Commit bea80520 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: c6xdigio: introduce c6xdigio_get_encoder_bits() 



The 24-bit encoder value is read using 3-bits in the status register. The
data register is banged between each read of the status register to advance
the bits.

Introduce a helper function to handle this and remove the union encvaluetype
and struct encbitsbyte.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 721869e8

drivers/staging/comedi/drivers/c6xdigio.c

+35 −33
Original line number Diff line number Diff line
@@ -61,20 +61,6 @@ union pwmcmdtype { 
	unsigned cmd;		/*  assuming here that int is 32bit */

	struct pwmbitstype bits;

};

struct encbitstype {

	unsigned sb0:3;

	unsigned sb1:3;

	unsigned sb2:3;

	unsigned sb3:3;

	unsigned sb4:3;

	unsigned sb5:3;

	unsigned sb6:3;

	unsigned sb7:3;

};

union encvaluetype {

	unsigned value;

	struct encbitstype bits;

};



#define C6XDIGIO_TIME_OUT 20
@@ -100,6 +86,22 @@ static int c6xdigio_write_data(struct comedi_device *dev, 
	return c6xdigio_chk_status(dev, status);

}



static int c6xdigio_get_encoder_bits(struct comedi_device *dev,

				     unsigned int *bits,

				     unsigned int cmd,

				     unsigned int status)

{

	unsigned int val;



	val = inb(dev->iobase + C6XDIGIO_STATUS_REG);

	val >>= 3;

	val &= 0x07;



	*bits = val;



	return c6xdigio_write_data(dev, cmd, status);

}



static void c6xdigio_pwm_init(struct comedi_device *dev)

{

	c6xdigio_write_data(dev, 0x70, 0x00);
@@ -136,10 +138,10 @@ static void c6xdigio_pwm_write(struct comedi_device *dev, 
static int c6xdigio_encoder_read(struct comedi_device *dev,

				 unsigned int chan)

{

	unsigned int val = 0;

	unsigned int bits;

	unsigned ppcmd;

	union encvaluetype enc;



	enc.value = 0;

	if (chan == 0)

		ppcmd = 0x48;

	else
@@ -147,33 +149,33 @@ static int c6xdigio_encoder_read(struct comedi_device *dev, 


	c6xdigio_write_data(dev, ppcmd, 0x00);



	enc.bits.sb0 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd + 0x4, 0x80);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd + 0x04, 0x80);

	val |= (bits << 0);



	enc.bits.sb1 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd, 0x00);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd, 0x00);

	val |= (bits << 3);



	enc.bits.sb2 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd + 0x4, 0x80);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd + 0x04, 0x80);

	val |= (bits << 6);



	enc.bits.sb3 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd, 0x00);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd, 0x00);

	val |= (bits << 9);



	enc.bits.sb4 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd + 0x4, 0x80);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd + 0x04, 0x80);

	val |= (bits << 12);



	enc.bits.sb5 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd, 0x00);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd, 0x00);

	val |= (bits << 15);



	enc.bits.sb6 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd + 0x4, 0x80);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd + 0x04, 0x80);

	val |= (bits << 18);



	enc.bits.sb7 = ((inb(dev->iobase + C6XDIGIO_STATUS_REG) >> 3) & 0x7);

	c6xdigio_write_data(dev, ppcmd, 0x00);

	c6xdigio_get_encoder_bits(dev, &bits, ppcmd, 0x00);

	val |= (bits << 21);



	c6xdigio_write_data(dev, 0x00, 0x80);



	return enc.value ^ 0x800000;

	return val ^ 0x800000;

}



static void c6xdigio_encoder_reset(struct comedi_device *dev)