[PATCH 4.1 025/102] staging: comedi: adl_pci7x3x: fix digital output on PCI-7230

Greg Kroah-Hartman
2015-09-19T17:38:57Z

From: Ian Abbott <abbotti@mev.co.uk>

commit ad83dbd974feb2e2a8cc071a1d28782bd4d2c70e upstream.

The "adl_pci7x3x" driver replaced the "adl_pci7230" and "adl_pci7432"
drivers in commits 8f567c373c4b ("staging: comedi: new adl_pci7x3x
driver") and 657f77d173d3 ("staging: comedi: remove adl_pci7230 and
adl_pci7432 drivers"). Although the new driver code agrees with the
user manuals for the respective boards, digital outputs stopped working
on the PCI-7230. This has 16 digital output channels and the previous
adl_pci7230 driver shifted the 16 bit output state left by 16 bits
before writing to the hardware register. The new adl_pci7x3x driver
doesn't do that. Fix it in `adl_pci7x3x_do_insn_bits()` by checking
for the special case of the subdevice having only 16 channels and
duplicating the 16 bit output state into both halves of the 32-bit
register. That should work both for what the board actually does and
for what the user manual says it should do.

Fixes: 8f567c373c4b ("staging: comedi: new adl_pci7x3x driver")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/comedi/drivers/adl_pci7x3x.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

--- a/drivers/staging/comedi/drivers/adl_pci7x3x.c
+++ b/drivers/staging/comedi/drivers/adl_pci7x3x.c
@@ -120,8 +120,20 @@ static int adl_pci7x3x_do_insn_bits(stru
{
unsigned long reg = (unsigned long)s->private;

- if (comedi_dio_update_state(s, data))
- outl(s->state, dev->iobase + reg);
+ if (comedi_dio_update_state(s, data)) {
+ unsigned int val = s->state;
+
+ if (s->n_chan == 16) {
+ /*
+ * It seems the PCI-7230 needs the 16-bit DO state
+ * to be shifted left by 16 bits before being written
+ * to the 32-bit register. Set the value in both
+ * halves of the register to be sure.
+ */
+ val |= val << 16;
+ }
+ outl(val, dev->iobase + reg);
+ }

data[1] = s->state;