Re: [PATCH v4 15/17] iio: cros_ec: Expose hwfifo_timeout

[Jonathan Cameron <jic23@kernel.org>]

On Tue,  5 Nov 2019 14:26:50 -0800
Gwendal Grignou <gwendal@chromium.org> wrote:

> Expose EC minimal interrupt period through buffer/hwfifo_timeout:
> - Maximal timeout is limited to 65s.
> - When timeout for all sensors is set to 0, EC will not send events,
>   even if the sensor sampling rate is greater than 0.
> 
> Rename frequency to sampling_frequency to match IIO ABI.
Would have preferred this as two patches, but not that important as one
is really simple.

> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
One note on something else to tidy up inline (not relevant to this patch)
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> Changes in v4:
> - Check patch with --strict option
>     Alignement
> No changes in v3.
> Changes in v2:
> - Register fifo_attributes in sensors drivers that previously advertise
>   that feature.
> 
>  .../common/cros_ec_sensors/cros_ec_sensors.c  |  4 +-
>  .../cros_ec_sensors/cros_ec_sensors_core.c    | 95 ++++++++++++++-----
>  drivers/iio/light/cros_ec_light_prox.c        |  5 +-
>  drivers/iio/pressure/cros_ec_baro.c           |  5 +-
>  .../linux/iio/common/cros_ec_sensors_core.h   |  4 +-
>  5 files changed, 82 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> index 9d0b8ad7a0a5..6f511f9067d9 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> @@ -237,6 +237,8 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
> +
>  	indio_dev->info = &ec_sensors_info;
>  	state = iio_priv(indio_dev);
>  	for (channel = state->channels, i = CROS_EC_SENSOR_X;
> @@ -248,7 +250,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
>  			BIT(IIO_CHAN_INFO_CALIBSCALE);
>  		channel->info_mask_shared_by_all =
>  			BIT(IIO_CHAN_INFO_SCALE) |
> -			BIT(IIO_CHAN_INFO_FREQUENCY) |
>  			BIT(IIO_CHAN_INFO_SAMP_FREQ);
>  		channel->info_mask_shared_by_all_available =
>  			BIT(IIO_CHAN_INFO_SAMP_FREQ);
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> index 879b69527cae..62dc1e4aa7a8 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> @@ -11,6 +11,7 @@
>  #include <linux/iio/common/cros_ec_sensors_core.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/kfifo_buf.h>
> +#include <linux/iio/sysfs.h>
>  #include <linux/iio/trigger_consumer.h>
>  #include <linux/iio/triggered_buffer.h>
>  #include <linux/kernel.h>
> @@ -84,6 +85,77 @@ static void get_default_min_max_freq(enum motionsensor_type type,
>  	}
>  }
>  
> +static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
> +				      int rate)
> +{
> +	int ret;
> +
> +	if (rate > U16_MAX)
> +		rate = U16_MAX;
> +
> +	mutex_lock(&st->cmd_lock);
> +	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> +	st->param.ec_rate.data = rate;
> +	ret = cros_ec_motion_send_host_cmd(st, 0);
> +	mutex_unlock(&st->cmd_lock);
> +	return ret;
> +}
> +
> +static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
> +						 struct device_attribute *attr,
> +						 const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +	int integer, fract, ret;
> +	int latency;
> +
> +	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
> +	if (ret)
> +		return ret;
> +
> +	/* EC rate is in ms. */
> +	latency = integer * 1000 + fract / 1000;
> +	ret = cros_ec_sensor_set_ec_rate(st, latency);
> +	if (ret < 0)
> +		return ret;
> +
> +	return len;
> +}
> +
> +static ssize_t cros_ec_sensor_get_report_latency(struct device *dev,
> +						 struct device_attribute *attr,
> +						 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +	int latency, ret;
> +
> +	mutex_lock(&st->cmd_lock);
> +	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> +	st->param.ec_rate.data = EC_MOTION_SENSE_NO_VALUE;
> +
> +	ret = cros_ec_motion_send_host_cmd(st, 0);
> +	latency = st->resp->ec_rate.ret;
> +	mutex_unlock(&st->cmd_lock);
> +	if (ret < 0)
> +		return ret;
> +
> +	return sprintf(buf, "%d.%06u\n",
> +		       latency / 1000,
> +		       (latency % 1000) * 1000);
> +}
> +
> +static IIO_DEVICE_ATTR(hwfifo_timeout, 0644,
> +		       cros_ec_sensor_get_report_latency,
> +		       cros_ec_sensor_set_report_latency, 0);
> +
> +const struct attribute *cros_ec_sensor_fifo_attributes[] = {
> +	&iio_dev_attr_hwfifo_timeout.dev_attr.attr,
> +	NULL,
> +};
> +EXPORT_SYMBOL_GPL(cros_ec_sensor_fifo_attributes);
> +
>  int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
>  			      s16 *data,
>  			      s64 timestamp)
> @@ -616,18 +688,6 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> -		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> -		st->param.ec_rate.data =
> -			EC_MOTION_SENSE_NO_VALUE;
> -
> -		ret = cros_ec_motion_send_host_cmd(st, 0);
> -		if (ret)
> -			break;
> -
> -		*val = st->resp->ec_rate.ret;
> -		ret = IIO_VAL_INT;
> -		break;
> -	case IIO_CHAN_INFO_FREQUENCY:
>  		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
>  		st->param.sensor_odr.data =
>  			EC_MOTION_SENSE_NO_VALUE;
> @@ -697,7 +757,7 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
>  	int ret;
>  
>  	switch (mask) {
> -	case IIO_CHAN_INFO_FREQUENCY:
> +	case IIO_CHAN_INFO_SAMP_FREQ:
>  		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
>  		st->param.sensor_odr.data = val;
>  
> @@ -706,15 +766,6 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
>  
>  		ret = cros_ec_motion_send_host_cmd(st, 0);
>  		break;
> -	case IIO_CHAN_INFO_SAMP_FREQ:
> -		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> -		st->param.ec_rate.data = val;
> -
> -		ret = cros_ec_motion_send_host_cmd(st, 0);
> -		if (ret)
> -			break;
> -		st->curr_sampl_freq = val;
> -		break;
>  	default:
>  		ret = -EINVAL;
>  		break;
> diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
> index ccdc6d8958c6..863d01994aae 100644
> --- a/drivers/iio/light/cros_ec_light_prox.c
> +++ b/drivers/iio/light/cros_ec_light_prox.c
> @@ -184,6 +184,8 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
> +
>  	indio_dev->info = &cros_ec_light_prox_info;
>  	state = iio_priv(indio_dev);
>  	state->core.type = state->core.resp->info.type;
> @@ -192,8 +194,7 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
>  
>  	/* Common part */
>  	channel->info_mask_shared_by_all =
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_FREQUENCY);
> +		BIT(IIO_CHAN_INFO_SAMP_FREQ);
>  	channel->info_mask_shared_by_all_available =
>  		BIT(IIO_CHAN_INFO_SAMP_FREQ);
>  	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
> diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
> index e1c86b22676c..0dee943f955e 100644
> --- a/drivers/iio/pressure/cros_ec_baro.c
> +++ b/drivers/iio/pressure/cros_ec_baro.c
> @@ -140,6 +140,8 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
> +
>  	indio_dev->info = &cros_ec_baro_info;
>  	state = iio_priv(indio_dev);
>  	state->core.type = state->core.resp->info.type;
> @@ -149,8 +151,7 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
>  	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
>  	channel->info_mask_shared_by_all =
>  		BIT(IIO_CHAN_INFO_SCALE) |
> -		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -		BIT(IIO_CHAN_INFO_FREQUENCY);
> +		BIT(IIO_CHAN_INFO_SAMP_FREQ);
>  	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
>  	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
>  	channel->scan_type.shift = 0;
> diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
> index 96ea4551945e..5b0acc14c891 100644
> --- a/include/linux/iio/common/cros_ec_sensors_core.h
> +++ b/include/linux/iio/common/cros_ec_sensors_core.h
> @@ -50,7 +50,6 @@ typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
>   *				the timestamp. The timestamp is always last and
>   *				is always 8-byte aligned.
>   * @read_ec_sensors_data:	function used for accessing sensors values
> - * @cuur_sampl_freq:		current sampling period

Side note. Seems that 'frequencies' is not documented... 

>   */
>  struct cros_ec_sensors_core_state {
>  	struct cros_ec_device *ec;
> @@ -73,8 +72,6 @@ struct cros_ec_sensors_core_state {
>  	int (*read_ec_sensors_data)(struct iio_dev *indio_dev,
>  				    unsigned long scan_mask, s16 *data);
>  
> -	int curr_sampl_freq;
> -
>  	/* Table of known available frequencies : 0, Min and Max in mHz */
>  	int frequencies[3];
>  };
> @@ -116,5 +113,6 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
>  
>  /* List of extended channel specification for all sensors */
>  extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
> +extern const struct attribute *cros_ec_sensor_fifo_attributes[];
>  
>  #endif  /* __CROS_EC_SENSORS_CORE_H */