diff options
Diffstat (limited to 'drivers/staging/comedi/drivers.c')
| -rw-r--r-- | drivers/staging/comedi/drivers.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 5b15033a94bf..ab0e8ed47291 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -155,6 +155,36 @@ int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, } /** + * comedi_timeout() - busy-wait for a driver condition to occur. + * @dev: comedi_device struct + * @s: comedi_subdevice struct + * @insn: comedi_insn struct + * @cb: callback to check for the condition + * @context: private context from the driver + */ +int comedi_timeout(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + int (*cb)(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned long context), + unsigned long context) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS); + int ret; + + while (time_before(jiffies, timeout)) { + ret = cb(dev, s, insn, context); + if (ret != -EBUSY) + return ret; /* success (0) or non EBUSY errno */ + cpu_relax(); + } + return -ETIMEDOUT; +} +EXPORT_SYMBOL_GPL(comedi_timeout); + +/** * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices. * @dev: comedi_device struct * @s: comedi_subdevice struct |