* [PATCH v5 0/2] iio: potentiostat: add LMP91000 support
@ 2016-09-20 2:53 Matt Ranostay
2016-09-20 2:53 ` [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper Matt Ranostay
2016-09-20 2:53 ` [PATCH v5 2/2] iio: potentiostat: add LMP91000 support Matt Ranostay
0 siblings, 2 replies; 5+ messages in thread
From: Matt Ranostay @ 2016-09-20 2:53 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, Matt Ranostay
Changes from v1:
* Rename ti-adc1x1s.c driver to ti-adc161s626.c
* Switch from iio_channel_read() to using the industrialio-buffer-cb
interface
* Process data in ADC trigger handler for buffer callbacks
* Set the mux trigger to the ADC referenced by io-channels by default
Changes from v2:
* Fix configuration index shifting values
* Switch from wait_for_completion_interruptible to wait_for_completion_timeout
Changes from v3:
* Fix order of probe function error rollback
Changes from v4:
* Report back scale + offset from adc
* Switch temperature channel from IIO_VOLTAGE to IIO_TEMP with processing
* Add iio_read_channel_offset helper
Matt Ranostay (2):
iio: inkern: add iio_read_channel_offset helper
iio: potentiostat: add LMP91000 support
.../bindings/iio/potentiostat/lmp91000.txt | 30 ++
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/inkern.c | 18 +
drivers/iio/potentiostat/Kconfig | 22 ++
drivers/iio/potentiostat/Makefile | 6 +
drivers/iio/potentiostat/lmp91000.c | 439 +++++++++++++++++++++
include/linux/iio/consumer.h | 13 +
8 files changed, 530 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
create mode 100644 drivers/iio/potentiostat/Kconfig
create mode 100644 drivers/iio/potentiostat/Makefile
create mode 100644 drivers/iio/potentiostat/lmp91000.c
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper
2016-09-20 2:53 [PATCH v5 0/2] iio: potentiostat: add LMP91000 support Matt Ranostay
@ 2016-09-20 2:53 ` Matt Ranostay
2016-09-22 18:26 ` Jonathan Cameron
2016-09-20 2:53 ` [PATCH v5 2/2] iio: potentiostat: add LMP91000 support Matt Ranostay
1 sibling, 1 reply; 5+ messages in thread
From: Matt Ranostay @ 2016-09-20 2:53 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, Matt Ranostay
Allow access to underlying channel IIO_CHAN_INFO_OFFSET from a consumer
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
drivers/iio/inkern.c | 18 ++++++++++++++++++
include/linux/iio/consumer.h | 13 +++++++++++++
2 files changed, 31 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index c4757e6367e7..d90af439b0a3 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -658,6 +658,24 @@ err_unlock:
}
EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
+int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
+{
+ int ret;
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_OFFSET);
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_offset);
+
int iio_read_channel_processed(struct iio_channel *chan, int *val)
{
int ret;
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 9edccfba1ffb..638157234357 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -236,6 +236,19 @@ int iio_get_channel_type(struct iio_channel *channel,
enum iio_chan_type *type);
/**
+ * iio_read_channel_offset() - read the offset value for a channel
+ * @chan: The channel being queried.
+ * @val: First part of value read back.
+ * @val2: Second part of value read back.
+ *
+ * Note returns a description of what is in val and val2, such
+ * as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
+ * + val2/1e6
+ */
+int iio_read_channel_offset(struct iio_channel *chan, int *val,
+ int *val2);
+
+/**
* iio_read_channel_scale() - read the scale value for a channel
* @chan: The channel being queried.
* @val: First part of value read back.
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v5 2/2] iio: potentiostat: add LMP91000 support
2016-09-20 2:53 [PATCH v5 0/2] iio: potentiostat: add LMP91000 support Matt Ranostay
2016-09-20 2:53 ` [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper Matt Ranostay
@ 2016-09-20 2:53 ` Matt Ranostay
2016-09-22 18:25 ` Jonathan Cameron
1 sibling, 1 reply; 5+ messages in thread
From: Matt Ranostay @ 2016-09-20 2:53 UTC (permalink / raw)
To: linux-iio; +Cc: jic23, Matt Ranostay, Matt Ranostay
From: Matt Ranostay <mranostay@gmail.com>
Add support for the LMP91000 potentiostat which is used for chemical
sensing applications.
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
.../bindings/iio/potentiostat/lmp91000.txt | 30 ++
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/potentiostat/Kconfig | 22 ++
drivers/iio/potentiostat/Makefile | 6 +
drivers/iio/potentiostat/lmp91000.c | 439 +++++++++++++++++++++
6 files changed, 499 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
create mode 100644 drivers/iio/potentiostat/Kconfig
create mode 100644 drivers/iio/potentiostat/Makefile
create mode 100644 drivers/iio/potentiostat/lmp91000.c
diff --git a/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt b/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
new file mode 100644
index 000000000000..b9b621e94cd7
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
@@ -0,0 +1,30 @@
+* Texas Instruments LMP91000 potentiostat
+
+http://www.ti.com/lit/ds/symlink/lmp91000.pdf
+
+Required properties:
+
+ - compatible: should be "ti,lmp91000"
+ - reg: the I2C address of the device
+ - io-channels: the phandle of the iio provider
+
+ - ti,external-tia-resistor: if the property ti,tia-gain-ohm is not defined this
+ needs to be set to signal that an external resistor value is being used.
+
+Optional properties:
+
+ - ti,tia-gain-ohm: ohm value of the internal resistor for the transimpedance
+ amplifier. Must be 2750, 3500, 7000, 14000, 35000, 120000, or 350000 ohms.
+
+ - ti,rload-ohm: ohm value of the internal resistor load applied to the gas
+ sensor. Must be 10, 33, 50, or 100 (default) ohms.
+
+Example:
+
+lmp91000@48 {
+ compatible = "ti,lmp91000";
+ reg = <0x48>;
+ ti,tia-gain-ohm = <7500>;
+ ti,rload = <100>;
+ io-channels = <&adc>;
+};
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 505e921f0b19..ad5bbaefc18e 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -79,6 +79,7 @@ if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER
source "drivers/iio/potentiometer/Kconfig"
+source "drivers/iio/potentiostat/Kconfig"
source "drivers/iio/pressure/Kconfig"
source "drivers/iio/proximity/Kconfig"
source "drivers/iio/temperature/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 20f649073462..f7369b77ed94 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -28,6 +28,7 @@ obj-y += light/
obj-y += magnetometer/
obj-y += orientation/
obj-y += potentiometer/
+obj-y += potentiostat/
obj-y += pressure/
obj-y += proximity/
obj-y += temperature/
diff --git a/drivers/iio/potentiostat/Kconfig b/drivers/iio/potentiostat/Kconfig
new file mode 100644
index 000000000000..1e3baf2cc97d
--- /dev/null
+++ b/drivers/iio/potentiostat/Kconfig
@@ -0,0 +1,22 @@
+#
+# Potentiostat drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Digital potentiostats"
+
+config LMP91000
+ tristate "Texas Instruments LMP91000 potentiostat driver"
+ depends on I2C
+ select REGMAP_I2C
+ select IIO_BUFFER
+ select IIO_BUFFER_CB
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for the Texas Instruments
+ LMP91000 digital potentiostat chip.
+
+ To compile this driver as a module, choose M here: the
+ module will be called lmp91000
+
+endmenu
diff --git a/drivers/iio/potentiostat/Makefile b/drivers/iio/potentiostat/Makefile
new file mode 100644
index 000000000000..64d315ef4449
--- /dev/null
+++ b/drivers/iio/potentiostat/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for industrial I/O potentiostat drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_LMP91000) += lmp91000.o
diff --git a/drivers/iio/potentiostat/lmp91000.c b/drivers/iio/potentiostat/lmp91000.c
new file mode 100644
index 000000000000..aef11cd9d339
--- /dev/null
+++ b/drivers/iio/potentiostat/lmp91000.c
@@ -0,0 +1,439 @@
+/*
+ * lmp91000.c - Support for Texas Instruments digital potentiostats
+ *
+ * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * TODO: bias voltage + polarity control, and multiple chip support
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define LMP91000_REG_LOCK 0x01
+#define LMP91000_REG_TIACN 0x10
+#define LMP91000_REG_TIACN_GAIN_SHIFT 2
+
+#define LMP91000_REG_REFCN 0x11
+#define LMP91000_REG_REFCN_EXT_REF 0x20
+#define LMP91000_REG_REFCN_50_ZERO 0x80
+
+#define LMP91000_REG_MODECN 0x12
+#define LMP91000_REG_MODECN_3LEAD 0x03
+#define LMP91000_REG_MODECN_TEMP 0x07
+
+#define LMP91000_DRV_NAME "lmp91000"
+
+static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
+ 120000, 350000 };
+
+static const int lmp91000_rload[] = { 10, 33, 50, 100 };
+
+#define LMP91000_TEMP_BASE -40
+
+static const u16 lmp91000_temp_lut[] = {
+ 1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,
+ 1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,
+ 1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,
+ 1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,
+ 1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,
+ 1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,
+ 1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,
+ 1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,
+ 1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,
+ 1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,
+ 1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004, 996,
+ 987, 979, 971, 962, 954, 945, 937, 929, 920, 912,
+ 903, 895, 886, 878, 870, 861 };
+
+static const struct regmap_config lmp91000_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+struct lmp91000_data {
+ struct regmap *regmap;
+ struct device *dev;
+
+ struct iio_trigger *trig;
+ struct iio_cb_buffer *cb_buffer;
+ struct iio_channel *adc_chan;
+
+ struct completion completion;
+ u8 chan_select;
+
+ u32 buffer[4]; /* 64-bit data + 64-bit timestamp */
+};
+
+static const struct iio_chan_spec lmp91000_channels[] = {
+ { /* chemical channel mV */
+ .type = IIO_VOLTAGE,
+ .channel = 0,
+ .address = LMP91000_REG_MODECN_3LEAD,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 32,
+ .storagebits = 32,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+ { /* temperature channel mV */
+ .type = IIO_TEMP,
+ .channel = 1,
+ .address = LMP91000_REG_MODECN_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .scan_index = -1,
+ },
+};
+
+static int lmp91000_read(struct lmp91000_data *data, int channel, int *val)
+{
+ int state, ret;
+
+ ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
+ if (ret)
+ return -EINVAL;
+
+ ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
+ if (ret)
+ return -EINVAL;
+
+ /* delay till first temperature reading is complete */
+ if ((state != channel) && (channel == LMP91000_REG_MODECN_TEMP))
+ usleep_range(3000, 4000);
+
+ data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;
+
+ iio_trigger_poll_chained(data->trig);
+
+ ret = wait_for_completion_timeout(&data->completion, HZ);
+ reinit_completion(&data->completion);
+
+ if (!ret)
+ return -ETIMEDOUT;
+
+ *val = data->buffer[data->chan_select];
+
+ return 0;
+}
+
+static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = private;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct lmp91000_data *data = iio_priv(indio_dev);
+ int ret, val;
+
+ memset(data->buffer, 0, sizeof(data->buffer));
+
+ ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
+ if (!ret) {
+ data->buffer[0] = val;
+ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_get_time_ns(indio_dev));
+ }
+
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int lmp91000_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct lmp91000_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_PROCESSED: {
+ int ret = iio_channel_start_all_cb(data->cb_buffer);
+
+ if (ret)
+ return ret;
+
+ ret = lmp91000_read(data, chan->address, val);
+
+ iio_channel_stop_all_cb(data->cb_buffer);
+
+ if (ret)
+ return ret;
+
+ if (mask == IIO_CHAN_INFO_PROCESSED) {
+ int tmp, i;
+
+ ret = iio_convert_raw_to_processed(data->adc_chan,
+ *val, &tmp, 1);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
+ if (lmp91000_temp_lut[i] < tmp)
+ break;
+
+ *val = (LMP91000_TEMP_BASE + i) * 1000;
+ }
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_OFFSET:
+ return iio_read_channel_offset(data->adc_chan, val, val2);
+ case IIO_CHAN_INFO_SCALE:
+ return iio_read_channel_scale(data->adc_chan, val, val2);
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info lmp91000_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = lmp91000_read_raw,
+};
+
+static int lmp91000_read_config(struct lmp91000_data *data)
+{
+ struct device *dev = data->dev;
+ struct device_node *np = dev->of_node;
+ unsigned int reg, val;
+ int i, ret;
+
+ ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
+ if (ret) {
+ if (of_property_read_bool(np, "ti,external-tia-resistor"))
+ val = 0;
+ else {
+ dev_err(dev, "no ti,tia-gain-ohm defined");
+ return ret;
+ }
+ }
+
+ ret = -EINVAL;
+ for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
+ if (lmp91000_tia_gain[i] == val) {
+ reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
+ ret = 0;
+ break;
+ }
+ }
+
+ if (ret) {
+ dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
+ return ret;
+ }
+
+ ret = of_property_read_u32(np, "ti,rload-ohm", &val);
+ if (ret) {
+ val = 100;
+ dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
+ }
+
+ ret = -EINVAL;
+ for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
+ if (lmp91000_rload[i] == val) {
+ reg |= i;
+ ret = 0;
+ break;
+ }
+ }
+
+ if (ret) {
+ dev_err(dev, "invalid ti,rload-ohm %d\n", val);
+ return ret;
+ }
+
+ regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
+ regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
+ regmap_write(data->regmap, LMP91000_REG_REFCN, LMP91000_REG_REFCN_EXT_REF
+ | LMP91000_REG_REFCN_50_ZERO);
+ regmap_write(data->regmap, LMP91000_REG_LOCK, 1);
+
+ return 0;
+}
+
+static int lmp91000_buffer_cb(const void *val, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct lmp91000_data *data = iio_priv(indio_dev);
+
+ data->buffer[data->chan_select] = *((int *)val);
+ complete_all(&data->completion);
+
+ return 0;
+}
+
+static const struct iio_trigger_ops lmp91000_trigger_ops = {
+ .owner = THIS_MODULE,
+};
+
+
+static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct lmp91000_data *data = iio_priv(indio_dev);
+
+ return iio_channel_start_all_cb(data->cb_buffer);
+}
+
+static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct lmp91000_data *data = iio_priv(indio_dev);
+
+ iio_channel_stop_all_cb(data->cb_buffer);
+
+ return 0;
+}
+
+static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
+ .preenable = lmp91000_buffer_preenable,
+ .postenable = iio_triggered_buffer_postenable,
+ .predisable = lmp91000_buffer_predisable,
+};
+
+static int lmp91000_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct lmp91000_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ indio_dev->info = &lmp91000_info;
+ indio_dev->channels = lmp91000_channels;
+ indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
+ indio_dev->name = LMP91000_DRV_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ i2c_set_clientdata(client, indio_dev);
+
+ data = iio_priv(indio_dev);
+ data->dev = dev;
+ data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
+ if (IS_ERR(data->regmap)) {
+ dev_err(dev, "regmap initialization failed.\n");
+ return PTR_ERR(data->regmap);
+ }
+
+ data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
+ indio_dev->name, indio_dev->id);
+ if (!data->trig) {
+ dev_err(dev, "cannot allocate iio trigger.\n");
+ return -ENOMEM;
+ }
+
+ data->trig->ops = &lmp91000_trigger_ops;
+ data->trig->dev.parent = dev;
+ init_completion(&data->completion);
+
+ ret = lmp91000_read_config(data);
+ if (ret)
+ return ret;
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ &lmp91000_buffer_handler,
+ &lmp91000_buffer_setup_ops);
+ if (ret)
+ return ret;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_unreg_buffer;
+
+ data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
+ indio_dev);
+
+ if (IS_ERR(data->cb_buffer)) {
+ if (PTR_ERR(data->cb_buffer) == -ENODEV)
+ ret = -EPROBE_DEFER;
+ else
+ ret = PTR_ERR(data->cb_buffer);
+
+ goto error_unreg_device;
+ }
+ data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);
+
+ ret = iio_trigger_register(data->trig);
+ if (ret) {
+ dev_err(dev, "cannot register iio trigger.\n");
+ goto error_unreg_cb_buffer;
+ }
+
+ return iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
+ data->trig);
+
+error_unreg_cb_buffer:
+ iio_channel_release_all_cb(data->cb_buffer);
+
+error_unreg_device:
+ iio_device_unregister(indio_dev);
+
+error_unreg_buffer:
+ iio_triggered_buffer_cleanup(indio_dev);
+
+ return ret;
+}
+
+static int lmp91000_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct lmp91000_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ iio_channel_stop_all_cb(data->cb_buffer);
+ iio_channel_release_all_cb(data->cb_buffer);
+
+ iio_triggered_buffer_cleanup(indio_dev);
+ iio_trigger_unregister(data->trig);
+
+ return 0;
+}
+
+static const struct of_device_id lmp91000_of_match[] = {
+ { .compatible = "ti,lmp91000", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lmp91000_of_match);
+
+static const struct i2c_device_id lmp91000_id[] = {
+ { "lmp91000", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, lmp91000_id);
+
+static struct i2c_driver lmp91000_driver = {
+ .driver = {
+ .name = LMP91000_DRV_NAME,
+ .of_match_table = of_match_ptr(lmp91000_of_match),
+ },
+ .probe = lmp91000_probe,
+ .remove = lmp91000_remove,
+ .id_table = lmp91000_id,
+};
+module_i2c_driver(lmp91000_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("LMP91000 digital potentiostat");
+MODULE_LICENSE("GPL");
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v5 2/2] iio: potentiostat: add LMP91000 support
2016-09-20 2:53 ` [PATCH v5 2/2] iio: potentiostat: add LMP91000 support Matt Ranostay
@ 2016-09-22 18:25 ` Jonathan Cameron
0 siblings, 0 replies; 5+ messages in thread
From: Jonathan Cameron @ 2016-09-22 18:25 UTC (permalink / raw)
To: Matt Ranostay, linux-iio; +Cc: Matt Ranostay
On 20/09/16 03:53, Matt Ranostay wrote:
> From: Matt Ranostay <mranostay@gmail.com>
>
> Add support for the LMP91000 potentiostat which is used for chemical
> sensing applications.
>
> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Hi Matt,
A few ordering issues in the probe I didn't notice before.
Jonathan
> ---
> .../bindings/iio/potentiostat/lmp91000.txt | 30 ++
> drivers/iio/Kconfig | 1 +
> drivers/iio/Makefile | 1 +
> drivers/iio/potentiostat/Kconfig | 22 ++
> drivers/iio/potentiostat/Makefile | 6 +
> drivers/iio/potentiostat/lmp91000.c | 439 +++++++++++++++++++++
> 6 files changed, 499 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
> create mode 100644 drivers/iio/potentiostat/Kconfig
> create mode 100644 drivers/iio/potentiostat/Makefile
> create mode 100644 drivers/iio/potentiostat/lmp91000.c
>
> diff --git a/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt b/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
> new file mode 100644
> index 000000000000..b9b621e94cd7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt
> @@ -0,0 +1,30 @@
> +* Texas Instruments LMP91000 potentiostat
> +
> +http://www.ti.com/lit/ds/symlink/lmp91000.pdf
> +
> +Required properties:
> +
> + - compatible: should be "ti,lmp91000"
> + - reg: the I2C address of the device
> + - io-channels: the phandle of the iio provider
> +
> + - ti,external-tia-resistor: if the property ti,tia-gain-ohm is not defined this
> + needs to be set to signal that an external resistor value is being used.
> +
> +Optional properties:
> +
> + - ti,tia-gain-ohm: ohm value of the internal resistor for the transimpedance
> + amplifier. Must be 2750, 3500, 7000, 14000, 35000, 120000, or 350000 ohms.
> +
> + - ti,rload-ohm: ohm value of the internal resistor load applied to the gas
> + sensor. Must be 10, 33, 50, or 100 (default) ohms.
> +
> +Example:
> +
> +lmp91000@48 {
> + compatible = "ti,lmp91000";
> + reg = <0x48>;
> + ti,tia-gain-ohm = <7500>;
> + ti,rload = <100>;
> + io-channels = <&adc>;
> +};
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index 505e921f0b19..ad5bbaefc18e 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -79,6 +79,7 @@ if IIO_TRIGGER
> source "drivers/iio/trigger/Kconfig"
> endif #IIO_TRIGGER
> source "drivers/iio/potentiometer/Kconfig"
> +source "drivers/iio/potentiostat/Kconfig"
> source "drivers/iio/pressure/Kconfig"
> source "drivers/iio/proximity/Kconfig"
> source "drivers/iio/temperature/Kconfig"
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index 20f649073462..f7369b77ed94 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -28,6 +28,7 @@ obj-y += light/
> obj-y += magnetometer/
> obj-y += orientation/
> obj-y += potentiometer/
> +obj-y += potentiostat/
> obj-y += pressure/
> obj-y += proximity/
> obj-y += temperature/
> diff --git a/drivers/iio/potentiostat/Kconfig b/drivers/iio/potentiostat/Kconfig
> new file mode 100644
> index 000000000000..1e3baf2cc97d
> --- /dev/null
> +++ b/drivers/iio/potentiostat/Kconfig
> @@ -0,0 +1,22 @@
> +#
> +# Potentiostat drivers
> +#
> +# When adding new entries keep the list in alphabetical order
> +
> +menu "Digital potentiostats"
> +
> +config LMP91000
> + tristate "Texas Instruments LMP91000 potentiostat driver"
> + depends on I2C
> + select REGMAP_I2C
> + select IIO_BUFFER
> + select IIO_BUFFER_CB
> + select IIO_TRIGGERED_BUFFER
> + help
> + Say yes here to build support for the Texas Instruments
> + LMP91000 digital potentiostat chip.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called lmp91000
> +
> +endmenu
> diff --git a/drivers/iio/potentiostat/Makefile b/drivers/iio/potentiostat/Makefile
> new file mode 100644
> index 000000000000..64d315ef4449
> --- /dev/null
> +++ b/drivers/iio/potentiostat/Makefile
> @@ -0,0 +1,6 @@
> +#
> +# Makefile for industrial I/O potentiostat drivers
> +#
> +
> +# When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_LMP91000) += lmp91000.o
> diff --git a/drivers/iio/potentiostat/lmp91000.c b/drivers/iio/potentiostat/lmp91000.c
> new file mode 100644
> index 000000000000..aef11cd9d339
> --- /dev/null
> +++ b/drivers/iio/potentiostat/lmp91000.c
> @@ -0,0 +1,439 @@
> +/*
> + * lmp91000.c - Support for Texas Instruments digital potentiostats
> + *
> + * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
> + *
> + * 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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * TODO: bias voltage + polarity control, and multiple chip support
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/consumer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#define LMP91000_REG_LOCK 0x01
> +#define LMP91000_REG_TIACN 0x10
> +#define LMP91000_REG_TIACN_GAIN_SHIFT 2
> +
> +#define LMP91000_REG_REFCN 0x11
> +#define LMP91000_REG_REFCN_EXT_REF 0x20
> +#define LMP91000_REG_REFCN_50_ZERO 0x80
> +
> +#define LMP91000_REG_MODECN 0x12
> +#define LMP91000_REG_MODECN_3LEAD 0x03
> +#define LMP91000_REG_MODECN_TEMP 0x07
> +
> +#define LMP91000_DRV_NAME "lmp91000"
> +
> +static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,
> + 120000, 350000 };
> +
> +static const int lmp91000_rload[] = { 10, 33, 50, 100 };
> +
> +#define LMP91000_TEMP_BASE -40
> +
> +static const u16 lmp91000_temp_lut[] = {
> + 1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,
> + 1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,
> + 1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,
> + 1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,
> + 1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,
> + 1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,
> + 1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,
> + 1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,
> + 1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,
> + 1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,
> + 1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004, 996,
> + 987, 979, 971, 962, 954, 945, 937, 929, 920, 912,
> + 903, 895, 886, 878, 870, 861 };
> +
> +static const struct regmap_config lmp91000_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
> +
> +struct lmp91000_data {
> + struct regmap *regmap;
> + struct device *dev;
> +
> + struct iio_trigger *trig;
> + struct iio_cb_buffer *cb_buffer;
> + struct iio_channel *adc_chan;
> +
> + struct completion completion;
> + u8 chan_select;
> +
> + u32 buffer[4]; /* 64-bit data + 64-bit timestamp */
> +};
> +
> +static const struct iio_chan_spec lmp91000_channels[] = {
> + { /* chemical channel mV */
> + .type = IIO_VOLTAGE,
> + .channel = 0,
> + .address = LMP91000_REG_MODECN_3LEAD,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 32,
> + .storagebits = 32,
> + },
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(1),
> + { /* temperature channel mV */
> + .type = IIO_TEMP,
> + .channel = 1,
> + .address = LMP91000_REG_MODECN_TEMP,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> + .scan_index = -1,
> + },
> +};
> +
> +static int lmp91000_read(struct lmp91000_data *data, int channel, int *val)
> +{
> + int state, ret;
> +
> + ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state);
> + if (ret)
> + return -EINVAL;
> +
> + ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel);
> + if (ret)
> + return -EINVAL;
> +
> + /* delay till first temperature reading is complete */
> + if ((state != channel) && (channel == LMP91000_REG_MODECN_TEMP))
> + usleep_range(3000, 4000);
> +
> + data->chan_select = channel != LMP91000_REG_MODECN_3LEAD;
> +
> + iio_trigger_poll_chained(data->trig);
> +
> + ret = wait_for_completion_timeout(&data->completion, HZ);
> + reinit_completion(&data->completion);
> +
> + if (!ret)
> + return -ETIMEDOUT;
> +
> + *val = data->buffer[data->chan_select];
> +
> + return 0;
> +}
> +
> +static irqreturn_t lmp91000_buffer_handler(int irq, void *private)
> +{
> + struct iio_poll_func *pf = private;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct lmp91000_data *data = iio_priv(indio_dev);
> + int ret, val;
> +
> + memset(data->buffer, 0, sizeof(data->buffer));
> +
> + ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val);
> + if (!ret) {
> + data->buffer[0] = val;
> + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> + iio_get_time_ns(indio_dev));
> + }
> +
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int lmp91000_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct lmp91000_data *data = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + case IIO_CHAN_INFO_PROCESSED: {
> + int ret = iio_channel_start_all_cb(data->cb_buffer);
> +
> + if (ret)
> + return ret;
> +
> + ret = lmp91000_read(data, chan->address, val);
> +
> + iio_channel_stop_all_cb(data->cb_buffer);
> +
> + if (ret)
> + return ret;
> +
> + if (mask == IIO_CHAN_INFO_PROCESSED) {
> + int tmp, i;
> +
> + ret = iio_convert_raw_to_processed(data->adc_chan,
> + *val, &tmp, 1);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++)
> + if (lmp91000_temp_lut[i] < tmp)
> + break;
> +
> + *val = (LMP91000_TEMP_BASE + i) * 1000;
> + }
> + return IIO_VAL_INT;
> + }
> + case IIO_CHAN_INFO_OFFSET:
> + return iio_read_channel_offset(data->adc_chan, val, val2);
> + case IIO_CHAN_INFO_SCALE:
> + return iio_read_channel_scale(data->adc_chan, val, val2);
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info lmp91000_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = lmp91000_read_raw,
> +};
> +
> +static int lmp91000_read_config(struct lmp91000_data *data)
> +{
> + struct device *dev = data->dev;
> + struct device_node *np = dev->of_node;
> + unsigned int reg, val;
> + int i, ret;
> +
> + ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val);
> + if (ret) {
> + if (of_property_read_bool(np, "ti,external-tia-resistor"))
> + val = 0;
> + else {
> + dev_err(dev, "no ti,tia-gain-ohm defined");
> + return ret;
> + }
> + }
> +
> + ret = -EINVAL;
> + for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) {
> + if (lmp91000_tia_gain[i] == val) {
> + reg = i << LMP91000_REG_TIACN_GAIN_SHIFT;
> + ret = 0;
> + break;
> + }
> + }
> +
> + if (ret) {
> + dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val);
> + return ret;
> + }
> +
> + ret = of_property_read_u32(np, "ti,rload-ohm", &val);
> + if (ret) {
> + val = 100;
> + dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val);
> + }
> +
> + ret = -EINVAL;
> + for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) {
> + if (lmp91000_rload[i] == val) {
> + reg |= i;
> + ret = 0;
> + break;
> + }
> + }
> +
> + if (ret) {
> + dev_err(dev, "invalid ti,rload-ohm %d\n", val);
> + return ret;
> + }
> +
> + regmap_write(data->regmap, LMP91000_REG_LOCK, 0);
> + regmap_write(data->regmap, LMP91000_REG_TIACN, reg);
> + regmap_write(data->regmap, LMP91000_REG_REFCN, LMP91000_REG_REFCN_EXT_REF
> + | LMP91000_REG_REFCN_50_ZERO);
> + regmap_write(data->regmap, LMP91000_REG_LOCK, 1);
> +
> + return 0;
> +}
> +
> +static int lmp91000_buffer_cb(const void *val, void *private)
> +{
> + struct iio_dev *indio_dev = private;
> + struct lmp91000_data *data = iio_priv(indio_dev);
> +
> + data->buffer[data->chan_select] = *((int *)val);
> + complete_all(&data->completion);
> +
> + return 0;
> +}
> +
> +static const struct iio_trigger_ops lmp91000_trigger_ops = {
> + .owner = THIS_MODULE,
> +};
> +
> +
> +static int lmp91000_buffer_preenable(struct iio_dev *indio_dev)
> +{
> + struct lmp91000_data *data = iio_priv(indio_dev);
> +
> + return iio_channel_start_all_cb(data->cb_buffer);
> +}
> +
> +static int lmp91000_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct lmp91000_data *data = iio_priv(indio_dev);
> +
> + iio_channel_stop_all_cb(data->cb_buffer);
> +
> + return 0;
> +}
> +
> +static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = {
> + .preenable = lmp91000_buffer_preenable,
> + .postenable = iio_triggered_buffer_postenable,
> + .predisable = lmp91000_buffer_predisable,
> +};
> +
> +static int lmp91000_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct lmp91000_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + indio_dev->info = &lmp91000_info;
> + indio_dev->channels = lmp91000_channels;
> + indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels);
> + indio_dev->name = LMP91000_DRV_NAME;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + i2c_set_clientdata(client, indio_dev);
> +
> + data = iio_priv(indio_dev);
> + data->dev = dev;
> + data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config);
> + if (IS_ERR(data->regmap)) {
> + dev_err(dev, "regmap initialization failed.\n");
> + return PTR_ERR(data->regmap);
> + }
> +
> + data->trig = devm_iio_trigger_alloc(data->dev, "%s-mux%d",
> + indio_dev->name, indio_dev->id);
> + if (!data->trig) {
> + dev_err(dev, "cannot allocate iio trigger.\n");
> + return -ENOMEM;
> + }
> +
> + data->trig->ops = &lmp91000_trigger_ops;
> + data->trig->dev.parent = dev;
> + init_completion(&data->completion);
> +
> + ret = lmp91000_read_config(data);
> + if (ret)
> + return ret;
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + &lmp91000_buffer_handler,
> + &lmp91000_buffer_setup_ops);
> + if (ret)
> + return ret;
> +
> + ret = iio_device_register(indio_dev);
I've been half asleep during previous reviews. This exposes the userspace
interfaces which makes for some nasty race conditions with everything that
follows. I think this needs to be pretty much that last thing to happen.
> + if (ret)
> + goto error_unreg_buffer;
> +
> + data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb,
> + indio_dev);
> +
> + if (IS_ERR(data->cb_buffer)) {
> + if (PTR_ERR(data->cb_buffer) == -ENODEV)
> + ret = -EPROBE_DEFER;
> + else
> + ret = PTR_ERR(data->cb_buffer);
> +
> + goto error_unreg_device;
> + }
> + data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer);
> +
> + ret = iio_trigger_register(data->trig);
> + if (ret) {
> + dev_err(dev, "cannot register iio trigger.\n");
> + goto error_unreg_cb_buffer;
> + }
> +
Technically there is a race here, be it a really short one against the trigger
register. Don't think anything prevents us doing this before registering the
trigger.
> + return iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer),
> + data->trig);
> +
> +error_unreg_cb_buffer:
> + iio_channel_release_all_cb(data->cb_buffer);
> +
> +error_unreg_device:
> + iio_device_unregister(indio_dev);
> +
> +error_unreg_buffer:
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> +}
> +
> +static int lmp91000_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct lmp91000_data *data = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> +
> + iio_channel_stop_all_cb(data->cb_buffer);
> + iio_channel_release_all_cb(data->cb_buffer);
> +
> + iio_triggered_buffer_cleanup(indio_dev);
> + iio_trigger_unregister(data->trig);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id lmp91000_of_match[] = {
> + { .compatible = "ti,lmp91000", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, lmp91000_of_match);
> +
> +static const struct i2c_device_id lmp91000_id[] = {
> + { "lmp91000", 0 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(i2c, lmp91000_id);
> +
> +static struct i2c_driver lmp91000_driver = {
> + .driver = {
> + .name = LMP91000_DRV_NAME,
> + .of_match_table = of_match_ptr(lmp91000_of_match),
> + },
> + .probe = lmp91000_probe,
> + .remove = lmp91000_remove,
> + .id_table = lmp91000_id,
> +};
> +module_i2c_driver(lmp91000_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
> +MODULE_DESCRIPTION("LMP91000 digital potentiostat");
> +MODULE_LICENSE("GPL");
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper
2016-09-20 2:53 ` [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper Matt Ranostay
@ 2016-09-22 18:26 ` Jonathan Cameron
0 siblings, 0 replies; 5+ messages in thread
From: Jonathan Cameron @ 2016-09-22 18:26 UTC (permalink / raw)
To: Matt Ranostay, linux-iio; +Cc: Matt Ranostay
On 20/09/16 03:53, Matt Ranostay wrote:
> Allow access to underlying channel IIO_CHAN_INFO_OFFSET from a consumer
>
> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Hmm. This one is useful enough to justify it's own function, but
sooner or later we should just have a single query that reads any
of the info_mask elements if present.
Bonus points for a generic function that allows code sharing even
for just the scale and offset cases that are now present.
If that function was also exported then all the better - would
need moving the info_mask define out to types.h probably so the
stuff in iio.h can remain opaque to consumers that aren't IIO
drivers.
Thanks,
Jonathan
> ---
> drivers/iio/inkern.c | 18 ++++++++++++++++++
> include/linux/iio/consumer.h | 13 +++++++++++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index c4757e6367e7..d90af439b0a3 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -658,6 +658,24 @@ err_unlock:
> }
> EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
>
> +int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
> +{
> + int ret;
> +
> + mutex_lock(&chan->indio_dev->info_exist_lock);
> + if (chan->indio_dev->info == NULL) {
> + ret = -ENODEV;
> + goto err_unlock;
> + }
> +
> + ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_OFFSET);
> +err_unlock:
> + mutex_unlock(&chan->indio_dev->info_exist_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(iio_read_channel_offset);
> +
> int iio_read_channel_processed(struct iio_channel *chan, int *val)
> {
> int ret;
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index 9edccfba1ffb..638157234357 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -236,6 +236,19 @@ int iio_get_channel_type(struct iio_channel *channel,
> enum iio_chan_type *type);
>
> /**
> + * iio_read_channel_offset() - read the offset value for a channel
> + * @chan: The channel being queried.
> + * @val: First part of value read back.
> + * @val2: Second part of value read back.
> + *
> + * Note returns a description of what is in val and val2, such
> + * as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
> + * + val2/1e6
> + */
> +int iio_read_channel_offset(struct iio_channel *chan, int *val,
> + int *val2);
> +
> +/**
> * iio_read_channel_scale() - read the scale value for a channel
> * @chan: The channel being queried.
> * @val: First part of value read back.
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-09-22 18:27 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-20 2:53 [PATCH v5 0/2] iio: potentiostat: add LMP91000 support Matt Ranostay
2016-09-20 2:53 ` [PATCH v5 1/2] iio: inkern: add iio_read_channel_offset helper Matt Ranostay
2016-09-22 18:26 ` Jonathan Cameron
2016-09-20 2:53 ` [PATCH v5 2/2] iio: potentiostat: add LMP91000 support Matt Ranostay
2016-09-22 18:25 ` Jonathan Cameron
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