iio: light: vcnl4000: Add interrupt support for vcnl4040

Add support to configure proximity sensor interrupts and threshold
limits for vcnl4040. If an interrupt is detected an event will be
pushed to the event interface.
Signed-off-by: NMårten Lindahl <marten.lindahl@axis.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230117190017.3789181-4-marten.lindahl@axis.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/vcnl4000.c

@@ -60,8 +60,11 @@
 
 #define VCNL4200_AL_CONF	0x00 /* Ambient light configuration */
 #define VCNL4200_PS_CONF1	0x03 /* Proximity configuration */
+#define VCNL4040_PS_THDL_LM	0x06 /* Proximity threshold low */
+#define VCNL4040_PS_THDH_LM	0x07 /* Proximity threshold high */
 #define VCNL4200_PS_DATA	0x08 /* Proximity data */
 #define VCNL4200_AL_DATA	0x09 /* Ambient light data */
+#define VCNL4040_INT_FLAGS	0x0b /* Interrupt register */
 #define VCNL4200_DEV_ID		0x0e /* Device ID, slave address and version */
 
 #define VCNL4040_DEV_ID		0x0c /* Device ID and version */
@@ -78,6 +81,9 @@
 #define VCNL4040_ALS_CONF_ALS_SHUTDOWN	BIT(0)
 #define VCNL4040_PS_CONF1_PS_SHUTDOWN	BIT(0)
 #define VCNL4040_PS_CONF2_PS_IT	GENMASK(3, 1) /* Proximity integration time */
+#define VCNL4040_PS_CONF2_PS_INT	GENMASK(9, 8) /* Proximity interrupt mode */
+#define VCNL4040_PS_IF_AWAY		BIT(8) /* Proximity event cross low threshold */
+#define VCNL4040_PS_IF_CLOSE		BIT(9) /* Proximity event cross high threshold */
 
 /* Bit masks for interrupt registers. */
 #define VCNL4010_INT_THR_SEL	BIT(0) /* Select threshold interrupt source */
@@ -138,6 +144,7 @@ struct vcnl4000_data {
 	enum vcnl4000_device_ids id;
 	int rev;
 	int al_scale;
+	u8 ps_int;		/* proximity interrupt mode */
 	const struct vcnl4000_chip_spec *chip_spec;
 	struct mutex vcnl4000_lock;
 	struct vcnl4200_channel vcnl4200_al;
@@ -256,6 +263,10 @@ static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool on)
 {
 	int ret;
 
+	/* Do not power down if interrupts are enabled */
+	if (!on && data->ps_int)
+		return 0;
+
 	ret = vcnl4000_write_als_enable(data, on);
 	if (ret < 0)
 		return ret;
@@ -297,6 +308,7 @@ static int vcnl4200_init(struct vcnl4000_data *data)
 	dev_dbg(&data->client->dev, "device id 0x%x", id);
 
 	data->rev = (ret >> 8) & 0xf;
+	data->ps_int = 0;
 
 	data->vcnl4200_al.reg = VCNL4200_AL_DATA;
 	data->vcnl4200_ps.reg = VCNL4200_PS_DATA;
@@ -797,6 +809,64 @@ static int vcnl4010_write_event(struct iio_dev *indio_dev,
 	}
 }
 
+static int vcnl4040_read_event(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)
+{
+	int ret;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = i2c_smbus_read_word_data(data->client,
+					       VCNL4040_PS_THDH_LM);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_EV_DIR_FALLING:
+		ret = i2c_smbus_read_word_data(data->client,
+					       VCNL4040_PS_THDL_LM);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int vcnl4040_write_event(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)
+{
+	int ret;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = i2c_smbus_write_word_data(data->client,
+						VCNL4040_PS_THDH_LM, val);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	case IIO_EV_DIR_FALLING:
+		ret = i2c_smbus_write_word_data(data->client,
+						VCNL4040_PS_THDL_LM, val);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
 static bool vcnl4010_is_thr_enabled(struct vcnl4000_data *data)
 {
 	int ret;
@@ -879,6 +949,86 @@ static int vcnl4010_write_event_config(struct iio_dev *indio_dev,
 	}
 }
 
+static int vcnl4040_read_event_config(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir)
+{
+	int ret;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
+	if (ret < 0)
+		return ret;
+
+	data->ps_int = FIELD_GET(VCNL4040_PS_CONF2_PS_INT, ret);
+
+	return (dir == IIO_EV_DIR_RISING) ?
+		FIELD_GET(VCNL4040_PS_IF_AWAY, ret) :
+		FIELD_GET(VCNL4040_PS_IF_CLOSE, ret);
+}
+
+static int vcnl4040_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)
+{
+	int ret;
+	u16 val, mask;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->vcnl4000_lock);
+
+	ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
+	if (ret < 0)
+		goto out;
+
+	if (dir == IIO_EV_DIR_RISING)
+		mask = VCNL4040_PS_IF_AWAY;
+	else
+		mask = VCNL4040_PS_IF_CLOSE;
+
+	val = state ? (ret | mask) : (ret & ~mask);
+
+	data->ps_int = FIELD_GET(VCNL4040_PS_CONF2_PS_INT, val);
+	ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, val);
+
+out:
+	mutex_unlock(&data->vcnl4000_lock);
+	data->chip_spec->set_power_state(data, data->ps_int != 0);
+
+	return ret;
+}
+
+static irqreturn_t vcnl4040_irq_thread(int irq, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = i2c_smbus_read_word_data(data->client, VCNL4040_INT_FLAGS);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	if (ret & VCNL4040_PS_IF_CLOSE) {
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_RISING),
+			       iio_get_time_ns(indio_dev));
+	}
+
+	if (ret & VCNL4040_PS_IF_AWAY) {
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_FALLING),
+			       iio_get_time_ns(indio_dev));
+	}
+
+	return IRQ_HANDLED;
+}
+
 static ssize_t vcnl4000_read_near_level(struct iio_dev *indio_dev,
 					uintptr_t priv,
 					const struct iio_chan_spec *chan,
@@ -1042,6 +1192,18 @@ static const struct iio_event_spec vcnl4000_event_spec[] = {
 	}
 };
 
+static const struct iio_event_spec vcnl4040_event_spec[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
 static const struct iio_chan_spec vcnl4000_channels[] = {
 	{
 		.type = IIO_LIGHT,
@@ -1090,6 +1252,8 @@ static const struct iio_chan_spec vcnl4040_channels[] = {
 			BIT(IIO_CHAN_INFO_INT_TIME),
 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_INT_TIME),
 		.ext_info = vcnl4000_ext_info,
+		.event_spec = vcnl4040_event_spec,
+		.num_event_specs = ARRAY_SIZE(vcnl4040_event_spec),
 	}
 };
 
@@ -1110,6 +1274,10 @@ static const struct iio_info vcnl4010_info = {
 static const struct iio_info vcnl4040_info = {
 	.read_raw = vcnl4000_read_raw,
 	.write_raw = vcnl4040_write_raw,
+	.read_event_value = vcnl4040_read_event,
+	.write_event_value = vcnl4040_write_event,
+	.read_event_config = vcnl4040_read_event_config,
+	.write_event_config = vcnl4040_write_event_config,
 	.read_avail = vcnl4040_read_avail,
 };
 
@@ -1146,6 +1314,7 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
 		.channels = vcnl4040_channels,
 		.num_channels = ARRAY_SIZE(vcnl4040_channels),
 		.info = &vcnl4040_info,
+		.irq_thread = vcnl4040_irq_thread,
 	},
 	[VCNL4200] = {
 		.prod = "VCNL4200",