[PATCH v2 2/6] iio:bmi160: add drdy interrupt support

Martin Kelly
2019-01-22T02:04:27Z

From: Martin Kelly <martin@martingkelly.com>

Add interrupt support for the data ready signal on the BMI160, which fires
an interrupt whenever new accelerometer/gyroscope data is ready to read.

Signed-off-by: Martin Kelly <martin@martingkelly.com>
---
v2:
- Drop "BOTH" interrupt setting.
- Change to "if (ret)" instead of "if (ret < 0)".
- Stylistic changes suggested by Jonathan Cameron.
- Fix bogus return check after iio_trigger_get.

arch/arm/boot/dts/Makefile | 1 +
drivers/iio/imu/bmi160/bmi160.h | 13 +-
drivers/iio/imu/bmi160/bmi160_core.c | 294 ++++++++++++++++++++++++++++++++++-
drivers/iio/imu/bmi160/bmi160_i2c.c | 3 +-
drivers/iio/imu/bmi160/bmi160_spi.c | 2 +-
5 files changed, 303 insertions(+), 10 deletions(-)

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index b0e966d625b9..df68910fc2c1 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -701,6 +701,7 @@ dtb-$(CONFIG_SOC_AM33XX) += \
am335x-base0033.dtb \
am335x-bone.dtb \
am335x-boneblack.dtb \
+ am335x-boneblack-bmi160-i2c1.dtb \
am335x-boneblack-wireless.dtb \
am335x-boneblue.dtb \
am335x-bonegreen.dtb \
diff --git a/drivers/iio/imu/bmi160/bmi160.h b/drivers/iio/imu/bmi160/bmi160.h
index 2351049d930b..0c5e67e0d35b 100644
--- a/drivers/iio/imu/bmi160/bmi160.h
+++ b/drivers/iio/imu/bmi160/bmi160.h
@@ -2,9 +2,20 @@
#ifndef BMI160_H_
#define BMI160_H_

+#include <linux/iio/iio.h>
+
+struct bmi160_data {
+ struct regmap *regmap;
+ struct iio_trigger *trig;
+};
+
extern const struct regmap_config bmi160_regmap_config;

int bmi160_core_probe(struct device *dev, struct regmap *regmap,
- const char *name, bool use_spi);
+ const char *name, bool use_spi, int irq);
+
+int bmi160_enable_irq(struct regmap *regmap, bool enable);
+
+int bmi160_probe_trigger(struct iio_dev *indio_dev, int irq, u32 irq_type);

#endif /* BMI160_H_ */
diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c
index ce61026d84c3..c848fc1bce61 100644
--- a/drivers/iio/imu/bmi160/bmi160_core.c
+++ b/drivers/iio/imu/bmi160/bmi160_core.c
@@ -3,21 +3,25 @@
* BMI160 - Bosch IMU (accel, gyro plus external magnetometer)
*
* Copyright (c) 2016, Intel Corporation.
+ * Copyright (c) 2019, Martin Kelly.
*
* IIO core driver for BMI160, with support for I2C/SPI busses
*
- * TODO: magnetometer, interrupts, hardware FIFO
+ * TODO: magnetometer, hardware FIFO
*/
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/acpi.h>
#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/of_irq.h>

#include <linux/iio/iio.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>

#include "bmi160.h"

@@ -61,8 +65,32 @@
#define BMI160_CMD_GYRO_PM_FAST_STARTUP 0x17
#define BMI160_CMD_SOFTRESET 0xB6

+#define BMI160_REG_INT_EN 0x51
+#define BMI160_DRDY_INT_EN BIT(4)
+
+#define BMI160_REG_INT_OUT_CTRL 0x53
+#define BMI160_INT_OUT_CTRL_MASK 0x0f
+#define BMI160_INT1_OUT_CTRL_SHIFT 0
+#define BMI160_INT2_OUT_CTRL_SHIFT 4
+#define BMI160_LEVEL_TRIGGERED BIT(0)
+#define BMI160_ACTIVE_HIGH BIT(1)
+#define BMI160_OPEN_DRAIN BIT(2)
+#define BMI160_OUTPUT_EN BIT(3)
+
+#define BMI160_REG_INT_LATCH 0x54
+#define BMI160_INT1_LATCH_MASK BIT(4)
+#define BMI160_INT2_LATCH_MASK BIT(5)
+
+/* INT1 and INT2 are in the opposite order as in INT_OUT_CTRL! */
+#define BMI160_REG_INT_MAP 0x56
+#define BMI160_INT1_MAP_DRDY_EN 0x80
+#define BMI160_INT2_MAP_DRDY_EN 0x08
+
#define BMI160_REG_DUMMY 0x7F

+#define BMI160_NORMAL_WRITE_USLEEP 2
+#define BMI160_SUSPENDED_WRITE_USLEEP 450
+
#define BMI160_ACCEL_PMU_MIN_USLEEP 3800
#define BMI160_GYRO_PMU_MIN_USLEEP 80000
#define BMI160_SOFTRESET_USLEEP 1000
@@ -105,8 +133,9 @@ enum bmi160_sensor_type {
BMI160_NUM_SENSORS /* must be last */
};

-struct bmi160_data {
- struct regmap *regmap;
+enum bmi160_int_pin {
+ BMI160_PIN_INT1,
+ BMI160_PIN_INT2
};

const struct regmap_config bmi160_regmap_config = {
@@ -495,7 +524,209 @@ static const char *bmi160_match_acpi_device(struct device *dev)
return dev_name(dev);
}

-static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
+static int bmi160_write_conf_reg(struct regmap *regmap, unsigned int reg,
+ unsigned int mask, unsigned int bits,
+ unsigned int write_usleep)
+{
+ int ret;
+ unsigned int val;
+
+ ret = regmap_read(regmap, reg, &val);
+ if (ret)
+ return ret;
+
+ val = (val & ~mask) | bits;
+
+ ret = regmap_write(regmap, reg, val);
+ if (ret)
+ return ret;
+
+ /*
+ * We need to wait after writing before we can write again. See the
+ * datasheet, page 93.
+ */
+ usleep_range(write_usleep, write_usleep + 1000);
+
+ return 0;
+}
+
+static int bmi160_config_pin(struct regmap *regmap, enum bmi160_int_pin pin,
+ bool open_drain, u8 irq_mask,
+ unsigned long write_usleep)
+{
+ int ret;
+ u8 int_out_ctrl_shift;
+ u8 int_latch_mask;
+ u8 int_map_mask;
+ u8 int_out_ctrl_mask;
+ u8 int_out_ctrl_bits;
+
+ switch (pin) {
+ case BMI160_PIN_INT1:
+ int_out_ctrl_shift = BMI160_INT1_OUT_CTRL_SHIFT;
+ int_latch_mask = BMI160_INT1_LATCH_MASK;
+ int_map_mask = BMI160_INT1_MAP_DRDY_EN;
+ break;
+ case BMI160_PIN_INT2:
+ int_out_ctrl_shift = BMI160_INT2_OUT_CTRL_SHIFT;
+ int_latch_mask = BMI160_INT2_LATCH_MASK;
+ int_map_mask = BMI160_INT2_MAP_DRDY_EN;
+ break;
+ }
+ int_out_ctrl_mask = BMI160_INT_OUT_CTRL_MASK << int_out_ctrl_shift;
+
+ /*
+ * Enable the requested pin with the right settings:
+ * - Push-pull/open-drain
+ * - Active low/high
+ * - Edge/level triggered
+ */
+ int_out_ctrl_bits = BMI160_OUTPUT_EN;
+ if (open_drain)
+ /* Default is push-pull. */
+ int_out_ctrl_bits |= BMI160_OPEN_DRAIN;
+ int_out_ctrl_bits |= irq_mask;
+ int_out_ctrl_bits <<= int_out_ctrl_shift;
+
+ ret = bmi160_write_conf_reg(regmap, BMI160_REG_INT_OUT_CTRL,
+ int_out_ctrl_mask, int_out_ctrl_bits,
+ write_usleep);
+ if (ret)
+ return ret;
+
+ /* Set the pin to input mode with no latching. */
+ ret = bmi160_write_conf_reg(regmap, BMI160_REG_INT_LATCH,
+ int_latch_mask, int_latch_mask,
+ write_usleep);
+ if (ret)
+ return ret;
+
+ /* Map interrupts to the requested pin. */
+ ret = bmi160_write_conf_reg(regmap, BMI160_REG_INT_MAP,
+ int_map_mask, int_map_mask,
+ write_usleep);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+int bmi160_enable_irq(struct regmap *regmap, bool enable)
+{
+ unsigned int enable_bit = 0;
+
+ if (enable)
+ enable_bit = BMI160_DRDY_INT_EN;
+
+ return bmi160_write_conf_reg(regmap, BMI160_REG_INT_EN,
+ BMI160_DRDY_INT_EN, enable_bit,
+ BMI160_NORMAL_WRITE_USLEEP);
+}
+EXPORT_SYMBOL(bmi160_enable_irq);
+
+static bool bmi160_parse_irqname(struct device_node *of_node, int irq,
+ enum bmi160_int_pin *pin)
+{
+ int ret;
+
+ /* of_irq_get_byname returns the IRQ number if the entry is found. */
+ ret = of_irq_get_byname(of_node, "INT1");
+ if (ret == irq) {
+ *pin = BMI160_PIN_INT1;
+ return true;
+ }
+
+ ret = of_irq_get_byname(of_node, "INT2");
+ if (ret == irq) {
+ *pin = BMI160_PIN_INT2;
+ return true;
+ }
+
+ return false;
+}
+
+static int bmi160_config_device_irq(struct iio_dev *indio_dev,
+ int irq, int irq_type)
+{
+ int ret;
+ bool success;
+ enum bmi160_int_pin int_pin;
+ bool open_drain;
+ const char *pin_name;
+ u8 irq_mask;
+ struct bmi160_data *data = iio_priv(indio_dev);
+ struct device *dev = regmap_get_device(data->regmap);
+
+ /* Edge-triggered, active-low is the default if we set all zeroes. */
+ if (irq_type == IRQF_TRIGGER_RISING)
+ irq_mask = BMI160_ACTIVE_HIGH | BMI160_LEVEL_TRIGGERED;
+ else if (irq_type == IRQF_TRIGGER_FALLING)
+ irq_mask = BMI160_LEVEL_TRIGGERED;
+ else if (irq_type == IRQF_TRIGGER_HIGH)
+ irq_mask = BMI160_ACTIVE_HIGH;
+ else if (irq_type == IRQF_TRIGGER_LOW)
+ irq_mask = 0;
+ else {
+ dev_err(&indio_dev->dev,
+ "Invalid interrupt type 0x%x specified\n", irq_type);
+ return -EINVAL;
+ }
+
+ success = bmi160_parse_irqname(dev->of_node, irq, &int_pin);
+ if (!success) {
+ dev_err(&indio_dev->dev,
+ "interrupt-names for IRQ %d must be set to either \"INT1\" or \"INT2\"",
+ irq);
+ return -EINVAL;
+ }
+
+ open_drain = of_property_read_bool(dev->of_node, "bmi160,open-drain");
+
+ ret = bmi160_config_pin(data->regmap, int_pin, open_drain, irq_mask,
+ BMI160_NORMAL_WRITE_USLEEP);
+ if (ret) {
+ switch (int_pin) {
+ case BMI160_PIN_INT1:
+ pin_name = "INT1";
+ break;
+ case BMI160_PIN_INT2:
+ pin_name = "INT2";
+ break;
+ }
+ dev_err(&indio_dev->dev, "Failed to configure %s IRQ pin",
+ pin_name);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int bmi160_setup_irq(struct iio_dev *indio_dev, int irq)
+{
+ struct irq_data *desc;
+ u32 irq_type;
+ int ret;
+
+ desc = irq_get_irq_data(irq);
+ if (!desc) {
+ dev_warn(&indio_dev->dev, "Could not find IRQ %d\n", irq);
+ return -EINVAL;
+ }
+
+ irq_type = irqd_get_trigger_type(desc);
+
+ ret = bmi160_config_device_irq(indio_dev, irq, irq_type);
+ if (ret)
+ return ret;
+
+ ret = bmi160_probe_trigger(indio_dev, irq, irq_type);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int bmi160_chip_init(struct bmi160_data *data, bool use_spi, int irq)
{
int ret;
unsigned int val;
@@ -518,7 +749,7 @@ static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
}

ret = regmap_read(data->regmap, BMI160_REG_CHIP_ID, &val);
- if (ret < 0) {
+ if (ret) {
dev_err(dev, "Error reading chip id\n");
return ret;
}
@@ -539,6 +770,49 @@ static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
return 0;
}

+static int bmi160_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool enable)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct bmi160_data *data = iio_priv(indio_dev);
+
+ return bmi160_enable_irq(data->regmap, enable);
+}
+
+static const struct iio_trigger_ops bmi160_trigger_ops = {
+ .set_trigger_state = &bmi160_data_rdy_trigger_set_state,
+};
+
+int bmi160_probe_trigger(struct iio_dev *indio_dev, int irq, u32 irq_type)
+{
+ struct bmi160_data *data = iio_priv(indio_dev);
+ int ret;
+
+ data->trig = devm_iio_trigger_alloc(&indio_dev->dev, "%s-dev%d",
+ indio_dev->name, indio_dev->id);
+
+ if (data->trig == NULL)
+ return -ENOMEM;
+
+ ret = devm_request_irq(&indio_dev->dev, irq,
+ &iio_trigger_generic_data_rdy_poll,
+ irq_type, "bmi160", data->trig);
+ if (ret < 0)
+ return ret;
+
+ data->trig->dev.parent = regmap_get_device(data->regmap);
+ data->trig->ops = &bmi160_trigger_ops;
+ iio_trigger_set_drvdata(data->trig, indio_dev);
+
+ ret = devm_iio_trigger_register(&indio_dev->dev, data->trig);
+ if (ret)
+ return ret;
+
+ indio_dev->trig = iio_trigger_get(data->trig);
+
+ return 0;
+}
+
static void bmi160_chip_uninit(void *data)
{
struct bmi160_data *bmi_data = data;
@@ -548,7 +822,7 @@ static void bmi160_chip_uninit(void *data)
}

int bmi160_core_probe(struct device *dev, struct regmap *regmap,
- const char *name, bool use_spi)
+ const char *name, bool use_spi, int irq)
{
struct iio_dev *indio_dev;
struct bmi160_data *data;
@@ -562,7 +836,7 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap,
dev_set_drvdata(dev, indio_dev);
data->regmap = regmap;

- ret = bmi160_chip_init(data, use_spi);
+ ret = bmi160_chip_init(data, use_spi, irq);
if (ret < 0)
return ret;

@@ -585,6 +859,12 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap,
if (ret < 0)
return ret;

+ if (irq) {
+ ret = bmi160_setup_irq(indio_dev, irq);
+ if (ret)
+ return ret;
+ }
+
ret = devm_iio_device_register(dev, indio_dev);
if (ret < 0)
return ret;
diff --git a/drivers/iio/imu/bmi160/bmi160_i2c.c b/drivers/iio/imu/bmi160/bmi160_i2c.c
index e36f5e82d400..98467d73c887 100644
--- a/drivers/iio/imu/bmi160/bmi160_i2c.c
+++ b/drivers/iio/imu/bmi160/bmi160_i2c.c
@@ -32,7 +32,8 @@ static int bmi160_i2c_probe(struct i2c_client *client,
if (id)
name = id->name;

- return bmi160_core_probe(&client->dev, regmap, name, false);
+ return bmi160_core_probe(&client->dev, regmap,
+ name, false, client->irq);
}

static const struct i2c_device_id bmi160_i2c_id[] = {
diff --git a/drivers/iio/imu/bmi160/bmi160_spi.c b/drivers/iio/imu/bmi160/bmi160_spi.c
index c19e3df35559..23e323518873 100644
--- a/drivers/iio/imu/bmi160/bmi160_spi.c
+++ b/drivers/iio/imu/bmi160/bmi160_spi.c
@@ -24,7 +24,7 @@ static int bmi160_spi_probe(struct spi_device *spi)
(int)PTR_ERR(regmap));
return PTR_ERR(regmap);
}
- return bmi160_core_probe(&spi->dev, regmap, id->name, true);
+ return bmi160_core_probe(&spi->dev, regmap, id->name, true, spi->irq);
}

static const struct spi_device_id bmi160_spi_id[] = {
--
2.11.0