From: Ian Abbott Date: Tue, 27 Oct 2015 16:59:14 +0000 (+0000) Subject: staging: comedi: comedi_test: support scan_begin_src == TRIG_FOLLOW X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=783ddaebd3978cb9a1c6899899b2208a96d2b9f0;p=linux-beck.git staging: comedi: comedi_test: support scan_begin_src == TRIG_FOLLOW It is quite common for COMEDI subdevices that support commands to support setting `scan_begin_src` to `TRIG_FOLLOW`. This means the next scan begins once all conversions in the current scan are complete. Support the following timing combinations for the AI subdevice: scan_begin_src == TRIG_TIMER && convert_src == TRIG_TIMER scan_begin_src == TRIG_TIMER && convert_src == TRIG_NOW scan_begin_src == TRIG_FOLLOW && convert_src == TRIG_TIMER The actual scan period in microseconds is stored in the `scan_period` member of the private data structure `struct waveform_private`. An `unsigned int` is still wide enough, because the conversion period is no more than `UINT_MAX / 1000` microseconds and the number of conversions is no more than 16 (`N_CHANS * 2`). Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index f011fbd2fd96..cc35bd645d1b 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -239,7 +239,8 @@ static int waveform_ai_cmdtest(struct comedi_device *dev, /* Step 1 : check if triggers are trivially valid */ err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW); - err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); + err |= comedi_check_trigger_src(&cmd->scan_begin_src, + TRIG_FOLLOW | TRIG_TIMER); err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW | TRIG_TIMER); err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); @@ -255,6 +256,9 @@ static int waveform_ai_cmdtest(struct comedi_device *dev, /* Step 2b : and mutually compatible */ + if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW) + err |= -EINVAL; /* scan period would be 0 */ + if (err) return 2; @@ -262,11 +266,21 @@ static int waveform_ai_cmdtest(struct comedi_device *dev, err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); - if (cmd->convert_src == TRIG_NOW) + if (cmd->convert_src == TRIG_NOW) { err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0); + } else { /* cmd->convert_src == TRIG_TIMER */ + if (cmd->scan_begin_src == TRIG_FOLLOW) { + err |= comedi_check_trigger_arg_min(&cmd->convert_arg, + NSEC_PER_USEC); + } + } - err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, - NSEC_PER_USEC); + if (cmd->scan_begin_src == TRIG_FOLLOW) { + err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0); + } else { /* cmd->scan_begin_src == TRIG_TIMER */ + err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, + NSEC_PER_USEC); + } err |= comedi_check_trigger_arg_min(&cmd->chanlist_len, 1); err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, @@ -274,7 +288,7 @@ static int waveform_ai_cmdtest(struct comedi_device *dev, if (cmd->stop_src == TRIG_COUNT) err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1); - else /* TRIG_NONE */ + else /* cmd->stop_src == TRIG_NONE */ err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); if (err) @@ -288,22 +302,27 @@ static int waveform_ai_cmdtest(struct comedi_device *dev, arg = min(arg, rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); - /* limit convert_arg to keep scan_begin_arg in range */ - limit = UINT_MAX / cmd->scan_end_arg; - limit = rounddown(limit, (unsigned int)NSEC_PER_SEC); - arg = min(arg, limit); + if (cmd->scan_begin_arg == TRIG_TIMER) { + /* limit convert_arg to keep scan_begin_arg in range */ + limit = UINT_MAX / cmd->scan_end_arg; + limit = rounddown(limit, (unsigned int)NSEC_PER_SEC); + arg = min(arg, limit); + } err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg); } - /* round scan_begin_arg to nearest microsecond */ - arg = cmd->scan_begin_arg; - arg = min(arg, rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); - arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); - if (cmd->convert_src == TRIG_TIMER) { - /* but ensure scan_begin_arg is large enough */ - arg = max(arg, cmd->convert_arg * cmd->scan_end_arg); + if (cmd->scan_begin_src == TRIG_TIMER) { + /* round scan_begin_arg to nearest microsecond */ + arg = cmd->scan_begin_arg; + arg = min(arg, + rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); + arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); + if (cmd->convert_src == TRIG_TIMER) { + /* but ensure scan_begin_arg is large enough */ + arg = max(arg, cmd->convert_arg * cmd->scan_end_arg); + } + err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); } - err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); if (err) return 4; @@ -323,13 +342,18 @@ static int waveform_ai_cmd(struct comedi_device *dev, return -1; } - devpriv->scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; - if (cmd->convert_src == TRIG_NOW) devpriv->convert_period = 0; - else /* TRIG_TIMER */ + else /* cmd->convert_src == TRIG_TIMER */ devpriv->convert_period = cmd->convert_arg / NSEC_PER_USEC; + if (cmd->scan_begin_src == TRIG_FOLLOW) { + devpriv->scan_period = devpriv->convert_period * + cmd->scan_end_arg; + } else { /* cmd->scan_begin_src == TRIG_TIMER */ + devpriv->scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; + } + devpriv->last = ktime_get(); devpriv->usec_current = ((u32)ktime_to_us(devpriv->last)) % devpriv->usec_period;