iio: gyro: itg3200: add suspend/resume support.

PATCH Applied NeilBrown 3 participants 3 messages Feb 24, 2015 – Apr 19, 2015 IIO

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NeilBrown

author

2015-02-24 02:24 UTC #0 lore raw

PATCH v2 1/1 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 <[email protected]>

Acked-by Hartmut Knaack <[email protected]>

Signed-off-by NeilBrown <[email protected]>

---
v1 of this was sent in November. I got some useful feedback, but then got distracted by something. Sorry for the long gap.
NeilBrown

drivers/iio/gyro/itg3200_core.c +25 -4

index 6a8020d48140..f0fd94055d88 100644
@@ -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,

Jonathan Cameron

maintainer Applied

2015-03-09 14:55 UTC #1 lore raw

Quoted 4 lines · NeilBrown

Unless we put the device to sleep when not it use, it wastes 6mA.

Quoted 8 lines

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 <[email protected]>
Acked-by Hartmut Knaack <[email protected]>
Signed-off-by NeilBrown <[email protected]>

Applied to the togreg branch of iio.git. Initially pushed out as testing for the autobuilders to play with it.

Thanks,

Jonathan

Quoted 5 lines

---
v1 of this was sent in November. I got some useful feedback, but then got distracted by something. Sorry for the long gap.
NeilBrown

Not to worry, I've got lots of stuff in that category ;(

Quoted 64 lines

drivers/iio/gyro/itg3200_core.c +25 -4

index 6a8020d48140..f0fd94055d88 100644
@@ -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,

Hartmut Knaack

2015-04-19 10:56 UTC #2 lore raw

In reply to NeilBrown

NeilBrown schrieb am 24.02.2015 um 03:24:

Quoted 11 lines

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 <[email protected]>
Acked-by Hartmut Knaack <[email protected]>

I don't recall acking on this. Anyway, no objection on the patch content.

Hartmut

Quoted 70 lines

Signed-off-by NeilBrown <[email protected]>

---
v1 of this was sent in November. I got some useful feedback, but then got distracted by something. Sorry for the long gap.
NeilBrown

drivers/iio/gyro/itg3200_core.c +25 -4

index 6a8020d48140..f0fd94055d88 100644
@@ -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,