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path: root/drivers/staging/iio/magnetometer/ak8975.c
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Diffstat (limited to 'drivers/staging/iio/magnetometer/ak8975.c')
-rw-r--r--drivers/staging/iio/magnetometer/ak8975.c130
1 files changed, 90 insertions, 40 deletions
diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c
index 420f206cf517..700f96c70273 100644
--- a/drivers/staging/iio/magnetometer/ak8975.c
+++ b/drivers/staging/iio/magnetometer/ak8975.c
@@ -206,7 +206,7 @@ static int ak8975_setup(struct i2c_client *client)
}
/* Precalculate scale factor for each axis and
- store in the device data. */
+ store in the device data. */
data->raw_to_gauss[0] = ((data->asa[0] + 128) * 30) >> 8;
data->raw_to_gauss[1] = ((data->asa[1] + 128) * 30) >> 8;
data->raw_to_gauss[2] = ((data->asa[2] + 128) * 30) >> 8;
@@ -316,6 +316,59 @@ static ssize_t show_scale(struct device *dev, struct device_attribute *devattr,
return sprintf(buf, "%ld\n", data->raw_to_gauss[this_attr->address]);
}
+static int wait_conversion_complete_gpio(struct ak8975_data *data)
+{
+ struct i2c_client *client = data->client;
+ u8 read_status;
+ u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
+ int ret;
+
+ /* Wait for the conversion to complete. */
+ while (timeout_ms) {
+ msleep(AK8975_CONVERSION_DONE_POLL_TIME);
+ if (gpio_get_value(data->eoc_gpio))
+ break;
+ timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
+ }
+ if (!timeout_ms) {
+ dev_err(&client->dev, "Conversion timeout happened\n");
+ return -EINVAL;
+ }
+
+ ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status);
+ if (ret < 0) {
+ dev_err(&client->dev, "Error in reading ST1\n");
+ return ret;
+ }
+ return read_status;
+}
+
+static int wait_conversion_complete_polled(struct ak8975_data *data)
+{
+ struct i2c_client *client = data->client;
+ u8 read_status;
+ u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
+ int ret;
+
+ /* Wait for the conversion to complete. */
+ while (timeout_ms) {
+ msleep(AK8975_CONVERSION_DONE_POLL_TIME);
+ ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status);
+ if (ret < 0) {
+ dev_err(&client->dev, "Error in reading ST1\n");
+ return ret;
+ }
+ if (read_status)
+ break;
+ timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
+ }
+ if (!timeout_ms) {
+ dev_err(&client->dev, "Conversion timeout happened\n");
+ return -EINVAL;
+ }
+ return read_status;
+}
+
/*
* Emits the raw flux value for the x, y, or z axis.
*/
@@ -326,7 +379,6 @@ static ssize_t show_raw(struct device *dev, struct device_attribute *devattr,
struct ak8975_data *data = indio_dev->dev_data;
struct i2c_client *client = data->client;
struct iio_dev_attr *this_attr = to_iio_dev_attr(devattr);
- u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
u16 meas_reg;
s16 raw;
u8 read_status;
@@ -352,23 +404,14 @@ static ssize_t show_raw(struct device *dev, struct device_attribute *devattr,
}
/* Wait for the conversion to complete. */
- while (timeout_ms) {
- msleep(AK8975_CONVERSION_DONE_POLL_TIME);
- if (gpio_get_value(data->eoc_gpio))
- break;
- timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
- }
- if (!timeout_ms) {
- dev_err(&client->dev, "Conversion timeout happened\n");
- ret = -EINVAL;
+ if (data->eoc_gpio)
+ ret = wait_conversion_complete_gpio(data);
+ else
+ ret = wait_conversion_complete_polled(data);
+ if (ret < 0)
goto exit;
- }
- ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status);
- if (ret < 0) {
- dev_err(&client->dev, "Error in reading ST1\n");
- goto exit;
- }
+ read_status = ret;
if (read_status & AK8975_REG_ST1_DRDY_MASK) {
ret = ak8975_read_data(client, AK8975_REG_ST2, 1, &read_status);
@@ -431,6 +474,11 @@ static struct attribute_group ak8975_attr_group = {
.attrs = ak8975_attr,
};
+static const struct iio_info ak8975_info = {
+ .attrs = &ak8975_attr_group,
+ .driver_module = THIS_MODULE,
+};
+
static int ak8975_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -454,25 +502,26 @@ static int ak8975_probe(struct i2c_client *client,
data->eoc_irq = client->irq;
data->eoc_gpio = irq_to_gpio(client->irq);
- if (!data->eoc_gpio) {
- dev_err(&client->dev, "failed, no valid GPIO\n");
- err = -EINVAL;
- goto exit_free;
- }
-
- err = gpio_request(data->eoc_gpio, "ak_8975");
- if (err < 0) {
- dev_err(&client->dev, "failed to request GPIO %d, error %d\n",
- data->eoc_gpio, err);
- goto exit_free;
- }
+ /* We may not have a GPIO based IRQ to scan, that is fine, we will
+ poll if so */
+ if (data->eoc_gpio > 0) {
+ err = gpio_request(data->eoc_gpio, "ak_8975");
+ if (err < 0) {
+ dev_err(&client->dev,
+ "failed to request GPIO %d, error %d\n",
+ data->eoc_gpio, err);
+ goto exit_free;
+ }
- err = gpio_direction_input(data->eoc_gpio);
- if (err < 0) {
- dev_err(&client->dev, "Failed to configure input direction for"
- " GPIO %d, error %d\n", data->eoc_gpio, err);
- goto exit_gpio;
- }
+ err = gpio_direction_input(data->eoc_gpio);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Failed to configure input direction for GPIO %d, error %d\n",
+ data->eoc_gpio, err);
+ goto exit_gpio;
+ }
+ } else
+ data->eoc_gpio = 0; /* No GPIO available */
/* Perform some basic start-of-day setup of the device. */
err = ak8975_setup(client);
@@ -482,16 +531,15 @@ static int ak8975_probe(struct i2c_client *client,
}
/* Register with IIO */
- data->indio_dev = iio_allocate_device();
+ data->indio_dev = iio_allocate_device(0);
if (data->indio_dev == NULL) {
err = -ENOMEM;
goto exit_gpio;
}
data->indio_dev->dev.parent = &client->dev;
- data->indio_dev->attrs = &ak8975_attr_group;
+ data->indio_dev->info = &ak8975_info;
data->indio_dev->dev_data = (void *)(data);
- data->indio_dev->driver_module = THIS_MODULE;
data->indio_dev->modes = INDIO_DIRECT_MODE;
err = iio_device_register(data->indio_dev);
@@ -503,7 +551,8 @@ static int ak8975_probe(struct i2c_client *client,
exit_free_iio:
iio_free_device(data->indio_dev);
exit_gpio:
- gpio_free(data->eoc_gpio);
+ if (data->eoc_gpio)
+ gpio_free(data->eoc_gpio);
exit_free:
kfree(data);
exit:
@@ -517,7 +566,8 @@ static int ak8975_remove(struct i2c_client *client)
iio_device_unregister(data->indio_dev);
iio_free_device(data->indio_dev);
- gpio_free(data->eoc_gpio);
+ if (data->eoc_gpio)
+ gpio_free(data->eoc_gpio);
kfree(data);
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