[PATCH v5 1/3] iio: adc: Add support for DLN2 ADC

From: Jack Andersen
Date: Wed Jul 05 2017 - 17:14:42 EST


This patch adds support for Diolan DLN2 ADC via IIO's ADC interface.
ADC is the fourth and final component of the DLN2 for the kernel.

Signed-off-by: Jack Andersen <jackoalan@xxxxxxxxx>
---
Changes in v2:
- Address Peter's remarks; bringing consistency to C99 syntax, dev_dbg usage,
and error handling.
- Remove probe/remove logging.
- Utilize stack-allocated buffer for pushing into IIO.
- Add timestamp channel to IIO spec.

Suggested-by: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>
---
Changes in v3:
- Remove lazy channel enabling; integrating with update_channel_mode instead.
- Implement memcpy demux table similar to subsystem core.
- Use iio_triggered_buffer_setup to create buffer.

Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---
Changes in v4:
- Remove unrelated, erronous change to lsgpio.c
---
Changes in v5:
- Use of devm functions wherever possible.
- Use iio_device_claim_direct_mode.
- Variable declaration more consistent with C style.
- MFD modifications in separate patch.
Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 9 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/dln2-adc.c | 719 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 729 insertions(+)
create mode 100644 drivers/iio/adc/dln2-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 614fa41..196d2ce 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -239,6 +239,15 @@ config DA9150_GPADC
To compile this driver as a module, choose M here: the module will be
called berlin2-adc.

+config DLN2_ADC
+ tristate "Diolan DLN-2 ADC driver support"
+ depends on MFD_DLN2
+ help
+ Say yes here to build support for Diolan DLN-2 ADC.
+
+ This driver can also be built as a module. If so, the module will be
+ called adc_dln2.
+
config ENVELOPE_DETECTOR
tristate "Envelope detector using a DAC and a comparator"
depends on OF
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index b546736a..7ea0bf3 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
obj-$(CONFIG_CPCAP_ADC) += cpcap-adc.o
obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
+obj-$(CONFIG_DLN2_ADC) += dln2-adc.o
obj-$(CONFIG_ENVELOPE_DETECTOR) += envelope-detector.o
obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
obj-$(CONFIG_FSL_MX25_ADC) += fsl-imx25-gcq.o
diff --git a/drivers/iio/adc/dln2-adc.c b/drivers/iio/adc/dln2-adc.c
new file mode 100644
index 0000000..649bbef9b
--- /dev/null
+++ b/drivers/iio/adc/dln2-adc.c
@@ -0,0 +1,719 @@
+/*
+ * Driver for the Diolan DLN-2 USB-ADC adapter
+ *
+ * Copyright (c) 2017 Jack Andersen
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/dln2.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/kfifo_buf.h>
+
+#define DLN2_ADC_MOD_NAME "dln2-adc"
+
+#define DLN2_ADC_ID 0x06
+
+#define DLN2_ADC_GET_CHANNEL_COUNT DLN2_CMD(0x01, DLN2_ADC_ID)
+#define DLN2_ADC_ENABLE DLN2_CMD(0x02, DLN2_ADC_ID)
+#define DLN2_ADC_DISABLE DLN2_CMD(0x03, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_ENABLE DLN2_CMD(0x05, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_DISABLE DLN2_CMD(0x06, DLN2_ADC_ID)
+#define DLN2_ADC_SET_RESOLUTION DLN2_CMD(0x08, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_GET_VAL DLN2_CMD(0x0A, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_GET_ALL_VAL DLN2_CMD(0x0B, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_SET_CFG DLN2_CMD(0x0C, DLN2_ADC_ID)
+#define DLN2_ADC_CHANNEL_GET_CFG DLN2_CMD(0x0D, DLN2_ADC_ID)
+#define DLN2_ADC_CONDITION_MET_EV DLN2_CMD(0x10, DLN2_ADC_ID)
+
+#define DLN2_ADC_EVENT_NONE 0
+#define DLN2_ADC_EVENT_BELOW 1
+#define DLN2_ADC_EVENT_LEVEL_ABOVE 2
+#define DLN2_ADC_EVENT_OUTSIDE 3
+#define DLN2_ADC_EVENT_INSIDE 4
+#define DLN2_ADC_EVENT_ALWAYS 5
+
+#define DLN2_ADC_MAX_CHANNELS 8
+#define DLN2_ADC_DATA_BITS 10
+
+/*
+ * Plays similar role to iio_demux_table in subsystem core; except allocated
+ * in a fixed 8-element array.
+ */
+struct dln2_adc_demux_table {
+ unsigned int from;
+ unsigned int to;
+ unsigned int length;
+};
+
+struct dln2_adc {
+ struct platform_device *pdev;
+ struct iio_chan_spec iio_channels[DLN2_ADC_MAX_CHANNELS + 1];
+ int port, trigger_chan;
+ struct iio_trigger *trig;
+ struct mutex mutex;
+ /* Cached sample period in milliseconds */
+ unsigned int sample_period;
+ /* Demux table */
+ unsigned int demux_count;
+ struct dln2_adc_demux_table demux[DLN2_ADC_MAX_CHANNELS];
+ /* Precomputed timestamp padding offset and length */
+ unsigned int ts_pad_offset, ts_pad_length;
+};
+
+struct dln2_adc_port_chan {
+ u8 port;
+ u8 chan;
+};
+
+struct dln2_adc_get_all_vals {
+ __le16 channel_mask;
+ __le16 values[DLN2_ADC_MAX_CHANNELS];
+};
+
+static void dln2_adc_add_demux(struct dln2_adc *dln2,
+ unsigned int in_loc, unsigned int out_loc,
+ unsigned int length)
+{
+ struct dln2_adc_demux_table *p = dln2->demux_count ?
+ &dln2->demux[dln2->demux_count - 1] : NULL;
+
+ if (p && p->from + p->length == in_loc &&
+ p->to + p->length == out_loc) {
+ p->length += length;
+ } else if (dln2->demux_count < DLN2_ADC_MAX_CHANNELS) {
+ p = &dln2->demux[dln2->demux_count++];
+ p->from = in_loc;
+ p->to = out_loc;
+ p->length = length;
+ }
+}
+
+static void dln2_adc_update_demux(struct dln2_adc *dln2)
+{
+ int in_ind = -1, out_ind;
+ unsigned int in_loc = 0, out_loc = 0;
+ struct iio_dev *indio_dev = platform_get_drvdata(dln2->pdev);
+
+ /* Clear out any old demux */
+ dln2->demux_count = 0;
+
+ /* Optimize all 8-channels case */
+ if (indio_dev->masklength &&
+ (*indio_dev->active_scan_mask & 0xff) == 0xff) {
+ dln2_adc_add_demux(dln2, 0, 0, 16);
+ dln2->ts_pad_offset = 0;
+ dln2->ts_pad_length = 0;
+ return;
+ }
+
+ /* Build demux table from fixed 8-channels to active_scan_mask */
+ for_each_set_bit(out_ind,
+ indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ /* Handle timestamp separately */
+ if (out_ind == DLN2_ADC_MAX_CHANNELS)
+ break;
+ for (++in_ind; in_ind != out_ind; ++in_ind)
+ in_loc += 2;
+ dln2_adc_add_demux(dln2, in_loc, out_loc, 2);
+ out_loc += 2;
+ in_loc += 2;
+ }
+
+ if (indio_dev->scan_timestamp) {
+ size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1;
+
+ dln2->ts_pad_offset = out_loc;
+ dln2->ts_pad_length = ts_offset * sizeof(int64_t) - out_loc;
+ } else {
+ dln2->ts_pad_offset = 0;
+ dln2->ts_pad_length = 0;
+ }
+}
+
+static int dln2_adc_get_chan_count(struct dln2_adc *dln2)
+{
+ int ret;
+ u8 port = dln2->port;
+ u8 count;
+ int olen = sizeof(count);
+
+ ret = dln2_transfer(dln2->pdev, DLN2_ADC_GET_CHANNEL_COUNT,
+ &port, sizeof(port), &count, &olen);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+ if (olen < sizeof(count))
+ return -EPROTO;
+
+ return count;
+}
+
+static int dln2_adc_set_port_resolution(struct dln2_adc *dln2)
+{
+ int ret;
+ struct dln2_adc_port_chan port_chan = {
+ .port = dln2->port,
+ .chan = DLN2_ADC_DATA_BITS,
+ };
+
+ ret = dln2_transfer_tx(dln2->pdev, DLN2_ADC_SET_RESOLUTION,
+ &port_chan, sizeof(port_chan));
+ if (ret < 0)
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+
+ return ret;
+}
+
+static int dln2_adc_set_chan_enabled(struct dln2_adc *dln2,
+ int channel, bool enable)
+{
+ int ret;
+ struct dln2_adc_port_chan port_chan = {
+ .port = dln2->port,
+ .chan = channel,
+ };
+ u16 cmd = enable ? DLN2_ADC_CHANNEL_ENABLE : DLN2_ADC_CHANNEL_DISABLE;
+
+ ret = dln2_transfer_tx(dln2->pdev, cmd, &port_chan, sizeof(port_chan));
+ if (ret < 0)
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+
+ return ret;
+}
+
+static int dln2_adc_set_port_enabled(struct dln2_adc *dln2, bool enable,
+ u16 *conflict_out)
+{
+ int ret;
+ u8 port = dln2->port;
+ __le16 conflict;
+ int olen = sizeof(conflict);
+ u16 cmd = enable ? DLN2_ADC_ENABLE : DLN2_ADC_DISABLE;
+
+ if (conflict_out)
+ *conflict_out = 0;
+
+ ret = dln2_transfer(dln2->pdev, cmd, &port, sizeof(port),
+ &conflict, &olen);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s(%d)\n",
+ __func__, (int)enable);
+ if (conflict_out && enable && olen >= sizeof(conflict))
+ *conflict_out = le16_to_cpu(conflict);
+ return ret;
+ }
+ if (enable && olen < sizeof(conflict))
+ return -EPROTO;
+
+ return ret;
+}
+
+static int dln2_adc_set_chan_period(struct dln2_adc *dln2,
+ unsigned int channel, unsigned int period)
+{
+ int ret;
+ struct {
+ struct dln2_adc_port_chan port_chan;
+ __u8 type;
+ __le16 period;
+ __le16 low;
+ __le16 high;
+ } __packed set_cfg = {
+ .port_chan.port = dln2->port,
+ .port_chan.chan = channel,
+ .type = period ? DLN2_ADC_EVENT_ALWAYS : DLN2_ADC_EVENT_NONE,
+ .period = cpu_to_le16(period)
+ };
+
+ ret = dln2_transfer_tx(dln2->pdev, DLN2_ADC_CHANNEL_SET_CFG,
+ &set_cfg, sizeof(set_cfg));
+ if (ret < 0)
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+
+ return ret;
+}
+
+static int dln2_adc_read(struct dln2_adc *dln2, unsigned int channel)
+{
+ int ret, i;
+ struct iio_dev *indio_dev = platform_get_drvdata(dln2->pdev);
+ u16 conflict;
+ __le16 value;
+ int olen = sizeof(value);
+ struct dln2_adc_port_chan port_chan = {
+ .port = dln2->port,
+ .chan = channel,
+ };
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ ret = dln2_adc_set_chan_enabled(dln2, channel, true);
+ if (ret < 0)
+ goto release_direct;
+
+ ret = dln2_adc_set_port_enabled(dln2, true, &conflict);
+ if (ret < 0) {
+ if (conflict) {
+ dev_err(&dln2->pdev->dev,
+ "ADC pins conflict with mask %04X\n",
+ (int)conflict);
+ ret = -EBUSY;
+ }
+ goto disable_chan;
+ }
+
+ /*
+ * Call GET_VAL twice due to initial zero-return immediately after
+ * enabling channel.
+ */
+ for (i = 0; i < 2; ++i) {
+ ret = dln2_transfer(dln2->pdev, DLN2_ADC_CHANNEL_GET_VAL,
+ &port_chan, sizeof(port_chan),
+ &value, &olen);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ goto disable_port;
+ }
+ if (olen < sizeof(value)) {
+ ret = -EPROTO;
+ goto disable_port;
+ }
+ }
+
+ ret = le16_to_cpu(value);
+
+disable_port:
+ dln2_adc_set_port_enabled(dln2, false, NULL);
+disable_chan:
+ dln2_adc_set_chan_enabled(dln2, channel, false);
+release_direct:
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+}
+
+static int dln2_adc_read_all(struct dln2_adc *dln2,
+ struct dln2_adc_get_all_vals *get_all_vals)
+{
+ int ret;
+ __u8 port = dln2->port;
+ int olen = sizeof(*get_all_vals);
+
+ ret = dln2_transfer(dln2->pdev, DLN2_ADC_CHANNEL_GET_ALL_VAL,
+ &port, sizeof(port), get_all_vals, &olen);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+ if (olen < sizeof(*get_all_vals))
+ return -EPROTO;
+
+ return ret;
+}
+
+static int dln2_adc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long mask)
+{
+ int ret;
+ unsigned int microhertz;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&dln2->mutex);
+ ret = dln2_adc_read(dln2, chan->channel);
+ mutex_unlock(&dln2->mutex);
+
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ /*
+ * Voltage reference is fixed at 3.3v
+ * 3.3 / (1 << 10) * 1000000000
+ */
+ *val = 0;
+ *val2 = 3222656;
+ return IIO_VAL_INT_PLUS_NANO;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (dln2->sample_period) {
+ microhertz = 1000000000 / dln2->sample_period;
+ *val = microhertz / 1000000;
+ *val2 = microhertz % 1000000;
+ } else {
+ *val = 0;
+ *val2 = 0;
+ }
+
+ return IIO_VAL_INT_PLUS_MICRO;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int dln2_adc_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ int ret;
+ unsigned int microhertz;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ microhertz = 1000000 * val + val2;
+
+ mutex_lock(&dln2->mutex);
+
+ dln2->sample_period =
+ microhertz ? 1000000000 / microhertz : UINT_MAX;
+ if (dln2->sample_period > 65535) {
+ dln2->sample_period = 65535;
+ dev_warn(&dln2->pdev->dev,
+ "clamping period to 65535ms\n");
+ }
+
+ /*
+ * The first requested channel is arbitrated as a shared
+ * trigger source, so only one event is registered with the
+ * DLN. The event handler will then read all enabled channel
+ * values using DLN2_ADC_CHANNEL_GET_ALL_VAL to maintain
+ * synchronization between ADC readings.
+ */
+ if (dln2->trigger_chan != -1)
+ ret = dln2_adc_set_chan_period(dln2,
+ dln2->trigger_chan, dln2->sample_period);
+ else
+ ret = 0;
+
+ mutex_unlock(&dln2->mutex);
+
+ return ret;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int dln2_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+ int chan_count = indio_dev->num_channels - 1;
+ int ret, i, j;
+
+ mutex_lock(&dln2->mutex);
+
+ for (i = 0; i < chan_count; ++i) {
+ ret = dln2_adc_set_chan_enabled(dln2, i,
+ test_bit(i, scan_mask));
+ if (ret < 0) {
+ for (j = 0; j < i; ++j)
+ dln2_adc_set_chan_enabled(dln2, j, false);
+ mutex_unlock(&dln2->mutex);
+ dev_err(&dln2->pdev->dev,
+ "Unable to enable ADC channel %d\n", i);
+ return -EBUSY;
+ }
+ }
+
+ dln2_adc_update_demux(dln2);
+
+ mutex_unlock(&dln2->mutex);
+
+ return 0;
+}
+
+#define DLN2_ADC_CHAN(lval, idx) { \
+ lval.type = IIO_VOLTAGE; \
+ lval.channel = idx; \
+ lval.indexed = 1; \
+ lval.info_mask_separate = BIT(IIO_CHAN_INFO_RAW); \
+ lval.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ); \
+ lval.scan_index = idx; \
+ lval.scan_type.sign = 'u'; \
+ lval.scan_type.realbits = DLN2_ADC_DATA_BITS; \
+ lval.scan_type.storagebits = 16; \
+ lval.scan_type.endianness = IIO_LE; \
+}
+
+/* Assignment version of IIO_CHAN_SOFT_TIMESTAMP */
+#define IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(lval, _si) { \
+ lval.type = IIO_TIMESTAMP; \
+ lval.channel = -1; \
+ lval.scan_index = _si; \
+ lval.scan_type.sign = 's'; \
+ lval.scan_type.realbits = 64; \
+ lval.scan_type.storagebits = 64; \
+}
+
+static const struct iio_info dln2_adc_info = {
+ .read_raw = dln2_adc_read_raw,
+ .write_raw = dln2_adc_write_raw,
+ .update_scan_mode = dln2_update_scan_mode,
+ .driver_module = THIS_MODULE,
+};
+
+static irqreturn_t dln2_adc_trigger_h(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct {
+ __le16 values[DLN2_ADC_MAX_CHANNELS];
+ int64_t timestamp_space;
+ } data;
+ struct dln2_adc_get_all_vals dev_data;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+ const struct dln2_adc_demux_table *t;
+ int ret, i;
+
+ mutex_lock(&dln2->mutex);
+ ret = dln2_adc_read_all(dln2, &dev_data);
+ mutex_unlock(&dln2->mutex);
+ if (ret < 0)
+ goto done;
+
+ /* Demux operation */
+ for (i = 0; i < dln2->demux_count; ++i) {
+ t = &dln2->demux[i];
+ memcpy((void *)data.values + t->to,
+ (void *)dev_data.values + t->from, t->length);
+ }
+
+ /* Zero padding space between values and timestamp */
+ if (dln2->ts_pad_length)
+ memset((void *)data.values + dln2->ts_pad_offset,
+ 0, dln2->ts_pad_length);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &data,
+ iio_get_time_ns(indio_dev));
+
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+ u16 conflict;
+ unsigned int trigger_chan;
+
+ mutex_lock(&dln2->mutex);
+
+ /* Enable ADC */
+ ret = dln2_adc_set_port_enabled(dln2, true, &conflict);
+ if (ret < 0) {
+ mutex_unlock(&dln2->mutex);
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ if (conflict) {
+ dev_err(&dln2->pdev->dev,
+ "ADC pins conflict with mask %04X\n",
+ (int)conflict);
+ ret = -EBUSY;
+ }
+ return ret;
+ }
+
+ /* Assign trigger channel based on first enabled channel */
+ trigger_chan = find_first_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength);
+ if (trigger_chan < DLN2_ADC_MAX_CHANNELS) {
+ dln2->trigger_chan = trigger_chan;
+ ret = dln2_adc_set_chan_period(dln2, dln2->trigger_chan,
+ dln2->sample_period);
+ mutex_unlock(&dln2->mutex);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+ } else {
+ dln2->trigger_chan = -1;
+ mutex_unlock(&dln2->mutex);
+ }
+
+ return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int dln2_adc_triggered_buffer_predisable(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ mutex_lock(&dln2->mutex);
+
+ /* Disable trigger channel */
+ if (dln2->trigger_chan != -1) {
+ dln2_adc_set_chan_period(dln2, dln2->trigger_chan, 0);
+ dln2->trigger_chan = -1;
+ }
+
+ /* Disable ADC */
+ ret = dln2_adc_set_port_enabled(dln2, false, NULL);
+
+ mutex_unlock(&dln2->mutex);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+
+ return iio_triggered_buffer_predisable(indio_dev);
+}
+
+static const struct iio_buffer_setup_ops dln2_adc_buffer_setup_ops = {
+ .postenable = dln2_adc_triggered_buffer_postenable,
+ .predisable = dln2_adc_triggered_buffer_predisable,
+};
+
+static void dln2_adc_event(struct platform_device *pdev, u16 echo,
+ const void *data, int len)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ /* Called via URB completion handler */
+ iio_trigger_poll(dln2->trig);
+}
+
+static const struct iio_trigger_ops dln2_adc_trigger_ops = {
+ .owner = THIS_MODULE,
+};
+
+static int dln2_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct dln2_adc *dln2;
+ struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct iio_dev *indio_dev;
+ int i, ret, chans;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*dln2));
+ if (!indio_dev) {
+ dev_err(dev, "failed allocating iio device\n");
+ return -ENOMEM;
+ }
+
+ dln2 = iio_priv(indio_dev);
+ dln2->pdev = pdev;
+ dln2->port = pdata->port;
+ dln2->trigger_chan = -1;
+ mutex_init(&dln2->mutex);
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ ret = dln2_adc_set_port_resolution(dln2);
+ if (ret < 0) {
+ dev_err(dev, "failed to set ADC resolution to 10 bits\n");
+ return ret;
+ }
+
+ chans = dln2_adc_get_chan_count(dln2);
+ if (chans < 0) {
+ dev_err(dev, "failed to get channel count: %d\n", chans);
+ return chans;
+ }
+ if (chans > DLN2_ADC_MAX_CHANNELS) {
+ chans = DLN2_ADC_MAX_CHANNELS;
+ dev_warn(dev, "clamping channels to %d\n",
+ DLN2_ADC_MAX_CHANNELS);
+ }
+
+ for (i = 0; i < chans; ++i)
+ DLN2_ADC_CHAN(dln2->iio_channels[i], i)
+ IIO_CHAN_SOFT_TIMESTAMP_ASSIGN(dln2->iio_channels[i], i);
+
+ indio_dev->name = DLN2_ADC_MOD_NAME;
+ indio_dev->dev.parent = dev;
+ indio_dev->info = &dln2_adc_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = dln2->iio_channels;
+ indio_dev->num_channels = chans + 1;
+ indio_dev->setup_ops = &dln2_adc_buffer_setup_ops;
+
+ dln2->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+ indio_dev->name, indio_dev->id);
+ if (!dln2->trig) {
+ dev_err(dev, "failed to allocate trigger\n");
+ return -ENOMEM;
+ }
+ dln2->trig->ops = &dln2_adc_trigger_ops;
+ iio_trigger_set_drvdata(dln2->trig, dln2);
+ devm_iio_trigger_register(dev, dln2->trig);
+ iio_trigger_set_immutable(indio_dev, dln2->trig);
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+ dln2_adc_trigger_h,
+ &dln2_adc_buffer_setup_ops);
+ if (ret) {
+ dev_err(dev, "failed to allocate triggered buffer: %d\n", ret);
+ return ret;
+ }
+
+ ret = dln2_register_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV,
+ dln2_adc_event);
+ if (ret) {
+ dev_err(dev, "failed to setup DLN2 periodic event: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret) {
+ dev_err(dev, "failed to register iio device: %d\n", ret);
+ goto unregister_event;
+ }
+
+ return ret;
+
+unregister_event:
+ dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV);
+
+ return ret;
+}
+
+static int dln2_adc_remove(struct platform_device *pdev)
+{
+ dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV);
+ return 0;
+}
+
+static struct platform_driver dln2_adc_driver = {
+ .driver.name = DLN2_ADC_MOD_NAME,
+ .probe = dln2_adc_probe,
+ .remove = dln2_adc_remove,
+};
+
+module_platform_driver(dln2_adc_driver);
+
+MODULE_AUTHOR("Jack Andersen <jackoalan@xxxxxxxxx");
+MODULE_DESCRIPTION("Driver for the Diolan DLN2 ADC interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dln2-adc");
--
1.9.1