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SubjectRe: [PATCH v5 1/3] iio: adc: Add support for DLN2 ADC
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On 5 July 2017 22:12:46 BST, Jack Andersen <jackoalan@gmail.com> wrote:
>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@gmail.com>

The remove order differs from opposite of probe due to use of devm after an non managed call.

Result doesn't pass the obviously correct test of the lazy maintainer :)
>---
>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@pmeerw.net>
>---
>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@kernel.org>
>---
>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@kernel.org>
>---
> 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);
Potential race here as iio_device_register will be unwound after this... Use non devm form
to keep ordering.
>+ 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@gmail.com");
>+MODULE_DESCRIPTION("Driver for the Diolan DLN2 ADC interface");
>+MODULE_LICENSE("GPL v2");
>+MODULE_ALIAS("platform:dln2-adc");

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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