From 73ef2b5387ff95ac24487934250e9749e8aaa217 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 29 Jul 2013 14:02:22 -0700 Subject: [PATCH] staging: comedi: das16: tidy up das16_ai_insn_read() Factor out the loop that waits for the ai conversion to complete. Tidy up the function a bit. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das16.c | 50 ++++++++++++++------------ 1 file changed, 27 insertions(+), 23 deletions(-) diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c index f6d0f7e868b2..a482bd524e9b 100644 --- a/drivers/staging/comedi/drivers/das16.c +++ b/drivers/staging/comedi/drivers/das16.c @@ -253,8 +253,6 @@ struct das16_board { unsigned int id; }; -#define DAS16_TIMEOUT 1000 - /* Period for timer interrupt in jiffies. It's a function * to deal with possibility of dynamic HZ patches */ static inline int timer_period(void) @@ -564,55 +562,61 @@ static void das16_reset(struct comedi_device *dev) outb(0, dev->iobase + DAS16_CNTR_CONTROL); } +static int das16_ai_wait_for_conv(struct comedi_device *dev, + unsigned int timeout) +{ + unsigned int status; + int i; + + for (i = 0; i < timeout; i++) { + status = inb(dev->iobase + DAS16_STATUS); + if (!(status & BUSY)) + return 0; + } + return -ETIME; +} + static int das16_ai_insn_read(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { const struct das16_board *board = comedi_board(dev); - int i, n; - int range; - int chan; + unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int range = CR_RANGE(insn->chanspec); + unsigned int val; + int ret; + int i; das16_ai_disable(dev); /* set multiplexer */ - chan = CR_CHAN(insn->chanspec); - chan |= CR_CHAN(insn->chanspec) << 4; - outb(chan, dev->iobase + DAS16_MUX); + outb(chan | (chan << 4), dev->iobase + DAS16_MUX); /* set gain */ if (board->ai_pg != das16_pg_none) { - range = CR_RANGE(insn->chanspec); outb((das16_gainlists[board->ai_pg])[range], dev->iobase + DAS16_GAIN); } - for (n = 0; n < insn->n; n++) { - unsigned int val; - + for (i = 0; i < insn->n; i++) { /* trigger conversion */ outb_p(0, dev->iobase + DAS16_TRIG); - for (i = 0; i < DAS16_TIMEOUT; i++) { - if (!(inb(dev->iobase + DAS16_STATUS) & BUSY)) - break; - } - if (i == DAS16_TIMEOUT) { - printk("das16: timeout\n"); - return -ETIME; - } + ret = das16_ai_wait_for_conv(dev, 1000); + if (ret) + return ret; val = inb(dev->iobase + DAS16_AI_MSB) << 8; val |= inb(dev->iobase + DAS16_AI_LSB); if (s->maxdata == 0x0fff) - data[n] >>= 4; + val >>= 4; val &= s->maxdata; - data[n] = val; + data[i] = val; } - return n; + return insn->n; } static int das16_di_insn_bits(struct comedi_device *dev, -- 2.39.5