[PATCH 3.7 - 3.12] staging: comedi: adl_pci7x3x: fix digital output on PCI-7230

[PATCH 3.7 - 3.12] staging: comedi: adl_pci7x3x: fix digital output on PCI-7230

[Ian Abbott]

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>
---
 drivers/staging/comedi/drivers/adl_pci7x3x.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/comedi/drivers/adl_pci7x3x.c b/drivers/staging/comedi/drivers/adl_pci7x3x.c
index 81b7203..c570ede 100644
--- a/drivers/staging/comedi/drivers/adl_pci7x3x.c
+++ b/drivers/staging/comedi/drivers/adl_pci7x3x.c
@@ -116,10 +116,21 @@ static int adl_pci7x3x_do_insn_bits(struct comedi_device *dev,
 	unsigned int bits = data[1];
 
 	if (mask) {
+		unsigned int val;
+
 		s->state &= ~mask;
 		s->state |= (bits & mask);
-
-		outl(s->state, dev->iobase + reg);
+		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);
 	}
 
 	/*
-- 
2.5.1

Re: [PATCH 3.7 - 3.12] staging: comedi: adl_pci7x3x: fix digital output on PCI-7230

[Jiri Slaby]

On 09/16/2015, 11:58 AM, Ian Abbott wrote:
> 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>

Applied to 3.12. Thanks.

> ---
>  drivers/staging/comedi/drivers/adl_pci7x3x.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/comedi/drivers/adl_pci7x3x.c b/drivers/staging/comedi/drivers/adl_pci7x3x.c
> index 81b7203..c570ede 100644
> --- a/drivers/staging/comedi/drivers/adl_pci7x3x.c
> +++ b/drivers/staging/comedi/drivers/adl_pci7x3x.c
> @@ -116,10 +116,21 @@ static int adl_pci7x3x_do_insn_bits(struct comedi_device *dev,
>  	unsigned int bits = data[1];
>  
>  	if (mask) {
> +		unsigned int val;
> +
>  		s->state &= ~mask;
>  		s->state |= (bits & mask);
> -
> -		outl(s->state, dev->iobase + reg);
> +		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);
>  	}
>  
>  	/*
> 


-- 
js
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