On 20/09/16 03:53, Matt Ranostay wrote: > From: Matt Ranostay <mranostay@xxxxxxxxx> > > 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@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.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@xxxxxxxxx>"); > +MODULE_DESCRIPTION("LMP91000 digital potentiostat"); > +MODULE_LICENSE("GPL"); > -- 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
