Re: [PATCH 6/8] iio: light: Add support for Azoteq IQS621 ambient light sensor

Jonathan Cameron
2019-10-22T11:39:00Z

On Sun, 20 Oct 2019 23:11:21 -0500
Jeff LaBundy <jeff@labundy.com> wrote:

> This patch adds support for the Azoteq IQS621 ambient light sensor,
> capable of reporting intensity directly in units of lux.

If they are in lux, should be using IIO_CHAN_INFO_PROCESSED to indicate
that. I was wondering why we had no scale then noticed this comment.

Other than that, this looks good to me. So with that tidied up in V2.
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

One trivial comment to perhaps drop an error print as overly verbose inline.

>
> Signed-off-by: Jeff LaBundy <jeff@labundy.com>
> ---
> drivers/iio/light/Kconfig | 10 ++
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/iqs621-als.c | 361 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 372 insertions(+)
> create mode 100644 drivers/iio/light/iqs621-als.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 4a1a883..aad26dc 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -162,6 +162,16 @@ config GP2AP020A00F
> To compile this driver as a module, choose M here: the
> module will be called gp2ap020a00f.
>
> +config IQS621_ALS
> + tristate "Azoteq IQS621 ambient light sensor"
> + depends on MFD_IQS62X
> + help
> + Say Y here if you want to build support for the Azoteq IQS621
> + ambient light sensor.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called iqs621-als.
> +
> config SENSORS_ISL29018
> tristate "Intersil 29018 light and proximity sensor"
> depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 00d1f9b..aa34358 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_IIO_CROS_EC_LIGHT_PROX) += cros_ec_light_prox.o
> obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
> obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
> obj-$(CONFIG_HID_SENSOR_PROX) += hid-sensor-prox.o
> +obj-$(CONFIG_IQS621_ALS) += iqs621-als.o
> obj-$(CONFIG_SENSORS_ISL29018) += isl29018.o
> obj-$(CONFIG_SENSORS_ISL29028) += isl29028.o
> obj-$(CONFIG_ISL29125) += isl29125.o
> diff --git a/drivers/iio/light/iqs621-als.c b/drivers/iio/light/iqs621-als.c
> new file mode 100644
> index 0000000..92a6173
> --- /dev/null
> +++ b/drivers/iio/light/iqs621-als.c
> @@ -0,0 +1,361 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Azoteq IQS621 Ambient Light Sensor
> + *
> + * Copyright (C) 2019
> + * Author: Jeff LaBundy <jeff@labundy.com>
> + */
> +
> +#include <linux/device.h>
> +#include <linux/iio/events.h>
> +#include <linux/iio/iio.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/iqs62x.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/notifier.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define IQS621_ALS_FLAGS 0x16
> +#define IQS621_ALS_FLAGS_LIGHT BIT(7)
> +
> +#define IQS621_ALS_UI_OUT 0x17
> +
> +#define IQS621_ALS_THRESH_DARK 0x80
> +#define IQS621_ALS_THRESH_DARK_MAX 1020
> +#define IQS621_ALS_THRESH_DARK_SHIFT 2
> +
> +#define IQS621_ALS_THRESH_LIGHT 0x81
> +#define IQS621_ALS_THRESH_LIGHT_MAX 4080
> +#define IQS621_ALS_THRESH_LIGHT_SHIFT 4
> +
> +struct iqs621_als_private {
> + struct iqs62x_core *iqs62x;
> + struct notifier_block notifier;
> + struct mutex lock;
> + bool event_en;
> + u8 thresh_light;
> + u8 thresh_dark;
> + u8 flags;
> +};
> +
> +static int iqs621_als_init(struct iqs621_als_private *iqs621_als)
> +{
> + struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
> + unsigned int val;
> + int error;
> +
> + mutex_lock(&iqs621_als->lock);
> +
> + error = regmap_write(iqs62x->map, IQS621_ALS_THRESH_LIGHT,
> + iqs621_als->thresh_light);
> + if (error)
> + goto err_mutex;
> +
> + error = regmap_write(iqs62x->map, IQS621_ALS_THRESH_DARK,
> + iqs621_als->thresh_dark);
> + if (error)
> + goto err_mutex;
> +
> + error = regmap_read(iqs62x->map, IQS621_ALS_FLAGS, &val);
> + if (error)
> + goto err_mutex;
> + iqs621_als->flags = val;
> +
> + error = regmap_update_bits(iqs62x->map, IQS620_GLBL_EVENT_MASK,
> + iqs62x->dev_desc->als_mask,
> + iqs621_als->event_en ? 0 : 0xFF);
> +
> +err_mutex:
> + mutex_unlock(&iqs621_als->lock);
> +
> + return error;
> +}
> +
> +static int iqs621_als_notifier(struct notifier_block *notifier,
> + unsigned long event_flags, void *context)
> +{
> + struct iqs62x_event_data *event_data = context;
> + struct iqs621_als_private *iqs621_als;
> + struct iio_dev *indio_dev;
> + enum iio_event_direction dir;
> + int error;
> +
> + iqs621_als = container_of(notifier, struct iqs621_als_private,
> + notifier);
> + indio_dev = iio_priv_to_dev(iqs621_als);
> +
> + if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
> + error = iqs621_als_init(iqs621_als);
> + if (error) {
> + dev_err(indio_dev->dev.parent,
> + "Failed to re-initialize device: %d\n", error);
> + return NOTIFY_BAD;
> + }
> +
> + return NOTIFY_OK;
> + }
> +
> + if (!((event_data->als_flags ^ iqs621_als->flags) &
> + IQS621_ALS_FLAGS_LIGHT))
> + return NOTIFY_DONE;
> +
> + iqs621_als->flags = event_data->als_flags;
> +
> + if (!iqs621_als->event_en)
> + return NOTIFY_OK;
> +
> + dir = iqs621_als->flags & IQS621_ALS_FLAGS_LIGHT ? IIO_EV_DIR_RISING :
> + IIO_EV_DIR_FALLING;
> +
> + iio_push_event(indio_dev,
> + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
> + IIO_EV_TYPE_THRESH, dir),
> + iio_get_time_ns(indio_dev));
> +
> + return NOTIFY_OK;
> +}
> +
> +static void iqs621_als_notifier_unregister(void *context)
> +{
> + struct iqs621_als_private *iqs621_als = context;
> + struct iio_dev *indio_dev = iio_priv_to_dev(iqs621_als);
> + int error;
> +
> + error = blocking_notifier_chain_unregister(&iqs621_als->iqs62x->nh,
> + &iqs621_als->notifier);
> + if (error)
> + dev_err(indio_dev->dev.parent,
> + "Failed to unregister notifier: %d\n", error);
> +}
> +
> +static int iqs621_als_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
> + struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
> + int error;
> + __le16 val_buf;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + error = regmap_raw_read(iqs62x->map, IQS621_ALS_UI_OUT,
> + &val_buf, sizeof(val_buf));
> + if (error)
> + return error;
> +
> + *val = le16_to_cpu(val_buf);
> + return IIO_VAL_INT;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int iqs621_als_read_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir)
> +{
> + struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
> +
> + return iqs621_als->event_en;
> +}
> +
> +static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + int state)
> +{
> + struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
> + struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
> + int error;
> +
> + mutex_lock(&iqs621_als->lock);
> +
> + error = regmap_update_bits(iqs62x->map, IQS620_GLBL_EVENT_MASK,
> + iqs62x->dev_desc->als_mask,
> + state ? 0 : 0xFF);
> + if (!error)
> + iqs621_als->event_en = state;
> +
> + mutex_unlock(&iqs621_als->lock);
> +
> + return error;
> +}
> +
> +static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + enum iio_event_info info,
> + int *val, int *val2)
> +{
> + struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + *val = iqs621_als->thresh_light;
> + *val <<= IQS621_ALS_THRESH_LIGHT_SHIFT;
> + return IIO_VAL_INT;
> +
> + case IIO_EV_DIR_FALLING:
> + *val = iqs621_als->thresh_dark;
> + *val <<= IQS621_ALS_THRESH_DARK_SHIFT;
> + return IIO_VAL_INT;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + enum iio_event_info info,
> + int val, int val2)
> +{
> + struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
> + struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
> + int error = -EINVAL;
> +
> + mutex_lock(&iqs621_als->lock);
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + if (val > IQS621_ALS_THRESH_LIGHT_MAX)
> + break;
> + val >>= IQS621_ALS_THRESH_LIGHT_SHIFT;
> +
> + error = regmap_write(iqs62x->map, IQS621_ALS_THRESH_LIGHT, val);
> + if (!error)
> + iqs621_als->thresh_light = val;
> + break;
> +
> + case IIO_EV_DIR_FALLING:
> + if (val > IQS621_ALS_THRESH_DARK)
> + break;
> + val >>= IQS621_ALS_THRESH_DARK_SHIFT;
> +
> + error = regmap_write(iqs62x->map, IQS621_ALS_THRESH_DARK, val);
> + if (!error)
> + iqs621_als->thresh_dark = val;
> + break;
> +
> + default:
> + break;
> + }
> +
> + mutex_unlock(&iqs621_als->lock);
> +
> + return error;
> +}
> +
> +static const struct iio_info iqs621_als_info = {
> + .read_raw = &iqs621_als_read_raw,
> + .read_event_config = iqs621_als_read_event_config,
> + .write_event_config = iqs621_als_write_event_config,
> + .read_event_value = iqs621_als_read_event_value,
> + .write_event_value = iqs621_als_write_event_value,
> +};
> +
> +static const struct iio_event_spec iqs621_als_events[] = {
> + {
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_EITHER,
> + .mask_separate = BIT(IIO_EV_INFO_ENABLE),
> + },
> + {
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_RISING,
> + .mask_separate = BIT(IIO_EV_INFO_VALUE),
> + },
> + {
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_FALLING,
> + .mask_separate = BIT(IIO_EV_INFO_VALUE),
> + },
> +};
> +
> +static const struct iio_chan_spec iqs621_als_channels[] = {
> + {
> + .type = IIO_LIGHT,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .event_spec = iqs621_als_events,
> + .num_event_specs = ARRAY_SIZE(iqs621_als_events),
> + },
> +};
> +
> +static int iqs621_als_probe(struct platform_device *pdev)
> +{
> + struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
> + struct iqs621_als_private *iqs621_als;
> + struct iio_dev *indio_dev;
> + unsigned int val;
> + int error;
> +
> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs621_als));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->dev.parent = &pdev->dev;
> + indio_dev->channels = iqs621_als_channels;
> + indio_dev->num_channels = ARRAY_SIZE(iqs621_als_channels);
> + indio_dev->name = iqs62x->dev_desc->dev_name;
> + indio_dev->info = &iqs621_als_info;
> +
> + iqs621_als = iio_priv(indio_dev);
> + iqs621_als->iqs62x = iqs62x;
> +
> + error = regmap_read(iqs62x->map, IQS621_ALS_THRESH_LIGHT, &val);
> + if (error)
> + return error;
> + iqs621_als->thresh_light = val;
> +
> + error = regmap_read(iqs62x->map, IQS621_ALS_THRESH_DARK, &val);
> + if (error)
> + return error;
> + iqs621_als->thresh_dark = val;
> +
> + mutex_init(&iqs621_als->lock);
> +
> + error = iqs621_als_init(iqs621_als);
> + if (error)
> + return error;
> +
> + iqs621_als->notifier.notifier_call = iqs621_als_notifier;
> + error = blocking_notifier_chain_register(&iqs621_als->iqs62x->nh,
> + &iqs621_als->notifier);
> + if (error) {
> + dev_err(&pdev->dev, "Failed to register notifier: %d\n", error);
> + return error;
> + }
> +
> + error = devm_add_action_or_reset(&pdev->dev,
> + iqs621_als_notifier_unregister,
> + iqs621_als);
> + if (error) {

This one can only fail if a memory allocation fails (IIRC) so it feels
a bit paranoid to worry about this little corner case when you are
fairly (correctly in my view) sparse in error message for other cases..

> + dev_err(&pdev->dev, "Failed to add action: %d\n", error);
> + return error;
> + }
> +
> + return devm_iio_device_register(&pdev->dev, indio_dev);
> +}
> +
> +static struct platform_driver iqs621_als_platform_driver = {
> + .driver = {
> + .name = IQS621_DRV_NAME_ALS,
> + },
> + .probe = iqs621_als_probe,
> +};
> +module_platform_driver(iqs621_als_platform_driver);
> +
> +MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
> +MODULE_DESCRIPTION("Azoteq IQS621 Ambient Light Sensor");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" IQS621_DRV_NAME_ALS);