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Date: Thu, 3 Mar 2016 09:24:03 +0100
From: Martin Kepplinger <martink@...teo.de>
To: jic23@...nel.org, knaack.h@....de, lars@...afoo.de,
pmeerw@...erw.net, christoph.muellner@...obroma-systems.com,
mfuzzey@...keon.com
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
Martin Kepplinger <martink@...teo.de>
Subject: [PATCH 3/4] iio: mma8452: add support for runtime power management
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@...teo.de>
Signed-off-by: Christoph Muellner <christoph.muellner@...obroma-systems.com>
---
drivers/iio/accel/mma8452.c | 118 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 108 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 9c4a84a..5ca0d16 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -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,
--
2.1.4
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