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staging: comedi: das800: introduce das800_ind_{write, read}()
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The GAS800_GAIN register contains some bits that enable indirect
writing to additional registers on the board through iobase + 2
and indirect reading of addition registers through iobase + 7.

Introduce some helper functions to handle the indirect register
write/read.

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>
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H Hartley Sweeten authored and Greg Kroah-Hartman committed Apr 23, 2013
1 parent fe9b085 commit 0a8fc08
Showing 1 changed file with 39 additions and 23 deletions.
62 changes: 39 additions & 23 deletions drivers/staging/comedi/drivers/das800.c
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Original file line number Diff line number Diff line change
Expand Up @@ -228,6 +228,27 @@ struct das800_private {
volatile int do_bits; /* digital output bits */
};

static void das800_ind_write(struct comedi_device *dev,
unsigned val, unsigned reg)
{
/*
* Select dev->iobase + 2 to be desired register
* then write to that register.
*/
outb(reg, dev->iobase + DAS800_GAIN);
outb(val, dev->iobase + 2);
}

static unsigned das800_ind_read(struct comedi_device *dev, unsigned reg)
{
/*
* Select dev->iobase + 7 to be desired register
* then read from that register.
*/
outb(reg, dev->iobase + DAS800_GAIN);
return inb(dev->iobase + 7);
}

/* enable_das800 makes the card start taking hardware triggered conversions */
static void enable_das800(struct comedi_device *dev)
{
Expand All @@ -239,20 +260,21 @@ static void enable_das800(struct comedi_device *dev)
/* enable fifo-half full interrupts for cio-das802/16 */
if (thisboard->resolution == 16)
outb(CIO_ENHF, dev->iobase + DAS800_GAIN);
outb(CONV_CONTROL, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be conversion control register */
outb(CONV_HCEN, dev->iobase + DAS800_CONV_CONTROL); /* enable hardware triggering */
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be control register 1 */
outb(CONTROL1_INTE | devpriv->do_bits, dev->iobase + DAS800_CONTROL1); /* enable card's interrupt */
/* enable hardware triggering */
das800_ind_write(dev, CONV_HCEN, CONV_CONTROL);
/* enable card's interrupt */
das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits, CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
}

/* disable_das800 stops hardware triggered conversions */
static void disable_das800(struct comedi_device *dev)
{
unsigned long irq_flags;

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONV_CONTROL, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be conversion control register */
outb(0x0, dev->iobase + DAS800_CONV_CONTROL); /* disable hardware triggering of conversions */
/* disable hardware triggering of conversions */
das800_ind_write(dev, 0x0, CONV_CONTROL);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
}

Expand Down Expand Up @@ -398,8 +420,8 @@ static int das800_ai_do_cmd(struct comedi_device *dev,
scan = (endChan << 3) | startChan;

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(SCAN_LIMITS, dev->iobase + DAS800_GAIN); /* select base address + 2 to be scan limits register */
outb(scan, dev->iobase + DAS800_SCAN_LIMITS); /* set scan limits */
/* set scan limits */
das800_ind_write(dev, scan, SCAN_LIMITS);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

/* set gain */
Expand Down Expand Up @@ -450,9 +472,9 @@ static int das800_ai_do_cmd(struct comedi_device *dev,
}

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONV_CONTROL, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be conversion control register */
outb(conv_bits, dev->iobase + DAS800_CONV_CONTROL);
das800_ind_write(dev, conv_bits, CONV_CONTROL);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

async->events = 0;
enable_das800(dev);
return 0;
Expand Down Expand Up @@ -488,8 +510,7 @@ static irqreturn_t das800_interrupt(int irq, void *d)

/* if hardware conversions are not enabled, then quit */
spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select base address + 7 to be STATUS2 register */
status = inb(dev->iobase + DAS800_STATUS2) & STATUS2_HCEN;
status = das800_ind_read(dev, CONTROL1) & STATUS2_HCEN;
/* don't release spinlock yet since we want to make sure no one else disables hardware conversions */
if (status == 0) {
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
Expand Down Expand Up @@ -542,9 +563,8 @@ static irqreturn_t das800_interrupt(int irq, void *d)
if (devpriv->count > 0 || devpriv->forever == 1) {
/* Re-enable card's interrupt.
* We already have spinlock, so indirect addressing is safe */
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be control register 1 */
outb(CONTROL1_INTE | devpriv->do_bits,
dev->iobase + DAS800_CONTROL1);
das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits,
CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
/* otherwise, stop taking data */
} else {
Expand Down Expand Up @@ -576,8 +596,7 @@ static int das800_ai_rinsn(struct comedi_device *dev,
chan = CR_CHAN(insn->chanspec);

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be control register 1 */
outb(chan | devpriv->do_bits, dev->iobase + DAS800_CONTROL1);
das800_ind_write(dev, chan | devpriv->do_bits, CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

/* set gain / range */
Expand Down Expand Up @@ -644,8 +663,7 @@ static int das800_do_wbits(struct comedi_device *dev,
devpriv->do_bits = wbits << 4;

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be control register 1 */
outb(devpriv->do_bits | CONTROL1_INTE, dev->iobase + DAS800_CONTROL1);
das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits, CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

data[1] = wbits;
Expand All @@ -661,8 +679,7 @@ static int das800_probe(struct comedi_device *dev)
int board;

spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(ID, dev->iobase + DAS800_GAIN);
id_bits = inb(dev->iobase + DAS800_ID) & 0x3;
id_bits = das800_ind_read(dev, ID) & 0x3;
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

board = thisboard - das800_boards;
Expand Down Expand Up @@ -801,8 +818,7 @@ static int das800_attach(struct comedi_device *dev, struct comedi_devconfig *it)

/* initialize digital out channels */
spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(CONTROL1, dev->iobase + DAS800_GAIN); /* select dev->iobase + 2 to be control register 1 */
outb(CONTROL1_INTE | devpriv->do_bits, dev->iobase + DAS800_CONTROL1);
das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits, CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);

return 0;
Expand Down

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