From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:42824 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937197AbdAHJng (ORCPT ); Sun, 8 Jan 2017 04:43:36 -0500 Subject: Re: [PATCH 04/19] staging: iio: isl29028: add power management support To: Brian Masney , linux-iio@vger.kernel.org References: <1480817983-32359-1-git-send-email-masneyb@onstation.org> <1480817983-32359-5-git-send-email-masneyb@onstation.org> Cc: gregkh@linuxfoundation.org, devel@driverdev.osuosl.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-kernel@vger.kernel.org, ldewangan@nvidia.com From: Jonathan Cameron Message-ID: <299bdab4-0cbb-3581-014f-9bb10fd86e81@kernel.org> Date: Sun, 4 Dec 2016 11:37:59 +0000 MIME-Version: 1.0 In-Reply-To: <1480817983-32359-5-git-send-email-masneyb@onstation.org> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 04/12/16 02:19, Brian Masney wrote: > This patch adds power management support to the isl29028 driver. > > Signed-off-by: Brian Masney Hmm. I'm not sure why we need the suspended boolean. I 'think' it's impossible to have a sysfs read in progress during suspend or resume. At least I hope it is as a lot of drivers will be broken otherwise :( Looks like this particular corner is only really present in light sensor drivers... Jonathan > --- > 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, >