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authorH Hartley Sweeten <hsweeten@visionengravers.com>2013-06-18 20:25:47 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-24 22:51:04 (GMT)
commit1fdd0fc5fe28cd11ecf64e77892a1d9a1fd89fbf (patch)
treea36a21eb6305fefd410830cc195ddaf70fea5743
parent89aaa92adffa5c57d9c2a545c7cb9809ddd3b615 (diff)
downloadlinux-fsl-qoriq-1fdd0fc5fe28cd11ecf64e77892a1d9a1fd89fbf.tar.xz
staging: comedi: pcmuio: cleanup DIO subdevice (*insn_{bits,config})
Use the pcmuio_{read,write}() helpers to read/write all 24 channels instead of handling the digital I/O as three separate ports. This simplifies both functions with minimal overhead. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/staging/comedi/drivers/pcmuio.c104
1 files changed, 29 insertions, 75 deletions
diff --git a/drivers/staging/comedi/drivers/pcmuio.c b/drivers/staging/comedi/drivers/pcmuio.c
index e52f6ae..d1f5fc0 100644
--- a/drivers/staging/comedi/drivers/pcmuio.c
+++ b/drivers/staging/comedi/drivers/pcmuio.c
@@ -203,51 +203,42 @@ static unsigned int pcmuio_read(struct comedi_device *dev,
return val;
}
+/*
+ * Each channel can be individually programmed for input or output.
+ * Writing a '0' to a channel causes the corresponding output pin
+ * to go to a high-z state (pulled high by an external 10K resistor).
+ * This allows it to be used as an input. When used in the input mode,
+ * a read reflects the inverted state of the I/O pin, such that a
+ * high on the pin will read as a '0' in the register. Writing a '1'
+ * to a bit position causes the pin to sink current (up to 12mA),
+ * effectively pulling it low.
+ */
static int pcmuio_dio_insn_bits(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
{
+ unsigned int mask = data[0] & s->io_bits; /* outputs only */
+ unsigned int bits = data[1];
int asic = s->index / 2;
int port = (s->index % 2) ? 3 : 0;
- unsigned long iobase = dev->iobase + (asic * ASIC_IOSIZE);
- int byte_no;
-
- /* NOTE:
- reading a 0 means this channel was high
- writine a 0 sets the channel high
- reading a 1 means this channel was low
- writing a 1 means set this channel low
-
- Therefore everything is always inverted. */
-
- /* The insn data is a mask in data[0] and the new data
- * in data[1], each channel cooresponding to a bit. */
+ unsigned int val;
- s->state = 0;
+ /* get inverted state of the channels from the port */
+ val = pcmuio_read(dev, asic, 0, port);
- for (byte_no = 0; byte_no < s->n_chan / CHANS_PER_PORT; ++byte_no) {
- /* bit offset of port in 32-bit doubleword */
- unsigned long offset = byte_no * 8;
- /* this 8-bit port's data */
- unsigned char byte = 0,
- /* The write mask for this port (if any) */
- write_mask_byte = (data[0] >> offset) & 0xff,
- /* The data byte for this port */
- data_byte = (data[1] >> offset) & 0xff;
+ /* get the true state of the channels */
+ s->state = val ^ ((0x1 << s->n_chan) - 1);
- byte = inb(iobase + PCMUIO_PORT_REG(port + byte_no));
+ if (mask) {
+ s->state &= ~mask;
+ s->state |= (mask & bits);
- if (write_mask_byte) {
- byte &= ~write_mask_byte;
- byte |= ~data_byte & write_mask_byte;
- outb(byte, iobase + PCMUIO_PORT_REG(port + byte_no));
- }
- /* save the digital input lines for this byte.. */
- s->state |= ((unsigned int)byte) << offset;
+ /* invert the state and update the channels */
+ val = s->state ^ ((0x1 << s->n_chan) - 1);
+ pcmuio_write(dev, val, asic, 0, port);
}
- /* now return the DIO lines to data[1] - note they came inverted! */
- data[1] = ~s->state;
+ data[1] = s->state;
return insn->n;
}
@@ -256,58 +247,21 @@ static int pcmuio_dio_insn_config(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
{
+ unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
int asic = s->index / 2;
int port = (s->index % 2) ? 3 : 0;
- unsigned long iobase = dev->iobase + (asic * ASIC_IOSIZE);
- unsigned int chan = CR_CHAN(insn->chanspec);
- int byte_no = chan / 8;
- int bit_no = chan % 8;
- unsigned char byte;
-
- /* NOTE:
- writing a 0 an IO channel's bit sets the channel to INPUT
- and pulls the line high as well
-
- writing a 1 to an IO channel's bit pulls the line low
-
- All channels are implicitly always in OUTPUT mode -- but when
- they are high they can be considered to be in INPUT mode..
-
- Thus, we only force channels low if the config request was INPUT,
- otherwise we do nothing to the hardware. */
switch (data[0]) {
case INSN_CONFIG_DIO_OUTPUT:
- /* save to io_bits -- don't actually do anything since
- all input channels are also output channels... */
- s->io_bits |= 1 << chan;
+ s->io_bits |= chan_mask;
break;
case INSN_CONFIG_DIO_INPUT:
- /* write a 0 to the actual register representing the channel
- to set it to 'input'. 0 means "float high". */
- byte = inb(iobase + PCMUIO_PORT_REG(port + byte_no));
- byte &= ~(1 << bit_no);
- /**< set input channel to '0' */
-
- /*
- * write out byte
- * This is the only time we actually affect the hardware
- * as all channels are implicitly output -- but input
- * channels are set to float-high.
- */
- outb(byte, iobase + PCMUIO_PORT_REG(port + byte_no));
-
- /* save to io_bits */
- s->io_bits &= ~(1 << chan);
+ s->io_bits &= ~chan_mask;
+ pcmuio_write(dev, s->io_bits, asic, 0, port);
break;
-
case INSN_CONFIG_DIO_QUERY:
- /* retrieve from shadow register */
- data[1] =
- (s->io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT;
- return insn->n;
+ data[1] = (s->io_bits & chan_mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
break;
-
default:
return -EINVAL;
break;