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path: root/drivers/iio/magnetometer/ak8975.c
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Diffstat (limited to 'drivers/iio/magnetometer/ak8975.c')
-rw-r--r--drivers/iio/magnetometer/ak8975.c154
1 files changed, 122 insertions, 32 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 609a2c401b5d..af8606cc7812 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -33,6 +33,7 @@
#include <linux/of_gpio.h>
#include <linux/acpi.h>
#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -379,37 +380,40 @@ struct ak8975_data {
u8 cntl_cache;
struct iio_mount_matrix orientation;
struct regulator *vdd;
+ struct regulator *vid;
};
/* Enable attached power regulator if any. */
-static int ak8975_power_on(struct i2c_client *client)
+static int ak8975_power_on(const struct ak8975_data *data)
{
- const struct iio_dev *indio_dev = i2c_get_clientdata(client);
- struct ak8975_data *data = iio_priv(indio_dev);
int ret;
- data->vdd = devm_regulator_get(&client->dev, "vdd");
- if (IS_ERR_OR_NULL(data->vdd)) {
- ret = PTR_ERR(data->vdd);
- if (ret == -ENODEV)
- ret = 0;
- } else {
- ret = regulator_enable(data->vdd);
+ ret = regulator_enable(data->vdd);
+ if (ret) {
+ dev_warn(&data->client->dev,
+ "Failed to enable specified Vdd supply\n");
+ return ret;
}
-
- if (ret)
- dev_err(&client->dev, "failed to enable Vdd supply: %d\n", ret);
- return ret;
+ ret = regulator_enable(data->vid);
+ if (ret) {
+ dev_warn(&data->client->dev,
+ "Failed to enable specified Vid supply\n");
+ return ret;
+ }
+ /*
+ * According to the datasheet the power supply rise time i 200us
+ * and the minimum wait time before mode setting is 100us, in
+ * total 300 us. Add some margin and say minimum 500us here.
+ */
+ usleep_range(500, 1000);
+ return 0;
}
/* Disable attached power regulator if any. */
-static void ak8975_power_off(const struct i2c_client *client)
+static void ak8975_power_off(const struct ak8975_data *data)
{
- const struct iio_dev *indio_dev = i2c_get_clientdata(client);
- const struct ak8975_data *data = iio_priv(indio_dev);
-
- if (!IS_ERR_OR_NULL(data->vdd))
- regulator_disable(data->vdd);
+ regulator_disable(data->vid);
+ regulator_disable(data->vdd);
}
/*
@@ -430,8 +434,8 @@ static int ak8975_who_i_am(struct i2c_client *client,
* AK8975 | DEVICE_ID | NA
* AK8963 | DEVICE_ID | NA
*/
- ret = i2c_smbus_read_i2c_block_data(client, AK09912_REG_WIA1,
- 2, wia_val);
+ ret = i2c_smbus_read_i2c_block_data_or_emulated(
+ client, AK09912_REG_WIA1, 2, wia_val);
if (ret < 0) {
dev_err(&client->dev, "Error reading WIA\n");
return ret;
@@ -543,9 +547,9 @@ static int ak8975_setup(struct i2c_client *client)
}
/* Get asa data and store in the device data. */
- ret = i2c_smbus_read_i2c_block_data(client,
- data->def->ctrl_regs[ASA_BASE],
- 3, data->asa);
+ ret = i2c_smbus_read_i2c_block_data_or_emulated(
+ client, data->def->ctrl_regs[ASA_BASE],
+ 3, data->asa);
if (ret < 0) {
dev_err(&client->dev, "Not able to read asa data\n");
return ret;
@@ -686,22 +690,31 @@ 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;
+ u16 buff;
int ret;
+ pm_runtime_get_sync(&data->client->dev);
+
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]);
+ ret = i2c_smbus_read_i2c_block_data_or_emulated(
+ client, def->data_regs[index],
+ sizeof(buff), (u8*)&buff);
if (ret < 0)
goto exit;
mutex_unlock(&data->lock);
- /* Clamp to valid range. */
- *val = clamp_t(s16, ret, -def->range, def->range);
+ pm_runtime_mark_last_busy(&data->client->dev);
+ pm_runtime_put_autosuspend(&data->client->dev);
+
+ /* Swap bytes and convert to valid range. */
+ buff = le16_to_cpu(buff);
+ *val = clamp_t(s16, buff, -def->range, def->range);
return IIO_VAL_INT;
exit:
@@ -825,7 +838,8 @@ static void ak8975_fill_buffer(struct iio_dev *indio_dev)
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());
+ iio_push_to_buffers_with_timestamp(indio_dev, buff,
+ iio_get_time_ns(indio_dev));
return;
unlock:
@@ -919,7 +933,15 @@ static int ak8975_probe(struct i2c_client *client,
data->def = &ak_def_array[chipset];
- err = ak8975_power_on(client);
+ /* Fetch the regulators */
+ data->vdd = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(data->vdd))
+ return PTR_ERR(data->vdd);
+ data->vid = devm_regulator_get(&client->dev, "vid");
+ if (IS_ERR(data->vid))
+ return PTR_ERR(data->vid);
+
+ err = ak8975_power_on(data);
if (err)
return err;
@@ -959,26 +981,93 @@ static int ak8975_probe(struct i2c_client *client,
goto cleanup_buffer;
}
+ /* Enable runtime PM */
+ pm_runtime_get_noresume(&client->dev);
+ pm_runtime_set_active(&client->dev);
+ pm_runtime_enable(&client->dev);
+ /*
+ * The device comes online in 500us, so add two orders of magnitude
+ * of delay before autosuspending: 50 ms.
+ */
+ pm_runtime_set_autosuspend_delay(&client->dev, 50);
+ pm_runtime_use_autosuspend(&client->dev);
+ pm_runtime_put(&client->dev);
+
return 0;
cleanup_buffer:
iio_triggered_buffer_cleanup(indio_dev);
power_off:
- ak8975_power_off(client);
+ ak8975_power_off(data);
return err;
}
static int ak8975_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ak8975_data *data = iio_priv(indio_dev);
+ pm_runtime_get_sync(&client->dev);
+ pm_runtime_put_noidle(&client->dev);
+ pm_runtime_disable(&client->dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
- ak8975_power_off(client);
+ ak8975_set_mode(data, POWER_DOWN);
+ ak8975_power_off(data);
return 0;
}
+#ifdef CONFIG_PM
+static int ak8975_runtime_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ak8975_data *data = iio_priv(indio_dev);
+ int ret;
+
+ /* Set the device in power down if it wasn't already */
+ ret = ak8975_set_mode(data, POWER_DOWN);
+ if (ret < 0) {
+ dev_err(&client->dev, "Error in setting power-down mode\n");
+ return ret;
+ }
+ /* Next cut the regulators */
+ ak8975_power_off(data);
+
+ return 0;
+}
+
+static int ak8975_runtime_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ak8975_data *data = iio_priv(indio_dev);
+ int ret;
+
+ /* Take up the regulators */
+ ak8975_power_on(data);
+ /*
+ * We come up in powered down mode, the reading routines will
+ * put us in the mode to read values later.
+ */
+ ret = ak8975_set_mode(data, POWER_DOWN);
+ if (ret < 0) {
+ dev_err(&client->dev, "Error in setting power-down mode\n");
+ return ret;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops ak8975_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
+ ak8975_runtime_resume, NULL)
+};
+
static const struct i2c_device_id ak8975_id[] = {
{"ak8975", AK8975},
{"ak8963", AK8963},
@@ -1006,6 +1095,7 @@ MODULE_DEVICE_TABLE(of, ak8975_of_match);
static struct i2c_driver ak8975_driver = {
.driver = {
.name = "ak8975",
+ .pm = &ak8975_dev_pm_ops,
.of_match_table = of_match_ptr(ak8975_of_match),
.acpi_match_table = ACPI_PTR(ak_acpi_match),
},