[PATCH v2 2/2] ti-adc081c: Initial triggered buffer support

Crestez Dan Leonard
2016-04-04T18:22:25Z

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@intel.com>
---
drivers/iio/adc/ti-adc081c.c | 63 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 54 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c
index 3b3c656..d024df2 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 {
@@ -69,18 +72,31 @@ 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, \
+ }, \
+}

struct adcxx1c_model {
+ const struct iio_chan_spec* channels;
int bits;
};

#define DEFINE_ADCxx1C_MODEL(_name, _bits) \
+ static const struct iio_chan_spec _name ## _channels[] = { \
+ ADCxx1C_CHAN((_bits)), \
+ IIO_CHAN_SOFT_TIMESTAMP(1), \
+ }; \
static const struct adcxx1c_model _name ## _model = { \
+ .channels = _name ## _channels, \
.bits = (_bits), \
}

@@ -88,11 +104,31 @@ DEFINE_ADCxx1C_MODEL(adc081c, 8);
DEFINE_ADCxx1C_MODEL(adc101c, 10);
DEFINE_ADCxx1C_MODEL(adc121c, 12);

+#define ADC081C_NUM_CHANNELS 2
+
static const struct iio_info adc081c_info = {
.read_raw = adc081c_read_raw,
.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[indio_dev->scan_bytes / 2];
+ 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)
{
@@ -125,18 +161,26 @@ 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:
+err_buffer_cleanup:
+ iio_triggered_buffer_cleanup(iio);
+err_regulator_disable:
regulator_disable(adc->ref);

return err;
@@ -148,6 +192,7 @@ 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;
--
2.5.5