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From:   =?UTF-8?q?Guido=20G=C3=BCnther?= <agx@sigxcpu.org>
To:     Tomas Novotny <tomas@novotny.cz>,
        Jonathan Cameron <jic23@kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        "Angus Ainslie (Purism)" <angus@akkea.ca>,
        =?UTF-8?q?Guido=20G=C3=BCnther?= <agx@sigxcpu.org>,
        Marco Felsch <m.felsch@pengutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] iio: vncl4000: Enable runtime pm for vcnl4200/4040
Date:   Mon, 20 Jan 2020 16:01:24 +0100
Message-Id: <65d5c7b562f9f7c17857310e8538afe0bb1b2ddb.1579531608.git.agx@sigxcpu.org>
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This is modelled after the vcnl4035 driver. The vcnl4000 does not seem
to have a way to save power so we just leave it running.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
 drivers/iio/light/vcnl4000.c | 126 +++++++++++++++++++++++++++++++++--
 1 file changed, 120 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index 8f198383626b..b0396a3f1915 100644
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -22,6 +22,7 @@
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/delay.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -57,6 +58,8 @@
 #define VCNL4000_AL_OD		BIT(4) /* start on-demand ALS measurement */
 #define VCNL4000_PS_OD		BIT(3) /* start on-demand proximity measurement */
 
+#define VCNL4000_SLEEP_DELAY_MS	2000 /* before we enter pm_runtime_suspend */
+
 enum vcnl4000_device_ids {
 	VCNL4000,
 	VCNL4010,
@@ -87,6 +90,7 @@ struct vcnl4000_chip_spec {
 	int (*init)(struct vcnl4000_data *data);
 	int (*measure_light)(struct vcnl4000_data *data, int *val);
 	int (*measure_proximity)(struct vcnl4000_data *data, int *val);
+	int (*set_power_state)(struct vcnl4000_data *data, bool on);
 };
 
 static const struct i2c_device_id vcnl4000_id[] = {
@@ -99,6 +103,12 @@ static const struct i2c_device_id vcnl4000_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
 
+static int vcnl4000_set_power_state(struct vcnl4000_data *data, bool on)
+{
+	/* no suspend op */
+	return 0;
+}
+
 static int vcnl4000_init(struct vcnl4000_data *data)
 {
 	int ret, prod_id;
@@ -127,9 +137,24 @@ static int vcnl4000_init(struct vcnl4000_data *data)
 	data->al_scale = 250000;
 	mutex_init(&data->vcnl4000_lock);
 
+	ret = data->chip_spec->set_power_state(data, true);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 };
 
+static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool on)
+{
+	u16 val = on ? 0 /* power on */ : 1 /* shut down */;
+	int ret;
+
+	ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, val);
+	if (ret < 0)
+		return ret;
+	return i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, val);
+}
+
 static int vcnl4200_init(struct vcnl4000_data *data)
 {
 	int ret, id;
@@ -155,11 +180,7 @@ static int vcnl4200_init(struct vcnl4000_data *data)
 
 	data->rev = (ret >> 8) & 0xf;
 
-	/* Set defaults and enable both channels */
-	ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, 0);
-	if (ret < 0)
-		return ret;
-	ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, 0);
+	ret = data->chip_spec->set_power_state(data, true);
 	if (ret < 0)
 		return ret;
 
@@ -291,24 +312,28 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
 		.init = vcnl4000_init,
 		.measure_light = vcnl4000_measure_light,
 		.measure_proximity = vcnl4000_measure_proximity,
+		.set_power_state = vcnl4000_set_power_state,
 	},
 	[VCNL4010] = {
 		.prod = "VCNL4010/4020",
 		.init = vcnl4000_init,
 		.measure_light = vcnl4000_measure_light,
 		.measure_proximity = vcnl4000_measure_proximity,
+		.set_power_state = vcnl4000_set_power_state,
 	},
 	[VCNL4040] = {
 		.prod = "VCNL4040",
 		.init = vcnl4200_init,
 		.measure_light = vcnl4200_measure_light,
 		.measure_proximity = vcnl4200_measure_proximity,
+		.set_power_state = vcnl4200_set_power_state,
 	},
 	[VCNL4200] = {
 		.prod = "VCNL4200",
 		.init = vcnl4200_init,
 		.measure_light = vcnl4200_measure_light,
 		.measure_proximity = vcnl4200_measure_proximity,
+		.set_power_state = vcnl4200_set_power_state,
 	},
 };
 
@@ -323,6 +348,23 @@ static const struct iio_chan_spec vcnl4000_channels[] = {
 	}
 };
 
+static int vcnl4000_set_pm_runtime_state(struct vcnl4000_data *data, bool on)
+{
+	struct device *dev = &data->client->dev;
+	int ret;
+
+	if (on) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0)
+			pm_runtime_put_noidle(dev);
+	} else {
+		pm_runtime_mark_last_busy(dev);
+		ret = pm_runtime_put_autosuspend(dev);
+	}
+
+	return ret;
+}
+
 static int vcnl4000_read_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int *val, int *val2, long mask)
@@ -332,6 +374,10 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
+		ret = vcnl4000_set_pm_runtime_state(data, true);
+		if  (ret < 0)
+			return ret;
+
 		switch (chan->type) {
 		case IIO_LIGHT:
 			ret = data->chip_spec->measure_light(data, val);
@@ -346,6 +392,7 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
 		default:
 			ret = -EINVAL;
 		}
+		vcnl4000_set_pm_runtime_state(data, false);
 		return ret;
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type != IIO_LIGHT)
@@ -394,7 +441,22 @@ static int vcnl4000_probe(struct i2c_client *client,
 	indio_dev->name = VCNL4000_DRV_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	return devm_iio_device_register(&client->dev, indio_dev);
+	ret = pm_runtime_set_active(&client->dev);
+	if (ret < 0)
+		goto fail_poweroff;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto fail_poweroff;
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, VCNL4000_SLEEP_DELAY_MS);
+	pm_runtime_use_autosuspend(&client->dev);
+
+	return 0;
+fail_poweroff:
+	data->chip_spec->set_power_state(data, false);
+	return ret;
 }
 
 static const struct of_device_id vcnl_4000_of_match[] = {
@@ -422,13 +484,65 @@ static const struct of_device_id vcnl_4000_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, vcnl_4000_of_match);
 
+static int vcnl4000_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	pm_runtime_dont_use_autosuspend(&client->dev);
+	pm_runtime_disable(&client->dev);
+	iio_device_unregister(indio_dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	return data->chip_spec->set_power_state(data, false);
+}
+
+static int __maybe_unused vcnl4000_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = data->chip_spec->set_power_state(data, false);
+
+	return ret;
+}
+
+static int __maybe_unused vcnl4000_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+	unsigned int msecs;
+	int ret;
+
+	ret = data->chip_spec->set_power_state(data, true);
+	if (ret < 0)
+		return ret;
+
+	/* wait for 1 ALS integration cycle */
+	msecs =  data->vcnl4200_al.sampling_rate ?
+		ktime_to_ms(data->vcnl4200_al.sampling_rate) : 100;
+	msleep(ktime_to_ms(msecs));
+
+	return 0;
+}
+
+static const struct dev_pm_ops vcnl4000_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(vcnl4000_runtime_suspend,
+			   vcnl4000_runtime_resume, NULL)
+};
+
 static struct i2c_driver vcnl4000_driver = {
 	.driver = {
 		.name   = VCNL4000_DRV_NAME,
+		.pm	= &vcnl4000_pm_ops,
 		.of_match_table = vcnl_4000_of_match,
 	},
 	.probe  = vcnl4000_probe,
 	.id_table = vcnl4000_id,
+	.remove	= vcnl4000_remove,
 };
 
 module_i2c_driver(vcnl4000_driver);
-- 
2.23.0