From 14d09f79d7b792d20131bc2f25a3d8a8e7cd593f Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 25 Oct 2012 15:09:47 -0700 Subject: [PATCH] staging: comedi: me_daq: fix me_ao_insn_write() This function is supposed to write to a single analog output channel. The channel number is packed in insn->chanspec, which is an unsigned int, and unpacked using the CR_CHAN() macro. Currently this function is trying to use the chanspec as an array. This works only if a single value is written. Fix the function so that the desired channel is determined and all the data is written to that channel. Also, fix the return. The comedi core expects insn_read functions to return the number of data values (insn->n). Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/me_daq.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/drivers/staging/comedi/drivers/me_daq.c b/drivers/staging/comedi/drivers/me_daq.c index 1efad5967d94..9f65a8ee78a4 100644 --- a/drivers/staging/comedi/drivers/me_daq.c +++ b/drivers/staging/comedi/drivers/me_daq.c @@ -409,22 +409,14 @@ static int me_ai_do_cmd(struct comedi_device *dev, return 0; } -/* - * ------------------------------------------------------------------ - * - * ANALOG OUTPUT SECTION - * - * ------------------------------------------------------------------ - */ - -/* Analog instant output */ static int me_ao_insn_write(struct comedi_device *dev, struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) + struct comedi_insn *insn, + unsigned int *data) { struct me_private_data *dev_private = dev->private; - int chan; - int rang; + unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int rang = CR_RANGE(insn->chanspec); int i; /* Enable all DAC */ @@ -437,9 +429,6 @@ static int me_ao_insn_write(struct comedi_device *dev, /* Set dac-control register */ for (i = 0; i < insn->n; i++) { - chan = CR_CHAN((&insn->chanspec)[i]); - rang = CR_RANGE((&insn->chanspec)[i]); - /* clear bits for this channel */ dev_private->dac_control &= ~(0x0880 >> chan); if (rang == 0) @@ -457,7 +446,6 @@ static int me_ao_insn_write(struct comedi_device *dev, /* Set data register */ for (i = 0; i < insn->n; i++) { - chan = CR_CHAN((&insn->chanspec)[i]); writew((data[0] & s->maxdata), dev_private->me_regbase + ME_DAC_DATA_A + (chan << 1)); dev_private->ao_readback[chan] = (data[0] & s->maxdata); @@ -466,7 +454,7 @@ static int me_ao_insn_write(struct comedi_device *dev, /* Update dac with data registers */ readw(dev_private->me_regbase + ME_DAC_UPDATE); - return i; + return insn->n; } static int me_ao_insn_read(struct comedi_device *dev, -- 2.20.1