Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754041AbbGWPtg (ORCPT ); Thu, 23 Jul 2015 11:49:36 -0400 Received: from smtp97.iad3a.emailsrvr.com ([173.203.187.97]:48920 "EHLO smtp97.iad3a.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753468AbbGWPr1 (ORCPT ); Thu, 23 Jul 2015 11:47:27 -0400 X-Sender-Id: abbotti@mev.co.uk From: Ian Abbott To: Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , Bernd Porr , Subject: [PATCH 5/6] staging: comedi: usbduxsigma: remove unused "convert" timing for AO Date: Thu, 23 Jul 2015 16:47:01 +0100 Message-Id: <1437666422-25222-6-git-send-email-abbotti@mev.co.uk> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1437666422-25222-1-git-send-email-abbotti@mev.co.uk> References: <1437666422-25222-1-git-send-email-abbotti@mev.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3928 Lines: 109 The `cmdtest` and `cmd` handlers for the AO subdevice (`usbduxsigma_ao_cmdtest()` and `usbduxsigma_ao_cmd()`) support "scan" timing of commands with all channels updated every "scan" period. There is some disabled code to use "convert" timing in high speed mode. That would allow channels to be updated sequentially every "convert" period. Since that code is incomplete and currently disabled, remove it to simplify the existing code. Signed-off-by: Ian Abbott --- drivers/staging/comedi/drivers/usbduxsigma.c | 58 ++++++++-------------------- 1 file changed, 17 insertions(+), 41 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c index 4655048..d97253e 100644 --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -838,28 +838,20 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, { struct usbduxsigma_private *devpriv = dev->private; int err = 0; - int high_speed; - unsigned int flags; - - /* high speed conversions are not used yet */ - high_speed = 0; /* (devpriv->high_speed) */ /* Step 1 : check if triggers are trivially valid */ err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT); - if (high_speed) { - /* - * start immediately a new scan - * the sampling rate is set by the coversion rate - */ - flags = TRIG_FOLLOW; - } else { - /* start a new scan (output at once) with a timer */ - flags = TRIG_TIMER; - } - err |= comedi_check_trigger_src(&cmd->scan_begin_src, flags); - + /* + * For now, always use "scan" timing with all channels updated at once + * (cmd->scan_begin_src == TRIG_TIMER, cmd->convert_src == TRIG_NOW). + * + * In a future version, "convert" timing with channels updated + * indivually may be supported in high speed mode + * (cmd->scan_begin_src == TRIG_FOLLOW, cmd->convert_src == TRIG_TIMER). + */ + err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW); err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); @@ -883,17 +875,7 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); - if (cmd->scan_begin_src == TRIG_FOLLOW) /* internal trigger */ - err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0); - - if (cmd->scan_begin_src == TRIG_TIMER) { - err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, - 1000000); - } - - /* not used now, is for later use */ - if (cmd->convert_src == TRIG_TIMER) - err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 125000); + err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 1000000); err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len); @@ -918,19 +900,13 @@ static int usbduxsigma_ao_cmd(struct comedi_device *dev, down(&devpriv->sem); - if (cmd->convert_src == TRIG_TIMER) { - /* - * timing of the conversion itself: every 125 us - * at high speed (not used yet) - */ - devpriv->ao_timer = cmd->convert_arg / 125000; - } else { - /* - * timing of the scan: every 1ms - * we get all channels at once - */ - devpriv->ao_timer = cmd->scan_begin_arg / 1000000; - } + /* + * For now, only "scan" timing is supported. A future version may + * support "convert" timing in high speed mode. + * + * Timing of the scan: every 1ms all channels updated at once. + */ + devpriv->ao_timer = cmd->scan_begin_arg / 1000000; devpriv->ao_counter = devpriv->ao_timer; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/