Message-ID: <548E1777.3080705@gmx.de>
Date:	Mon, 15 Dec 2014 00:04:23 +0100
From:	Hartmut Knaack <knaack.h@....de>
To:	Daniel Baluta <daniel.baluta@...el.com>, jic23@...nel.org,
	pmeerw@...erw.net, srinivas.pandruvada@...ux.intel.com
CC:	linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 5/6] iio: imu: kmx61: Add support for data ready triggers

Daniel Baluta schrieb am 03.12.2014 um 14:31:
> This creates a data ready trigger per IIO device.
> 
I found some issues here, and some recommendations. See inline.

> Signed-off-by: Daniel Baluta <daniel.baluta@...el.com>
> ---
>  drivers/iio/imu/Kconfig |   2 +
>  drivers/iio/imu/kmx61.c | 295 +++++++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 296 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/imu/Kconfig b/drivers/iio/imu/Kconfig
> index db4221d..5e610f7 100644
> --- a/drivers/iio/imu/Kconfig
> +++ b/drivers/iio/imu/Kconfig
> @@ -28,6 +28,8 @@ config ADIS16480
>  config KMX61
>  	tristate "Kionix KMX61 6-axis accelerometer and magnetometer"
>  	depends on I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
>  	help
>  	  Say Y here if you want to build a driver for Kionix KMX61 6-axis
>  	  accelerometer and magnetometer.
> diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
> index f69ae5a7..0f6816a 100644
> --- a/drivers/iio/imu/kmx61.c
> +++ b/drivers/iio/imu/kmx61.c
> @@ -20,9 +20,14 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
>  
>  #define KMX61_DRV_NAME "kmx61"
>  #define KMX61_GPIO_NAME "kmx61_int"
> +#define KMX61_IRQ_NAME "kmx61_event"
>  
>  #define KMX61_REG_WHO_AM_I	0x00
>  
> @@ -55,9 +60,11 @@
>  #define KMX61_MAG_ZOUT_L	0x16
>  #define KMX61_MAG_ZOUT_H	0x17
>  
> +#define KMX61_REG_INL		0x28
>  #define KMX61_REG_STBY		0x29
>  #define KMX61_REG_CTRL1		0x2A
>  #define KMX61_REG_ODCNTL	0x2C
> +#define KMX61_REG_INC1		0x2D
>  
>  #define KMX61_ACC_STBY_BIT	BIT(0)
>  #define KMX61_MAG_STBY_BIT	BIT(1)
> @@ -67,6 +74,13 @@
>  
>  #define KMX61_REG_CTRL1_GSEL_MASK	0x03
>  
> +#define KMX61_REG_CTRL1_BIT_RES		BIT(4)
> +#define KMX61_REG_CTRL1_BIT_DRDYE	BIT(5)
> +
> +#define KMX61_REG_INC1_BIT_DRDYM	BIT(1)
> +#define KMX61_REG_INC1_BIT_DRDYA	BIT(2)
> +#define KMX61_REG_INC1_BIT_IEN		BIT(5)
> +
>  #define KMX61_ACC_ODR_SHIFT	0
>  #define KMX61_MAG_ODR_SHIFT	4
>  #define KMX61_ACC_ODR_MASK	0x0F
> @@ -100,9 +114,13 @@ struct kmx61_data {
>  
>  	/* accelerometer specific data */
>  	struct iio_dev *acc_indio_dev;
> +	struct iio_trigger *acc_dready_trig;
> +	bool acc_dready_trig_on;
>  
>  	/* magnetometer specific data */
>  	struct iio_dev *mag_indio_dev;
> +	struct iio_trigger *mag_dready_trig;
> +	bool mag_dready_trig_on;
>  };
>  
>  enum kmx61_range {
> @@ -466,6 +484,69 @@ static int kmx61_chip_init(struct kmx61_data *data)
>  	return 0;
>  }
>  
> +static int kmx61_setup_new_data_interrupt(struct kmx61_data *data,
> +					  bool status, u8 device)
> +{
> +	u8 mode;
> +	int ret;
> +
> +	ret = kmx61_get_mode(data, &mode, KMX61_ACC | KMX61_MAG);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INC1);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
> +		return ret;
> +	}
> +
> +	if (status) {
> +		ret |= KMX61_REG_INC1_BIT_IEN;
> +		if (device & KMX61_ACC)
> +			ret |= KMX61_REG_INC1_BIT_DRDYA;
> +		if (device & KMX61_MAG)
> +			ret |=  KMX61_REG_INC1_BIT_DRDYM;
> +	} else {
> +		ret &= ~KMX61_REG_INC1_BIT_IEN;
> +		if (device & KMX61_ACC)
> +			ret &= ~KMX61_REG_INC1_BIT_DRDYA;
> +		if (device & KMX61_MAG)
> +			ret &= ~KMX61_REG_INC1_BIT_DRDYM;
> +	}
> +	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_INC1, ret);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error writing reg_int_ctrl1\n");
> +		return ret;
> +	}
> +
> +	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_CTRL1);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
> +		return ret;
> +	}
> +
> +	if (status)
> +		ret |= KMX61_REG_CTRL1_BIT_DRDYE;
> +	else
> +		ret &= ~KMX61_REG_CTRL1_BIT_DRDYE;
> +
> +	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
> +		return ret;
> +	}
> +
> +	ret = kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
No need to check ret here, could be simply: return kmx61_set_mode(...);
> +}
> +
>  /**
>   * kmx61_set_power_state() - set power state for kmx61 @device
>   * @data - kmx61 device private pointer
> @@ -626,11 +707,34 @@ static int kmx61_write_raw(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int kmx61_acc_validate_trigger(struct iio_dev *indio_dev,
> +				      struct iio_trigger *trig)
> +{
> +	struct kmx61_data *data = kmx61_get_data(indio_dev);
> +
> +	if (data->acc_dready_trig != trig)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int kmx61_mag_validate_trigger(struct iio_dev *indio_dev,
> +				      struct iio_trigger *trig)
> +{
> +	struct kmx61_data *data = kmx61_get_data(indio_dev);
> +
> +	if (data->mag_dready_trig != trig)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  static const struct iio_info kmx61_acc_info = {
>  	.driver_module		= THIS_MODULE,
>  	.read_raw		= kmx61_read_raw,
>  	.write_raw		= kmx61_write_raw,
>  	.attrs			= &kmx61_acc_attribute_group,
> +	.validate_trigger	= kmx61_acc_validate_trigger,
>  };
>  
>  static const struct iio_info kmx61_mag_info = {
> @@ -638,8 +742,109 @@ static const struct iio_info kmx61_mag_info = {
>  	.read_raw		= kmx61_read_raw,
>  	.write_raw		= kmx61_write_raw,
>  	.attrs			= &kmx61_mag_attribute_group,
> +	.validate_trigger	= kmx61_mag_validate_trigger,
> +};
> +
> +
> +static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
> +					    bool state)
> +{
> +	int ret = 0;
No need to initialize ret.
> +	u8 device;
> +
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct kmx61_data *data = iio_priv(indio_dev);
Shouldn't that be using kmx61_get_data()?
> +
> +	mutex_lock(&data->lock);
> +
> +	if (data->acc_dready_trig == trig)
> +		device = KMX61_ACC;
> +	else
> +		device = KMX61_MAG;
> +
> +	ret = kmx61_set_power_state(data, state, device);
> +	if (ret < 0) {
> +		mutex_unlock(&data->lock);
> +		return ret;
> +	}
> +
> +	ret = kmx61_setup_new_data_interrupt(data, state, device);
> +	if (ret < 0) {
> +		kmx61_set_power_state(data, false, device);
> +		mutex_unlock(&data->lock);
> +		return ret;
> +	}
> +
> +	if (data->acc_dready_trig == trig)
> +		data->acc_dready_trig_on = state;
> +	else
> +		data->mag_dready_trig_on = state;
> +
> +	mutex_unlock(&data->lock);
> +
> +	return 0;
Could reduce code repetition by placing an error-out label above the
mutex_unlock and then just do: return (ret < 0) ? ret : 0;
(Or even: return ret;)
> +}
> +
> +static int kmx61_trig_try_reenable(struct iio_trigger *trig)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct kmx61_data *data = kmx61_get_data(indio_dev);
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INL);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error reading reg_inl\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct iio_trigger_ops kmx61_trigger_ops = {
> +	.set_trigger_state = kmx61_data_rdy_trigger_set_state,
> +	.try_reenable = kmx61_trig_try_reenable,
> +	.owner = THIS_MODULE,
>  };
>  
> +static irqreturn_t kmx61_data_rdy_trig_poll(int irq, void *private)
> +{
> +	struct kmx61_data *data = private;
> +
> +	if (data->acc_dready_trig_on)
> +		iio_trigger_poll(data->acc_dready_trig);
> +	if (data->mag_dready_trig_on)
> +		iio_trigger_poll(data->mag_dready_trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t kmx61_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct kmx61_data *data = kmx61_get_data(indio_dev);
> +	int bit, ret, i = 0;
> +	s16 buffer[8];
> +
> +	mutex_lock(&data->lock);
> +	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
> +			 indio_dev->masklength) {
> +		ret = kmx61_read_measurement(data, KMX61_ACC_XOUT_L, bit);
> +		if (ret < 0) {
> +			mutex_unlock(&data->lock);
> +			goto err;
> +		}
> +		buffer[i++] = ret;
> +	}
> +	mutex_unlock(&data->lock);
> +
> +	iio_push_to_buffers(indio_dev, buffer);
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static const char *kmx61_match_acpi_device(struct device *dev)
>  {
>  	const struct acpi_device_id *id;
> @@ -702,6 +907,32 @@ static struct iio_dev *kmx61_indiodev_setup(struct kmx61_data *data,
>  	return indio_dev;
>  }
>  
> +static struct iio_trigger *kmx61_trigger_setup(struct kmx61_data *data,
> +					       struct iio_dev *indio_dev,
> +					       const char *tag)
> +{
> +	struct iio_trigger *trig;
> +	int ret;
> +
> +	trig = devm_iio_trigger_alloc(&data->client->dev,
> +				      "%s-%s-dev%d",
> +				      indio_dev->name,
> +				      tag,
> +				      indio_dev->id);
> +	if (!trig)
> +		return ERR_PTR(-ENOMEM);
> +
> +	trig->dev.parent = &data->client->dev;
> +	trig->ops = &kmx61_trigger_ops;
> +	iio_trigger_set_drvdata(trig, indio_dev);
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return trig;
> +}
> +
>  static int kmx61_probe(struct i2c_client *client,
>  		       const struct i2c_device_id *id)
>  {
> @@ -748,10 +979,55 @@ static int kmx61_probe(struct i2c_client *client,
>  	if (client->irq < 0)
>  		client->irq = kmx61_gpio_probe(client, data);
>  
> +	if (client->irq >= 0) {
> +		ret = devm_request_threaded_irq(&client->dev, client->irq,
> +						kmx61_data_rdy_trig_poll,
> +						NULL,
> +						IRQF_TRIGGER_RISING,
> +						KMX61_IRQ_NAME,
> +						data);
> +		if (ret)
> +			goto err_chip_uninit;
> +
> +		data->acc_dready_trig =
> +			kmx61_trigger_setup(data, data->acc_indio_dev,
> +					    "dready");
> +		if (IS_ERR(data->acc_dready_trig))
> +			return PTR_ERR(data->acc_dready_trig);
Better store error value in ret and goto err_chip_uninit.
> +
> +		data->mag_dready_trig =
> +			kmx61_trigger_setup(data, data->mag_indio_dev,
> +					    "dready");
> +		if (IS_ERR(data->mag_dready_trig)) {
> +			ret = PTR_ERR(data->mag_dready_trig);
> +			goto err_trigger_unregister;
> +		}
> +
> +		ret = iio_triggered_buffer_setup(data->acc_indio_dev,
> +						 &iio_pollfunc_store_time,
> +						 kmx61_trigger_handler,
> +						 NULL);
> +		if (ret < 0) {
> +			dev_err(&data->client->dev,
> +				"Failed to setup acc triggered buffer\n");
> +			goto err_trigger_unregister;
> +		}
> +
> +		ret = iio_triggered_buffer_setup(data->mag_indio_dev,
> +						 &iio_pollfunc_store_time,
> +						 kmx61_trigger_handler,
> +						 NULL);
> +		if (ret < 0) {
> +			dev_err(&data->client->dev,
> +				"Failed to setup mag triggered buffer\n");
> +			goto err_trigger_unregister;
Better make sure to call iio_triggered_buffer_cleanup for data->acc_indio_dev?
> +		}
> +	}
> +
>  	ret = iio_device_register(data->acc_indio_dev);
>  	if (ret < 0) {
>  		dev_err(&client->dev, "Failed to register acc iio device\n");
> -		goto err_chip_uninit;
> +		goto err_buffer_cleanup;
>  	}
>  
>  	ret = iio_device_register(data->mag_indio_dev);
> @@ -774,6 +1050,16 @@ err_iio_unregister_mag:
>  	iio_device_unregister(data->mag_indio_dev);
>  err_iio_unregister_acc:
>  	iio_device_unregister(data->acc_indio_dev);
> +err_buffer_cleanup:
> +	if (client->irq >= 0) {
> +		iio_triggered_buffer_cleanup(data->acc_indio_dev);
> +		iio_triggered_buffer_cleanup(data->mag_indio_dev);
> +	}
> +err_trigger_unregister:
> +	if (data->acc_dready_trig)
> +		iio_trigger_unregister(data->acc_dready_trig);
> +	if (data->mag_dready_trig)
> +		iio_trigger_unregister(data->mag_dready_trig);
>  err_chip_uninit:
>  	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
>  	return ret;
> @@ -790,6 +1076,13 @@ static int kmx61_remove(struct i2c_client *client)
>  	iio_device_unregister(data->acc_indio_dev);
>  	iio_device_unregister(data->mag_indio_dev);
>  
> +	if (client->irq >= 0) {
> +		iio_triggered_buffer_cleanup(data->acc_indio_dev);
> +		iio_triggered_buffer_cleanup(data->mag_indio_dev);
> +		iio_trigger_unregister(data->acc_dready_trig);
> +		iio_trigger_unregister(data->mag_dready_trig);
Minor nitpick: could be in reverse order of initialization (mag before acc).
Although we missed it for iio_device_unregister() :-(
> +	}
> +
>  	mutex_lock(&data->lock);
>  	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
>  	mutex_unlock(&data->lock);
> 

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