Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Alexandru Ardelean <alexandru.ardelean@analog.com>
To:     <linux-iio@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
CC:     <jic23@kernel.org>, <mcoquelin.stm32@gmail.com>,
        <alexandre.torgue@st.com>,
        Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH] iio: stm32-dfsdm-adc: keep a reference to the iio device on the state struct
Date:   Fri, 22 May 2020 16:08:04 +0300
Message-ID: <20200522130804.631508-1-alexandru.ardelean@analog.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type:   text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

We may want to get rid of the iio_priv_to_dev() helper. The reason is that
we will hide some of the members of the iio_dev structure (to prevent
drivers from accessing them directly), and that will also mean hiding the
implementation of the iio_priv_to_dev() helper inside the IIO core.

Hiding the implementation of iio_priv_to_dev() implies that some fast-paths
may not be fast anymore, so a general idea is to try to get rid of the
iio_priv_to_dev() altogether.
The iio_priv() helper won't be affected by the rework.

For this driver, not using iio_priv_to_dev(), means keeping a reference to
the IIO device on the state struct.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/iio/adc/stm32-dfsdm-adc.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 76a60d93fe23..ff7a6afa4558 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -69,6 +69,7 @@ struct stm32_dfsdm_dev_data {
 
 struct stm32_dfsdm_adc {
 	struct stm32_dfsdm *dfsdm;
+	struct iio_dev *indio_dev;
 	const struct stm32_dfsdm_dev_data *dev_data;
 	unsigned int fl_id;
 	unsigned int nconv;
@@ -332,7 +333,7 @@ static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev,
 
 static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	const struct iio_chan_spec *chan;
 	unsigned int bit;
@@ -352,7 +353,7 @@ static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc)
 
 static void stm32_dfsdm_stop_channel(struct stm32_dfsdm_adc *adc)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	const struct iio_chan_spec *chan;
 	unsigned int bit;
@@ -422,7 +423,7 @@ static int stm32_dfsdm_filter_set_trig(struct stm32_dfsdm_adc *adc,
 				       unsigned int fl_id,
 				       struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	u32 jextsel = 0, jexten = STM32_DFSDM_JEXTEN_DISABLED;
 	int ret;
@@ -451,7 +452,7 @@ static int stm32_dfsdm_channels_configure(struct stm32_dfsdm_adc *adc,
 					  unsigned int fl_id,
 					  struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 	struct stm32_dfsdm_filter_osr *flo = &fl->flo[0];
@@ -495,7 +496,7 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
 					unsigned int fl_id,
 					struct iio_trigger *trig)
 {
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 	struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
@@ -1314,7 +1315,7 @@ static const struct iio_info stm32_dfsdm_info_adc = {
 static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
 {
 	struct stm32_dfsdm_adc *adc = arg;
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	struct regmap *regmap = adc->dfsdm->regmap;
 	unsigned int status, int_en;
 
@@ -1569,6 +1570,7 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 
 	adc = iio_priv(iio);
 	adc->dfsdm = dev_get_drvdata(dev->parent);
+	adc->indio_dev = iio;
 
 	iio->dev.parent = dev;
 	iio->dev.of_node = np;
@@ -1651,7 +1653,7 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 {
 	struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 
 	if (adc->dev_data->type == DFSDM_AUDIO)
 		of_platform_depopulate(&pdev->dev);
@@ -1664,7 +1666,7 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
 static int __maybe_unused stm32_dfsdm_adc_suspend(struct device *dev)
 {
 	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 
 	if (iio_buffer_enabled(indio_dev))
 		__stm32_dfsdm_predisable(indio_dev);
@@ -1675,7 +1677,7 @@ static int __maybe_unused stm32_dfsdm_adc_suspend(struct device *dev)
 static int __maybe_unused stm32_dfsdm_adc_resume(struct device *dev)
 {
 	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);
-	struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+	struct iio_dev *indio_dev = adc->indio_dev;
 	const struct iio_chan_spec *chan;
 	struct stm32_dfsdm_channel *ch;
 	int i, ret;
-- 
2.25.1