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

Jonathan Cameron
2019-01-26T20:17:56Z

On Mon, 21 Jan 2019 18:04:27 -0800
Martin Kelly <martin@martingkelly.com> wrote:

> 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>

Various minor bits inline. I would also, if possible like Daniel to
take a glance at this series before we apply it. I don't know this hardware
at all well!

Jonathan

> ---
> 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 \

Separate patch for this.

> 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 bmi160...
> +
> + 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;
> + }

Given both could be provided, and we are implying a preference,
why not just get INT1 first by name and if it's not there try for
INT2? No need for this separate does the name match query.

> +
> + 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;

That seems unlikely. Why on a rising trigger are we setting a flag
that is named to imply it sets level triggering?

> + 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);

Why not do that within bmi160_config_pin? Then we have
return bmi160_config_pin..

> + 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 bmi160_probe_trigger... It's either zero or it's not.
Either way this gives the same as you have here.

> +
> + 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) {

This should be a separate patch, not rolled in here. It's
a good cleanup but within this patch it's noise.

> 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
>