diff options
Diffstat (limited to 'drivers/iio/pressure/mpl115.c')
| -rw-r--r-- | drivers/iio/pressure/mpl115.c | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/drivers/iio/pressure/mpl115.c b/drivers/iio/pressure/mpl115.c index 5bf5b9abe6f1..02ea38c8a3e4 100644 --- a/drivers/iio/pressure/mpl115.c +++ b/drivers/iio/pressure/mpl115.c @@ -4,12 +4,13 @@ * * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net> * - * TODO: shutdown pin + * TODO: synchronization with system suspend */ #include <linux/module.h> #include <linux/iio/iio.h> #include <linux/delay.h> +#include <linux/gpio/consumer.h> #include "mpl115.h" @@ -27,6 +28,7 @@ struct mpl115_data { s16 a0; s16 b1, b2; s16 c12; + struct gpio_desc *shutdown; const struct mpl115_ops *ops; }; @@ -102,16 +104,24 @@ static int mpl115_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_PROCESSED: + pm_runtime_get_sync(data->dev); ret = mpl115_comp_pressure(data, val, val2); if (ret < 0) return ret; + pm_runtime_mark_last_busy(data->dev); + pm_runtime_put_autosuspend(data->dev); + return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_RAW: + pm_runtime_get_sync(data->dev); /* temperature -5.35 C / LSB, 472 LSB is 25 C */ ret = mpl115_read_temp(data); if (ret < 0) return ret; + pm_runtime_mark_last_busy(data->dev); + pm_runtime_put_autosuspend(data->dev); *val = ret >> 6; + return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: *val = -605; @@ -168,6 +178,8 @@ int mpl115_probe(struct device *dev, const char *name, if (ret) return ret; + dev_set_drvdata(dev, indio_dev); + ret = data->ops->read(data->dev, MPL115_A0); if (ret < 0) return ret; @@ -185,10 +197,58 @@ int mpl115_probe(struct device *dev, const char *name, return ret; data->c12 = ret; + data->shutdown = devm_gpiod_get_optional(dev, "shutdown", + GPIOD_OUT_LOW); + if (IS_ERR(data->shutdown)) + return dev_err_probe(dev, PTR_ERR(data->shutdown), + "cannot get shutdown gpio\n"); + + if (data->shutdown) { + /* Enable runtime PM */ + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + /* + * As the device takes 3 ms to come up with a fresh + * reading after power-on and 5 ms to actually power-on, + * do not shut it down unnecessarily. Set autosuspend to + * 2000 ms. + */ + pm_runtime_set_autosuspend_delay(dev, 2000); + pm_runtime_use_autosuspend(dev); + pm_runtime_put(dev); + + dev_dbg(dev, "low-power mode enabled"); + } else + dev_dbg(dev, "low-power mode disabled"); + return devm_iio_device_register(dev, indio_dev); } EXPORT_SYMBOL_NS_GPL(mpl115_probe, IIO_MPL115); +static int mpl115_runtime_suspend(struct device *dev) +{ + struct mpl115_data *data = iio_priv(dev_get_drvdata(dev)); + + gpiod_set_value(data->shutdown, 1); + + return 0; +} + +static int mpl115_runtime_resume(struct device *dev) +{ + struct mpl115_data *data = iio_priv(dev_get_drvdata(dev)); + + gpiod_set_value(data->shutdown, 0); + usleep_range(5000, 6000); + + return 0; +} + +EXPORT_NS_RUNTIME_DEV_PM_OPS(mpl115_dev_pm_ops, mpl115_runtime_suspend, + mpl115_runtime_resume, NULL, IIO_MPL115); + MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); MODULE_DESCRIPTION("Freescale MPL115 pressure/temperature driver"); MODULE_LICENSE("GPL"); |