diff options
Diffstat (limited to 'drivers/iio/potentiostat/lmp91000.c')
| -rw-r--r-- | drivers/iio/potentiostat/lmp91000.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/drivers/iio/potentiostat/lmp91000.c b/drivers/iio/potentiostat/lmp91000.c new file mode 100644 index 000000000000..e22714365022 --- /dev/null +++ b/drivers/iio/potentiostat/lmp91000.c @@ -0,0 +1,446 @@ +/* + * 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_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer), + data->trig); + if (ret) { + dev_err(dev, "cannot set immutable trigger.\n"); + return ret; + } + + ret = iio_trigger_register(data->trig); + if (ret) { + dev_err(dev, "cannot register iio trigger.\n"); + return ret; + } + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + &lmp91000_buffer_handler, + &lmp91000_buffer_setup_ops); + if (ret) + goto error_unreg_trigger; + + 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_buffer; + } + + data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer); + + ret = iio_device_register(indio_dev); + if (ret) + goto error_unreg_cb_buffer; + + return 0; + +error_unreg_cb_buffer: + iio_channel_release_all_cb(data->cb_buffer); + +error_unreg_buffer: + iio_triggered_buffer_cleanup(indio_dev); + +error_unreg_trigger: + iio_trigger_unregister(data->trig); + + 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"); |