[PATCH 04/19] staging: iio: isl29028: add power management support

[Brian Masney]

This patch adds power management support to the isl29028 driver.

Signed-off-by: Brian Masney <masn...@onstation.org>
---
 drivers/staging/iio/light/isl29028.c | 59 ++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/staging/iio/light/isl29028.c 
b/drivers/staging/iio/light/isl29028.c
index 4f819a8..e96a8cb 100644
--- a/drivers/staging/iio/light/isl29028.c
+++ b/drivers/staging/iio/light/isl29028.c
@@ -75,6 +75,7 @@ struct isl29028_chip {
 
        int                     lux_scale;
        enum isl29028_als_ir_mode       als_ir_mode;
+       bool                            suspended;
 };
 
 static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
@@ -274,6 +275,12 @@ static int isl29028_write_raw(struct iio_dev *indio_dev,
        int ret = -EINVAL;
 
        mutex_lock(&chip->lock);
+
+       if (chip->suspended) {
+               ret = -EBUSY;
+               goto write_done;
+       }
+
        switch (chan->type) {
        case IIO_PROXIMITY:
                if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
@@ -322,6 +329,8 @@ static int isl29028_write_raw(struct iio_dev *indio_dev,
                dev_err(dev, "Unsupported channel type\n");
                break;
        }
+
+write_done:
        mutex_unlock(&chip->lock);
        return ret;
 }
@@ -335,6 +344,12 @@ static int isl29028_read_raw(struct iio_dev *indio_dev,
        int ret = -EINVAL;
 
        mutex_lock(&chip->lock);
+
+       if (chip->suspended) {
+               ret = -EBUSY;
+               goto read_done;
+       }
+
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
        case IIO_CHAN_INFO_PROCESSED:
@@ -374,6 +389,8 @@ static int isl29028_read_raw(struct iio_dev *indio_dev,
                dev_err(dev, "mask value 0x%08lx not supported\n", mask);
                break;
        }
+
+read_done:
        mutex_unlock(&chip->lock);
        return ret;
 }
@@ -437,6 +454,9 @@ static int isl29028_chip_init_and_power_on(struct 
isl29028_chip *chip)
        ret = isl29028_set_als_scale(chip, chip->lux_scale);
        if (ret < 0)
                dev_err(dev, "setting als scale failed, err = %d\n", ret);
+
+       chip->suspended = false;
+
        return ret;
 }
 
@@ -479,6 +499,7 @@ static int isl29028_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, indio_dev);
        mutex_init(&chip->lock);
+       chip->suspended = true;
 
        chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
        if (IS_ERR(chip->regmap)) {
@@ -530,6 +551,43 @@ static int isl29028_probe(struct i2c_client *client,
        return 0;
 }
 
+static int __maybe_unused isl29028_suspend(struct device *dev)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+       struct isl29028_chip *chip = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&chip->lock);
+
+       ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
+       if (ret < 0)
+               dev_err(dev, "%s(): Error %d turning off chip\n", __func__,
+                       ret);
+
+       chip->suspended = true;
+
+       mutex_unlock(&chip->lock);
+
+       return ret;
+}
+
+static int __maybe_unused isl29028_resume(struct device *dev)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+       struct isl29028_chip *chip = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&chip->lock);
+
+       ret = isl29028_chip_init_and_power_on(chip);
+
+       mutex_unlock(&chip->lock);
+
+       return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(isl29028_pm_ops, isl29028_suspend, isl29028_resume);
+
 static const struct i2c_device_id isl29028_id[] = {
        {"isl29028", 0},
        {}
@@ -546,6 +604,7 @@ MODULE_DEVICE_TABLE(of, isl29028_of_match);
 static struct i2c_driver isl29028_driver = {
        .driver  = {
                .name = "isl29028",
+               .pm = &isl29028_pm_ops,
                .of_match_table = isl29028_of_match,
        },
        .probe   = isl29028_probe,
-- 
2.7.4