// SPDX-License-Identifier: GPL-2.0+ /* * lmp91000.c - Support for Texas Instruments digital potentiostats * * Copyright (C) 2016, 2018 * Author: Matt Ranostay * * TODO: bias voltage + polarity control, and multiple chip support */ #include #include #include #include #include #include #include #include #include #include #include #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; /* 64-bit data + 64-bit naturally aligned timestamp */ u32 buffer[4] __aligned(8); }; 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 = { .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")) { dev_err(dev, "no ti,tia-gain-ohm defined and external resistor not specified\n"); return ret; } val = 0; } 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 = { }; 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->dev.parent = &client->dev; 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", }, { .compatible = "ti,lmp91002", }, { }, }; MODULE_DEVICE_TABLE(of, lmp91000_of_match); static const struct i2c_device_id lmp91000_id[] = { { "lmp91000", 0 }, { "lmp91002", 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 "); MODULE_DESCRIPTION("LMP91000 digital potentiostat"); MODULE_LICENSE("GPL");