This will be used together with an external trigger (e.g hrtimer based
software trigger).
Signed-off-by: Gregor Boirie <gregor.boirie@xxxxxxxxxx>
---
drivers/iio/magnetometer/Kconfig | 2 +
drivers/iio/magnetometer/ak8975.c | 135 +++++++++++++++++++++++++++++++-------
2 files changed, 112 insertions(+), 25 deletions(-)
diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index 021dc53..d9834ed 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -9,6 +9,8 @@ config AK8975
tristate "Asahi Kasei AK 3-Axis Magnetometer"
depends on I2C
depends on GPIOLIB || COMPILE_TEST
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Asahi Kasei AK8975, AK8963,
AK09911 or AK09912 3-Axis Magnetometer.
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 3814a6a..de1663d 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -36,6 +36,12 @@
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regulator/consumer.h>
+
/*
* Register definitions, as well as various shifts and masks to get at the
* individual fields of the registers.
@@ -634,22 +640,15 @@ static int wait_conversion_complete_interrupt(struct ak8975_data *data)
return ret > 0 ? 0 : -ETIME;
}
-/*
- * Emits the raw flux value for the x, y, or z axis.
- */
-static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
+static int ak8975_start_read_axis(struct ak8975_data *data,
+ const struct i2c_client *client)
{
- struct ak8975_data *data = iio_priv(indio_dev);
- struct i2c_client *client = data->client;
- int ret;
-
- mutex_lock(&data->lock);
-
/* Set up the device for taking a sample. */
- ret = ak8975_set_mode(data, MODE_ONCE);
+ int ret = ak8975_set_mode(data, MODE_ONCE);
+
if (ret < 0) {
dev_err(&client->dev, "Error in setting operating mode\n");
- goto exit;
+ return ret;
}
/* Wait for the conversion to complete. */
@@ -660,7 +659,7 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
else
ret = wait_conversion_complete_polled(data);
if (ret < 0)
- goto exit;
+ return ret;
/* This will be executed only for non-interrupt based waiting case */
if (ret & data->def->ctrl_masks[ST1_DRDY]) {
@@ -668,32 +667,45 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
data->def->ctrl_regs[ST2]);
if (ret < 0) {
dev_err(&client->dev, "Error in reading ST2\n");
- goto exit;
+ return ret;
}
if (ret & (data->def->ctrl_masks[ST2_DERR] |
data->def->ctrl_masks[ST2_HOFL])) {
dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
- ret = -EINVAL;
- goto exit;
+ return -EINVAL;
}
}
- /* Read the flux value from the appropriate register
- (the register is specified in the iio device attributes). */
- ret = i2c_smbus_read_word_data(client, data->def->data_regs[index]);
- if (ret < 0) {
- dev_err(&client->dev, "Read axis data fails\n");
+ return 0;
+}
+
+/* Retrieve raw flux value for one of the x, y, or z axis. */
+static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
+{
+ struct ak8975_data *data = iio_priv(indio_dev);
+ const struct i2c_client *client = data->client;
+ const struct ak_def *def = data->def;
+ int ret;
+
+ mutex_lock(&data->lock);
+
+ ret = ak8975_start_read_axis(data, client);
+ if (ret)
+ goto exit;
+
+ ret = i2c_smbus_read_word_data(client, def->data_regs[index]);
+ if (ret < 0)
goto exit;
- }
mutex_unlock(&data->lock);
/* Clamp to valid range. */
- *val = clamp_t(s16, ret, -data->def->range, data->def->range);
+ *val = clamp_t(s16, ret, -def->range, def->range);
return IIO_VAL_INT;
exit:
mutex_unlock(&data->lock);
+ dev_err(&client->dev, "Error in reading axis\n");
return ret;
}
@@ -745,12 +757,22 @@ static const struct attribute_group ak8975_attrs_group = {
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.address = index, \
+ .scan_index = index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_CPU \
+ } \
}
static const struct iio_chan_spec ak8975_channels[] = {
AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
+ IIO_CHAN_SOFT_TIMESTAMP(3),
};
+static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
+
static const struct iio_info ak8975_info = {
.read_raw = &ak8975_read_raw,
.driver_module = THIS_MODULE,
@@ -785,6 +807,56 @@ static const char *ak8975_match_acpi_device(struct device *dev,
return dev_name(dev);
}
+static void ak8975_fill_buffer(struct iio_dev *indio_dev)
+{
+ struct ak8975_data *data = iio_priv(indio_dev);
+ const struct i2c_client *client = data->client;
+ const struct ak_def *def = data->def;
+ int ret;
+ s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
+
+ mutex_lock(&data->lock);
+
+ ret = ak8975_start_read_axis(data, client);
+ if (ret)
+ goto unlock;
+
+ /*
+ * For each axis, read the flux value from the appropriate register
+ * (the register is specified in the iio device attributes).
+ */
+ ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
+ def->data_regs[0],
+ 3 * sizeof(buff[0]),
+ (u8 *)buff);
+ if (ret < 0)
+ goto unlock;
+
+ mutex_unlock(&data->lock);
+
+ /* Clamp to valid range. */
+ buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range);
+ buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range);
+ buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns());
+ return;
+
+unlock:
+ mutex_unlock(&data->lock);
+ dev_err(&client->dev, "Error in reading axes block\n");
+}
+
+static irqreturn_t ak8975_handle_trigger(int irq, void *p)
+{
+ const struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+
+ ak8975_fill_buffer(indio_dev);
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
static int ak8975_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -889,15 +961,27 @@ static int ak8975_probe(struct i2c_client *client,
indio_dev->dev.parent = &client->dev;
indio_dev->channels = ak8975_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
+ indio_dev->available_scan_masks = ak8975_scan_masks;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = name;
- err = iio_device_register(indio_dev);
- if (err)
+ err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
+ NULL);
+ if (err) {
+ dev_err(&client->dev, "triggered buffer setup failed\n");
goto power_off;
+ }
+
+ err = iio_device_register(indio_dev);
+ if (err) {
+ dev_err(&client->dev, "device register failed\n");
+ goto cleanup_buffer;
+ }
return 0;
+cleanup_buffer:
+ iio_triggered_buffer_cleanup(indio_dev);
power_off:
ak8975_power_off(client);
return err;
@@ -908,6 +992,7 @@ static int ak8975_remove(struct i2c_client *client)
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
ak8975_power_off(client);
return 0;
--
2.1.4
--
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