linux-kernel - Re: [PATCH v3 2/2] ti-adc081c: Initial triggered buffer support

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Date:	Sun, 17 Apr 2016 10:46:29 +0100
From:	Jonathan Cameron <jic23@...nel.org>
To:	Crestez Dan Leonard <leonard.crestez@...el.com>,
	linux-iio@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Hartmut Knaack <knaack.h@....de>,
	Lars-Peter Clausen <lars@...afoo.de>,
	Peter Meerwald-Stadler <pmeerw@...erw.net>,
	Daniel Baluta <daniel.baluta@...el.com>
Subject: Re: [PATCH v3 2/2] ti-adc081c: Initial triggered buffer support

On 11/04/16 15:24, Crestez Dan Leonard wrote:
> Using this requires software triggers like CONFIG_IIO_HRTIMER_TRIGGER.
> 
> The device can be configured to do internal periodic sampling but does not
> offer some sort of interrupt on data ready. Interrupts can only trigger when
> values get out of a specific range.
> 
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@...el.com>
One totally trivial comment inline.

Applied to the togreg branch of iio.git - pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan
> ---
>  drivers/iio/adc/ti-adc081c.c | 77 ++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 64 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c
> index b977340..9fd032d 100644
> --- a/drivers/iio/adc/ti-adc081c.c
> +++ b/drivers/iio/adc/ti-adc081c.c
> @@ -24,6 +24,9 @@
>  #include <linux/of.h>
>  
>  #include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>  #include <linux/regulator/consumer.h>
>  
>  struct adc081c {
> @@ -69,21 +72,42 @@ static int adc081c_read_raw(struct iio_dev *iio,
>  	return -EINVAL;
>  }
>  
> -static const struct iio_chan_spec adc081c_channel = {
> -	.type = IIO_VOLTAGE,
> -	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> -	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> -};
> +#define ADCxx1C_CHAN(_bits) {					\
> +	.type = IIO_VOLTAGE,					\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.scan_type = {						\
> +		.sign = 'u',					\
> +		.realbits = (_bits),				\
> +		.storagebits = 16,				\
> +		.shift = 12 - (_bits),				\
> +		.endianness = IIO_CPU,				\
> +	},							\
> +}
> +
> +#define DEFINE_ADCxx1C_CHANNELS(_name, _bits)				\
> +	static const struct iio_chan_spec _name ## _channels[] = {	\
> +		ADCxx1C_CHAN((_bits)),					\
> +		IIO_CHAN_SOFT_TIMESTAMP(1),				\
> +	};								\
> +
> +#define ADC081C_NUM_CHANNELS 2
>  
>  struct adcxx1c_model {
> +	const struct iio_chan_spec* channels;
>  	int bits;
>  };
>  
> -#define ADCxx1C_MODEL(_bits)						\
> +#define ADCxx1C_MODEL(_name, _bits)					\
>  	{								\
> +		.channels = _name ## _channels,				\
>  		.bits = (_bits),					\
>  	}
>  
> +DEFINE_ADCxx1C_CHANNELS(adc081c,  8);
> +DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
> +DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
> +
>  /* Model ids are indexes in _models array */
>  enum adcxx1c_model_id {
>  	ADC081C = 0,
> @@ -92,9 +116,9 @@ enum adcxx1c_model_id {
>  };
>  
>  static struct adcxx1c_model adcxx1c_models[] = {
> -	ADCxx1C_MODEL( 8),
> -	ADCxx1C_MODEL(10),
> -	ADCxx1C_MODEL(12),
> +	ADCxx1C_MODEL(adc081c,  8),
> +	ADCxx1C_MODEL(adc101c, 10),
> +	ADCxx1C_MODEL(adc121c, 12),
>  };
>  
>  static const struct iio_info adc081c_info = {
> @@ -102,6 +126,24 @@ static const struct iio_info adc081c_info = {
>  	.driver_module = THIS_MODULE,
>  };
>  
> +static irqreturn_t adc081c_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct adc081c *data = iio_priv(indio_dev);
> +	u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */
> +	int ret;
> +
> +	ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
> +	if (ret < 0)
> +		goto out;
> +	buf[0] = ret;
> +	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
> +out:
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +}
> +
>  static int adc081c_probe(struct i2c_client *client,
>  			 const struct i2c_device_id *id)
>  {
> @@ -134,18 +176,26 @@ static int adc081c_probe(struct i2c_client *client,
>  	iio->modes = INDIO_DIRECT_MODE;
>  	iio->info = &adc081c_info;
>  
> -	iio->channels = &adc081c_channel;
> -	iio->num_channels = 1;
> +	iio->channels = model->channels;
> +	iio->num_channels = ADC081C_NUM_CHANNELS;
> +
> +	err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL);
> +	if (err < 0) {
> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +		goto err_regulator_disable;
> +	}
>  
>  	err = iio_device_register(iio);
>  	if (err < 0)
> -		goto regulator_disable;
> +		goto err_buffer_cleanup;
>  
>  	i2c_set_clientdata(client, iio);
>  
>  	return 0;
>  
> -regulator_disable:
Technically an unrelated change, but can't say I really care!
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(iio);
> +err_regulator_disable:
>  	regulator_disable(adc->ref);
>  
>  	return err;
> @@ -157,6 +207,7 @@ static int adc081c_remove(struct i2c_client *client)
>  	struct adc081c *adc = iio_priv(iio);
>  
>  	iio_device_unregister(iio);
> +	iio_triggered_buffer_cleanup(iio);
>  	regulator_disable(adc->ref);
>  
>  	return 0;
>