From bea8052074691c70526ae6a555d25f111c0aad0a Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 10 Mar 2014 14:07:33 -0700 Subject: [PATCH] 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: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/c6xdigio.c | 68 ++++++++++++----------- 1 file changed, 35 insertions(+), 33 deletions(-) diff --git a/drivers/staging/comedi/drivers/c6xdigio.c b/drivers/staging/comedi/drivers/c6xdigio.c index a05196b56ed4..7c2c19f47289 100644 --- a/drivers/staging/comedi/drivers/c6xdigio.c +++ b/drivers/staging/comedi/drivers/c6xdigio.c @@ -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) -- 2.30.2