Commit 19d0a872 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: c6xdigio: tidy up c6xdigio_pwm_write() 



The 10-bit pwm value (2-498) is written by banging 2-bits in the data register.

Refactor this function to remove the need for the union pcmcmdtype and struct
pwmbitstype.

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 bea80520

drivers/staging/comedi/drivers/c6xdigio.c

+17 −24
Original line number Original line Diff line number Diff line
@@ -50,18 +50,6 @@ This driver will not work with a 2.4 kernel. 
#define C6XDIGIO_STATUS_REG	0x01

#define C6XDIGIO_STATUS_REG	0x01

#define C6XDIGIO_CTRL_REG	0x02

#define C6XDIGIO_CTRL_REG	0x02





struct pwmbitstype {

	unsigned sb0:2;

	unsigned sb1:2;

	unsigned sb2:2;

	unsigned sb3:2;

	unsigned sb4:2;

};

union pwmcmdtype {

	unsigned cmd;		/*  assuming here that int is 32bit */

	struct pwmbitstype bits;

};



#define C6XDIGIO_TIME_OUT 20

#define C6XDIGIO_TIME_OUT 20





static int c6xdigio_chk_status(struct comedi_device *dev, unsigned long context)

static int c6xdigio_chk_status(struct comedi_device *dev, unsigned long context)
@@ -113,25 +101,30 @@ static void c6xdigio_pwm_init(struct comedi_device *dev) 
static void c6xdigio_pwm_write(struct comedi_device *dev,

static void c6xdigio_pwm_write(struct comedi_device *dev,

			       unsigned int chan, unsigned int val)

			       unsigned int chan, unsigned int val)

{

{

	unsigned int bits;

	unsigned ppcmd;

	unsigned ppcmd;

	union pwmcmdtype pwm;



	pwm.cmd = val;

	if (pwm.cmd > 498)

		pwm.cmd = 498;

	if (pwm.cmd < 2)

		pwm.cmd = 2;





	if (chan == 0)

	if (chan == 0)

		ppcmd = 0x28;

		ppcmd = 0x28;

	else

	else

		ppcmd = 0x30;

		ppcmd = 0x30;





	c6xdigio_write_data(dev, ppcmd + pwm.bits.sb0, 0x00);

	if (val > 498)

	c6xdigio_write_data(dev, ppcmd + pwm.bits.sb1 + 0x4, 0x80);

		val = 498;

	c6xdigio_write_data(dev, ppcmd + pwm.bits.sb2, 0x00);

	if (val < 2)

	c6xdigio_write_data(dev, ppcmd + pwm.bits.sb3 + 0x4, 0x80);

		val = 2;

	c6xdigio_write_data(dev, ppcmd + pwm.bits.sb4, 0x00);



	bits = (val >> 0) & 0x03;

	c6xdigio_write_data(dev, ppcmd + bits, 0x00);

	bits = (val >> 2) & 0x03;

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

	bits = (val >> 4) & 0x03;

	c6xdigio_write_data(dev, ppcmd + bits, 0x00);

	bits = (val >> 6) & 0x03;

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

	bits = (val >> 8) & 0x03;

	c6xdigio_write_data(dev, ppcmd + bits, 0x00);



	c6xdigio_write_data(dev, 0x00, 0x80);

	c6xdigio_write_data(dev, 0x00, 0x80);

}

}