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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-23 17:50:16 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-23 17:50:16 -0400
commitd5bd1eba19230347acfc4960581a15bfb459a615 (patch)
tree8fc05e23b81792591d99550a93f463790e897e42 /drivers/iio/temperature/maxim_thermocouple.c
parent1d9e3a07cb80ca7c8f4efcfcc6c4ca10790d9645 (diff)
parent87557ade38f3d465f4935d63d74a7590e7d69e1a (diff)
Merge tag 'iio-for-4.9a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into work-testing
Jonathan writes: First round of new features, device support and cleanups for IIO in the 4.9 cycle. Device support * ak8974 - New driver and bindings for this 2009 vintage magnetometer (it was very popular back then!) * atlas-ph-sensor - ORP sensor support(I had to look up what one of these was) * cio-dac - New driver for Measurement Computing DAC boards * dmard06 - New driver for Domintech DMARDO6 accelerometer. Also vendor prefix. * dmard09 - New driver for Domintech DMARD09 accelerometer. * maxim-thermocouple - max6675 and max31855 new driver * mt6577 auxdac - new driver for this Mediatek chip mt2701, mt6577 and mt8173 have this hardware. * ti-adc161s626 - new driver for this TI single channel differential ADC. * vcnl4000 - support vcnl4010 and vcnl4020 which are compatible for all features currently supported by this driver. New features * Core - Allow retrieving of underlying iio_dev from a callback buffer handle. This is needed to allow client drivers to perform operations such as configuring the trigger used. * hid-sensors - asynchronous resume support to avoid really long resume times. * kxcjk-1013 - add the mysterious KIOX000A ACPI id seen in the wild. * Tools - lsiio now enumerates processed as well as raw channels. Cleanup * ad7298 - use iio_device_claim_direct_mode and friends to simplify locking around mode switching and drop some boilerplate. * ad7793 - use iio_device_claim_direct_mode and friends to simplify locking around mode switching and drop some boilerplate. * ade7854 - checkpatch fixups (alignment of parameters) * atlas-ph-sensor - use iio_device_claim_direct_mode and friends to simplify locking around mode switching and drop some boilerplate. - Switch to REGCACHE_NONE as there are no useful register to cache. * bma180 - use iio_device_claim_direct_mode and friends to simplify locking around mode switching and drop some boilerplate. * hdc100x - Add mention of the HDC1000 and HDC1008 to the Kconfig help text. * isl29018 - Add driver specific prefixes to defines and function names. - Remove excessive logging. - Drop newlines which add nothing to readability. - General tidying up of comments. - Drop I2C_CLASS_HWMON as irrelevant to driver. * isl29028 - Add driver specific prefixes to defines, enums and function names. - Drop comma's from available attribute output as not ABI compliant. - Drop I2C_CLASS_HWMON as irrelevant to driver. * kxsd9 - devicetree bindings. * mag3110 - This one wasn't locking to protect against mode switches during raw_reads. Use the iio_claim_direct_mode function to fix this buglet. * maxim-theromcouple - Fix missing selects for triggered buffer support in Kconfig. * nau7802 - Use complete instead of complete_all as only one completion at a time. * sx9500 - Use complete instead of complete_all as only one completion at a time. * us5182d - Add a missing error code asignment instead of checking the result of an already checked statement. * vcnl4000 - Use BIT macro where appropriate. - Refactor return codes in read_raw callback. - Add some missing locking for concurrent accesses to the device.
Diffstat (limited to 'drivers/iio/temperature/maxim_thermocouple.c')
-rw-r--r--drivers/iio/temperature/maxim_thermocouple.c281
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c
new file mode 100644
index 000000000000..030827ec8f3a
--- /dev/null
+++ b/drivers/iio/temperature/maxim_thermocouple.c
@@ -0,0 +1,281 @@
+/*
+ * 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,
+ MAX31855,
+};
+
+const 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),
+};
+
+const struct iio_chan_spec max31855_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,
+ .address = 0,
+ .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),
+};
+
+static const unsigned long max31855_scan_masks[] = {0x3, 0};
+
+struct maxim_thermocouple_chip {
+ const struct iio_chan_spec *channels;
+ const unsigned long *scan_masks;
+ u8 num_channels;
+ u8 read_size;
+
+ /* bit-check for valid input */
+ u32 status_bit;
+};
+
+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),
+ },
+ [MAX31855] = {
+ .channels = max31855_channels,
+ .num_channels = ARRAY_SIZE(max31855_channels),
+ .read_size = 4,
+ .scan_masks = max31855_scan_masks,
+ .status_bit = BIT(16),
+ },
+};
+
+struct maxim_thermocouple_data {
+ struct spi_device *spi;
+ const struct maxim_thermocouple_chip *chip;
+
+ u8 buffer[16] ____cacheline_aligned;
+};
+
+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;
+
+ ret = spi_read(data->spi, data->buffer, data->chip->read_size);
+ if (!ret) {
+ 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 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;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = maxim_thermocouple_read(data, chan, val);
+ iio_device_release_direct_mode(indio_dev);
+
+ if (!ret)
+ return 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;
+ }
+
+ 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;
+ const 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->available_scan_masks = chip->scan_masks;
+ 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},
+ {"max31855", MAX31855},
+ {},
+};
+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");