Re: [PATCH v2] iio: dac: ad5592r-base: Replace indio_dev->mlock with own device lock

From: Jonathan Cameron
Date: Thu May 21 2020 - 14:38:32 EST


On Wed, 20 May 2020 15:02:01 +0300
Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> wrote:

> As part of the general cleanup of indio_dev->mlock, this change replaces
> it with a local lock on the device's state structure.
> This also removes unused iio_dev pointers.
>
> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
> drivers/iio/dac/ad5592r-base.c | 30 +++++++++++++++---------------
> drivers/iio/dac/ad5592r-base.h | 1 +
> 2 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c
> index e2110113e884..410e90e5f75f 100644
> --- a/drivers/iio/dac/ad5592r-base.c
> +++ b/drivers/iio/dac/ad5592r-base.c
> @@ -156,7 +156,6 @@ static void ad5592r_gpio_cleanup(struct ad5592r_state *st)
> static int ad5592r_reset(struct ad5592r_state *st)
> {
> struct gpio_desc *gpio;
> - struct iio_dev *iio_dev = iio_priv_to_dev(st);
>
> gpio = devm_gpiod_get_optional(st->dev, "reset", GPIOD_OUT_LOW);
> if (IS_ERR(gpio))
> @@ -166,10 +165,10 @@ static int ad5592r_reset(struct ad5592r_state *st)
> udelay(1);
> gpiod_set_value(gpio, 1);
> } else {
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
> /* Writing this magic value resets the device */
> st->ops->reg_write(st, AD5592R_REG_RESET, 0xdac);
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
> }
>
> udelay(250);
> @@ -197,7 +196,6 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
> const struct ad5592r_rw_ops *ops = st->ops;
> int ret;
> unsigned i;
> - struct iio_dev *iio_dev = iio_priv_to_dev(st);
> u8 pulldown = 0, tristate = 0, dac = 0, adc = 0;
> u16 read_back;
>
> @@ -247,7 +245,7 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
> }
> }
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
>
> /* Pull down unused pins to GND */
> ret = ops->reg_write(st, AD5592R_REG_PULLDOWN, pulldown);
> @@ -285,7 +283,7 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
> ret = -EIO;
>
> err_unlock:
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
> @@ -314,11 +312,11 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
> if (!chan->output)
> return -EINVAL;
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = st->ops->write_dac(st, chan->channel, val);
> if (!ret)
> st->cached_dac[chan->channel] = val;
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> case IIO_CHAN_INFO_SCALE:
> if (chan->type == IIO_VOLTAGE) {
> @@ -333,12 +331,12 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
> else
> return -EINVAL;
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
>
> ret = st->ops->reg_read(st, AD5592R_REG_CTRL,
> &st->cached_gp_ctrl);
> if (ret < 0) {
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
> @@ -360,7 +358,7 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
>
> ret = st->ops->reg_write(st, AD5592R_REG_CTRL,
> st->cached_gp_ctrl);
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return ret;
> }
> @@ -382,7 +380,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
>
> switch (m) {
> case IIO_CHAN_INFO_RAW:
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
>
> if (!chan->output) {
> ret = st->ops->read_adc(st, chan->channel, &read_val);
> @@ -419,7 +417,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
> } else {
> int mult;
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
>
> if (chan->output)
> mult = !!(st->cached_gp_ctrl &
> @@ -437,7 +435,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
> case IIO_CHAN_INFO_OFFSET:
> ret = ad5592r_get_vref(st);
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&st->lock);
>
> if (st->cached_gp_ctrl & AD5592R_REG_CTRL_ADC_RANGE)
> *val = (-34365 * 25) / ret;
> @@ -450,7 +448,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
> }
>
> unlock:
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
> @@ -625,6 +623,8 @@ int ad5592r_probe(struct device *dev, const char *name,
> iio_dev->info = &ad5592r_info;
> iio_dev->modes = INDIO_DIRECT_MODE;
>
> + mutex_init(&st->lock);
> +
> ad5592r_init_scales(st, ad5592r_get_vref(st));
>
> ret = ad5592r_reset(st);
> diff --git a/drivers/iio/dac/ad5592r-base.h b/drivers/iio/dac/ad5592r-base.h
> index 4774e4cd9c11..23dac2f1ff8a 100644
> --- a/drivers/iio/dac/ad5592r-base.h
> +++ b/drivers/iio/dac/ad5592r-base.h
> @@ -52,6 +52,7 @@ struct ad5592r_state {
> struct regulator *reg;
> struct gpio_chip gpiochip;
> struct mutex gpio_lock; /* Protect cached gpio_out, gpio_val, etc. */
> + struct mutex lock;
> unsigned int num_channels;
> const struct ad5592r_rw_ops *ops;
> int scale_avail[2][2];