From f2426e4f72e70dec50741dce04014962a45d417d Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 10 Feb 2014 11:49:01 -0700 Subject: [PATCH] staging: comedi: skel: use comedi_timeout() Use comedi_timeout() to wait for the analog input end-of-conversion. Since this is the sample skeleton driver, add comments about how the callback function works with comedi_timeout(). Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/skel.c | 39 +++++++++++++++++++-------- 1 file changed, 28 insertions(+), 11 deletions(-) diff --git a/drivers/staging/comedi/drivers/skel.c b/drivers/staging/comedi/drivers/skel.c index e800e73738e..a4933683a57 100644 --- a/drivers/staging/comedi/drivers/skel.c +++ b/drivers/staging/comedi/drivers/skel.c @@ -141,6 +141,29 @@ static int skel_ns_to_timer(unsigned int *ns, int round) return *ns; } +/* + * This function doesn't require a particular form, this is just + * what happens to be used in some of the drivers. The comedi_timeout() + * helper uses this callback to check for the end-of-conversion while + * waiting for up to 1 second. This function should return 0 when the + * conversion is finished and -EBUSY to keep waiting. Any other errno + * will terminate comedi_timeout() and return that errno to the caller. + * If the timeout occurs, comedi_timeout() will return -ETIMEDOUT. + */ +static int skel_ai_eoc(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned long context) +{ + unsigned int status; + + /* status = inb(dev->iobase + SKEL_STATUS); */ + status = 1; + if (status) + return 0; + return -EBUSY; +} + /* * "instructions" read/write data in "one-shot" or "software-triggered" * mode. @@ -149,9 +172,9 @@ static int skel_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) { const struct skel_board *thisboard = comedi_board(dev); - int n, i; + int n; unsigned int d; - unsigned int status; + int ret; /* a typical programming sequence */ @@ -165,17 +188,11 @@ static int skel_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, /* trigger conversion */ /* outw(0,dev->iobase + SKEL_CONVERT); */ -#define TIMEOUT 100 /* wait for conversion to end */ - for (i = 0; i < TIMEOUT; i++) { - status = 1; - /* status = inb(dev->iobase + SKEL_STATUS); */ - if (status) - break; - } - if (i == TIMEOUT) { + ret = comedi_timeout(dev, s, insn, skel_ai_eoc, 0); + if (ret) { dev_warn(dev->class_dev, "ai timeout\n"); - return -ETIMEDOUT; + return ret; } /* read data */ -- 2.46.0