From 4f76463d3b8f8cc0cac5bb292ec766848f3f4fa1 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 5 Aug 2013 15:00:05 -0700 Subject: [PATCH] staging: comedi: core: introduce comedi_dio_insn_config() DIO subdevices always handle the INSN_CONFIG_DIO_{INPUT,OUTPUT} instructions to configure the dio channels. They also always handle the INSN_CONFIG_DIO_QUERY instruction to query the configuration of a dio channel. Introduce a helper function to handle the (*insn_config) boilerplate for comedi DIO subdevices. This function has the same parameters as (*insn_config) functions with an additional parameter to allow the caller to pass a 'mask' value for grouped dio channels. This function returns: 0 if the instruction was successful but requires additional handling by the caller (INSN_CONFIG_DIO_{INPUT,OUTPUT} insn->n if the instruction was handled (INSN_CONFIG_DIO_QUERY) -EINVAL for all unhandled instructions The caller is responsible for actually configuring the hardware based on the configuration (s->io_bits). Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedidev.h | 4 ++++ drivers/staging/comedi/drivers.c | 40 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h index 98058b9..f2f75b9 100644 --- a/drivers/staging/comedi/comedidev.h +++ b/drivers/staging/comedi/comedidev.h @@ -342,6 +342,10 @@ void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset, /* drivers.c - general comedi driver functions */ +int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *, + struct comedi_insn *, unsigned int *data, + unsigned int mask); + void *comedi_alloc_devpriv(struct comedi_device *, size_t); int comedi_alloc_subdevices(struct comedi_device *, int); diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 791a26b..60fd81c 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -150,6 +150,46 @@ int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, return -EINVAL; } +/** + * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices. + * @dev: comedi_device struct + * @s: comedi_subdevice struct + * @insn: comedi_insn struct + * @data: parameters for the @insn + * @mask: io_bits mask for grouped channels + */ +int comedi_dio_insn_config(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data, + unsigned int mask) +{ + unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec); + + if (!mask) + mask = chan_mask; + + switch (data[0]) { + case INSN_CONFIG_DIO_INPUT: + s->io_bits &= ~mask; + break; + + case INSN_CONFIG_DIO_OUTPUT: + s->io_bits |= mask; + break; + + case INSN_CONFIG_DIO_QUERY: + data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT; + return insn->n; + + default: + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_dio_insn_config); + static int insn_rw_emulate_bits(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) -- 2.7.4