[PATCH v2 5/7] iio: temperature: Add support for Azoteq IQS620AT temperature sensor

Jeff LaBundy
2019-12-09T00:38:50Z

This patch adds support for the Azoteq IQS620AT temperature sensor,
capable of reporting its absolute die temperature.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
---
Changes in v2:
- Moved the driver from hwmon to iio
- Merged 'Copyright' and 'Author' lines into one in introductory comments
- Replaced 'error' with 'ret' throughout
- Eliminated tabbed alignment of platform_driver struct members
- Changed Kconfig "depends on" logic to MFD_IQS62X || COMPILE_TEST

drivers/iio/temperature/Kconfig | 10 ++++
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/iqs620at-temp.c | 97 +++++++++++++++++++++++++++++++++
3 files changed, 108 insertions(+)
create mode 100644 drivers/iio/temperature/iqs620at-temp.c

diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index e1ccb40..f1f2a14 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -4,6 +4,16 @@
#
menu "Temperature sensors"

+config IQS620AT_TEMP
+ tristate "Azoteq IQS620AT temperature sensor"
+ depends on MFD_IQS62X || COMPILE_TEST
+ help
+ Say Y here if you want to build support for the Azoteq IQS620AT
+ temperature sensor.
+
+ To compile this driver as a module, choose M here: the module
+ will be called iqs620at-temp.
+
config LTC2983
tristate "Analog Devices Multi-Sensor Digital Temperature Measurement System"
depends on SPI
diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index d6b850b..90c1131 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -3,6 +3,7 @@
# Makefile for industrial I/O temperature drivers
#

+obj-$(CONFIG_IQS620AT_TEMP) += iqs620at-temp.o
obj-$(CONFIG_LTC2983) += ltc2983.o
obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
diff --git a/drivers/iio/temperature/iqs620at-temp.c b/drivers/iio/temperature/iqs620at-temp.c
new file mode 100644
index 0000000..d20cb6ad
--- /dev/null
+++ b/drivers/iio/temperature/iqs620at-temp.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Azoteq IQS620AT Temperature Sensor
+ *
+ * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
+ */
+
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/mfd/iqs62x.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define IQS620_TEMP_UI_OUT 0x1A
+
+#define IQS620_TEMP_SCALE 1000
+#define IQS620_TEMP_OFFSET (-100)
+
+static int iqs620_temp_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct iqs62x_core *iqs62x = iio_device_get_drvdata(indio_dev);
+ int ret;
+ __le16 val_buf;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = regmap_raw_read(iqs62x->map, IQS620_TEMP_UI_OUT, &val_buf,
+ sizeof(val_buf));
+ if (ret)
+ return ret;
+
+ *val = le16_to_cpu(val_buf);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = IQS620_TEMP_SCALE;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_OFFSET:
+ *val = IQS620_TEMP_OFFSET;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info iqs620_temp_info = {
+ .read_raw = &iqs620_temp_read_raw,
+};
+
+static const struct iio_chan_spec iqs620_temp_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ },
+};
+
+static int iqs620_temp_probe(struct platform_device *pdev)
+{
+ struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
+ struct iio_dev *indio_dev;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, 0);
+ if (!indio_dev)
+ return -ENOMEM;
+
+ iio_device_set_drvdata(indio_dev, iqs62x);
+
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->channels = iqs620_temp_channels;
+ indio_dev->num_channels = ARRAY_SIZE(iqs620_temp_channels);
+ indio_dev->name = iqs62x->dev_desc->dev_name;
+ indio_dev->info = &iqs620_temp_info;
+
+ return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static struct platform_driver iqs620_temp_platform_driver = {
+ .driver = {
+ .name = IQS620_DRV_NAME_TEMP,
+ },
+ .probe = iqs620_temp_probe,
+};
+module_platform_driver(iqs620_temp_platform_driver);
+
+MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
+MODULE_DESCRIPTION("Azoteq IQS620AT Temperature Sensor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" IQS620_DRV_NAME_TEMP);
--
2.7.4