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linux/drivers/iio/potentiostat/lmp91000.c
Lars-Peter Clausen e78c1f5710 iio: lmp91000: Set parent device 
Initialize the parent of the IIO device to the device that registered it.
This makes sure that the IIO device appears the right level in the device
hierarchy.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-02-19 12:01:52 +00:00

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/*
* 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->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", },
{ },
};
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");
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