/*
- * DAC driver for the Apex Embedded Systems STX104
+ * IIO driver for the Apex Embedded Systems STX104
* Copyright (C) 2016 William Breathitt Gray
*
* This program is free software; you can redistribute it and/or modify
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/isa.h>
+#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
-#define STX104_NUM_CHAN 2
-
-#define STX104_CHAN(chan) { \
+#define STX104_OUT_CHAN(chan) { \
.type = IIO_VOLTAGE, \
.channel = chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.indexed = 1, \
.output = 1 \
}
+#define STX104_IN_CHAN(chan, diff) { \
+ .type = IIO_VOLTAGE, \
+ .channel = chan, \
+ .channel2 = chan, \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .indexed = 1, \
+ .differential = diff \
+}
+
+#define STX104_NUM_OUT_CHAN 2
#define STX104_EXTENT 16
* @base: base port address of the IIO device
*/
struct stx104_iio {
- unsigned chan_out_states[STX104_NUM_CHAN];
- unsigned base;
+ unsigned int chan_out_states[STX104_NUM_OUT_CHAN];
+ unsigned int base;
};
/**
struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
struct stx104_iio *const priv = iio_priv(indio_dev);
+ unsigned int adc_config;
+ int adbu;
+ int gain;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ /* get gain configuration */
+ adc_config = inb(priv->base + 11);
+ gain = adc_config & 0x3;
+
+ *val = 1 << gain;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_RAW:
+ if (chan->output) {
+ *val = priv->chan_out_states[chan->channel];
+ return IIO_VAL_INT;
+ }
+
+ /* select ADC channel */
+ outb(chan->channel | (chan->channel << 4), priv->base + 2);
+
+ /* trigger ADC sample capture and wait for completion */
+ outb(0, priv->base);
+ while (inb(priv->base + 8) & BIT(7));
+
+ *val = inw(priv->base);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ /* get ADC bipolar/unipolar configuration */
+ adc_config = inb(priv->base + 11);
+ adbu = !(adc_config & BIT(2));
+
+ *val = -32768 * adbu;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ /* get ADC bipolar/unipolar and gain configuration */
+ adc_config = inb(priv->base + 11);
+ adbu = !(adc_config & BIT(2));
+ gain = adc_config & 0x3;
+
+ *val = 5;
+ *val2 = 15 - adbu + gain;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
- if (mask != IIO_CHAN_INFO_RAW)
- return -EINVAL;
-
- *val = priv->chan_out_states[chan->channel];
-
- return IIO_VAL_INT;
+ return -EINVAL;
}
static int stx104_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
struct stx104_iio *const priv = iio_priv(indio_dev);
- const unsigned chan_addr_offset = 2 * chan->channel;
- if (mask != IIO_CHAN_INFO_RAW)
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ /* Only four gain states (x1, x2, x4, x8) */
+ switch (val) {
+ case 1:
+ outb(0, priv->base + 11);
+ break;
+ case 2:
+ outb(1, priv->base + 11);
+ break;
+ case 4:
+ outb(2, priv->base + 11);
+ break;
+ case 8:
+ outb(3, priv->base + 11);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+ case IIO_CHAN_INFO_RAW:
+ if (chan->output) {
+ /* DAC can only accept up to a 16-bit value */
+ if ((unsigned int)val > 65535)
+ return -EINVAL;
+
+ priv->chan_out_states[chan->channel] = val;
+ outw(val, priv->base + 4 + 2 * chan->channel);
+
+ return 0;
+ }
return -EINVAL;
+ }
- priv->chan_out_states[chan->channel] = val;
- outw(val, priv->base + 4 + chan_addr_offset);
-
- return 0;
+ return -EINVAL;
}
static const struct iio_info stx104_info = {
.write_raw = stx104_write_raw
};
-static const struct iio_chan_spec stx104_channels[STX104_NUM_CHAN] = {
- STX104_CHAN(0),
- STX104_CHAN(1)
+/* single-ended input channels configuration */
+static const struct iio_chan_spec stx104_channels_sing[] = {
+ STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
+ STX104_IN_CHAN(0, 0), STX104_IN_CHAN(1, 0), STX104_IN_CHAN(2, 0),
+ STX104_IN_CHAN(3, 0), STX104_IN_CHAN(4, 0), STX104_IN_CHAN(5, 0),
+ STX104_IN_CHAN(6, 0), STX104_IN_CHAN(7, 0), STX104_IN_CHAN(8, 0),
+ STX104_IN_CHAN(9, 0), STX104_IN_CHAN(10, 0), STX104_IN_CHAN(11, 0),
+ STX104_IN_CHAN(12, 0), STX104_IN_CHAN(13, 0), STX104_IN_CHAN(14, 0),
+ STX104_IN_CHAN(15, 0)
+};
+/* differential input channels configuration */
+static const struct iio_chan_spec stx104_channels_diff[] = {
+ STX104_OUT_CHAN(0), STX104_OUT_CHAN(1),
+ STX104_IN_CHAN(0, 1), STX104_IN_CHAN(1, 1), STX104_IN_CHAN(2, 1),
+ STX104_IN_CHAN(3, 1), STX104_IN_CHAN(4, 1), STX104_IN_CHAN(5, 1),
+ STX104_IN_CHAN(6, 1), STX104_IN_CHAN(7, 1)
};
static int stx104_gpio_get_direction(struct gpio_chip *chip,
indio_dev->info = &stx104_info;
indio_dev->modes = INDIO_DIRECT_MODE;
- indio_dev->channels = stx104_channels;
- indio_dev->num_channels = STX104_NUM_CHAN;
+
+ /* determine if differential inputs */
+ if (inb(base[id] + 8) & BIT(5)) {
+ indio_dev->num_channels = ARRAY_SIZE(stx104_channels_diff);
+ indio_dev->channels = stx104_channels_diff;
+ } else {
+ indio_dev->num_channels = ARRAY_SIZE(stx104_channels_sing);
+ indio_dev->channels = stx104_channels_sing;
+ }
+
indio_dev->name = dev_name(dev);
priv = iio_priv(indio_dev);
priv->base = base[id];
+ /* configure device for software trigger operation */
+ outb(0, base[id] + 9);
+
+ /* initialize gain setting to x1 */
+ outb(0, base[id] + 11);
+
/* initialize DAC output to 0V */
outw(0, base[id] + 4);
outw(0, base[id] + 6);
module_isa_driver(stx104_driver, num_stx104);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
-MODULE_DESCRIPTION("Apex Embedded Systems STX104 DAC driver");
+MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver");
MODULE_LICENSE("GPL v2");
projects / linux.git / commitdiff