Commit bc11ca4a authored by Gregor Boirie's avatar Gregor Boirie Committed by Jonathan Cameron
Browse files

iio:magnetometer:ak8975: triggered buffer support 



This will be used together with an external trigger (e.g hrtimer based
software trigger).

Signed-off-by: default avatarGregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent fbbc5e70

drivers/iio/magnetometer/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ config AK8975 
	tristate "Asahi Kasei AK 3-Axis Magnetometer"

	depends on I2C

	depends on GPIOLIB || COMPILE_TEST

	select IIO_BUFFER

	select IIO_TRIGGERED_BUFFER

	help

	  Say yes here to build support for Asahi Kasei AK8975, AK8963,

	  AK09911 or AK09912 3-Axis Magnetometer.

drivers/iio/magnetometer/ak8975.c

+110 −25
Original line number Diff line number Diff line
@@ -36,6 +36,12 @@ 


#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/buffer.h>

#include <linux/iio/trigger.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>

#include <linux/regulator/consumer.h>



/*

 * Register definitions, as well as various shifts and masks to get at the

 * individual fields of the registers.
@@ -633,22 +639,15 @@ static int wait_conversion_complete_interrupt(struct ak8975_data *data) 
	return ret > 0 ? 0 : -ETIME;

}



/*

 * Emits the raw flux value for the x, y, or z axis.

 */

static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)

static int ak8975_start_read_axis(struct ak8975_data *data,

				  const struct i2c_client *client)

{

	struct ak8975_data *data = iio_priv(indio_dev);

	struct i2c_client *client = data->client;

	int ret;



	mutex_lock(&data->lock);



	/* Set up the device for taking a sample. */

	ret = ak8975_set_mode(data, MODE_ONCE);

	int ret = ak8975_set_mode(data, MODE_ONCE);



	if (ret < 0) {

		dev_err(&client->dev, "Error in setting operating mode\n");

		goto exit;

		return ret;

	}



	/* Wait for the conversion to complete. */
@@ -659,7 +658,7 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 
	else

		ret = wait_conversion_complete_polled(data);

	if (ret < 0)

		goto exit;

		return ret;



	/* This will be executed only for non-interrupt based waiting case */

	if (ret & data->def->ctrl_masks[ST1_DRDY]) {
@@ -667,32 +666,45 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 
					       data->def->ctrl_regs[ST2]);

		if (ret < 0) {

			dev_err(&client->dev, "Error in reading ST2\n");

			goto exit;

			return ret;

		}

		if (ret & (data->def->ctrl_masks[ST2_DERR] |

			   data->def->ctrl_masks[ST2_HOFL])) {

			dev_err(&client->dev, "ST2 status error 0x%x\n", ret);

			ret = -EINVAL;

			goto exit;

			return -EINVAL;

		}

	}



	/* Read the flux value from the appropriate register

	   (the register is specified in the iio device attributes). */

	ret = i2c_smbus_read_word_data(client, data->def->data_regs[index]);

	if (ret < 0) {

		dev_err(&client->dev, "Read axis data fails\n");

		goto exit;

	return 0;

}



/* Retrieve raw flux value for one of the x, y, or z axis.  */

static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)

{

	struct ak8975_data *data = iio_priv(indio_dev);

	const struct i2c_client *client = data->client;

	const struct ak_def *def = data->def;

	int ret;



	mutex_lock(&data->lock);



	ret = ak8975_start_read_axis(data, client);

	if (ret)

		goto exit;



	ret = i2c_smbus_read_word_data(client, def->data_regs[index]);

	if (ret < 0)

		goto exit;



	mutex_unlock(&data->lock);



	/* Clamp to valid range. */

	*val = clamp_t(s16, ret, -data->def->range, data->def->range);

	*val = clamp_t(s16, ret, -def->range, def->range);

	return IIO_VAL_INT;



exit:

	mutex_unlock(&data->lock);

	dev_err(&client->dev, "Error in reading axis\n");

	return ret;

}
@@ -722,12 +734,22 @@ static int ak8975_read_raw(struct iio_dev *indio_dev, 
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\

			     BIT(IIO_CHAN_INFO_SCALE),			\

		.address = index,					\

		.scan_index = index,					\

		.scan_type = {						\

			.sign = 's',					\

			.realbits = 16,					\

			.storagebits = 16,				\

			.endianness = IIO_CPU				\

		}							\

	}



static const struct iio_chan_spec ak8975_channels[] = {

	AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),

	IIO_CHAN_SOFT_TIMESTAMP(3),

};



static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };



static const struct iio_info ak8975_info = {

	.read_raw = &ak8975_read_raw,

	.driver_module = THIS_MODULE,
@@ -756,6 +778,56 @@ static const char *ak8975_match_acpi_device(struct device *dev, 
	return dev_name(dev);

}



static void ak8975_fill_buffer(struct iio_dev *indio_dev)

{

	struct ak8975_data *data = iio_priv(indio_dev);

	const struct i2c_client *client = data->client;

	const struct ak_def *def = data->def;

	int ret;

	s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */



	mutex_lock(&data->lock);



	ret = ak8975_start_read_axis(data, client);

	if (ret)

		goto unlock;



	/*

	 * For each axis, read the flux value from the appropriate register

	 * (the register is specified in the iio device attributes).

	 */

	ret = i2c_smbus_read_i2c_block_data_or_emulated(client,

							def->data_regs[0],

							3 * sizeof(buff[0]),

							(u8 *)buff);

	if (ret < 0)

		goto unlock;



	mutex_unlock(&data->lock);



	/* Clamp to valid range. */

	buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range);

	buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range);

	buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range);



	iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns());

	return;



unlock:

	mutex_unlock(&data->lock);

	dev_err(&client->dev, "Error in reading axes block\n");

}



static irqreturn_t ak8975_handle_trigger(int irq, void *p)

{

	const struct iio_poll_func *pf = p;

	struct iio_dev *indio_dev = pf->indio_dev;



	ak8975_fill_buffer(indio_dev);

	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;

}



static int ak8975_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{
@@ -845,15 +917,27 @@ static int ak8975_probe(struct i2c_client *client, 
	indio_dev->channels = ak8975_channels;

	indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);

	indio_dev->info = &ak8975_info;

	indio_dev->available_scan_masks = ak8975_scan_masks;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->name = name;



	err = iio_device_register(indio_dev);

	if (err)

	err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,

					 NULL);

	if (err) {

		dev_err(&client->dev, "triggered buffer setup failed\n");

		goto power_off;

	}



	err = iio_device_register(indio_dev);

	if (err) {

		dev_err(&client->dev, "device register failed\n");

		goto cleanup_buffer;

	}



	return 0;



cleanup_buffer:

	iio_triggered_buffer_cleanup(indio_dev);

power_off:

	ak8975_power_off(client);

	return err;
@@ -864,6 +948,7 @@ static int ak8975_remove(struct i2c_client *client) 
	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	ak8975_power_off(client);



	return 0;