[PATCH 08/12] iio: imu: inv_icm42600: add device interrupt trigger

[Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>]

Add INT1 interrupt support and use it as an iio trigger.
Support interrupt edge and level, active high or low.
Push-pull configuration only.

Trigger enables FIFO and will be useful with buffer support.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
---
 drivers/iio/imu/inv_icm42600/Kconfig          |   1 +
 drivers/iio/imu/inv_icm42600/Makefile         |   1 +
 drivers/iio/imu/inv_icm42600/inv_icm42600.h   |   8 +-
 .../iio/imu/inv_icm42600/inv_icm42600_core.c  |  19 +-
 .../iio/imu/inv_icm42600/inv_icm42600_i2c.c   |   2 +-
 .../iio/imu/inv_icm42600/inv_icm42600_spi.c   |   2 +-
 .../imu/inv_icm42600/inv_icm42600_trigger.c   | 177 ++++++++++++++++++
 7 files changed, 206 insertions(+), 4 deletions(-)
 create mode 100644 drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c

diff --git a/drivers/iio/imu/inv_icm42600/Kconfig b/drivers/iio/imu/inv_icm42600/Kconfig
index 22390a72f0a3..7b3eaeb2aa4a 100644
--- a/drivers/iio/imu/inv_icm42600/Kconfig
+++ b/drivers/iio/imu/inv_icm42600/Kconfig
@@ -2,6 +2,7 @@
 
 config INV_ICM42600
 	tristate
+	select IIO_TRIGGER
 
 config INV_ICM42600_I2C
 	tristate "InvenSense ICM-426xx I2C driver"
diff --git a/drivers/iio/imu/inv_icm42600/Makefile b/drivers/iio/imu/inv_icm42600/Makefile
index 48965824f00c..e1f2aacbe888 100644
--- a/drivers/iio/imu/inv_icm42600/Makefile
+++ b/drivers/iio/imu/inv_icm42600/Makefile
@@ -5,6 +5,7 @@ inv-icm42600-y += inv_icm42600_core.o
 inv-icm42600-y += inv_icm42600_gyro.o
 inv-icm42600-y += inv_icm42600_accel.o
 inv-icm42600-y += inv_icm42600_temp.o
+inv-icm42600-y += inv_icm42600_trigger.o
 
 obj-$(CONFIG_INV_ICM42600_I2C) += inv-icm42600-i2c.o
 inv-icm42600-i2c-y += inv_icm42600_i2c.o
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600.h b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
index bc963b3d1800..175c1f67faee 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600.h
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
@@ -13,6 +13,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/pm.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
 
 enum inv_icm42600_chip {
 	INV_CHIP_ICM42600,
@@ -122,6 +123,7 @@ struct inv_icm42600_suspended {
  *  @suspended:		suspended sensors configuration.
  *  @indio_gyro:	gyroscope IIO device.
  *  @indio_accel:	accelerometer IIO device.
+ *  @trigger:		device internal interrupt trigger
  */
 struct inv_icm42600_state {
 	struct mutex lock;
@@ -135,6 +137,7 @@ struct inv_icm42600_state {
 	struct inv_icm42600_suspended suspended;
 	struct iio_dev *indio_gyro;
 	struct iio_dev *indio_accel;
+	struct iio_trigger *trigger;
 };
 
 /* Virtual register addresses: @bank on MSB (4 upper bits), @address on LSB */
@@ -370,11 +373,14 @@ int inv_icm42600_set_temp_conf(struct inv_icm42600_state *st, bool enable,
 int inv_icm42600_debugfs_reg(struct iio_dev *indio_dev, unsigned int reg,
 			     unsigned int writeval, unsigned int *readval);
 
-int inv_icm42600_core_probe(struct regmap *regmap, int chip,
+int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 			    inv_icm42600_bus_setup bus_setup);
 
 int inv_icm42600_gyro_init(struct inv_icm42600_state *st);
 
 int inv_icm42600_accel_init(struct inv_icm42600_state *st);
 
+int inv_icm42600_trigger_init(struct inv_icm42600_state *st, int irq,
+			      int irq_type);
+
 #endif
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
index 4e33f263d3ea..1102c54396e3 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
@@ -447,11 +447,13 @@ static void inv_icm42600_disable_pm(void *_data)
 	pm_runtime_disable(dev);
 }
 
-int inv_icm42600_core_probe(struct regmap *regmap, int chip,
+int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 			    inv_icm42600_bus_setup bus_setup)
 {
 	struct device *dev = regmap_get_device(regmap);
 	struct inv_icm42600_state *st;
+	struct irq_data *irq_desc;
+	int irq_type;
 	int ret;
 
 	BUILD_BUG_ON(ARRAY_SIZE(inv_icm42600_hw) != INV_CHIP_NB);
@@ -460,6 +462,16 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip,
 		return -ENODEV;
 	}
 
+	/* get irq data, set trigger falling by default */
+	irq_desc = irq_get_irq_data(irq);
+	if (!irq_desc) {
+		dev_err(dev, "could not find IRQ %d\n", irq);
+		return -EINVAL;
+	}
+	irq_type = irqd_get_trigger_type(irq_desc);
+	if (!irq_type)
+		irq_type = IRQF_TRIGGER_FALLING;
+
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
 	if (!st)
 		return -ENOMEM;
@@ -503,6 +515,11 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip,
 	if (ret)
 		return ret;
 
+	/* setup interrupt trigger */
+	ret = inv_icm42600_trigger_init(st, irq, irq_type);
+	if (ret)
+		return ret;
+
 	/* create and init gyroscope iio device */
 	ret = inv_icm42600_gyro_init(st);
 	if (ret)
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_i2c.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_i2c.c
index b61f993beacf..b1478ece43f6 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_i2c.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_i2c.c
@@ -70,7 +70,7 @@ static int inv_icm42600_probe(struct i2c_client *client,
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	return inv_icm42600_core_probe(regmap, chip,
+	return inv_icm42600_core_probe(regmap, chip, client->irq,
 				       inv_icm42600_i2c_bus_setup);
 }
 
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_spi.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_spi.c
index 835ced68a3a3..ec784f9e3c2c 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_spi.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_spi.c
@@ -70,7 +70,7 @@ static int inv_icm42600_probe(struct spi_device *spi)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	return inv_icm42600_core_probe(regmap, chip,
+	return inv_icm42600_core_probe(regmap, chip, spi->irq,
 				       inv_icm42600_spi_bus_setup);
 }
 
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c
new file mode 100644
index 000000000000..7a5e76305f0b
--- /dev/null
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "inv_icm42600.h"
+
+static irqreturn_t inv_icm42600_trigger_timestamp(int irq, void *_data)
+{
+	struct inv_icm42600_state *st = _data;
+
+	if (st->indio_gyro)
+		iio_pollfunc_store_time(irq, st->indio_gyro->pollfunc);
+	if (st->indio_accel)
+		iio_pollfunc_store_time(irq, st->indio_accel->pollfunc);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t inv_icm42600_trigger_int_handler(int irq, void *_data)
+{
+	struct inv_icm42600_state *st = _data;
+	struct device *dev = regmap_get_device(st->map);
+	unsigned int status;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = regmap_read(st->map, INV_ICM42600_REG_INT_STATUS, &status);
+	if (ret)
+		goto out_unlock;
+	dev_dbg(dev, "int_status = %#02x\n", status);
+
+	/* FIFO full */
+	if (status & INV_ICM42600_INT_STATUS_FIFO_FULL)
+		dev_warn(dev, "FIFO full data lost!\n");
+
+	/* FIFO threshold reached */
+	if (status & INV_ICM42600_INT_STATUS_FIFO_THS)
+		iio_trigger_poll_chained(st->trigger);
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	return IRQ_HANDLED;
+}
+
+static int inv_icm42600_trigger_set_state(struct iio_trigger *trig, bool state)
+{
+	struct inv_icm42600_state *st = iio_trigger_get_drvdata(trig);
+	unsigned int val;
+	uint16_t dummy;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	/*
+	 * IIO buffers preenable and postdisable are managing power on/off.
+	 * update_scan_mode is setting data FIFO enabled.
+	 */
+	if (state) {
+		/* set FIFO threshold interrupt */
+		val = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;
+		ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
+					 val, val);
+		if (ret)
+			goto out_unlock;
+		/* flush FIFO data */
+		ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
+				   INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
+		if (ret)
+			goto out_unlock;
+		/* set FIFO in streaming mode */
+		ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
+				   INV_ICM42600_FIFO_CONFIG_STREAM);
+		if (ret)
+			goto out_unlock;
+		/* workaround: dummy read of FIFO count */
+		ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT,
+				       &dummy, sizeof(dummy));
+	} else {
+		/* set FIFO in bypass mode */
+		ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
+				   INV_ICM42600_FIFO_CONFIG_BYPASS);
+		if (ret)
+			goto out_unlock;
+		/* flush FIFO data */
+		ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
+				   INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
+		if (ret)
+			goto out_unlock;
+		/* disable FIFO threshold interrupt */
+		val = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;
+		ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
+					 val, 0);
+	}
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	return ret;
+}
+
+static int inv_icm42600_trigger_validate(struct iio_trigger *trig,
+					 struct iio_dev *indio_dev)
+{
+	struct inv_icm42600_state *st = iio_trigger_get_drvdata(trig);
+
+	if (iio_device_get_drvdata(indio_dev) != st)
+		return -ENODEV;
+
+	return 0;
+}
+
+static const struct iio_trigger_ops inv_icm42600_trigger_ops = {
+	.set_trigger_state = &inv_icm42600_trigger_set_state,
+	.validate_device = &inv_icm42600_trigger_validate,
+};
+
+int inv_icm42600_trigger_init(struct inv_icm42600_state *st, int irq,
+			      int irq_type)
+{
+	struct device *dev = regmap_get_device(st->map);
+	unsigned int val;
+	int ret;
+
+	st->trigger = devm_iio_trigger_alloc(dev, "%s-dev", st->name);
+	if (!st->trigger)
+		return -ENOMEM;
+
+	st->trigger->dev.parent = dev;
+	st->trigger->ops = &inv_icm42600_trigger_ops;
+	iio_trigger_set_drvdata(st->trigger, st);
+
+	/* configure INT1 with correct mode */
+	/* falling or both-edge */
+	if (irq_type & IRQF_TRIGGER_FALLING) {
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_LOW;
+	} else if (irq_type == IRQF_TRIGGER_RISING) {
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_HIGH;
+	} else if (irq_type == IRQF_TRIGGER_LOW) {
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_LOW |
+				INV_ICM42600_INT_CONFIG_INT1_LATCHED;
+	} else if (irq_type == IRQF_TRIGGER_HIGH) {
+		val = INV_ICM42600_INT_CONFIG_INT1_ACTIVE_LOW |
+				INV_ICM42600_INT_CONFIG_INT1_LATCHED;
+	} else {
+		dev_err(dev, "invalid interrupt type %#x\n", irq_type);
+		return -EINVAL;
+	}
+	val |= INV_ICM42600_INT_CONFIG_INT1_PUSH_PULL;
+	ret = regmap_write(st->map, INV_ICM42600_REG_INT_CONFIG, val);
+	if (ret)
+		return ret;
+
+	/* Deassert async reset for proper INT pin operation (cf datasheet) */
+	ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_CONFIG1,
+				 INV_ICM42600_INT_CONFIG1_ASYNC_RESET, 0);
+	if (ret)
+		return ret;
+
+	ret = devm_request_threaded_irq(dev, irq,
+					inv_icm42600_trigger_timestamp,
+					inv_icm42600_trigger_int_handler,
+					irq_type, "inv_icm42600", st);
+	if (ret)
+		return ret;
+
+	return devm_iio_trigger_register(dev, st->trigger);
+}
-- 
2.17.1