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134 lines
3.0 KiB
134 lines
3.0 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302 |
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* |
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* Copyright 2010 Analog Devices Inc. |
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* |
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* Conversion to hwmon from IIO done by Jonathan Cameron <[email protected]> |
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*/ |
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#include <linux/device.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/sysfs.h> |
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#include <linux/spi/spi.h> |
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#include <linux/module.h> |
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#include <linux/err.h> |
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#include <linux/hwmon.h> |
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#include <linux/hwmon-sysfs.h> |
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#include <linux/bitops.h> |
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/* |
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* AD7314 temperature masks |
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*/ |
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#define AD7314_TEMP_MASK 0x7FE0 |
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#define AD7314_TEMP_SHIFT 5 |
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/* |
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* ADT7301 and ADT7302 temperature masks |
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*/ |
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#define ADT7301_TEMP_MASK 0x3FFF |
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enum ad7314_variant { |
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adt7301, |
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adt7302, |
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ad7314, |
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}; |
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struct ad7314_data { |
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struct spi_device *spi_dev; |
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u16 rx ____cacheline_aligned; |
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}; |
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static int ad7314_spi_read(struct ad7314_data *chip) |
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{ |
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int ret; |
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ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx)); |
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if (ret < 0) { |
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dev_err(&chip->spi_dev->dev, "SPI read error\n"); |
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return ret; |
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} |
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return be16_to_cpu(chip->rx); |
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} |
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static ssize_t ad7314_temperature_show(struct device *dev, |
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struct device_attribute *attr, |
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char *buf) |
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{ |
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struct ad7314_data *chip = dev_get_drvdata(dev); |
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s16 data; |
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int ret; |
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ret = ad7314_spi_read(chip); |
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if (ret < 0) |
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return ret; |
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switch (spi_get_device_id(chip->spi_dev)->driver_data) { |
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case ad7314: |
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data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT; |
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data = sign_extend32(data, 9); |
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return sprintf(buf, "%d\n", 250 * data); |
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case adt7301: |
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case adt7302: |
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/* |
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* Documented as a 13 bit twos complement register |
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* with a sign bit - which is a 14 bit 2's complement |
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* register. 1lsb - 31.25 milli degrees centigrade |
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*/ |
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data = ret & ADT7301_TEMP_MASK; |
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data = sign_extend32(data, 13); |
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return sprintf(buf, "%d\n", |
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DIV_ROUND_CLOSEST(data * 3125, 100)); |
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default: |
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return -EINVAL; |
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} |
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} |
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static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0); |
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static struct attribute *ad7314_attrs[] = { |
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&sensor_dev_attr_temp1_input.dev_attr.attr, |
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NULL, |
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}; |
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ATTRIBUTE_GROUPS(ad7314); |
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static int ad7314_probe(struct spi_device *spi_dev) |
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{ |
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struct ad7314_data *chip; |
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struct device *hwmon_dev; |
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chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL); |
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if (chip == NULL) |
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return -ENOMEM; |
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chip->spi_dev = spi_dev; |
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hwmon_dev = devm_hwmon_device_register_with_groups(&spi_dev->dev, |
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spi_dev->modalias, |
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chip, ad7314_groups); |
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return PTR_ERR_OR_ZERO(hwmon_dev); |
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} |
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static const struct spi_device_id ad7314_id[] = { |
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{ "adt7301", adt7301 }, |
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{ "adt7302", adt7302 }, |
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{ "ad7314", ad7314 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(spi, ad7314_id); |
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static struct spi_driver ad7314_driver = { |
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.driver = { |
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.name = "ad7314", |
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}, |
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.probe = ad7314_probe, |
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.id_table = ad7314_id, |
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}; |
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module_spi_driver(ad7314_driver); |
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MODULE_AUTHOR("Sonic Zhang <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver"); |
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MODULE_LICENSE("GPL v2");
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