RE: [PATCH 2/2 v2] staging: comedi: ni_daq_700: add AI range and input mode switching

[Hartley Sweeten]

On Thursday, May 29, 2014 5:29 AM, Ian Abbott wrote:
> From: Fred Brooks <frederick.brooks@xxxxxxxxxxxxx>
>
> Add support for switching the input range and the single-ended/
> differential input mode for the AI subdevice.  We needed to clear the
> FIFO of data before the conversion to handle card mode switching
> glitches.
>
> [ Minor whitespace fixes and driver comment reformatting.  - Ian ]
>
> Signed-off-by: Fred Brooks <frederick.brooks@xxxxxxxxxxxxx>
> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
> ---
> v2: Set authorship to Fred Brooks and updated patch description as
> suggested by Dan Carpenter.
> ---
>  drivers/staging/comedi/drivers/ni_daq_700.c | 53 +++++++++++++++++++++++------
>  1 file changed, 43 insertions(+), 10 deletions(-)

Ian,

I couple nitpicks on this patch but nothing big. Ignore all of these
comments if you wish.

Reviewed-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>

> diff --git a/drivers/staging/comedi/drivers/ni_daq_700.c b/drivers/staging/comedi/drivers/ni_daq_700.c
> index 55d80ef..e66c0b9 100644
> --- a/drivers/staging/comedi/drivers/ni_daq_700.c
> +++ b/drivers/staging/comedi/drivers/ni_daq_700.c
> @@ -24,21 +24,30 @@
>   *   based on ni_daq_dio24 by Daniel Vecino Castel <dvecino@xxxxxxx>
>   * Devices: [National Instruments] PCMCIA DAQ-Card-700 (ni_daq_700)
>   * Status: works
> - * Updated: Wed, 19 Sep 2012 12:07:20 +0000
> + * Updated: Wed, 21 May 2014 12:07:20 +0000
>   *
>   * The daqcard-700 appears in Comedi as a  digital I/O subdevice (0) with
> - * 16 channels and a analog input subdevice (1) with 16 single-ended channels.
> + * 16 channels and a analog input subdevice (1) with 16 single-ended channels
> + * or 8 differential channels, and three input ranges.
>   *
>   * Digital:  The channel 0 corresponds to the daqcard-700's output
>   * port, bit 0; channel 8 corresponds to the input port, bit 0.
>   *
>   * Digital direction configuration: channels 0-7 output, 8-15 input.
>   *
> - * Analog: The input  range is 0 to 4095 for -10 to +10 volts
> + * Analog: The input  range is 0 to 4095 with a default of -10 to +10 volts.
> + * Valid ranges:
> + *       0 for -10 to 10V bipolar
> + *       1 for -5 to 5V bipolar
> + *       2 for -2.5 to 2.5V bipolar
> + *
>   * IRQ is assigned but not used.
>   *
>   * Version 0.1	Original DIO only driver
>   * Version 0.2	DIO and basic AI analog input support on 16 se channels
> + * Version 0.3	Add SE or DIFF mode and range switching +-10,+-5,+-2.5
> + *		Clear the FIFO of data before the conversion to handle card
> + *		mode switching glitches.

Is this version information really necessary? 

>   *
>   * Manuals:	Register level:	http://www.ni.com/pdf/manuals/340698.pdf
>   *		User Manual:	http://www.ni.com/pdf/manuals/320676d.pdf
> @@ -68,6 +77,17 @@
>  #define CDA_R2		0x0A	/* RW 8bit */
>  #define CMO_R		0x0B	/* RO 8bit */
>  #define TIC_R		0x06	/* WO 8bit */
> +/* daqcard700 modes */
> +#define CMD_R3_DIFF     0x04    /* diff mode */
> +
> +static const struct comedi_lrange range_daq700_ai = {
> +	3,
> +	{
> +		BIP_RANGE(10),
> +		BIP_RANGE(5),
> +		BIP_RANGE(2.5)
> +	}
> +};

The "normal" form for this in the comedi drivers is:

	3, {
 
>  static int daq700_dio_insn_bits(struct comedi_device *dev,
>  				struct comedi_subdevice *s,
> @@ -130,20 +150,34 @@ static int daq700_ai_rinsn(struct comedi_device *dev,
>  			   struct comedi_subdevice *s,
>  			   struct comedi_insn *insn, unsigned int *data)
>  {
> -	int n, chan;
> +	int n;
>  	int d;
>  	int ret;
> +	unsigned int chan	= CR_CHAN(insn->chanspec);
> +	unsigned int aref	= CR_AREF(insn->chanspec);
> +	unsigned int range	= CR_RANGE(insn->chanspec);
> +	unsigned int r3_bits	= 0;

Is the whitespace really necessary on the initialized variables?

Also, I think the uninitialized variables should be listed after the
initialized ones.

> +
> +	/* set channel input modes */
> +	if (aref == AREF_DIFF)
> +		r3_bits |= CMD_R3_DIFF;
> +	/* write channel mode/range */
> +	if (range >= 1)
> +		range++;        /* convert range to hardware value */
> +	outb(r3_bits | (range & 0x03), dev->iobase + CMD_R3);
>  
> -	chan = CR_CHAN(insn->chanspec);
>  	/* write channel to multiplexer */
>  	/* set mask scan bit high to disable scanning */
> -	outb(chan | 0x80, dev->iobase + CMD_R1);
> +	outb((chan & 0x0f) | 0x80, dev->iobase + CMD_R1);
>  
>  	/* convert n samples */
>  	for (n = 0; n < insn->n; n++) {
>  		/* trigger conversion with out0 L to H */
>  		outb(0x00, dev->iobase + CMD_R2); /* enable ADC conversions */
>  		outb(0x30, dev->iobase + CMO_R); /* mode 0 out0 L, from H */
> +		outb(0x00, dev->iobase + ADCLEAR_R);	/* clear the ADC FIFO */
> +		/* read 16bit junk from FIFO to clear */
> +		inw(dev->iobase + ADFIFO_R);
>  		/* mode 1 out0 H, L to H, start conversion */
>  		outb(0x32, dev->iobase + CMO_R);
>  
> @@ -219,11 +253,10 @@ static int daq700_auto_attach(struct comedi_device *dev,
>  	/* DAQCard-700 ai */
>  	s = &dev->subdevices[1];
>  	s->type = COMEDI_SUBD_AI;
> -	/* we support single-ended (ground)  */
> -	s->subdev_flags = SDF_READABLE | SDF_GROUND;
> +	s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_DIFF;
>  	s->n_chan = 16;
>  	s->maxdata = (1 << 12) - 1;
> -	s->range_table = &range_bipolar10;
> +	s->range_table = &range_daq700_ai;
>  	s->insn_read = daq700_ai_rinsn;
>  	daq700_ai_config(dev, s);
>  
> @@ -260,5 +293,5 @@ module_comedi_pcmcia_driver(daq700_driver, daq700_cs_driver);
>  MODULE_AUTHOR("Fred Brooks <nsaspook@xxxxxxxxxxxx>");
>  MODULE_DESCRIPTION(
>  	"Comedi driver for National Instruments PCMCIA DAQCard-700 DIO/AI");
> -MODULE_VERSION("0.2.00");
> +MODULE_VERSION("0.3.00");

Is the MODULE_VERSION necessary? The vmk80xx and this driver are the only
ones that have it.

>  MODULE_LICENSE("GPL");
> -- 
> 1.9.2

Regards,
Hartley

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