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Subject[RFC 9/9] iio: (RFC) illustrate creation/destruction of hrtimer trigger upon buffer enable
Date
This also raises the question of how to programmatically set the period of
the hrtimer from the owner driver, I had to locally copy iio_hrtimer_info
Maybe this should go to linux/iio/hrtimer_trigger.h ?

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
---
drivers/iio/adc/ina2xx-iio.c | 74 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 73 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ina2xx-iio.c b/drivers/iio/adc/ina2xx-iio.c
index e47f30d..5f61296b 100644
--- a/drivers/iio/adc/ina2xx-iio.c
+++ b/drivers/iio/adc/ina2xx-iio.c
@@ -19,6 +19,7 @@
*
* Configurable 7-bit I2C slave address from 0x40 to 0x4F
*/
+
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -32,6 +33,10 @@
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

+#include <linux/iio/trigger.h>
+#include <linux/iio/sw_trigger.h>
+
+
/*
* INA2XX registers definition
*/
@@ -96,6 +101,7 @@ struct ina2xx_config {

struct ina2xx_chip_info {
const struct ina2xx_config *config;
+ struct iio_sw_trigger *swtrig;
struct mutex state_lock;
long rshunt;
int avg;
@@ -283,6 +289,11 @@ static int ina2xx_write_raw(struct iio_dev *indio_dev,

mutex_lock(&chip->state_lock);

+ if (iio_buffer_enabled(indio_dev)) {
+ ret = -EBUSY;
+ goto _err;
+ }
+
ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
if (ret < 0)
goto _err;
@@ -316,6 +327,13 @@ _err:
return ret;
}

+/* FIXME */
+struct iio_hrtimer_info {
+ struct iio_sw_trigger swt;
+ struct hrtimer timer;
+ unsigned long sampling_frequency;
+ ktime_t period;
+};

static ssize_t ina2xx_averaging_steps_show(struct device *dev,
struct device_attribute *attr,
@@ -387,6 +405,7 @@ static int ina2xx_debug_reg(struct iio_dev *indio_dev,
return regmap_read(chip->regmap, reg, readval);
}

+
static s64 prev_ns;

static irqreturn_t ina2xx_trigger_handler(int irq, void *p)
@@ -478,6 +497,58 @@ static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
return ina2xx_calibrate(chip);
}

+
+static int ina2xx_trigger_create(struct iio_dev *indio_dev)
+{
+ struct iio_sw_trigger *swtrig;
+ struct iio_hrtimer_info *info;
+ struct ina2xx_chip_info *chip = iio_priv(indio_dev);
+
+ swtrig = iio_sw_trigger_create("hrtimer", indio_dev->name);
+ if (IS_ERR(swtrig))
+ return -EINVAL;
+
+ info = iio_trigger_get_drvdata(swtrig->trigger);
+
+ mutex_lock(&chip->state_lock);
+
+ info->sampling_frequency = chip->freq;
+ info->period = ktime_set(0, NSEC_PER_SEC / chip->freq);
+
+ chip->swtrig = swtrig;
+ indio_dev->trig = swtrig->trigger;
+
+ mutex_unlock(&chip->state_lock);
+
+ iio_trigger_get(indio_dev->trig);
+
+ return 0;
+}
+
+int ina2xx_trigger_destroy(struct iio_dev *indio_dev)
+{
+ struct ina2xx_chip_info *chip = iio_priv(indio_dev);
+
+ mutex_lock(&chip->state_lock);
+
+ iio_trigger_put(indio_dev->trig);
+ iio_sw_trigger_destroy(chip->swtrig);
+
+ indio_dev->trig = NULL;
+
+ mutex_unlock(&chip->state_lock);
+
+ return 0;
+}
+
+
+static const struct iio_buffer_setup_ops ina2xx_buffer_setup_ops = {
+ .enable_trigger = &ina2xx_trigger_create,
+ .postenable = &iio_triggered_buffer_postenable,
+ .predisable = &iio_triggered_buffer_predisable,
+ .postdisable = &ina2xx_trigger_destroy,
+};
+
static int ina2xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -547,7 +618,8 @@ static int ina2xx_probe(struct i2c_client *client,
}

ret = iio_triggered_buffer_setup(indio_dev, NULL,
- &ina2xx_trigger_handler, NULL);
+ &ina2xx_trigger_handler,
+ &ina2xx_buffer_setup_ops);
if (ret)
return ret;

--
1.9.1


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