From 863e07c9f83c9674c0176771c40b56b48657e1e5 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 29 Apr 2014 12:59:30 -0700 Subject: [PATCH] staging: comedi: das16m1: don't calc pacer divisors twice The analog input async command can use the pacer for the convert_src. The (*do_cmdtest) calculates the divisors when validating the cmd argument. There is no reason to recalc the divisors in the (*do_cmd). Just use the values from the private data. Refactor das16m1_set_pacer() to use the i8254_set_mode() and i8254_write() helpers instead of i8254_load(). This allows us to use the I8254_* defines when setting the mode to clarify the code. Tidy up das16m1_cmd_exec() a bit. The pacer only needs to be set when the convert_src is TRIG_TIMER. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das16m1.c | 41 ++++++++---------------- 1 file changed, 14 insertions(+), 27 deletions(-) diff --git a/drivers/staging/comedi/drivers/das16m1.c b/drivers/staging/comedi/drivers/das16m1.c index a9cd21068ea8..4fe30cc254e3 100644 --- a/drivers/staging/comedi/drivers/das16m1.c +++ b/drivers/staging/comedi/drivers/das16m1.c @@ -254,26 +254,16 @@ static int das16m1_cmd_test(struct comedi_device *dev, return 0; } -/* This function takes a time in nanoseconds and sets the * - * 2 pacer clocks to the closest frequency possible. It also * - * returns the actual sampling period. */ -static unsigned int das16m1_set_pacer(struct comedi_device *dev, - unsigned int ns, int rounding_flags) +static void das16m1_set_pacer(struct comedi_device *dev) { struct das16m1_private_struct *devpriv = dev->private; + unsigned long timer_base = dev->iobase + DAS16M1_8254_SECOND; - i8253_cascade_ns_to_timer_2div(I8254_OSC_BASE_10MHZ, - &devpriv->divisor1, - &devpriv->divisor2, - &ns, rounding_flags); + i8254_set_mode(timer_base, 0, 1, I8254_MODE2 | I8254_BINARY); + i8254_set_mode(timer_base, 0, 2, I8254_MODE2 | I8254_BINARY); - /* Write the values of ctr1 and ctr2 into counters 1 and 2 */ - i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 1, devpriv->divisor1, - 2); - i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 2, devpriv->divisor2, - 2); - - return ns; + i8254_write(timer_base, 0, 1, devpriv->divisor1); + i8254_write(timer_base, 0, 2, devpriv->divisor2); } static int das16m1_cmd_exec(struct comedi_device *dev, @@ -307,10 +297,14 @@ static int das16m1_cmd_exec(struct comedi_device *dev, outb(byte, dev->iobase + DAS16M1_QUEUE_DATA); } - /* set counter mode and counts */ - cmd->convert_arg = - das16m1_set_pacer(dev, cmd->convert_arg, - cmd->flags & TRIG_ROUND_MASK); + /* enable interrupts and set internal pacer counter mode and counts */ + devpriv->control_state &= ~PACER_MASK; + if (cmd->convert_src == TRIG_TIMER) { + das16m1_set_pacer(dev); + devpriv->control_state |= INT_PACER; + } else { /* TRIG_EXT */ + devpriv->control_state |= EXT_PACER; + } /* set control & status register */ byte = 0; @@ -323,13 +317,6 @@ static int das16m1_cmd_exec(struct comedi_device *dev, /* clear interrupt bit */ outb(0, dev->iobase + DAS16M1_CLEAR_INTR); - /* enable interrupts and internal pacer */ - devpriv->control_state &= ~PACER_MASK; - if (cmd->convert_src == TRIG_TIMER) - devpriv->control_state |= INT_PACER; - else - devpriv->control_state |= EXT_PACER; - devpriv->control_state |= INTE; outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL); -- 2.20.1