* [PATCH] iio: temperature: add support for Maxim thermocouple chips
@ 2016-05-27 1:31 Matt Ranostay
2016-05-27 1:58 ` Marek Vasut
2016-05-27 12:46 ` Daniel Baluta
0 siblings, 2 replies; 4+ messages in thread
From: Matt Ranostay @ 2016-05-27 1:31 UTC (permalink / raw)
To: jic23; +Cc: linux-iio, Matt Ranostay, Marek Vasut, Matt Porter
Add initial driver support for MAX6675, and MAX31885 thermocouple chips.
Cc: Marek Vasut <marex@denx.de>
Cc: Matt Porter <mporter@konsulko.com>
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
.../iio/temperature/maxim_thermocouple.txt | 21 ++
drivers/iio/temperature/Kconfig | 14 ++
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/maxim_thermocouple.c | 278 +++++++++++++++++++++
4 files changed, 314 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
create mode 100644 drivers/iio/temperature/maxim_thermocouple.c
diff --git a/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
new file mode 100644
index 0000000..7ab4aa1
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
@@ -0,0 +1,21 @@
+Maxim thermocouple support
+
+* https://datasheets.maximintegrated.com/en/ds/MAX6675.pdf
+* https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf
+
+Required properties:
+
+ - compatible: must be "maxim,max31885" or "maxim,max6675"
+ - reg: SPI chip select number for the device
+ - spi-max-frequency: must be 4300000
+ - spi-cpha: must be defined for max6675 to enable SPI mode 1
+
+ Refer to spi/spi-bus.txt for generic SPI slave bindings
+
+Example:
+
+ max31885@0 {
+ compatible = "maxim,max31885";
+ reg = <0>;
+ spi-max-frequency = <4300000>;
+ };
diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index c4664e5..c9f5342 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -3,6 +3,20 @@
#
menu "Temperature sensors"
+config MAXIM_THERMOCOUPLE
+ tristate "Maxim thermocouple sensors"
+ depends on SPI
+ help
+ If you say yes here you get support for the Maxim series of
+ thermocouple sensors connected via SPI.
+
+ Supported sensors:
+ * MAX6675
+ * MAX31885
+
+ This driver can also be built as a module. If so, the module will
+ be called maxim_thermocouple.
+
config MLX90614
tristate "MLX90614 contact-less infrared sensor"
depends on I2C
diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index 02bc79d..78c3de0 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -2,6 +2,7 @@
# Makefile for industrial I/O temperature drivers
#
+obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
obj-$(CONFIG_MLX90614) += mlx90614.o
obj-$(CONFIG_TMP006) += tmp006.o
obj-$(CONFIG_TSYS01) += tsys01.o
diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
new file mode 100644
index 0000000..c9c9be9
--- /dev/null
+++ b/drivers/iio/temperature/maxim_thermocouple.c
@@ -0,0 +1,278 @@
+/*
+ * maxim_thermocouple.c - Support for Maxim thermocouple chips
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define MAXIM_THERMOCOUPLE_DRV_NAME "maxim_thermocouple"
+
+enum {
+ MAX6675,
+ MAX31885,
+};
+
+struct iio_chan_spec max6675_channels[] = {
+ { /* thermocouple temperature */
+ .type = IIO_TEMP,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 13,
+ .storagebits = 16,
+ .shift = 3,
+ .endianness = IIO_BE,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+struct iio_chan_spec max31885_channels[] = {
+ { /* thermocouple temperature */
+ .type = IIO_TEMP,
+ .address = 2,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 14,
+ .storagebits = 16,
+ .shift = 2,
+ .endianness = IIO_BE,
+ },
+ },
+ { /* cold junction temperature */
+ .type = IIO_TEMP,
+ .channel2 = IIO_MOD_TEMP_AMBIENT,
+ .modified = 1,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 12,
+ .storagebits = 16,
+ .shift = 4,
+ .endianness = IIO_BE,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+struct maxim_thermocouple_chip {
+ const struct iio_chan_spec *channels;
+ int num_channels;
+ int read_size;
+
+ /* bit-check for valid input */
+ int status_bit;
+};
+
+struct maxim_thermocouple_chip maxim_thermocouple_chips[] = {
+ [MAX6675] = {
+ .channels = max6675_channels,
+ .num_channels = ARRAY_SIZE(max6675_channels),
+ .read_size = 2,
+ .status_bit = BIT(2),
+ },
+ [MAX31885] = {
+ .channels = max31885_channels,
+ .num_channels = ARRAY_SIZE(max31885_channels),
+ .read_size = 4,
+ .status_bit = BIT(16),
+ },
+};
+
+struct maxim_thermocouple_data {
+ struct spi_device *spi;
+ struct maxim_thermocouple_chip *chip;
+
+ u8 buffer[16]; /* 4 byte data + 4 byte padding + 8 byte timestamp */
+};
+
+static int maxim_thermocouple_read(struct maxim_thermocouple_data *data,
+ struct iio_chan_spec const *chan, int *val)
+{
+ unsigned int storage_bytes = data->chip->read_size;
+ unsigned int shift = chan->scan_type.shift + (chan->address * 8);
+ unsigned int buf;
+ int ret;
+
+ ret = spi_read(data->spi, (void *) &buf, storage_bytes);
+ if (ret)
+ return ret;
+
+ switch (storage_bytes) {
+ case 2:
+ *val = be16_to_cpu(buf);
+ break;
+ case 4:
+ *val = be32_to_cpu(buf);
+ break;
+ }
+
+ /* check to be sure this is a valid reading */
+ if (*val & data->chip->status_bit)
+ return -EINVAL;
+
+ *val = sign_extend32(*val >> shift, chan->scan_type.realbits - 1);
+
+ return 0;
+}
+
+static irqreturn_t maxim_thermocouple_trigger_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = private;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct maxim_thermocouple_data *data = iio_priv(indio_dev);
+ int ret;
+
+ /* userspace HAL must do validation of data pushed to buffers */
+ ret = spi_read(data->spi, (void *) &data->buffer, data->chip->read_size);
+ if (!ret)
+ 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 maxim_thermocouple_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct maxim_thermocouple_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ mutex_lock(&indio_dev->mlock);
+
+ if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
+ ret = -EBUSY;
+ goto error_busy;
+ }
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = maxim_thermocouple_read(data, chan, val);
+ if (!ret)
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->channel2) {
+ case IIO_MOD_TEMP_AMBIENT:
+ *val = 62;
+ *val2 = 500000; /* 1000 * 0.0625 */
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ default:
+ *val = 250; /* 1000 * 0.25 */
+ ret = IIO_VAL_INT;
+ };
+ break;
+ }
+
+error_busy:
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static const struct iio_info maxim_thermocouple_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = maxim_thermocouple_read_raw,
+};
+
+static int maxim_thermocouple_probe(struct spi_device *spi)
+{
+ const struct spi_device_id *id = spi_get_device_id(spi);
+ struct iio_dev *indio_dev;
+ struct maxim_thermocouple_data *data;
+ struct maxim_thermocouple_chip *chip =
+ &maxim_thermocouple_chips[id->driver_data];
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ indio_dev->info = &maxim_thermocouple_info;
+ indio_dev->name = MAXIM_THERMOCOUPLE_DRV_NAME;
+ indio_dev->channels = chip->channels;
+ indio_dev->num_channels = chip->num_channels;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ data = iio_priv(indio_dev);
+ data->spi = spi;
+ data->chip = chip;
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ maxim_thermocouple_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 maxim_thermocouple_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+
+ return 0;
+}
+
+static const struct spi_device_id maxim_thermocouple_id[] = {
+ {"max6675", MAX6675},
+ {"max31885", MAX31885},
+ {},
+};
+MODULE_DEVICE_TABLE(spi, maxim_thermocouple_id);
+
+static struct spi_driver maxim_thermocouple_driver = {
+ .driver = {
+ .name = MAXIM_THERMOCOUPLE_DRV_NAME,
+ },
+ .probe = maxim_thermocouple_probe,
+ .remove = maxim_thermocouple_remove,
+ .id_table = maxim_thermocouple_id,
+};
+module_spi_driver(maxim_thermocouple_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("Maxim thermocouple sensors");
+MODULE_LICENSE("GPL");
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: temperature: add support for Maxim thermocouple chips
2016-05-27 1:31 [PATCH] iio: temperature: add support for Maxim thermocouple chips Matt Ranostay
@ 2016-05-27 1:58 ` Marek Vasut
2016-05-27 2:19 ` Matt Ranostay
2016-05-27 12:46 ` Daniel Baluta
1 sibling, 1 reply; 4+ messages in thread
From: Marek Vasut @ 2016-05-27 1:58 UTC (permalink / raw)
To: Matt Ranostay, jic23; +Cc: linux-iio, Matt Porter
On 05/27/2016 03:31 AM, Matt Ranostay wrote:
> Add initial driver support for MAX6675, and MAX31885 thermocouple chips.
>
> Cc: Marek Vasut <marex@denx.de>
> Cc: Matt Porter <mporter@konsulko.com>
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> ---
> .../iio/temperature/maxim_thermocouple.txt | 21 ++
> drivers/iio/temperature/Kconfig | 14 ++
> drivers/iio/temperature/Makefile | 1 +
> drivers/iio/temperature/maxim_thermocouple.c | 278 +++++++++++++++++++++
> 4 files changed, 314 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
> create mode 100644 drivers/iio/temperature/maxim_thermocouple.c
>
> diff --git a/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
> new file mode 100644
> index 0000000..7ab4aa1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
> @@ -0,0 +1,21 @@
> +Maxim thermocouple support
> +
> +* https://datasheets.maximintegrated.com/en/ds/MAX6675.pdf
> +* https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf
> +
> +Required properties:
> +
> + - compatible: must be "maxim,max31885" or "maxim,max6675"
> + - reg: SPI chip select number for the device
> + - spi-max-frequency: must be 4300000
> + - spi-cpha: must be defined for max6675 to enable SPI mode 1
> +
> + Refer to spi/spi-bus.txt for generic SPI slave bindings
Fullstop is missing here at the end of the sentence ;-)
> +
> +Example:
> +
> + max31885@0 {
> + compatible = "maxim,max31885";
> + reg = <0>;
> + spi-max-frequency = <4300000>;
> + };
> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
> index c4664e5..c9f5342 100644
> --- a/drivers/iio/temperature/Kconfig
> +++ b/drivers/iio/temperature/Kconfig
> @@ -3,6 +3,20 @@
> #
> menu "Temperature sensors"
>
> +config MAXIM_THERMOCOUPLE
> + tristate "Maxim thermocouple sensors"
> + depends on SPI
> + help
> + If you say yes here you get support for the Maxim series of
> + thermocouple sensors connected via SPI.
> +
> + Supported sensors:
> + * MAX6675
> + * MAX31885
> +
> + This driver can also be built as a module. If so, the module will
> + be called maxim_thermocouple.
> +
> config MLX90614
> tristate "MLX90614 contact-less infrared sensor"
> depends on I2C
> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
> index 02bc79d..78c3de0 100644
> --- a/drivers/iio/temperature/Makefile
> +++ b/drivers/iio/temperature/Makefile
> @@ -2,6 +2,7 @@
> # Makefile for industrial I/O temperature drivers
> #
>
> +obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
> obj-$(CONFIG_MLX90614) += mlx90614.o
> obj-$(CONFIG_TMP006) += tmp006.o
> obj-$(CONFIG_TSYS01) += tsys01.o
> diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
> new file mode 100644
> index 0000000..c9c9be9
> --- /dev/null
> +++ b/drivers/iio/temperature/maxim_thermocouple.c
> @@ -0,0 +1,278 @@
> +/*
> + * maxim_thermocouple.c - Support for Maxim thermocouple chips
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/mutex.h>
> +#include <linux/err.h>
> +#include <linux/spi/spi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +
> +#define MAXIM_THERMOCOUPLE_DRV_NAME "maxim_thermocouple"
> +
> +enum {
> + MAX6675,
> + MAX31885,
> +};
> +
> +struct iio_chan_spec max6675_channels[] = {
static const ?
> + { /* thermocouple temperature */
> + .type = IIO_TEMP,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 13,
> + .storagebits = 16,
> + .shift = 3,
> + .endianness = IIO_BE,
> + },
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(1),
> +};
> +
> +struct iio_chan_spec max31885_channels[] = {
Also static const ?
> + { /* thermocouple temperature */
> + .type = IIO_TEMP,
> + .address = 2,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 14,
> + .storagebits = 16,
> + .shift = 2,
> + .endianness = IIO_BE,
> + },
> + },
> + { /* cold junction temperature */
> + .type = IIO_TEMP,
> + .channel2 = IIO_MOD_TEMP_AMBIENT,
> + .modified = 1,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 1,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 12,
> + .storagebits = 16,
> + .shift = 4,
> + .endianness = IIO_BE,
> + },
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(2),
> +};
> +
> +struct maxim_thermocouple_chip {
> + const struct iio_chan_spec *channels;
> + int num_channels;
> + int read_size;
> +
> + /* bit-check for valid input */
> + int status_bit;
I believe all of the members can be const and the structure below can
also be static const.
> +};
> +
> +struct maxim_thermocouple_chip maxim_thermocouple_chips[] = {
> + [MAX6675] = {
> + .channels = max6675_channels,
> + .num_channels = ARRAY_SIZE(max6675_channels),
> + .read_size = 2,
> + .status_bit = BIT(2),
> + },
> + [MAX31885] = {
> + .channels = max31885_channels,
> + .num_channels = ARRAY_SIZE(max31885_channels),
> + .read_size = 4,
> + .status_bit = BIT(16),
> + },
> +};
> +
> +struct maxim_thermocouple_data {
> + struct spi_device *spi;
> + struct maxim_thermocouple_chip *chip;
> +
> + u8 buffer[16]; /* 4 byte data + 4 byte padding + 8 byte timestamp */
> +};
> +
> +static int maxim_thermocouple_read(struct maxim_thermocouple_data *data,
> + struct iio_chan_spec const *chan, int *val)
> +{
> + unsigned int storage_bytes = data->chip->read_size;
> + unsigned int shift = chan->scan_type.shift + (chan->address * 8);
> + unsigned int buf;
> + int ret;
> +
> + ret = spi_read(data->spi, (void *) &buf, storage_bytes);
> + if (ret)
> + return ret;
> +
> + switch (storage_bytes) {
> + case 2:
> + *val = be16_to_cpu(buf);
> + break;
> + case 4:
> + *val = be32_to_cpu(buf);
> + break;
if (storage_bytes == 2)
*val ...
else if (storage_bytes == 4)
*val ...
is half the length of the code :-)
> + }
> +
> + /* check to be sure this is a valid reading */
> + if (*val & data->chip->status_bit)
> + return -EINVAL;
> +
> + *val = sign_extend32(*val >> shift, chan->scan_type.realbits - 1);
> +
> + return 0;
> +}
> +
> +static irqreturn_t maxim_thermocouple_trigger_handler(int irq, void *private)
> +{
> + struct iio_poll_func *pf = private;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct maxim_thermocouple_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + /* userspace HAL must do validation of data pushed to buffers */
> + ret = spi_read(data->spi, (void *) &data->buffer, data->chip->read_size);
I suspect you this should be
ret = spi_read(data->spi, data->buffer, data->chip->read_size);
since data->buffer is already (u8 *). The compiler didn't generate an
error because you typecast the second argument.
> + if (!ret)
> + 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 maxim_thermocouple_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct maxim_thermocouple_data *data = iio_priv(indio_dev);
> + int ret = -EINVAL;
> +
> + mutex_lock(&indio_dev->mlock);
> +
> + if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
> + ret = -EBUSY;
> + goto error_busy;
> + }
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + ret = maxim_thermocouple_read(data, chan, val);
> + if (!ret)
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->channel2) {
> + case IIO_MOD_TEMP_AMBIENT:
> + *val = 62;
> + *val2 = 500000; /* 1000 * 0.0625 */
> + ret = IIO_VAL_INT_PLUS_MICRO;
> + break;
> + default:
> + *val = 250; /* 1000 * 0.25 */
> + ret = IIO_VAL_INT;
> + };
> + break;
> + }
> +
> +error_busy:
> + mutex_unlock(&indio_dev->mlock);
> +
> + return ret;
> +}
> +
> +static const struct iio_info maxim_thermocouple_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = maxim_thermocouple_read_raw,
> +};
> +
> +static int maxim_thermocouple_probe(struct spi_device *spi)
> +{
> + const struct spi_device_id *id = spi_get_device_id(spi);
> + struct iio_dev *indio_dev;
> + struct maxim_thermocouple_data *data;
> + struct maxim_thermocouple_chip *chip =
> + &maxim_thermocouple_chips[id->driver_data];
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + indio_dev->info = &maxim_thermocouple_info;
> + indio_dev->name = MAXIM_THERMOCOUPLE_DRV_NAME;
> + indio_dev->channels = chip->channels;
> + indio_dev->num_channels = chip->num_channels;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + data = iio_priv(indio_dev);
> + data->spi = spi;
> + data->chip = chip;
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + maxim_thermocouple_trigger_handler, NULL);
> + if (ret)
> + return ret;
> +
> + ret = iio_device_register(indio_dev);
devm_iio_device_register() ?
> + if (ret)
> + goto error_unreg_buffer;
> +
> + return 0;
> +
> +error_unreg_buffer:
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> +}
> +
> +static int maxim_thermocouple_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return 0;
> +}
> +
> +static const struct spi_device_id maxim_thermocouple_id[] = {
> + {"max6675", MAX6675},
> + {"max31885", MAX31885},
> + {},
> +};
> +MODULE_DEVICE_TABLE(spi, maxim_thermocouple_id);
> +
> +static struct spi_driver maxim_thermocouple_driver = {
> + .driver = {
> + .name = MAXIM_THERMOCOUPLE_DRV_NAME,
> + },
> + .probe = maxim_thermocouple_probe,
> + .remove = maxim_thermocouple_remove,
> + .id_table = maxim_thermocouple_id,
> +};
> +module_spi_driver(maxim_thermocouple_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
> +MODULE_DESCRIPTION("Maxim thermocouple sensors");
> +MODULE_LICENSE("GPL");
>
--
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: temperature: add support for Maxim thermocouple chips
2016-05-27 1:58 ` Marek Vasut
@ 2016-05-27 2:19 ` Matt Ranostay
0 siblings, 0 replies; 4+ messages in thread
From: Matt Ranostay @ 2016-05-27 2:19 UTC (permalink / raw)
To: Marek Vasut; +Cc: Jonathan Cameron, linux-iio@vger.kernel.org, Matt Porter
On Thu, May 26, 2016 at 6:58 PM, Marek Vasut <marex@denx.de> wrote:
> On 05/27/2016 03:31 AM, Matt Ranostay wrote:
>> Add initial driver support for MAX6675, and MAX31885 thermocouple chips.
>>
>> Cc: Marek Vasut <marex@denx.de>
>> Cc: Matt Porter <mporter@konsulko.com>
>> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
>> ---
>> .../iio/temperature/maxim_thermocouple.txt | 21 ++
>> drivers/iio/temperature/Kconfig | 14 ++
>> drivers/iio/temperature/Makefile | 1 +
>> drivers/iio/temperature/maxim_thermocouple.c | 278 +++++++++++++++++++++
>> 4 files changed, 314 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
>> create mode 100644 drivers/iio/temperature/maxim_thermocouple.c
>>
>> diff --git a/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
>> new file mode 100644
>> index 0000000..7ab4aa1
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/temperature/maxim_thermocouple.txt
>> @@ -0,0 +1,21 @@
>> +Maxim thermocouple support
>> +
>> +* https://datasheets.maximintegrated.com/en/ds/MAX6675.pdf
>> +* https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf
>> +
>> +Required properties:
>> +
>> + - compatible: must be "maxim,max31885" or "maxim,max6675"
>> + - reg: SPI chip select number for the device
>> + - spi-max-frequency: must be 4300000
>> + - spi-cpha: must be defined for max6675 to enable SPI mode 1
>> +
>> + Refer to spi/spi-bus.txt for generic SPI slave bindings
>
> Fullstop is missing here at the end of the sentence ;-)
>
>> +
>> +Example:
>> +
>> + max31885@0 {
>> + compatible = "maxim,max31885";
>> + reg = <0>;
>> + spi-max-frequency = <4300000>;
>> + };
>> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
>> index c4664e5..c9f5342 100644
>> --- a/drivers/iio/temperature/Kconfig
>> +++ b/drivers/iio/temperature/Kconfig
>> @@ -3,6 +3,20 @@
>> #
>> menu "Temperature sensors"
>>
>> +config MAXIM_THERMOCOUPLE
>> + tristate "Maxim thermocouple sensors"
>> + depends on SPI
>> + help
>> + If you say yes here you get support for the Maxim series of
>> + thermocouple sensors connected via SPI.
>> +
>> + Supported sensors:
>> + * MAX6675
>> + * MAX31885
>> +
>> + This driver can also be built as a module. If so, the module will
>> + be called maxim_thermocouple.
>> +
>> config MLX90614
>> tristate "MLX90614 contact-less infrared sensor"
>> depends on I2C
>> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
>> index 02bc79d..78c3de0 100644
>> --- a/drivers/iio/temperature/Makefile
>> +++ b/drivers/iio/temperature/Makefile
>> @@ -2,6 +2,7 @@
>> # Makefile for industrial I/O temperature drivers
>> #
>>
>> +obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
>> obj-$(CONFIG_MLX90614) += mlx90614.o
>> obj-$(CONFIG_TMP006) += tmp006.o
>> obj-$(CONFIG_TSYS01) += tsys01.o
>> diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
>> new file mode 100644
>> index 0000000..c9c9be9
>> --- /dev/null
>> +++ b/drivers/iio/temperature/maxim_thermocouple.c
>> @@ -0,0 +1,278 @@
>> +/*
>> + * maxim_thermocouple.c - Support for Maxim thermocouple chips
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/mutex.h>
>> +#include <linux/err.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +
>> +#define MAXIM_THERMOCOUPLE_DRV_NAME "maxim_thermocouple"
>> +
>> +enum {
>> + MAX6675,
>> + MAX31885,
>> +};
>> +
>> +struct iio_chan_spec max6675_channels[] = {
>
> static const ?
>
>> + { /* thermocouple temperature */
>> + .type = IIO_TEMP,
>> + .info_mask_separate =
>> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
>> + .scan_index = 0,
>> + .scan_type = {
>> + .sign = 's',
>> + .realbits = 13,
>> + .storagebits = 16,
>> + .shift = 3,
>> + .endianness = IIO_BE,
>> + },
>> + },
>> + IIO_CHAN_SOFT_TIMESTAMP(1),
>> +};
>> +
>> +struct iio_chan_spec max31885_channels[] = {
>
> Also static const ?
>
>> + { /* thermocouple temperature */
>> + .type = IIO_TEMP,
>> + .address = 2,
>> + .info_mask_separate =
>> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
>> + .scan_index = 0,
>> + .scan_type = {
>> + .sign = 's',
>> + .realbits = 14,
>> + .storagebits = 16,
>> + .shift = 2,
>> + .endianness = IIO_BE,
>> + },
>> + },
>> + { /* cold junction temperature */
>> + .type = IIO_TEMP,
>> + .channel2 = IIO_MOD_TEMP_AMBIENT,
>> + .modified = 1,
>> + .info_mask_separate =
>> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
>> + .scan_index = 1,
>> + .scan_type = {
>> + .sign = 's',
>> + .realbits = 12,
>> + .storagebits = 16,
>> + .shift = 4,
>> + .endianness = IIO_BE,
>> + },
>> + },
>> + IIO_CHAN_SOFT_TIMESTAMP(2),
>> +};
>> +
>> +struct maxim_thermocouple_chip {
>> + const struct iio_chan_spec *channels;
>> + int num_channels;
>> + int read_size;
>> +
>> + /* bit-check for valid input */
>> + int status_bit;
>
> I believe all of the members can be const and the structure below can
> also be static const.
Yeah missed that. Will fix in v2
>
>> +};
>> +
>> +struct maxim_thermocouple_chip maxim_thermocouple_chips[] = {
>> + [MAX6675] = {
>> + .channels = max6675_channels,
>> + .num_channels = ARRAY_SIZE(max6675_channels),
>> + .read_size = 2,
>> + .status_bit = BIT(2),
>> + },
>> + [MAX31885] = {
>> + .channels = max31885_channels,
>> + .num_channels = ARRAY_SIZE(max31885_channels),
>> + .read_size = 4,
>> + .status_bit = BIT(16),
>> + },
>> +};
>> +
>> +struct maxim_thermocouple_data {
>> + struct spi_device *spi;
>> + struct maxim_thermocouple_chip *chip;
>> +
>> + u8 buffer[16]; /* 4 byte data + 4 byte padding + 8 byte timestamp */
>> +};
>> +
>> +static int maxim_thermocouple_read(struct maxim_thermocouple_data *data,
>> + struct iio_chan_spec const *chan, int *val)
>> +{
>> + unsigned int storage_bytes = data->chip->read_size;
>> + unsigned int shift = chan->scan_type.shift + (chan->address * 8);
>> + unsigned int buf;
>> + int ret;
>> +
>> + ret = spi_read(data->spi, (void *) &buf, storage_bytes);
>> + if (ret)
>> + return ret;
>> +
>> + switch (storage_bytes) {
>> + case 2:
>> + *val = be16_to_cpu(buf);
>> + break;
>> + case 4:
>> + *val = be32_to_cpu(buf);
>> + break;
>
> if (storage_bytes == 2)
> *val ...
> else if (storage_bytes == 4)
> *val ...
>
> is half the length of the code :-)
>
>> + }
>> +
>> + /* check to be sure this is a valid reading */
>> + if (*val & data->chip->status_bit)
>> + return -EINVAL;
>> +
>> + *val = sign_extend32(*val >> shift, chan->scan_type.realbits - 1);
>> +
>> + return 0;
>> +}
>> +
>> +static irqreturn_t maxim_thermocouple_trigger_handler(int irq, void *private)
>> +{
>> + struct iio_poll_func *pf = private;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> + struct maxim_thermocouple_data *data = iio_priv(indio_dev);
>> + int ret;
>> +
>> + /* userspace HAL must do validation of data pushed to buffers */
>> + ret = spi_read(data->spi, (void *) &data->buffer, data->chip->read_size);
>
> I suspect you this should be
>
> ret = spi_read(data->spi, data->buffer, data->chip->read_size);
>
> since data->buffer is already (u8 *). The compiler didn't generate an
> error because you typecast the second argument.
Ah of course. also gets rid of the only warning from checkpatch.pl as well...
>
>> + if (!ret)
>> + 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 maxim_thermocouple_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2, long mask)
>> +{
>> + struct maxim_thermocouple_data *data = iio_priv(indio_dev);
>> + int ret = -EINVAL;
>> +
>> + mutex_lock(&indio_dev->mlock);
>> +
>> + if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
>> + ret = -EBUSY;
>> + goto error_busy;
>> + }
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>> + ret = maxim_thermocouple_read(data, chan, val);
>> + if (!ret)
>> + ret = IIO_VAL_INT;
>> + break;
>> + case IIO_CHAN_INFO_SCALE:
>> + switch (chan->channel2) {
>> + case IIO_MOD_TEMP_AMBIENT:
>> + *val = 62;
>> + *val2 = 500000; /* 1000 * 0.0625 */
>> + ret = IIO_VAL_INT_PLUS_MICRO;
>> + break;
>> + default:
>> + *val = 250; /* 1000 * 0.25 */
>> + ret = IIO_VAL_INT;
>> + };
>> + break;
>> + }
>> +
>> +error_busy:
>> + mutex_unlock(&indio_dev->mlock);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct iio_info maxim_thermocouple_info = {
>> + .driver_module = THIS_MODULE,
>> + .read_raw = maxim_thermocouple_read_raw,
>> +};
>> +
>> +static int maxim_thermocouple_probe(struct spi_device *spi)
>> +{
>> + const struct spi_device_id *id = spi_get_device_id(spi);
>> + struct iio_dev *indio_dev;
>> + struct maxim_thermocouple_data *data;
>> + struct maxim_thermocouple_chip *chip =
>> + &maxim_thermocouple_chips[id->driver_data];
>> + int ret;
>> +
>> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
>> + if (!indio_dev)
>> + return -ENOMEM;
>> +
>> + indio_dev->info = &maxim_thermocouple_info;
>> + indio_dev->name = MAXIM_THERMOCOUPLE_DRV_NAME;
>> + indio_dev->channels = chip->channels;
>> + indio_dev->num_channels = chip->num_channels;
>> + indio_dev->modes = INDIO_DIRECT_MODE;
>> +
>> + data = iio_priv(indio_dev);
>> + data->spi = spi;
>> + data->chip = chip;
>> +
>> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> + maxim_thermocouple_trigger_handler, NULL);
>> + if (ret)
>> + return ret;
>> +
>> + ret = iio_device_register(indio_dev);
>
> devm_iio_device_register() ?
Can't because of the iio_triggered_buffer_cleanup that is required
since we are using software triggers.
>
>> + if (ret)
>> + goto error_unreg_buffer;
>> +
>> + return 0;
>> +
>> +error_unreg_buffer:
>> + iio_triggered_buffer_cleanup(indio_dev);
>> +
>> + return ret;
>> +}
>> +
>> +static int maxim_thermocouple_remove(struct spi_device *spi)
>> +{
>> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +
>> + iio_device_unregister(indio_dev);
>> + iio_triggered_buffer_cleanup(indio_dev);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct spi_device_id maxim_thermocouple_id[] = {
>> + {"max6675", MAX6675},
>> + {"max31885", MAX31885},
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(spi, maxim_thermocouple_id);
>> +
>> +static struct spi_driver maxim_thermocouple_driver = {
>> + .driver = {
>> + .name = MAXIM_THERMOCOUPLE_DRV_NAME,
>> + },
>> + .probe = maxim_thermocouple_probe,
>> + .remove = maxim_thermocouple_remove,
>> + .id_table = maxim_thermocouple_id,
>> +};
>> +module_spi_driver(maxim_thermocouple_driver);
>> +
>> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
>> +MODULE_DESCRIPTION("Maxim thermocouple sensors");
>> +MODULE_LICENSE("GPL");
>>
>
>
> --
> Best regards,
> Marek Vasut
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: temperature: add support for Maxim thermocouple chips
2016-05-27 1:31 [PATCH] iio: temperature: add support for Maxim thermocouple chips Matt Ranostay
2016-05-27 1:58 ` Marek Vasut
@ 2016-05-27 12:46 ` Daniel Baluta
1 sibling, 0 replies; 4+ messages in thread
From: Daniel Baluta @ 2016-05-27 12:46 UTC (permalink / raw)
To: Matt Ranostay
Cc: Jonathan Cameron, linux-iio@vger.kernel.org, Marek Vasut,
Matt Porter
> +static int maxim_thermocouple_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct maxim_thermocouple_data *data = iio_priv(indio_dev);
> + int ret = -EINVAL;
> +
> + mutex_lock(&indio_dev->mlock);
> +
Lets try to use here iio_device_claim_direct_mode wrappers.
> + if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
> + ret = -EBUSY;
> + goto error_busy;
> + }
thanks,
Daniel.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-05-27 12:46 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2016-05-27 1:31 [PATCH] iio: temperature: add support for Maxim thermocouple chips Matt Ranostay
2016-05-27 1:58 ` Marek Vasut
2016-05-27 2:19 ` Matt Ranostay
2016-05-27 12:46 ` Daniel Baluta
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