[PATCH 6/6] iio: light: Updated Vishay Capella cm32181 ambient light sensor driver.

[Kevin Tsai]

- Added Interrupt support.

Signed-off-by: Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>
---
 drivers/iio/light/cm32181.c | 156 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 153 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index b7abd46..1ae32a0 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -47,6 +47,10 @@
 /* ALS_WL register */
 #define CM32181_ALS_WL_DEFAULT		0x0000
 
+/* STATUS register */
+#define CM32181_STATUS_ALS_IF_L		BIT(15)
+#define CM32181_STATUS_ALS_IF_H		BIT(14)
+
 /* Software parameters */
 #define CM32181_HW_ID			0x81
 #define CM32181_MLUX_PER_BIT		5	/* ALS_SM=01 IT=800ms */
@@ -122,7 +126,8 @@ void cm32181_parse_dt(struct cm32181_chip *chip)
 	if (!of_property_read_u32(dn, "capella,mlux_per_bit", &temp_val))
 		als_info->mlux_per_bit = (int)temp_val;
 	if (!of_property_read_u32(dn, "capella,thd_percent", &temp_val))
-		als_info->thd_percent = (int)temp_val;
+		if (((int)temp_val >= 0) && ((int)temp_val < 100))
+			als_info->thd_percent = (int)temp_val;
 }
 #endif
 
@@ -173,6 +178,63 @@ static int cm32181_reg_init(struct cm32181_chip *chip)
 }
 
 /**
+ * cm32181_interrupt() - enable/disable interrupt
+ * @chip:       pointer of struct cm32181_chip
+ * @ int_en:	truen for enable; false for disable
+ *
+ * Enable/disable interrupt mode
+ *
+ * Return: 0 for success; otherwise for error code.
+ */
+static int cm32181_interrupt(struct cm32181_chip *cm32181, bool int_en)
+{
+	int ret;
+
+	mutex_lock(&cm32181->lock);
+	if (int_en)
+		cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
+			CM32181_CMD_ALS_INT_EN;
+	else
+		cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
+			~CM32181_CMD_ALS_INT_EN;
+
+	ret = i2c_smbus_write_word_data(cm32181->client,
+			CM32181_REG_ADDR_CMD,
+			cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
+	mutex_unlock(&cm32181->lock);
+	return ret;
+}
+
+static irqreturn_t cm32181_irq_handler(int irq, void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
+	struct i2c_client *client = cm32181->client;
+	int ret;
+	u64 ev_code;
+
+	ret = i2c_smbus_read_word_data(cm32181->client,
+			CM32181_REG_ADDR_STATUS);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"%s: Data read failed: %d\n", __func__, ret);
+		return IRQ_NONE;
+	}
+
+	if (!(ret & (CM32181_STATUS_ALS_IF_H | CM32181_STATUS_ALS_IF_L)))
+		return IRQ_NONE;
+
+	ev_code = IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
+				0,
+				IIO_EV_TYPE_THRESH,
+				IIO_EV_DIR_EITHER);
+
+	iio_push_event(indio_dev, ev_code, iio_get_time_ns());
+
+	return IRQ_HANDLED;
+}
+
+/**
  * cm32181_read_als_it() - Get sensor integration time
  * @chip:	pointer of struct cm32181_chip
  * @val:	pointer of int to load the integration (sec)
@@ -242,6 +304,51 @@ static int cm32181_write_als_it(struct cm32181_chip *chip, int val, int val2)
 }
 
 /**
+ * cm32181_ials_read() - read ALS raw data
+ * @chip:       pointer of struct cm32181_chip
+ *
+ * Read the ALS raw data and update the interrupt threshold windows.
+ *
+ * Return: Positive value is ALS raw data, otherwise is error code.
+ */
+static int cm32181_als_read(struct cm32181_chip *chip)
+{
+	struct i2c_client *client = chip->client;
+	struct cm32181_als_info *als_info = chip->als_info;
+	u16 als, wh, wl, delta;
+	int ret;
+
+	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
+	if (ret < 0)
+		return ret;
+
+	als = (u16)ret;
+
+	if (als_info->thd_percent) {
+		delta = als * als_info->thd_percent / 100;
+		if (delta < 3)
+			delta = 3;
+		wh = (als + delta > 0xFFFF) ? 0xFFFF : (als + delta);
+		wl = (als < delta) ? 0 : (als - delta);
+
+		ret = i2c_smbus_write_word_data(client,
+			CM32181_REG_ADDR_ALS_WH, wh);
+		if (ret < 0)
+			return ret;
+		chip->conf_regs[CM32181_REG_ADDR_ALS_WH] = wh;
+
+		ret = i2c_smbus_write_word_data(client,
+			CM32181_REG_ADDR_ALS_WL, wl);
+		if (ret < 0)
+			return ret;
+		chip->conf_regs[CM32181_REG_ADDR_ALS_WL] = wl;
+		ret = als;
+	}
+
+	return ret;
+}
+
+/**
  * cm32181_get_lux() - report current lux value
  * @chip:	pointer of struct cm32181_chip
  *
@@ -252,7 +359,6 @@ static int cm32181_write_als_it(struct cm32181_chip *chip, int val, int val2)
  */
 static int cm32181_get_lux(struct cm32181_chip *chip)
 {
-	struct i2c_client *client = chip->client;
 	struct cm32181_als_info *als_info = chip->als_info;
 	int ret;
 	int val, val2;
@@ -268,7 +374,7 @@ static int cm32181_get_lux(struct cm32181_chip *chip)
 	lux *= als_info->mlux_per_bit_base_it;
 	lux = div_u64(lux, als_it);
 
-	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
+	ret = cm32181_als_read(chip);
 	if (ret < 0)
 		return ret;
 
@@ -350,6 +456,15 @@ static ssize_t cm32181_get_it_available(struct device *dev,
 	return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
 }
 
+static const struct iio_event_spec cm32181_event_spec[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+				BIT(IIO_EV_INFO_ENABLE),
+	}
+};
+
 static const struct iio_chan_spec cm32181_channels[] = {
 	{
 		.type = IIO_LIGHT,
@@ -357,6 +472,8 @@ static const struct iio_chan_spec cm32181_channels[] = {
 			BIT(IIO_CHAN_INFO_PROCESSED) |
 			BIT(IIO_CHAN_INFO_CALIBSCALE) |
 			BIT(IIO_CHAN_INFO_INT_TIME),
+		.event_spec = cm32181_event_spec,
+		.num_event_specs = ARRAY_SIZE(cm32181_event_spec),
 	}
 };
 
@@ -383,6 +500,7 @@ static int cm32181_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct cm32181_chip *chip;
+	struct cm32181_als_info *als_info;
 	struct iio_dev *indio_dev;
 	int ret;
 
@@ -412,11 +530,35 @@ static int cm32181_probe(struct i2c_client *client,
 		return ret;
 	}
 
+	als_info = chip->als_info;
+	if (als_info->thd_percent && client->irq) {
+		ret = request_threaded_irq(client->irq, NULL,
+					cm32181_irq_handler,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					indio_dev->name, indio_dev);
+		if (ret < 0) {
+			dev_err(&client->dev, "%s: request irq failed\n",
+				__func__);
+			return ret;
+		}
+
+		ret = cm32181_interrupt(chip, true);
+		if (ret) {
+			als_info->thd_percent = 0;
+			dev_err(&client->dev,
+				"%s: failed to enable interrupt\n", __func__);
+		}
+	} else {
+		als_info->thd_percent = 0;	/* Polling Mode */
+	}
+
 	ret = devm_iio_device_register(&client->dev, indio_dev);
 	if (ret) {
 		dev_err(&client->dev,
 			"%s: regist device failed\n",
 			__func__);
+		if (als_info->thd_percent)
+			free_irq(client->irq, indio_dev);
 		return ret;
 	}
 
@@ -425,9 +567,17 @@ static int cm32181_probe(struct i2c_client *client,
 
 static int cm32181_remove(struct i2c_client *client)
 {
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct cm32181_chip *chip = iio_priv(indio_dev);
+	struct cm32181_als_info *als_info = chip->als_info;
+
+	cm32181_interrupt(chip, false);
 	i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
 		CM32181_CMD_ALS_DISABLE);
 
+	if (als_info->thd_percent)
+		free_irq(client->irq, indio_dev);
+
 	return 0;
 }
 
-- 
1.8.3.1

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