From 62319bceef42015d5e774e1db2e21fb5853a01bc Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 5 Oct 2015 14:23:11 -0700 Subject: [PATCH] staging: comedi: quatech_daqp_cs: avoid calculating pacer divisor multiple times The pacer will either be used to trigger each conversion or to start each scan. Modify the (*do_cmdtest) so that one one divisor calculation is needed. Save the divisor value in the private data so that the (*do_cmd) does not have to do the calculation again. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- .../staging/comedi/drivers/quatech_daqp_cs.c | 45 ++++++++----------- 1 file changed, 18 insertions(+), 27 deletions(-) diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c index b56d126869e3..e9e43139157d 100644 --- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c +++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c @@ -144,6 +144,7 @@ #define DAQP_MAX_TIMER_SPEED 10000 /* 100 kHz in nanoseconds */ struct daqp_private { + unsigned int pacer_div; int stop; }; @@ -359,17 +360,18 @@ static int daqp_ns_to_timer(unsigned int *ns, unsigned int flags) return timer; } -/* cmdtest tests a particular command to see if it is valid. - * Using the cmdtest ioctl, a user can create a valid cmd - * and then have it executed by the cmd ioctl. - * - * cmdtest returns 1,2,3,4 or 0, depending on which tests - * the command passes. - */ +static void daqp_set_pacer(struct comedi_device *dev, unsigned int val) +{ + outb(val & 0xff, dev->iobase + DAQP_PACER_LOW_REG); + outb((val >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG); + outb((val >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG); +} static int daqp_ai_cmdtest(struct comedi_device *dev, - struct comedi_subdevice *s, struct comedi_cmd *cmd) + struct comedi_subdevice *s, + struct comedi_cmd *cmd) { + struct daqp_private *devpriv = dev->private; int err = 0; unsigned int arg; @@ -440,16 +442,14 @@ static int daqp_ai_cmdtest(struct comedi_device *dev, /* step 4: fix up any arguments */ - if (cmd->scan_begin_src == TRIG_TIMER) { - arg = cmd->scan_begin_arg; - daqp_ns_to_timer(&arg, cmd->flags); - err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); - } - if (cmd->convert_src == TRIG_TIMER) { arg = cmd->convert_arg; - daqp_ns_to_timer(&arg, cmd->flags); + devpriv->pacer_div = daqp_ns_to_timer(&arg, cmd->flags); err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg); + } else if (cmd->scan_begin_src == TRIG_TIMER) { + arg = cmd->scan_begin_arg; + devpriv->pacer_div = daqp_ns_to_timer(&arg, cmd->flags); + err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); } if (err) @@ -462,7 +462,6 @@ static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) { struct daqp_private *devpriv = dev->private; struct comedi_cmd *cmd = &s->async->cmd; - int counter; int scanlist_start_on_every_entry; int threshold; int ret; @@ -488,20 +487,12 @@ static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) * each scan, so we program the pacer clock to this frequency * and only set the SCANLIST_START bit on the first entry. */ + daqp_set_pacer(dev, devpriv->pacer_div); - if (cmd->convert_src == TRIG_TIMER) { - counter = daqp_ns_to_timer(&cmd->convert_arg, cmd->flags); - outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW_REG); - outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG); - outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG); + if (cmd->convert_src == TRIG_TIMER) scanlist_start_on_every_entry = 1; - } else { - counter = daqp_ns_to_timer(&cmd->scan_begin_arg, cmd->flags); - outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW_REG); - outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG); - outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG); + else scanlist_start_on_every_entry = 0; - } /* Program scan list */ for (i = 0; i < cmd->chanlist_len; i++) { -- 2.34.1