mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
305 lines
7.3 KiB
305 lines
7.3 KiB
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* maxim_thermocouple.c - Support for Maxim thermocouple chips |
|
* |
|
* Copyright (C) 2016-2018 Matt Ranostay |
|
* Author: <[email protected]> |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/init.h> |
|
#include <linux/mutex.h> |
|
#include <linux/err.h> |
|
#include <linux/of.h> |
|
#include <linux/of_device.h> |
|
#include <linux/spi/spi.h> |
|
#include <linux/iio/iio.h> |
|
#include <linux/iio/sysfs.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, |
|
MAX31855K, |
|
MAX31855J, |
|
MAX31855N, |
|
MAX31855S, |
|
MAX31855T, |
|
MAX31855E, |
|
MAX31855R, |
|
}; |
|
|
|
static const char maxim_tc_types[] = { |
|
'K', '?', 'K', 'J', 'N', 'S', 'T', 'E', 'R' |
|
}; |
|
|
|
static 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) | |
|
BIT(IIO_CHAN_INFO_THERMOCOUPLE_TYPE), |
|
.scan_index = 0, |
|
.scan_type = { |
|
.sign = 's', |
|
.realbits = 13, |
|
.storagebits = 16, |
|
.shift = 3, |
|
.endianness = IIO_BE, |
|
}, |
|
}, |
|
IIO_CHAN_SOFT_TIMESTAMP(1), |
|
}; |
|
|
|
static 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) | |
|
BIT(IIO_CHAN_INFO_THERMOCOUPLE_TYPE), |
|
.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; |
|
}; |
|
|
|
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), |
|
}, |
|
[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; |
|
char tc_type; |
|
}; |
|
|
|
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); |
|
__be16 buf16; |
|
__be32 buf32; |
|
int ret; |
|
|
|
switch (storage_bytes) { |
|
case 2: |
|
ret = spi_read(data->spi, (void *)&buf16, storage_bytes); |
|
*val = be16_to_cpu(buf16); |
|
break; |
|
case 4: |
|
ret = spi_read(data->spi, (void *)&buf32, storage_bytes); |
|
*val = be32_to_cpu(buf32); |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
} |
|
|
|
if (ret) |
|
return ret; |
|
|
|
/* 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; |
|
case IIO_CHAN_INFO_THERMOCOUPLE_TYPE: |
|
*val = data->tc_type; |
|
ret = IIO_VAL_CHAR; |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static const struct iio_info maxim_thermocouple_info = { |
|
.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 int chip_type = (id->driver_data == MAX6675) ? MAX6675 : MAX31855; |
|
const struct maxim_thermocouple_chip *chip = |
|
&maxim_thermocouple_chips[chip_type]; |
|
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; |
|
data->tc_type = maxim_tc_types[id->driver_data]; |
|
|
|
ret = devm_iio_triggered_buffer_setup(&spi->dev, |
|
indio_dev, NULL, |
|
maxim_thermocouple_trigger_handler, NULL); |
|
if (ret) |
|
return ret; |
|
|
|
if (id->driver_data == MAX31855) |
|
dev_warn(&spi->dev, "generic max31855 ID is deprecated\nplease use more specific part type"); |
|
|
|
return devm_iio_device_register(&spi->dev, indio_dev); |
|
} |
|
|
|
static const struct spi_device_id maxim_thermocouple_id[] = { |
|
{"max6675", MAX6675}, |
|
{"max31855", MAX31855}, |
|
{"max31855k", MAX31855K}, |
|
{"max31855j", MAX31855J}, |
|
{"max31855n", MAX31855N}, |
|
{"max31855s", MAX31855S}, |
|
{"max31855t", MAX31855T}, |
|
{"max31855e", MAX31855E}, |
|
{"max31855r", MAX31855R}, |
|
{}, |
|
}; |
|
MODULE_DEVICE_TABLE(spi, maxim_thermocouple_id); |
|
|
|
static const struct of_device_id maxim_thermocouple_of_match[] = { |
|
{ .compatible = "maxim,max6675" }, |
|
{ .compatible = "maxim,max31855" }, |
|
{ .compatible = "maxim,max31855k" }, |
|
{ .compatible = "maxim,max31855j" }, |
|
{ .compatible = "maxim,max31855n" }, |
|
{ .compatible = "maxim,max31855s" }, |
|
{ .compatible = "maxim,max31855t" }, |
|
{ .compatible = "maxim,max31855e" }, |
|
{ .compatible = "maxim,max31855r" }, |
|
{ }, |
|
}; |
|
MODULE_DEVICE_TABLE(of, maxim_thermocouple_of_match); |
|
|
|
static struct spi_driver maxim_thermocouple_driver = { |
|
.driver = { |
|
.name = MAXIM_THERMOCOUPLE_DRV_NAME, |
|
.of_match_table = maxim_thermocouple_of_match, |
|
}, |
|
.probe = maxim_thermocouple_probe, |
|
.id_table = maxim_thermocouple_id, |
|
}; |
|
module_spi_driver(maxim_thermocouple_driver); |
|
|
|
MODULE_AUTHOR("Matt Ranostay <[email protected]>"); |
|
MODULE_DESCRIPTION("Maxim thermocouple sensors"); |
|
MODULE_LICENSE("GPL");
|
|
|