* [PATCH] iio: dac: ad5755: Replace indio_dev->mlock with own device lock
@ 2020-05-14 9:06 Sergiu Cuciurean
2020-05-16 15:21 ` Jonathan Cameron
0 siblings, 1 reply; 2+ messages in thread
From: Sergiu Cuciurean @ 2020-05-14 9:06 UTC (permalink / raw)
To: linux-kernel, linux-iio
Cc: Sergiu Cuciurean, Lars-Peter Clausen, Michael Hennerich,
Stefan Popa, Jonathan Cameron, Hartmut Knaack,
Peter Meerwald-Stadler
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 changes some internal functions to pass the pointer to the
state-struct vs a ref to indio_dev just to access the state-struct again.
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
---
drivers/iio/dac/ad5755.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
index 388ddd14bfd0..7723bd313fc6 100644
--- a/drivers/iio/dac/ad5755.c
+++ b/drivers/iio/dac/ad5755.c
@@ -82,6 +82,7 @@ struct ad5755_chip_info {
* @pwr_down: bitmask which contains hether a channel is powered down or not
* @ctrl: software shadow of the channel ctrl registers
* @channels: iio channel spec for the device
+ * @lock lock to protect the data buffer during SPI ops
* @data: spi transfer buffers
*/
struct ad5755_state {
@@ -90,6 +91,7 @@ struct ad5755_state {
unsigned int pwr_down;
unsigned int ctrl[AD5755_NUM_CHANNELS];
struct iio_chan_spec channels[AD5755_NUM_CHANNELS];
+ struct mutex lock;
/*
* DMA (thus cache coherency maintenance) requires the
@@ -174,11 +176,12 @@ static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
unsigned int val)
{
+ struct ad5755_state *st = iio_priv(indio_dev);
int ret;
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
ret = ad5755_write_unlocked(indio_dev, reg, val);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret;
}
@@ -186,11 +189,12 @@ static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
unsigned int reg, unsigned int val)
{
+ struct ad5755_state *st = iio_priv(indio_dev);
int ret;
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret;
}
@@ -211,7 +215,7 @@ static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
},
};
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
@@ -220,7 +224,7 @@ static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
if (ret >= 0)
ret = be32_to_cpu(st->data[1].d32) & 0xffff;
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret;
}
@@ -246,7 +250,7 @@ static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
struct ad5755_state *st = iio_priv(indio_dev);
unsigned int mask = BIT(channel);
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
if ((bool)(st->pwr_down & mask) == pwr_down)
goto out_unlock;
@@ -266,7 +270,7 @@ static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
}
out_unlock:
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return 0;
}
@@ -746,6 +750,8 @@ static int ad5755_probe(struct spi_device *spi)
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->num_channels = AD5755_NUM_CHANNELS;
+ mutex_init(&st->lock);
+
if (spi->dev.of_node)
pdata = ad5755_parse_dt(&spi->dev);
else
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] iio: dac: ad5755: Replace indio_dev->mlock with own device lock
2020-05-14 9:06 [PATCH] iio: dac: ad5755: Replace indio_dev->mlock with own device lock Sergiu Cuciurean
@ 2020-05-16 15:21 ` Jonathan Cameron
0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Cameron @ 2020-05-16 15:21 UTC (permalink / raw)
To: Sergiu Cuciurean
Cc: linux-kernel, linux-iio, Lars-Peter Clausen, Michael Hennerich,
Stefan Popa, Hartmut Knaack, Peter Meerwald-Stadler
On Thu, 14 May 2020 12:06:05 +0300
Sergiu Cuciurean <sergiu.cuciurean@analog.com> 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 changes some internal functions to pass the pointer to the
> state-struct vs a ref to indio_dev just to access the state-struct again.
>
> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Applied to the togreg branch of iio.git.
An observation on this one is that, with the local lock we always
have the iio_priv() structure where we are calling the various
write functions. Those take the indio_dev and use it just to get
the iio_priv(). May be worth a follow up to tidy that up and just
pass the private state structure directly into the various write
functions.
Jonathan
> ---
> drivers/iio/dac/ad5755.c | 22 ++++++++++++++--------
> 1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
> index 388ddd14bfd0..7723bd313fc6 100644
> --- a/drivers/iio/dac/ad5755.c
> +++ b/drivers/iio/dac/ad5755.c
> @@ -82,6 +82,7 @@ struct ad5755_chip_info {
> * @pwr_down: bitmask which contains hether a channel is powered down or not
> * @ctrl: software shadow of the channel ctrl registers
> * @channels: iio channel spec for the device
> + * @lock lock to protect the data buffer during SPI ops
> * @data: spi transfer buffers
> */
> struct ad5755_state {
> @@ -90,6 +91,7 @@ struct ad5755_state {
> unsigned int pwr_down;
> unsigned int ctrl[AD5755_NUM_CHANNELS];
> struct iio_chan_spec channels[AD5755_NUM_CHANNELS];
> + struct mutex lock;
>
> /*
> * DMA (thus cache coherency maintenance) requires the
> @@ -174,11 +176,12 @@ static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
> static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
> unsigned int val)
> {
> + struct ad5755_state *st = iio_priv(indio_dev);
> int ret;
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = ad5755_write_unlocked(indio_dev, reg, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return ret;
> }
> @@ -186,11 +189,12 @@ static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
> static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
> unsigned int reg, unsigned int val)
> {
> + struct ad5755_state *st = iio_priv(indio_dev);
> int ret;
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return ret;
> }
> @@ -211,7 +215,7 @@ static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
> },
> };
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
>
> st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
> st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
> @@ -220,7 +224,7 @@ static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
> if (ret >= 0)
> ret = be32_to_cpu(st->data[1].d32) & 0xffff;
>
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return ret;
> }
> @@ -246,7 +250,7 @@ static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
> struct ad5755_state *st = iio_priv(indio_dev);
> unsigned int mask = BIT(channel);
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
>
> if ((bool)(st->pwr_down & mask) == pwr_down)
> goto out_unlock;
> @@ -266,7 +270,7 @@ static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
> }
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return 0;
> }
> @@ -746,6 +750,8 @@ static int ad5755_probe(struct spi_device *spi)
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->num_channels = AD5755_NUM_CHANNELS;
>
> + mutex_init(&st->lock);
> +
> if (spi->dev.of_node)
> pdata = ad5755_parse_dt(&spi->dev);
> else
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2020-05-14 9:06 [PATCH] iio: dac: ad5755: Replace indio_dev->mlock with own device lock Sergiu Cuciurean
2020-05-16 15:21 ` Jonathan Cameron
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