Add support for the LMP91000 potentiostat which is used for chemical sensing applications. Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx> --- .../bindings/iio/potentiostat/lmp91000.txt | 28 ++ drivers/iio/Kconfig | 1 + drivers/iio/Makefile | 1 + drivers/iio/potentiostat/Kconfig | 21 ++ drivers/iio/potentiostat/Makefile | 6 + drivers/iio/potentiostat/lmp91000.c | 303 +++++++++++++++++++++ 6 files changed, 360 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..636c548cedee --- /dev/null +++ b/Documentation/devicetree/bindings/iio/potentiostat/lmp91000.txt @@ -0,0 +1,28 @@ +* 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 and channel of the iio provider + +Optional properties: + + - ti,tia-gain-ohm: ohm value on the feedback loop for the transimpedance + amplifier. Must be 0 (external resistor, default), 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 = <&adc1x1s 0>; +}; diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 6743b18194fb..a31a8cf2c330 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -87,6 +87,7 @@ 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 87e4c4369e2f..2b6e2762a886 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -29,6 +29,7 @@ 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..591682c05ae9 --- /dev/null +++ b/drivers/iio/potentiostat/Kconfig @@ -0,0 +1,21 @@ +# +# 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_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..fe90172eac28 --- /dev/null +++ b/drivers/iio/potentiostat/lmp91000.c @@ -0,0 +1,303 @@ +/* + * lmp91000.c - Support for Texas Instruments digital potentiostats + * + * Copyright (C) 2016 Matt Ranostay <mranostay@xxxxxxxxx> + * + * 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_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 }; + +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_channel *vout_chan; + + u8 buffer[16]; /* 32-bit data + 32-bit padding + 64-bit timestamp */ +}; + +static const struct iio_chan_spec lmp91000_channels[] = { + { /* chemical channel mV */ + .type = IIO_VOLTAGE, + .channel = 0, + .indexed = 1, + .address = LMP91000_REG_MODECN_3LEAD, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 32, + .storagebits = 32, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(1), + { /* temperature channel mV */ + .type = IIO_VOLTAGE, + .channel = 1, + .indexed = 1, + .address = LMP91000_REG_MODECN_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .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); + + ret = iio_read_channel_raw(data->vout_chan, val); + if (ret < 0) + return ret; + + return 0; +} + +static irqreturn_t lmp91000_trigger_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; + + ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val); + if (!ret) { + *((int *) data->buffer) = val; + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, + iio_get_time_ns()); + } + + 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); + int ret; + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + if (iio_device_claim_direct_mode(indio_dev)) + return -EBUSY; + + ret = lmp91000_read(data, chan->address, val); + if (!ret) + ret = IIO_VAL_INT; + + iio_device_release_direct_mode(indio_dev); + + return ret; +} + +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; + int i, val1, val2, ret; + + ret = of_property_read_u32(np, "ti,tia-gain-ohm", &val1); + if (ret) { + val1 = 0; + dev_info(dev, "no ti,tia-gain-ohm defined, default to external\n"); + } + + ret = of_property_read_u32(np, "ti,rload-ohm", &val2); + if (ret) { + val2 = 100; + dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val2); + } + + ret = -EINVAL; + for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) { + if (lmp91000_tia_gain[i] == val1) { + val1 = i; + ret = 0; + break; + } + } + + if (ret) { + dev_err(dev, "invalid ti,tia-gain-ohm %d", val1); + return ret; + } + + ret = -EINVAL; + for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) { + if (lmp91000_rload[i] == val2) { + val2 = i; + ret = 0; + break; + } + } + + if (ret) { + dev_err(dev, "invalid ti,rload-ohm %d", val2); + return ret; + } + + regmap_write(data->regmap, LMP91000_REG_LOCK, 0); + regmap_write(data->regmap, LMP91000_REG_TIACN, + (val1 << LMP91000_REG_TIACN_GAIN_SHIFT) | val2); + 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_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; + struct iio_channel *vout_chan; + int ret; + + vout_chan = iio_channel_get(dev, NULL); + if (IS_ERR(vout_chan)) + return -EPROBE_DEFER; + + 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->vout_chan = vout_chan; + 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); + } + + ret = lmp91000_read_config(data); + if (ret) + return ret; + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + lmp91000_trigger_handler, NULL); + if (ret) + return ret; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_unreg_buffer; + + return 0; + +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_triggered_buffer_cleanup(indio_dev); + iio_channel_release(data->vout_chan); + + 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@xxxxxxxxx>"); +MODULE_DESCRIPTION("LMP91000 digital potentiostat"); +MODULE_LICENSE("GPL"); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
