans = devpriv->nchans;
+ write_mask = data[0];
+ data_bits = data[1];
+ base_chan = CR_CHAN(insn->chanspec);
+ /* do a maximum of 32 channels, starting from base_chan. */
+ n_left = devpriv->nchans - base_chan;
+ if (n_left > 32)
+ n_left = 32;
- /*
- * The insn data is a mask in data[0] and the new data
- * in data[1], each channel cooresponding to a bit.
- */
- for (i = 0; num_done < nchans && i < devpriv->ndevs; ++i) {
- struct bonded_device *bdev = devpriv->devs[i];
- /*
- * Grab the channel mask and data of only the bits corresponding
- * to this subdevice.. need to shift them to zero position of
- * course.
- */
- /* Bits corresponding to this subdev. */
- unsigned int subdev_mask = ((1 << bdev->nchans) - 1);
- unsigned int write_mask, data_bits;
-
- /* Argh, we have >= LSAMPL_BITS chans.. take all bits */
- if (bdev->nchans >= LSAMPL_BITS)
- subdev_mask = (unsigned int)(-1);
-
- write_mask = (data[0] >> num_done) & subdev_mask;
- data_bits = (data[1] >> num_done) & subdev_mask;
-
- /* Read/Write the new digital lines */
- if (comedi_dio_bitfield(bdev->dev, bdev->subdev, write_mask,
- &data_bits) != 2)
- return -EINVAL;
+ n_done = 0;
+ devs = devpriv->devs;
+ do {
+ struct bonded_device *bdev = *devs++;
- /* Make room for the new bits in data[1], the return value */
- data[1] &= ~(subdev_mask << num_done);
- /* Put the bits in the return value */
- data[1] |= (data_bits & subdev_mask) << num_done;
- /* Save the new bits to the saved state.. */
- s->state = data[1];
+ if (base_chan < bdev->nchans) {
+ /* base channel falls within bonded device */
+ unsigned int b_chans, b_mask, b_write_mask, b_data_bits;
+ int ret;
- num_done += bdev->nchans;
- }
+ /*
+ * Get num channels to do for bonded device and set
+ * up mask and data bits for bonded device.
+ */
+ b_chans = bdev->nchans - base_chan;
+ if (b_chans > n_left)
+ b_chans = n_left;
+ b_mask = (1U << b_chans) - 1;
+ b_write_mask = (write_mask >> n_done) & b_mask;
+ b_data_bits = (data_bits >> n_done) & b_mask;
+ /* Read/Write the new digital lines. */
+ ret = comedi_dio_bitfield2(bdev->dev, bdev->subdev,
+ b_write_mask, &b_data_bits,
+ base_chan);
+ if (ret < 0)
+ return ret;
+ /* Place read bits into data[1]. */
+ data[1] &= ~(b_mask << n_done);
+ data[1] |= (b_data_bits & b_mask) << n_done;
+ /*
+ * Set up for following bonded device (if still have
+ * channels to read/write).
+ */
+ base_chan = 0;
+ n_done += b_chans;
+ n_left -= b_chans;
+ } else {
+ /* Skip bonded devices before base channel. */
+ base_chan -= bdev->nchans;
+ }
+ } while (n_left);
return insn->n;
}
diff --git a/drivers/staging/comedi/kcomedilib/kcomedilib_main.c b/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
index c7e809b..cd60677 100644
--- a/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
+++ b/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
@@ -159,28 +159,53 @@ int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
}
EXPORT_SYMBOL_GPL(comedi_dio_config);
-int comedi_dio_bitfield(struct comedi_device *dev, unsigned int subdev,
- unsigned int mask, unsigned int *bits)
+int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
+ unsigned int mask, unsigned int *bits,
+ unsigned int base_channel)
{
struct comedi_insn insn;
unsigned int data[2];
+ unsigned int n_chan;
+ unsigned int shift;
int ret;
+ if (subdev >= dev->n_subdevices)
+ return -EINVAL;
+
+ base_channel = CR_CHAN(base_channel);
+ n_chan = comedi_get_n_channels(dev, subdev);
+ if (base_channel >= n_chan)
+ return -EINVAL;
+
memset(&insn, 0, sizeof(insn));
insn.insn = INSN_BITS;
+ insn.chanspec = base_channel;
insn.n = 2;
insn.subdev = subdev;
data[0] = mask;
data[1] = *bits;
- ret = comedi_do_insn(dev, &insn, data);
-
- *bits = data[1];
+ /*
+ * Most drivers ignore the base channel in insn->chanspec.
+ * Fix this here if the subdevice has <= 32 channels.
+ */
+ if (n_chan <= 32) {
+ shift = base_channel;
+ if (shift) {
+ insn.chanspec = 0;
+ data[0] <<= shift;
+ data[1] <<= shift;
+ }
+ } else {
+ shift = 0;
+ }
+ ret = comedi_do_insn(dev, &insn, data);
+ *bits = data[1] >> shift;
return ret;
}
-EXPORT_SYMBOL_GPL(comedi_dio_bitfield);
+EXPORT_SYMBOL_GPL(comedi_dio_bitfield2);
int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
unsigned int subd)
--
1.8.3.2
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