[PATCH 7/8] iio: proximity: Add support for Azoteq IQS622 proximity sensor

[Jeff LaBundy <jeff@labundy.com>]

This patch adds support for the Azoteq IQS622 proximity sensor,
capable of reporting a unitless measurement of a target's prox-
imity to the sensor.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
---
 drivers/iio/proximity/Kconfig       |  10 ++
 drivers/iio/proximity/Makefile      |   1 +
 drivers/iio/proximity/iqs622-prox.c | 334 ++++++++++++++++++++++++++++++++++++
 3 files changed, 345 insertions(+)
 create mode 100644 drivers/iio/proximity/iqs622-prox.c

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index d536014..2366fd7 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -21,6 +21,16 @@ endmenu
 
 menu "Proximity and distance sensors"
 
+config IQS622_PROX
+	tristate "Azoteq IQS622 proximity sensor"
+	depends on MFD_IQS62X
+	help
+	  Say Y here if you want to build support for the Azoteq IQS622
+	  proximity sensor.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called iqs622-prox.
+
 config ISL29501
 	tristate "Intersil ISL29501 Time Of Flight sensor"
 	depends on I2C
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index 0bb5f9d..802ba9d 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -5,6 +5,7 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_AS3935)		+= as3935.o
+obj-$(CONFIG_IQS622_PROX)	+= iqs622-prox.o
 obj-$(CONFIG_ISL29501)		+= isl29501.o
 obj-$(CONFIG_LIDAR_LITE_V2)	+= pulsedlight-lidar-lite-v2.o
 obj-$(CONFIG_MB1232)		+= mb1232.o
diff --git a/drivers/iio/proximity/iqs622-prox.c b/drivers/iio/proximity/iqs622-prox.c
new file mode 100644
index 0000000..a805fb21
--- /dev/null
+++ b/drivers/iio/proximity/iqs622-prox.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Azoteq IQS622 Proximity 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/property.h>
+#include <linux/regmap.h>
+
+#define IQS622_IR_FLAGS				0x16
+#define IQS622_IR_FLAGS_TOUCH			BIT(1)
+#define IQS622_IR_FLAGS_PROX			BIT(0)
+
+#define IQS622_IR_UI_OUT			0x17
+
+#define IQS622_IR_THRESH_PROX			0x91
+#define IQS622_IR_THRESH_PROX_MAX		255
+#define IQS622_IR_THRESH_PROX_SHIFT		0
+
+#define IQS622_IR_THRESH_TOUCH			0x92
+#define IQS622_IR_THRESH_TOUCH_MAX		1020
+#define IQS622_IR_THRESH_TOUCH_SHIFT		2
+
+struct iqs622_prox_private {
+	struct iqs62x_core *iqs62x;
+	struct notifier_block notifier;
+	struct mutex lock;
+	bool thresh_prox;
+	bool event_en;
+	u8 thresh;
+	u8 flags;
+};
+
+static int iqs622_prox_init(struct iqs622_prox_private *iqs622_prox)
+{
+	struct iqs62x_core *iqs62x = iqs622_prox->iqs62x;
+	unsigned int val;
+	int error;
+
+	mutex_lock(&iqs622_prox->lock);
+
+	error = regmap_write(iqs62x->map,
+			     iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX :
+							IQS622_IR_THRESH_TOUCH,
+			     iqs622_prox->thresh);
+	if (error)
+		goto err_mutex;
+
+	error = regmap_read(iqs62x->map, IQS622_IR_FLAGS, &val);
+	if (error)
+		goto err_mutex;
+	iqs622_prox->flags = val;
+
+	error = regmap_update_bits(iqs62x->map, IQS620_GLBL_EVENT_MASK,
+				   iqs62x->dev_desc->ir_mask,
+				   iqs622_prox->event_en ? 0 : 0xFF);
+
+err_mutex:
+	mutex_unlock(&iqs622_prox->lock);
+
+	return error;
+}
+
+static int iqs622_prox_notifier(struct notifier_block *notifier,
+				unsigned long event_flags, void *context)
+{
+	struct iqs62x_event_data *event_data = context;
+	struct iqs622_prox_private *iqs622_prox;
+	struct iio_dev *indio_dev;
+	enum iio_event_direction dir;
+	int error;
+	u8 flags_mask;
+
+	iqs622_prox = container_of(notifier, struct iqs622_prox_private,
+				   notifier);
+	indio_dev = iio_priv_to_dev(iqs622_prox);
+
+	if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
+		error = iqs622_prox_init(iqs622_prox);
+		if (error) {
+			dev_err(indio_dev->dev.parent,
+				"Failed to re-initialize device: %d\n", error);
+			return NOTIFY_BAD;
+		}
+
+		return NOTIFY_OK;
+	}
+
+	flags_mask = iqs622_prox->thresh_prox ? IQS622_IR_FLAGS_PROX :
+						IQS622_IR_FLAGS_TOUCH;
+
+	if (!((event_data->ir_flags ^ iqs622_prox->flags) & flags_mask))
+		return NOTIFY_DONE;
+
+	iqs622_prox->flags = event_data->ir_flags;
+
+	if (!iqs622_prox->event_en)
+		return NOTIFY_OK;
+
+	dir = iqs622_prox->flags & flags_mask ? IIO_EV_DIR_RISING :
+						IIO_EV_DIR_FALLING;
+
+	iio_push_event(indio_dev,
+		       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+					    IIO_EV_TYPE_THRESH, dir),
+		       iio_get_time_ns(indio_dev));
+
+	return NOTIFY_OK;
+}
+
+static void iqs622_prox_notifier_unregister(void *context)
+{
+	struct iqs622_prox_private *iqs622_prox = context;
+	struct iio_dev *indio_dev = iio_priv_to_dev(iqs622_prox);
+	int error;
+
+	error = blocking_notifier_chain_unregister(&iqs622_prox->iqs62x->nh,
+						   &iqs622_prox->notifier);
+	if (error)
+		dev_err(indio_dev->dev.parent,
+			"Failed to unregister notifier: %d\n", error);
+}
+
+static int iqs622_prox_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct iqs622_prox_private *iqs622_prox = iio_priv(indio_dev);
+	struct iqs62x_core *iqs62x = iqs622_prox->iqs62x;
+	int error;
+	__le16 val_buf;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		error = regmap_raw_read(iqs62x->map, IQS622_IR_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 iqs622_prox_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 iqs622_prox_private *iqs622_prox = iio_priv(indio_dev);
+
+	return iqs622_prox->event_en;
+}
+
+static int iqs622_prox_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 iqs622_prox_private *iqs622_prox = iio_priv(indio_dev);
+	struct iqs62x_core *iqs62x = iqs622_prox->iqs62x;
+	int error;
+
+	mutex_lock(&iqs622_prox->lock);
+
+	error = regmap_update_bits(iqs62x->map, IQS620_GLBL_EVENT_MASK,
+				   iqs62x->dev_desc->ir_mask, state ? 0 : 0xFF);
+	if (!error)
+		iqs622_prox->event_en = state;
+
+	mutex_unlock(&iqs622_prox->lock);
+
+	return error;
+}
+
+static int iqs622_prox_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 iqs622_prox_private *iqs622_prox = iio_priv(indio_dev);
+
+	*val = iqs622_prox->thresh;
+	*val <<= (iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX_SHIFT :
+					     IQS622_IR_THRESH_TOUCH_SHIFT);
+
+	return IIO_VAL_INT;
+}
+
+static int iqs622_prox_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 iqs622_prox_private *iqs622_prox = iio_priv(indio_dev);
+	struct iqs62x_core *iqs62x = iqs622_prox->iqs62x;
+	int error = -EINVAL;
+
+	mutex_lock(&iqs622_prox->lock);
+
+	if (val > (iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX_MAX :
+					      IQS622_IR_THRESH_TOUCH_MAX))
+		goto err_mutex;
+	val >>= (iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX_SHIFT :
+					    IQS622_IR_THRESH_TOUCH_SHIFT);
+
+	error = regmap_write(iqs62x->map,
+			     iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX :
+							IQS622_IR_THRESH_TOUCH,
+			     val);
+	if (!error)
+		iqs622_prox->thresh = val;
+
+err_mutex:
+	mutex_unlock(&iqs622_prox->lock);
+
+	return error;
+}
+
+static const struct iio_info iqs622_prox_info = {
+	.read_raw = &iqs622_prox_read_raw,
+	.read_event_config = iqs622_prox_read_event_config,
+	.write_event_config = iqs622_prox_write_event_config,
+	.read_event_value = iqs622_prox_read_event_value,
+	.write_event_value = iqs622_prox_write_event_value,
+};
+
+static const struct iio_event_spec iqs622_prox_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+				 BIT(IIO_EV_INFO_VALUE),
+	},
+};
+
+static const struct iio_chan_spec iqs622_prox_channels[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.event_spec = iqs622_prox_events,
+		.num_event_specs = ARRAY_SIZE(iqs622_prox_events),
+	},
+};
+
+static int iqs622_prox_probe(struct platform_device *pdev)
+{
+	struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
+	struct iqs622_prox_private *iqs622_prox;
+	struct iio_dev *indio_dev;
+	unsigned int val;
+	int error;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs622_prox));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->channels = iqs622_prox_channels;
+	indio_dev->num_channels = ARRAY_SIZE(iqs622_prox_channels);
+	indio_dev->name = iqs62x->dev_desc->dev_name;
+	indio_dev->info = &iqs622_prox_info;
+
+	iqs622_prox = iio_priv(indio_dev);
+	iqs622_prox->iqs62x = iqs62x;
+
+	iqs622_prox->thresh_prox = device_property_read_bool(&pdev->dev,
+							     "azoteq,use-prox");
+
+	error = regmap_read(iqs62x->map,
+			    iqs622_prox->thresh_prox ? IQS622_IR_THRESH_PROX :
+						       IQS622_IR_THRESH_TOUCH,
+			    &val);
+	if (error)
+		return error;
+	iqs622_prox->thresh = val;
+
+	mutex_init(&iqs622_prox->lock);
+
+	error = iqs622_prox_init(iqs622_prox);
+	if (error)
+		return error;
+
+	iqs622_prox->notifier.notifier_call = iqs622_prox_notifier;
+	error = blocking_notifier_chain_register(&iqs622_prox->iqs62x->nh,
+						 &iqs622_prox->notifier);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to register notifier: %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action_or_reset(&pdev->dev,
+					 iqs622_prox_notifier_unregister,
+					 iqs622_prox);
+	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 iqs622_prox_platform_driver = {
+	.driver = {
+		.name	= IQS622_DRV_NAME_PROX,
+	},
+	.probe		= iqs622_prox_probe,
+};
+module_platform_driver(iqs622_prox_platform_driver);
+
+MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
+MODULE_DESCRIPTION("Azoteq IQS622 Proximity Sensor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" IQS622_DRV_NAME_PROX);
-- 
2.7.4