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iio: mma8452: add support for runtime power management

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This adds support for runtime power management and, if configured, activates
automatic standby after 2 seconds of inactivity.

Inactivity means no read of acceleration values and no events triggered or
activated.

If CONFIG_PM is not set, this doesn't change anything for existing users.

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Martin Kepplinger 2016-03-03 09:24:03 +01:00 committed by Jonathan Cameron
parent e866853d67
commit 96c0cb2bbf
1 changed files with 108 additions and 10 deletions
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118
drivers/iio/accel/mma8452.c
View file

@ -31,6 +31,7 @@
#include <linux/delay.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/pm_runtime.h>
#define MMA8452_STATUS 0x00
#define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
@ -92,6 +93,8 @@
#define MMA8652_DEVICE_ID 0x4a
#define MMA8653_DEVICE_ID 0x5a
#define MMA8452_AUTO_SUSPEND_DELAY_MS 2000
struct mma8452_data {
struct i2c_client *client;
struct mutex lock;
@ -172,6 +175,31 @@ static int mma8452_drdy(struct mma8452_data *data)
return -EIO;
}
static int mma8452_set_runtime_pm_state(struct i2c_client *client, bool on)
{
#ifdef CONFIG_PM
int ret;
if (on) {
ret = pm_runtime_get_sync(&client->dev);
} else {
pm_runtime_mark_last_busy(&client->dev);
ret = pm_runtime_put_autosuspend(&client->dev);
}
if (ret < 0) {
dev_err(&client->dev,
"failed to change power state to %d\n", on);
if (on)
pm_runtime_put_noidle(&client->dev);
return ret;
}
#endif
return 0;
}
static int mma8452_read(struct mma8452_data *data, __be16 buf[3])
{
int ret = mma8452_drdy(data);
@ -179,8 +207,16 @@ static int mma8452_read(struct mma8452_data *data, __be16 buf[3])
if (ret < 0)
return ret;
return i2c_smbus_read_i2c_block_data(data->client, MMA8452_OUT_X,
3 * sizeof(__be16), (u8 *)buf);
ret = mma8452_set_runtime_pm_state(data->client, true);
if (ret)
return ret;
ret = i2c_smbus_read_i2c_block_data(data->client, MMA8452_OUT_X,
3 * sizeof(__be16), (u8 *)buf);
ret = mma8452_set_runtime_pm_state(data->client, false);
return ret;
}
static ssize_t mma8452_show_int_plus_micros(char *buf, const int (*vals)[2],
@ -707,7 +743,11 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
{
struct mma8452_data *data = iio_priv(indio_dev);
const struct mma_chip_info *chip = data->chip_info;
int val;
int val, ret;
ret = mma8452_set_runtime_pm_state(data->client, state);
if (ret)
return ret;
switch (dir) {
case IIO_EV_DIR_FALLING:
@ -1139,7 +1179,11 @@ static int mma8452_data_rdy_trigger_set_state(struct iio_trigger *trig,
{
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct mma8452_data *data = iio_priv(indio_dev);
int reg;
int reg, ret;
ret = mma8452_set_runtime_pm_state(data->client, state);
if (ret)
return ret;
reg = i2c_smbus_read_byte_data(data->client, MMA8452_CTRL_REG4);
if (reg < 0)
@ -1365,6 +1409,15 @@ static int mma8452_probe(struct i2c_client *client,
goto buffer_cleanup;
}
ret = pm_runtime_set_active(&client->dev);
if (ret < 0)
goto buffer_cleanup;
pm_runtime_enable(&client->dev);
pm_runtime_set_autosuspend_delay(&client->dev,
MMA8452_AUTO_SUSPEND_DELAY_MS);
pm_runtime_use_autosuspend(&client->dev);
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
@ -1389,6 +1442,11 @@ static int mma8452_remove(struct i2c_client *client)
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
pm_runtime_disable(&client->dev);
pm_runtime_set_suspended(&client->dev);
pm_runtime_put_noidle(&client->dev);
iio_triggered_buffer_cleanup(indio_dev);
mma8452_trigger_cleanup(indio_dev);
mma8452_standby(iio_priv(indio_dev));
@ -1396,6 +1454,45 @@ static int mma8452_remove(struct i2c_client *client)
return 0;
}
#ifdef CONFIG_PM
static int mma8452_runtime_suspend(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct mma8452_data *data = iio_priv(indio_dev);
int ret;
mutex_lock(&data->lock);
ret = mma8452_standby(data);
mutex_unlock(&data->lock);
if (ret < 0) {
dev_err(&data->client->dev, "powering off device failed\n");
return -EAGAIN;
}
return 0;
}
static int mma8452_runtime_resume(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct mma8452_data *data = iio_priv(indio_dev);
int ret, sleep_val;
ret = mma8452_active(data);
if (ret < 0)
return ret;
ret = mma8452_get_odr_index(data);
sleep_val = 1000 / mma8452_samp_freq[ret][0];
if (sleep_val < 20)
usleep_range(sleep_val * 1000, 20000);
else
msleep_interruptible(sleep_val);
return 0;
}
#endif
#ifdef CONFIG_PM_SLEEP
static int mma8452_suspend(struct device *dev)
{
@ -1408,13 +1505,14 @@ static int mma8452_resume(struct device *dev)
return mma8452_active(iio_priv(i2c_get_clientdata(
to_i2c_client(dev))));
}
static SIMPLE_DEV_PM_OPS(mma8452_pm_ops, mma8452_suspend, mma8452_resume);
#define MMA8452_PM_OPS (&mma8452_pm_ops)
#else
#define MMA8452_PM_OPS NULL
#endif
static const struct dev_pm_ops mma8452_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(mma8452_suspend, mma8452_resume)
SET_RUNTIME_PM_OPS(mma8452_runtime_suspend,
mma8452_runtime_resume, NULL)
};
static const struct i2c_device_id mma8452_id[] = {
{ "mma8452", mma8452 },
{ "mma8453", mma8453 },
@ -1428,7 +1526,7 @@ static struct i2c_driver mma8452_driver = {
.driver = {
.name = "mma8452",
.of_match_table = of_match_ptr(mma8452_dt_ids),
.pm = MMA8452_PM_OPS,
.pm = &mma8452_pm_ops,
},
.probe = mma8452_probe,
.remove = mma8452_remove,