From 43b9778eeb789fbfad3ce66da3bbb3440440fbb8 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 11 Sep 2012 10:47:08 -0700 Subject: [PATCH] staging: comedi: comedi_fc: introduce cfc_check_trigger_src All of the comedi drivers that support the 'cmd' callback also require a 'do_cmdtest' callback. The do_cmdtest validates the comedi_cmd before it is executed. "Step 1" of each do_cmdtest does a trivial validation of the trigger sources by doing something like this for each trigger: int err = 0; unsigned int tmp; tmp = cmd->start_src; src &= TRIG_NOW; if (!src || tmp != src) err++; /* Test the remaining triggers similarly */ if (err) return 1; Introduce a helper function in comedi_fc to handle this boilerplate. The drivers can then just do: err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW); /* Test the remaining triggers similarly */ if (err) return 1; Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/comedi_fc.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/staging/comedi/drivers/comedi_fc.h b/drivers/staging/comedi/drivers/comedi_fc.h index 4b2cfd327995..1f0839171887 100644 --- a/drivers/staging/comedi/drivers/comedi_fc.h +++ b/drivers/staging/comedi/drivers/comedi_fc.h @@ -73,4 +73,24 @@ static inline unsigned int cfc_bytes_per_scan(struct comedi_subdevice *subd) return num_samples * bytes_per_sample(subd); } +/** + * cfc_check_trigger_src() - trivially validate a comedi_cmd trigger source + * @src: pointer to the trigger source to validate + * @flags: bitmask of valid TRIG_* for the trigger + * + * This is used in "step 1" of the do_cmdtest functions of comedi drivers + * to vaildate the comedi_cmd triggers. The mask of the @src against the + * @flags allows the userspace comedilib to pass all the comedi_cmd + * triggers as TRIG_ANY and get back a bitmask of the valid trigger sources. + */ +static inline int cfc_check_trigger_src(unsigned int *src, unsigned int flags) +{ + unsigned int orig_src = *src; + + *src = orig_src & flags; + if (*src == TRIG_INVALID || *src != orig_src) + return -EINVAL; + return 0; +} + #endif /* _COMEDI_FC_H */ -- 2.20.1