diff options
| -rw-r--r-- | drivers/staging/comedi/drivers/pcmmio.c | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/drivers/staging/comedi/drivers/pcmmio.c b/drivers/staging/comedi/drivers/pcmmio.c index 42d7f1479323..d51fa69a89ac 100644 --- a/drivers/staging/comedi/drivers/pcmmio.c +++ b/drivers/staging/comedi/drivers/pcmmio.c @@ -122,6 +122,14 @@ Configuration Options: #define PCMMIO_AO_CMD_CHAN_SEL(x) (((x) & 0x03) << 1) #define PCMMIO_AO_CMD_CHAN_SEL_ALL (0x0f << 0) #define PCMMIO_AO_STATUS_REG 0x0b +#define PCMMIO_AO_STATUS_DATA_READY (1 << 7) +#define PCMMIO_AO_STATUS_DATA_DMA_PEND (1 << 6) +#define PCMMIO_AO_STATUS_CMD_DMA_PEND (1 << 5) +#define PCMMIO_AO_STATUS_IRQ_PEND (1 << 4) +#define PCMMIO_AO_STATUS_DATA_DRQ_ENA (1 << 2) +#define PCMMIO_AO_STATUS_REG_SEL (1 << 3) +#define PCMMIO_AO_STATUS_CMD_DRQ_ENA (1 << 1) +#define PCMMIO_AO_STATUS_IRQ_ENA (1 << 0) #define PCMMIO_AO_RESOURCE_ENA_REG 0x0b #define PCMMIO_AO_2ND_DAC_OFFSET 0x04 @@ -885,22 +893,16 @@ static int ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, return n; } -static int wait_dac_ready(unsigned long iobase) +static int pcmmio_ao_wait_for_eoc(unsigned long iobase, unsigned int timeout) { - unsigned long retry = 100000L; - - /* This may seem like an absurd way to handle waiting and violates the - "no busy waiting" policy. The fact is that the hardware is - normally so fast that we usually only need one time through the loop - anyway. The longer timeout is for rare occasions and for detecting - non-existent hardware. */ + unsigned char status; - while (retry--) { - if (inb(iobase + 3) & 0x80) + while (timeout--) { + status = inb(iobase + PCMMIO_AO_STATUS_REG); + if (status & PCMMIO_AO_STATUS_DATA_READY) return 0; - } - return 1; + return -ETIME; } static int pcmmio_ao_insn_write(struct comedi_device *dev, @@ -914,6 +916,7 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev, unsigned int range = CR_RANGE(insn->chanspec); unsigned int val = devpriv->ao_readback[chan]; unsigned char cmd = 0; + int ret; int i; /* @@ -932,7 +935,9 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev, outb(PCMMIO_AO_LSB_SPAN(range), iobase + PCMMIO_AO_LSB_REG); outb(0, iobase + PCMMIO_AO_MSB_REG); outb(cmd | PCMMIO_AO_CMD_WR_SPAN_UPDATE, iobase + PCMMIO_AO_CMD_REG); - wait_dac_ready(iobase); + ret = pcmmio_ao_wait_for_eoc(iobase, 100000); + if (ret) + return ret; for (i = 0; i < insn->n; i++) { val = data[i]; @@ -942,7 +947,9 @@ static int pcmmio_ao_insn_write(struct comedi_device *dev, outb((val >> 8) & 0xff, iobase + PCMMIO_AO_MSB_REG); outb(cmd | PCMMIO_AO_CMD_WR_CODE_UPDATE, iobase + PCMMIO_AO_CMD_REG); - wait_dac_ready(iobase); + ret = pcmmio_ao_wait_for_eoc(iobase, 100000); + if (ret) + return ret; devpriv->ao_readback[chan] = val; } |