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

Jeff LaBundy
2019-10-21T04:19:22Z

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

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) {
+ 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);
--
2.7.4