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Message-ID: <56DC29A0.8030603@kernel.org>
Date: Sun, 6 Mar 2016 12:59:12 +0000
From: Jonathan Cameron <jic23@...nel.org>
To: Martin Kepplinger <martink@...teo.de>, 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
Subject: Re: [PATCH 3/4] iio: mma8452: add support for runtime power
management
On 03/03/16 08:24, Martin Kepplinger wrote:
> 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>
Looks good. Applied to the togreg branch of iio.git - initially pushed out
as testing for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> 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,
>
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