[PATCH v2] iio: adc: Add support for DLN2 ADC

From: Jack Andersen
Date: Thu Jun 22 2017 - 18:31:50 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>
---
drivers/iio/adc/Kconfig | 9 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/dln2-adc.c | 644 +++++++++++++++++++++++++++++++++++++++++++++
drivers/mfd/dln2.c | 12 +
4 files changed, 666 insertions(+)
create mode 100644 drivers/iio/adc/dln2-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 401f47b..78d7455 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 9339bec..378bc65 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..6c58b76
--- /dev/null
+++ b/drivers/iio/adc/dln2-adc.c
@@ -0,0 +1,644 @@
+/*
+ * 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/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
+
+struct dln2_adc {
+ struct platform_device *pdev;
+ int port;
+ struct iio_trigger *trig;
+ struct mutex mutex;
+ /* Set once initialized */
+ bool port_enabled;
+ /* Set once resolution request made to HW */
+ bool resolution_set;
+ /* Bitmask requesting enabled channels */
+ unsigned long chans_requested;
+ /* Bitmask indicating enabled channels on HW */
+ unsigned long chans_enabled;
+ /* Channel that is arbitrated for event trigger */
+ int trigger_chan;
+};
+
+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 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;
+ }
+
+ return 0;
+}
+
+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;
+ }
+
+ return 0;
+}
+
+static int dln2_adc_set_port_enabled(struct dln2_adc *dln2, bool enable)
+{
+ int ret;
+ u8 port = dln2->port;
+ __le16 conflict;
+ int olen = sizeof(conflict);
+
+ u16 cmd = enable ? DLN2_ADC_ENABLE : DLN2_ADC_DISABLE;
+
+ 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);
+ return ret;
+ }
+ if (enable && olen < sizeof(conflict))
+ return -EPROTO;
+
+ return 0;
+}
+
+/*
+ * ADC channels are lazily enabled due to the pins being shared with GPIO
+ * channels. Enabling channels requires taking the ADC port offline, specifying
+ * the resolution, individually enabling channels, then putting the port back
+ * online. If GPIO pins have already been exported by gpio_dln2, EINVAL is
+ * reported.
+ */
+static int dln2_adc_update_enabled_chans(struct dln2_adc *dln2)
+{
+ int ret, i, chan_count;
+ struct iio_dev *indio_dev;
+
+ if (dln2->chans_enabled == dln2->chans_requested)
+ return 0;
+
+ indio_dev = platform_get_drvdata(dln2->pdev);
+ chan_count = indio_dev->num_channels;
+
+ if (dln2->port_enabled) {
+ ret = dln2_adc_set_port_enabled(dln2, false);
+ if (ret < 0)
+ return ret;
+ dln2->port_enabled = false;
+ }
+
+ if (!dln2->resolution_set) {
+ ret = dln2_adc_set_port_resolution(dln2);
+ if (ret < 0)
+ return ret;
+ dln2->resolution_set = true;
+ }
+
+ for (i = 0; i < chan_count; ++i) {
+ bool requested = dln2->chans_requested & (1 << i);
+ bool enabled = dln2->chans_enabled & (1 << i);
+
+ if (requested == enabled)
+ continue;
+ ret = dln2_adc_set_chan_enabled(dln2, i, requested);
+ if (ret < 0)
+ return ret;
+ }
+
+ dln2->chans_enabled = dln2->chans_requested;
+
+ ret = dln2_adc_set_port_enabled(dln2, true);
+ if (ret < 0)
+ return ret;
+ dln2->port_enabled = true;
+
+ return 0;
+}
+
+static int dln2_adc_get_chan_freq(struct dln2_adc *dln2, unsigned int channel)
+{
+ int ret;
+ struct dln2_adc_port_chan port_chan = {
+ .port = dln2->port,
+ .chan = channel,
+ };
+ struct {
+ __u8 type;
+ __le16 period;
+ __le16 low;
+ __le16 high;
+ } __packed get_cfg;
+ int olen = sizeof(get_cfg);
+
+ ret = dln2_transfer(dln2->pdev, DLN2_ADC_CHANNEL_GET_CFG,
+ &port_chan, sizeof(port_chan), &get_cfg, &olen);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+ if (olen < sizeof(get_cfg))
+ return -EPROTO;
+
+ return get_cfg.period;
+}
+
+static int dln2_adc_set_chan_freq(struct dln2_adc *dln2, unsigned int channel,
+ unsigned int freq)
+{
+ 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 = freq ? DLN2_ADC_EVENT_ALWAYS : DLN2_ADC_EVENT_NONE,
+ .period = cpu_to_le16(freq)
+ };
+
+ 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;
+ }
+ return 0;
+}
+
+static int dln2_adc_read(struct dln2_adc *dln2, unsigned int channel)
+{
+ int ret;
+ int old_chans_requested = dln2->chans_requested;
+
+ dln2->chans_requested |= (1 << channel);
+ ret = dln2_adc_update_enabled_chans(dln2);
+ if (ret < 0) {
+ dln2->chans_requested = old_chans_requested;
+ return ret;
+ }
+ dln2->port_enabled = true;
+
+ struct dln2_adc_port_chan port_chan = {
+ .port = dln2->port,
+ .chan = channel,
+ };
+ __le16 value;
+ int olen = sizeof(value);
+
+ 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__);
+ return ret;
+ }
+ if (olen < sizeof(value))
+ return -EPROTO;
+
+ return le16_to_cpu(value);
+}
+
+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 0;
+}
+
+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;
+ 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:
+ *val = 0;
+ /* 3.3 / (1 << 10) * 1000000000 */
+ *val2 = 3222656;
+ return IIO_VAL_INT_PLUS_NANO;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ mutex_lock(&dln2->mutex);
+ if (dln2->trigger_chan == -1)
+ ret = 0;
+ else
+ ret = dln2_adc_get_chan_freq(dln2, dln2->trigger_chan);
+ mutex_unlock(&dln2->mutex);
+
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
+ *val2 = (ret % 1000) * 1000;
+ 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 freq;
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ freq = val * 1000 + val2 / 1000;
+ if (freq > 65535) {
+ freq = 65535;
+ dev_warn(&dln2->pdev->dev,
+ "clamping freq to 65535ms\n");
+ }
+ mutex_lock(&dln2->mutex);
+
+ /*
+ * 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)
+ dln2->trigger_chan = chan->channel;
+ ret = dln2_adc_set_chan_freq(dln2, dln2->trigger_chan, freq);
+
+ mutex_unlock(&dln2->mutex);
+
+ if (ret < 0)
+ return ret;
+
+ return 0;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+#define DLN2_ADC_CHAN(idx) { \
+ .type = IIO_VOLTAGE, \
+ .channel = idx, \
+ .indexed = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),\
+ .scan_index = idx, \
+ .scan_type.sign = 'u', \
+ .scan_type.realbits = DLN2_ADC_DATA_BITS, \
+ .scan_type.storagebits = 16, \
+ .scan_type.endianness = IIO_LE, \
+}
+
+static const struct iio_chan_spec dln2_adc_iio_channels[] = {
+ DLN2_ADC_CHAN(0),
+ DLN2_ADC_CHAN(1),
+ DLN2_ADC_CHAN(2),
+ DLN2_ADC_CHAN(3),
+ DLN2_ADC_CHAN(4),
+ DLN2_ADC_CHAN(5),
+ DLN2_ADC_CHAN(6),
+ DLN2_ADC_CHAN(7),
+ IIO_CHAN_SOFT_TIMESTAMP(8),
+};
+
+static const struct iio_info dln2_adc_info = {
+ .read_raw = dln2_adc_read_raw,
+ .write_raw = dln2_adc_write_raw,
+ .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);
+ int old_chans_requested;
+ int i, j;
+
+ mutex_lock(&dln2->mutex);
+
+ old_chans_requested = dln2->chans_requested;
+ dln2->chans_requested |= *indio_dev->active_scan_mask;
+ if (dln2_adc_update_enabled_chans(dln2) < 0) {
+ dln2->chans_requested = old_chans_requested;
+ mutex_unlock(&dln2->mutex);
+ goto done;
+ }
+
+ if (dln2_adc_read_all(dln2, &dev_data) < 0) {
+ mutex_unlock(&dln2->mutex);
+ goto done;
+ }
+
+ mutex_unlock(&dln2->mutex);
+
+ for (i = 0, j = 0;
+ i < bitmap_weight(indio_dev->active_scan_mask,
+ indio_dev->masklength); i++, j++) {
+ j = find_next_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength, j);
+ data.values[i] = dev_data.values[j];
+ }
+
+ 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);
+
+ mutex_lock(&dln2->mutex);
+ dln2->chans_requested |= *indio_dev->active_scan_mask;
+ ret = dln2_adc_update_enabled_chans(dln2);
+ mutex_unlock(&dln2->mutex);
+ if (ret < 0) {
+ dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+ return ret;
+ }
+
+ return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static const struct iio_buffer_setup_ops dln2_adc_buffer_setup_ops = {
+ .postenable = dln2_adc_triggered_buffer_postenable,
+ .predisable = iio_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);
+
+ 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;
+ struct iio_buffer *buffer;
+ int ret;
+ int chans;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(struct dln2_adc));
+ 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;
+ mutex_init(&dln2->mutex);
+ dln2->port_enabled = false;
+ dln2->resolution_set = false;
+ dln2->chans_requested = 0;
+ dln2->chans_enabled = 0;
+ dln2->trigger_chan = -1;
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ chans = dln2_adc_get_chan_count(dln2);
+ if (chans < 0) {
+ dev_err(dev, "failed to get channel count: %d\n", chans);
+ ret = chans;
+ goto dealloc_dev;
+ }
+ if (chans > DLN2_ADC_MAX_CHANNELS) {
+ chans = DLN2_ADC_MAX_CHANNELS;
+ dev_warn(dev, "clamping channels to %d\n",
+ DLN2_ADC_MAX_CHANNELS);
+ }
+
+ 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_BUFFER_TRIGGERED;
+ indio_dev->channels = dln2_adc_iio_channels;
+ indio_dev->num_channels = chans + 1;
+ indio_dev->setup_ops = &dln2_adc_buffer_setup_ops;
+
+ dln2->trig = devm_iio_trigger_alloc(dev, "samplerate");
+ if (!dln2->trig) {
+ dev_err(dev, "failed to allocate trigger\n");
+ ret = -ENOMEM;
+ goto dealloc_dev;
+ }
+ dln2->trig->ops = &dln2_adc_trigger_ops;
+ iio_trigger_set_drvdata(dln2->trig, dln2);
+ iio_trigger_register(dln2->trig);
+ iio_trigger_set_immutable(indio_dev, dln2->trig);
+
+ buffer = devm_iio_kfifo_allocate(dev);
+ if (!buffer) {
+ dev_err(dev, "failed to allocate kfifo\n");
+ ret = -ENOMEM;
+ goto dealloc_trigger;
+ }
+
+ iio_device_attach_buffer(indio_dev, buffer);
+
+ indio_dev->pollfunc = iio_alloc_pollfunc(NULL,
+ &dln2_adc_trigger_h,
+ IRQF_ONESHOT,
+ indio_dev,
+ "samplerate");
+
+ if (!indio_dev->pollfunc) {
+ ret = -ENOMEM;
+ goto dealloc_kfifo;
+ }
+
+ ret = dln2_register_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV,
+ dln2_adc_event);
+ if (ret) {
+ dev_err(dev, "failed to register event cb: %d\n", ret);
+ goto dealloc_pollfunc;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(dev, "failed to register iio device: %d\n", ret);
+ goto dealloc_pollfunc;
+ }
+
+ return 0;
+
+dealloc_pollfunc:
+ iio_dealloc_pollfunc(indio_dev->pollfunc);
+dealloc_kfifo:
+dealloc_trigger:
+ iio_trigger_unregister(dln2->trig);
+dealloc_dev:
+
+ return ret;
+}
+
+static int dln2_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct dln2_adc *dln2 = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ dln2_unregister_event_cb(pdev, DLN2_ADC_CONDITION_MET_EV);
+ iio_trigger_unregister(dln2->trig);
+ iio_dealloc_pollfunc(indio_dev->pollfunc);
+
+ 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");
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
index 704e189..a22ab8c 100644
--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -53,6 +53,7 @@ enum dln2_handle {
DLN2_HANDLE_GPIO,
DLN2_HANDLE_I2C,
DLN2_HANDLE_SPI,
+ DLN2_HANDLE_ADC,
DLN2_HANDLES
};

@@ -663,6 +664,12 @@ static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
.port = 0,
};

+/* Only one ADC port supported */
+static struct dln2_platform_data dln2_pdata_adc = {
+ .handle = DLN2_HANDLE_ADC,
+ .port = 0,
+};
+
static const struct mfd_cell dln2_devs[] = {
{
.name = "dln2-gpio",
@@ -679,6 +686,11 @@ static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
.platform_data = &dln2_pdata_spi,
.pdata_size = sizeof(struct dln2_platform_data),
},
+ {
+ .name = "dln2-adc",
+ .platform_data = &dln2_pdata_adc,
+ .pdata_size = sizeof(struct dln2_platform_data),
+ },
};

static void dln2_stop(struct dln2_dev *dln2)
--
1.9.1