Re: [PATCH v4 04/11] staging:iio:hmc5843: Add trigger handling

[Jonathan Cameron <jic23@kernel.org>]

On 10/16/13 23:19, Peter Meerwald wrote:
> v3:
> * use __be16 instead of s16
> v2 (thanks to Jonathan Cameron):
> * drop dynamic buffer allocation, buffer is in hmc5842_data
> * grab timestamp near data acquisition
> * restrict available scan masks (only read all axis)
> 
> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Applied to the togreg branch of iio.git

Thanks,
> ---
>  drivers/staging/iio/magnetometer/hmc5843.c | 69 ++++++++++++++++++++++++++----
>  1 file changed, 61 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/iio/magnetometer/hmc5843.c b/drivers/staging/iio/magnetometer/hmc5843.c
> index 78b97b0..aeaea09 100644
> --- a/drivers/staging/iio/magnetometer/hmc5843.c
> +++ b/drivers/staging/iio/magnetometer/hmc5843.c
> @@ -23,6 +23,9 @@
>  #include <linux/i2c.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
>  #include <linux/delay.h>
>  
>  #define HMC5843_CONFIG_REG_A			0x00
> @@ -124,6 +127,7 @@ struct hmc5843_data {
>  	u8 operating_mode;
>  	u8 range;
>  	const struct hmc5843_chip_info *variant;
> +	__be16 buffer[8]; /* 3x 16-bit channels + padding + 64-bit timestamp */
>  };
>  
>  /* The lower two bits contain the current conversion mode */
> @@ -403,7 +407,7 @@ static int hmc5843_read_raw(struct iio_dev *indio_dev,
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
> -		return hmc5843_read_measurement(data, chan->address, val);
> +		return hmc5843_read_measurement(data, chan->scan_index, val);
>  	case IIO_CHAN_INFO_SCALE:
>  		*val = 0;
>  		*val2 = data->variant->regval_to_nanoscale[data->range];
> @@ -468,6 +472,36 @@ static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct hmc5843_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->lock);
> +	ret = hmc5843_wait_measurement(data);
> +	if (ret < 0) {
> +		mutex_unlock(&data->lock);
> +		goto done;
> +	}
> +
> +	ret = i2c_smbus_read_i2c_block_data(data->client,
> +		HMC5843_DATA_OUT_MSB_REGS, 3 * sizeof(__be16),
> +			(u8 *) data->buffer);
> +	mutex_unlock(&data->lock);
> +	if (ret < 0)
> +		goto done;
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +		iio_get_time_ns());
> +
> +done:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  #define HMC5843_CHANNEL(axis, idx)					\
>  	{								\
>  		.type = IIO_MAGN,					\
> @@ -476,13 +510,15 @@ static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
>  		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
>  			BIT(IIO_CHAN_INFO_SAMP_FREQ),			\
> -		.address = idx						\
> +		.scan_index = idx,					\
> +		.scan_type = IIO_ST('s', 16, 16, IIO_BE),		\
>  	}
>  
>  static const struct iio_chan_spec hmc5843_channels[] = {
>  	HMC5843_CHANNEL(X, 0),
>  	HMC5843_CHANNEL(Y, 1),
>  	HMC5843_CHANNEL(Z, 2),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
>  };
>  
>  /* Beware: Y and Z are exchanged on HMC5883 */
> @@ -490,6 +526,7 @@ static const struct iio_chan_spec hmc5883_channels[] = {
>  	HMC5843_CHANNEL(X, 0),
>  	HMC5843_CHANNEL(Z, 1),
>  	HMC5843_CHANNEL(Y, 2),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
>  };
>  
>  static struct attribute *hmc5843_attributes[] = {
> @@ -539,12 +576,14 @@ static const struct iio_info hmc5843_info = {
>  	.driver_module = THIS_MODULE,
>  };
>  
> +static const unsigned long hmc5843_scan_masks[] = {0x7, 0};
> +
>  static int hmc5843_probe(struct i2c_client *client,
>  			 const struct i2c_device_id *id)
>  {
>  	struct hmc5843_data *data;
>  	struct iio_dev *indio_dev;
> -	int err = 0;
> +	int ret;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>  	if (indio_dev == NULL)
> @@ -562,20 +601,34 @@ static int hmc5843_probe(struct i2c_client *client,
>  	indio_dev->dev.parent = &client->dev;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->channels = data->variant->channels;
> -	indio_dev->num_channels = 3;
> +	indio_dev->num_channels = 4;
> +	indio_dev->available_scan_masks = hmc5843_scan_masks;
>  
>  	hmc5843_init(data);
>  
> -	err = iio_device_register(indio_dev);
> -	if (err)
> -		return err;
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +		hmc5843_trigger_handler, NULL);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0)
> +		goto buffer_cleanup;
>  
>  	return 0;
> +
> +buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	return ret;
>  }
>  
>  static int hmc5843_remove(struct i2c_client *client)
>  {
> -	iio_device_unregister(i2c_get_clientdata(client));
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
>  	 /*  sleep mode to save power */
>  	hmc5843_configure(client, HMC5843_MODE_SLEEP);
>  
>