From 21424e3fa81505f466841eaecaa373f160f44cf4 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 17 Aug 2015 16:58:24 -0700 Subject: [PATCH] staging: comedi: s526: remove s526_ai_insn_config() This (*insn_config) does not follow the comedi core API. It also would not work as expected. It appears to be trying to configure the analog input subdevice so that the (*insn_read) would read multiple channels (data[0]) and optionally enable the 15us delay (data[1]) needed for the multiplexor to change channels between samples. Unfortunately, the comedi core expects (*insn_read) operations to return 1 or more samples for a single channel, which is what the (*insn_read) in this driver does. The (*insn_config) is also enabling the analog input end-of-conversion interrupt. This isn't needed, and might be a problem since the driver does not currently request and interrupt. The enable bit does not need to be set for the end-of-conversion to occur in the interrupt status register. Remove the (*insn_config) and modify the (*insn_read) to automatically handle the 15us delay when needed. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/s526.c | 49 ++++++--------------------- 1 file changed, 11 insertions(+), 38 deletions(-) diff --git a/drivers/staging/comedi/drivers/s526.c b/drivers/staging/comedi/drivers/s526.c index 1a5aa3d3a36e..7cf6250bdf30 100644 --- a/drivers/staging/comedi/drivers/s526.c +++ b/drivers/staging/comedi/drivers/s526.c @@ -133,7 +133,7 @@ union cmReg { struct s526_private { unsigned int gpct_config[4]; - unsigned short ai_config; + unsigned short ai_ctrl; }; static void s526_gpct_write(struct comedi_device *dev, @@ -388,36 +388,6 @@ static int s526_gpct_winsn(struct comedi_device *dev, return insn->n; } -static int s526_ai_insn_config(struct comedi_device *dev, - struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) -{ - struct s526_private *devpriv = dev->private; - int result = -EINVAL; - - if (insn->n < 1) - return result; - - result = insn->n; - - /* data[0] : channels was set in relevant bits. - data[1] : delay - */ - /* COMMENT: abbotti 2008-07-24: I don't know why you'd want to - * enable channels here. The channel should be enabled in the - * INSN_READ handler. */ - - /* Enable ADC interrupt */ - outw(S526_INT_AI, dev->iobase + S526_INT_ENA_REG); - devpriv->ai_config = (data[0] & 0x3ff) << 5; - if (data[1] > 0) - devpriv->ai_config |= S526_AI_CTRL_DELAY;/* set the delay */ - - devpriv->ai_config |= 0x0001; /* ADC start bit */ - - return result; -} - static int s526_eoc(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, @@ -446,17 +416,21 @@ static int s526_ai_insn_read(struct comedi_device *dev, int ret; int i; - /* - * Set configured delay, enable conversion and read for requested - * channel only, set "ADC start" bit. - */ - ctrl = (devpriv->ai_config & S526_AI_CTRL_DELAY) | - S526_AI_CTRL_CONV(chan) | S526_AI_CTRL_READ(chan) | + ctrl = S526_AI_CTRL_CONV(chan) | S526_AI_CTRL_READ(chan) | S526_AI_CTRL_START; + if (ctrl != devpriv->ai_ctrl) { + /* + * The multiplexor needs to change, enable the 15us + * delay for the first sample. + */ + devpriv->ai_ctrl = ctrl; + ctrl |= S526_AI_CTRL_DELAY; + } for (i = 0; i < insn->n; i++) { /* trigger conversion */ outw(ctrl, dev->iobase + S526_AI_CTRL_REG); + ctrl &= ~S526_AI_CTRL_DELAY; /* wait for conversion to end */ ret = comedi_timeout(dev, s, insn, s526_eoc, S526_INT_AI); @@ -590,7 +564,6 @@ static int s526_attach(struct comedi_device *dev, struct comedi_devconfig *it) s->range_table = &range_bipolar10; s->len_chanlist = 16; s->insn_read = s526_ai_insn_read; - s->insn_config = s526_ai_insn_config; /* Analog Output subdevice */ s = &dev->subdevices[2]; -- 2.39.5