From 60d3e3bbd5992bb4478f9f99a4e4c5748a1a1ba7 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 24 Feb 2015 13:24:41 +1100 Subject: [PATCH] iio: gyro: itg3200: add suspend/resume support. Unless we put the device to sleep when not it use, it wastes 6mA. If the device is asleep on probe, the 'id' register sometimes mis-reads - so reset first. If the device responds at all a command sent to the address, it is almost certainly the correct device already. Acked-by: Manuel Stahl Acked-by: Hartmut Knaack Signed-off-by: NeilBrown Signed-off-by: Jonathan Cameron --- drivers/iio/gyro/itg3200_core.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c index 6a8020d48140..f0fd94055d88 100644 --- a/drivers/iio/gyro/itg3200_core.c +++ b/drivers/iio/gyro/itg3200_core.c @@ -223,6 +223,10 @@ static int itg3200_initial_setup(struct iio_dev *indio_dev) int ret; u8 val; + ret = itg3200_reset(indio_dev); + if (ret) + goto err_ret; + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); if (ret) goto err_ret; @@ -233,10 +237,6 @@ static int itg3200_initial_setup(struct iio_dev *indio_dev) goto err_ret; } - ret = itg3200_reset(indio_dev); - if (ret) - goto err_ret; - ret = itg3200_enable_full_scale(indio_dev); err_ret: return ret; @@ -351,6 +351,26 @@ static int itg3200_remove(struct i2c_client *client) return 0; } +static int __maybe_unused itg3200_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct itg3200 *st = iio_priv(indio_dev); + + dev_dbg(&st->i2c->dev, "suspend device"); + + return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT, + ITG3200_SLEEP); +} + +static int __maybe_unused itg3200_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + + return itg3200_initial_setup(indio_dev); +} + +static SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend, itg3200_resume); + static const struct i2c_device_id itg3200_id[] = { { "itg3200", 0 }, { } @@ -361,6 +381,7 @@ static struct i2c_driver itg3200_driver = { .driver = { .owner = THIS_MODULE, .name = "itg3200", + .pm = &itg3200_pm_ops, }, .id_table = itg3200_id, .probe = itg3200_probe,