Re: [PATCH 4/8] hwmon: Add support for Azoteq IQS620AT temperature sensor

Guenter Roeck
2019-10-21T15:38:30Z

On Sun, Oct 20, 2019 at 11:11:19PM -0500, Jeff LaBundy wrote:
> 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>

Seems to me this might be more feasible as iio driver.
Jonathan, what do you think ?

> ---
> drivers/hwmon/Kconfig | 12 +++++-
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/iqs620at-temp.c | 96 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 108 insertions(+), 1 deletion(-)
> create mode 100644 drivers/hwmon/iqs620at-temp.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 13a6b4a..3e56be6 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -385,6 +385,16 @@ config SENSORS_ATXP1
> This driver can also be built as a module. If so, the module
> will be called atxp1.
>
> +config SENSORS_IQS620AT
> + tristate "Azoteq IQS620AT temperature sensor"
> + depends on MFD_IQS62X
> + 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 SENSORS_DS620
> tristate "Dallas Semiconductor DS620"
> depends on I2C
> @@ -1593,7 +1603,7 @@ config SENSORS_ADS7871
>
> config SENSORS_AMC6821
> tristate "Texas Instruments AMC6821"
> - depends on I2C
> + depends on I2C

No unrelated changes, please, and most definitely no
unrelated whitespace changes.

> help
> If you say yes here you get support for the Texas Instruments
> AMC6821 hardware monitoring chips.
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 40c036e..2360add 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -83,6 +83,7 @@ obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
> obj-$(CONFIG_SENSORS_INA209) += ina209.o
> obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o
> obj-$(CONFIG_SENSORS_INA3221) += ina3221.o
> +obj-$(CONFIG_SENSORS_IQS620AT) += iqs620at-temp.o
> obj-$(CONFIG_SENSORS_IT87) += it87.o
> obj-$(CONFIG_SENSORS_JC42) += jc42.o
> obj-$(CONFIG_SENSORS_K8TEMP) += k8temp.o
> diff --git a/drivers/hwmon/iqs620at-temp.c b/drivers/hwmon/iqs620at-temp.c
> new file mode 100644
> index 0000000..0af49b6
> --- /dev/null
> +++ b/drivers/hwmon/iqs620at-temp.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Azoteq IQS620AT Temperature Sensor
> + *
> + * Copyright (C) 2019
> + * Author: Jeff LaBundy <jeff@labundy.com>
> + */
> +
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/hwmon.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
> +
> +static umode_t iqs620_temp_is_visible(const void *drvdata,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + if (type != hwmon_temp || attr != hwmon_temp_input)
> + return 0;
> +
> + return 0444;
> +}
> +
> +static int iqs620_temp_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct iqs62x_core *iqs62x = dev_get_drvdata(dev);
> + int error;
> + __le16 val_buf;
> +
> + if (type != hwmon_temp || attr != hwmon_temp_input)
> + return -EINVAL;

-EOPNOTSUPP
> +
> + error = regmap_raw_read(iqs62x->map, IQS620_TEMP_UI_OUT, &val_buf,
> + sizeof(val_buf));
> + if (error)
> + return error;
> +
> + *val = (le16_to_cpu(val_buf) - 100) * 1000;
> +
> + return 0;
> +}
> +
> +static const struct hwmon_ops iqs620_temp_ops = {
> + .is_visible = iqs620_temp_is_visible,
> + .read = iqs620_temp_read,
> +};
> +
> +static const struct hwmon_channel_info *iqs620_temp_channel_info[] = {
> + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
> + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
> + NULL
> +};
> +
> +static const struct hwmon_chip_info iqs620_temp_chip_info = {
> + .ops = &iqs620_temp_ops,
> + .info = iqs620_temp_channel_info,
> +};
> +
> +static int iqs620_temp_probe(struct platform_device *pdev)
> +{
> + struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
> + struct device *hdev;
> + int error = 0;
> +
> + hdev = devm_hwmon_device_register_with_info(&pdev->dev,
> + iqs62x->dev_desc->dev_name,
> + iqs62x,
> + &iqs620_temp_chip_info,
> + NULL);
> + if (IS_ERR(hdev)) {
> + error = PTR_ERR(hdev);
> + dev_err(&pdev->dev, "Failed to register device: %d\n", error);

Such an error would either be static, caused by bad attributes,
or a bad name, which is already logged, or a memory allocation
failure, which is also already logged. The error message does
therefore not add any value.

> + }
> +
> + return error;
> +}
> +
> +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
>