[PATCH] iio: tsl2583: add runtime power management support
From: Brian Masney
Date: Tue Apr 25 2017 - 04:07:00 EST
This patch adds runtime power management support to the tsl2583 driver.
The device is powered off after two seconds of inactivity. Verified that
the driver still functions correctly using a TSL2581 hooked up to a
Raspberry Pi 2.
Signed-off-by: Brian Masney <masneyb@xxxxxxxxxxxxx>
---
drivers/iio/light/tsl2583.c | 106 +++++++++++++++++++++++++++++++-------------
1 file changed, 76 insertions(+), 30 deletions(-)
diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
index a78b602..1679181 100644
--- a/drivers/iio/light/tsl2583.c
+++ b/drivers/iio/light/tsl2583.c
@@ -3,7 +3,7 @@
* within the TAOS tsl258x family of devices (tsl2580, tsl2581, tsl2583).
*
* Copyright (c) 2011, TAOS Corporation.
- * Copyright (c) 2016 Brian Masney <masneyb@xxxxxxxxxxxxx>
+ * Copyright (c) 2016-2017 Brian Masney <masneyb@xxxxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/pm_runtime.h>
/* Device Registers and Masks */
#define TSL2583_CNTRL 0x00
@@ -64,6 +65,8 @@
#define TSL2583_CHIP_ID 0x90
#define TSL2583_CHIP_ID_MASK 0xf0
+#define TSL2583_POWER_OFF_DELAY_MS 2000
+
/* Per-device data */
struct tsl2583_als_info {
u16 als_ch0;
@@ -108,7 +111,6 @@ struct tsl2583_chip {
struct tsl2583_settings als_settings;
int als_time_scale;
int als_saturation;
- bool suspended;
};
struct gainadj {
@@ -460,8 +462,6 @@ static int tsl2583_chip_init_and_power_on(struct iio_dev *indio_dev)
if (ret < 0)
return ret;
- chip->suspended = false;
-
return ret;
}
@@ -513,11 +513,6 @@ static ssize_t in_illuminance_calibrate_store(struct device *dev,
mutex_lock(&chip->als_mutex);
- if (chip->suspended) {
- ret = -EBUSY;
- goto done;
- }
-
ret = tsl2583_als_calibrate(indio_dev);
if (ret < 0)
goto done;
@@ -645,20 +640,36 @@ static const struct iio_chan_spec tsl2583_channels[] = {
},
};
+static int tsl2583_set_pm_runtime_busy(struct tsl2583_chip *chip, bool on)
+{
+ int ret;
+
+ if (on) {
+ ret = pm_runtime_get_sync(&chip->client->dev);
+ if (ret < 0)
+ pm_runtime_put_noidle(&chip->client->dev);
+ } else {
+ pm_runtime_mark_last_busy(&chip->client->dev);
+ ret = pm_runtime_put_autosuspend(&chip->client->dev);
+ }
+
+ return ret;
+}
+
static int tsl2583_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct tsl2583_chip *chip = iio_priv(indio_dev);
- int ret = -EINVAL;
+ int ret, pm_ret;
- mutex_lock(&chip->als_mutex);
+ ret = tsl2583_set_pm_runtime_busy(chip, true);
+ if (ret < 0)
+ return ret;
- if (chip->suspended) {
- ret = -EBUSY;
- goto read_done;
- }
+ mutex_lock(&chip->als_mutex);
+ ret = -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type == IIO_LIGHT) {
@@ -719,6 +730,18 @@ static int tsl2583_read_raw(struct iio_dev *indio_dev,
read_done:
mutex_unlock(&chip->als_mutex);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Preserve the ret variable if the call to
+ * tsl2583_set_pm_runtime_busy() is successful so the reading
+ * (if applicable) is returned to user space.
+ */
+ pm_ret = tsl2583_set_pm_runtime_busy(chip, false);
+ if (pm_ret < 0)
+ return pm_ret;
+
return ret;
}
@@ -727,15 +750,15 @@ static int tsl2583_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct tsl2583_chip *chip = iio_priv(indio_dev);
- int ret = -EINVAL;
+ int ret;
- mutex_lock(&chip->als_mutex);
+ ret = tsl2583_set_pm_runtime_busy(chip, true);
+ if (ret < 0)
+ return ret;
- if (chip->suspended) {
- ret = -EBUSY;
- goto write_done;
- }
+ mutex_lock(&chip->als_mutex);
+ ret = -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_CALIBBIAS:
if (chan->type == IIO_LIGHT) {
@@ -767,9 +790,15 @@ static int tsl2583_write_raw(struct iio_dev *indio_dev,
break;
}
-write_done:
mutex_unlock(&chip->als_mutex);
+ if (ret < 0)
+ return ret;
+
+ ret = tsl2583_set_pm_runtime_busy(chip, false);
+ if (ret < 0)
+ return ret;
+
return ret;
}
@@ -803,7 +832,6 @@ static int tsl2583_probe(struct i2c_client *clientp,
i2c_set_clientdata(clientp, indio_dev);
mutex_init(&chip->als_mutex);
- chip->suspended = true;
ret = i2c_smbus_read_byte_data(clientp,
TSL2583_CMD_REG | TSL2583_CHIPID);
@@ -826,6 +854,11 @@ static int tsl2583_probe(struct i2c_client *clientp,
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = chip->client->name;
+ pm_runtime_enable(&clientp->dev);
+ pm_runtime_set_autosuspend_delay(&clientp->dev,
+ TSL2583_POWER_OFF_DELAY_MS);
+ pm_runtime_use_autosuspend(&clientp->dev);
+
ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
if (ret) {
dev_err(&clientp->dev, "%s: iio registration failed\n",
@@ -836,16 +869,25 @@ static int tsl2583_probe(struct i2c_client *clientp,
/* Load up the V2 defaults (these are hard coded defaults for now) */
tsl2583_defaults(chip);
- /* Make sure the chip is on */
- ret = tsl2583_chip_init_and_power_on(indio_dev);
- if (ret < 0)
- return ret;
-
dev_info(&clientp->dev, "Light sensor found.\n");
return 0;
}
+static int tsl2583_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct tsl2583_chip *chip = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ pm_runtime_disable(&client->dev);
+ pm_runtime_set_suspended(&client->dev);
+ pm_runtime_put_noidle(&client->dev);
+
+ return tsl2583_set_power_state(chip, TSL2583_CNTL_PWR_OFF);
+}
+
static int __maybe_unused tsl2583_suspend(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
@@ -855,7 +897,6 @@ static int __maybe_unused tsl2583_suspend(struct device *dev)
mutex_lock(&chip->als_mutex);
ret = tsl2583_set_power_state(chip, TSL2583_CNTL_PWR_OFF);
- chip->suspended = true;
mutex_unlock(&chip->als_mutex);
@@ -877,7 +918,11 @@ static int __maybe_unused tsl2583_resume(struct device *dev)
return ret;
}
-static SIMPLE_DEV_PM_OPS(tsl2583_pm_ops, tsl2583_suspend, tsl2583_resume);
+static const struct dev_pm_ops tsl2583_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(tsl2583_suspend, tsl2583_resume, NULL)
+};
static struct i2c_device_id tsl2583_idtable[] = {
{ "tsl2580", 0 },
@@ -904,6 +949,7 @@ static struct i2c_driver tsl2583_driver = {
},
.id_table = tsl2583_idtable,
.probe = tsl2583_probe,
+ .remove = tsl2583_remove,
};
module_i2c_driver(tsl2583_driver);
--
2.9.3