From 96c0cb2bbfe0a58bd0c37cf34d50a20f9cd75aa8 Mon Sep 17 00:00:00 2001 From: Martin Kepplinger Date: Thu, 3 Mar 2016 09:24:03 +0100 Subject: [PATCH] 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 Signed-off-by: Christoph Muellner Signed-off-by: Jonathan Cameron --- 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 9c4a84a72ad4..5ca0d169f912 100644 --- a/drivers/iio/accel/mma8452.c +++ b/drivers/iio/accel/mma8452.c @@ -31,6 +31,7 @@ #include #include #include +#include #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, -- 2.20.1