Re: [PATCH v2] iio: stm32-adc: remove usage of iio_priv_to_dev() helper

From: Ardelean, Alexandru
Date: Tue May 26 2020 - 09:06:14 EST


On Mon, 2020-05-25 at 18:27 +0200, Fabrice Gasnier wrote:
> [External]
>
> On 5/25/20 11:07 AM, Alexandru Ardelean wrote:
> > 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, as the iio_dev
> > struct will keep a reference to the private information.
> >
> > For this driver, not using iio_priv_to_dev(), means reworking some
> > paths to
> > pass the iio device and using iio_priv() to access the private
> > information.
> >
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> > ---
> > drivers/iio/adc/stm32-adc.c | 108 +++++++++++++++++++-----------------
> > 1 file changed, 58 insertions(+), 50 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> > index ae622ee6d08c..9428c5c22712 100644
> > --- a/drivers/iio/adc/stm32-adc.c
> > +++ b/drivers/iio/adc/stm32-adc.c
> > @@ -162,10 +162,10 @@ struct stm32_adc_cfg {
> > struct stm32_adc_trig_info *trigs;
> > bool clk_required;
> > bool has_vregready;
> > - int (*prepare)(struct stm32_adc *);
> > - void (*start_conv)(struct stm32_adc *, bool dma);
> > - void (*stop_conv)(struct stm32_adc *);
> > - void (*unprepare)(struct stm32_adc *);
> > + int (*prepare)(struct iio_dev *);
> > + void (*start_conv)(struct iio_dev *, bool dma);
> > + void (*stop_conv)(struct iio_dev *);
> > + void (*unprepare)(struct iio_dev *);
> > const unsigned int *smp_cycles;
> > };
> >
> > @@ -538,10 +538,11 @@ static void stm32_adc_set_res(struct stm32_adc
> > *adc)
> >
> > static int stm32_adc_hw_stop(struct device *dev)
> > {
> > - struct stm32_adc *adc = dev_get_drvdata(dev);
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> >
> > if (adc->cfg->unprepare)
> > - adc->cfg->unprepare(adc);
> > + adc->cfg->unprepare(indio_dev);
> >
> > if (adc->clk)
> > clk_disable_unprepare(adc->clk);
> > @@ -551,7 +552,8 @@ static int stm32_adc_hw_stop(struct device *dev)
> >
> > static int stm32_adc_hw_start(struct device *dev)
> > {
> > - struct stm32_adc *adc = dev_get_drvdata(dev);
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> >
> > if (adc->clk) {
> > @@ -563,7 +565,7 @@ static int stm32_adc_hw_start(struct device *dev)
> > stm32_adc_set_res(adc);
> >
> > if (adc->cfg->prepare) {
> > - ret = adc->cfg->prepare(adc);
> > + ret = adc->cfg->prepare(indio_dev);
> > if (ret)
> > goto err_clk_dis;
> > }
> > @@ -587,8 +589,10 @@ static int stm32_adc_hw_start(struct device *dev)
> > * conversions, in IIO buffer modes. Otherwise, use ADC interrupt with
> > direct
> > * DR read instead (e.g. read_raw, or triggered buffer mode without
> > DMA).
> > */
> > -static void stm32f4_adc_start_conv(struct stm32_adc *adc, bool dma)
> > +static void stm32f4_adc_start_conv(struct iio_dev *indio_dev, bool
> > dma)
>
> Hi Alexandru,
>
> I've tested your patch. I've no objection, but found few build warnings
> (some of these routines have kernel-doc style).
>
> Building with W=1 makes warnings appear, like:
> drivers/iio/adc/stm32-adc.c:593: warning: Function parameter or member
> 'indio_dev' not described in 'stm32f4_adc_start_conv'
> drivers/iio/adc/stm32-adc.c:593: warning: Excess function parameter
> 'adc' description in 'stm32f4_adc_start_conv'
> ...
>
> Could you update routine's doc as well ?

Thanks.
Will send a V3 shortly.
The W=1 option looks interesting.
We might give this to interns/new-people to get them started.

>
> e.g. something like:
> - * @adc: stm32 adc instance
> + * @indio_dev: IIO device
>
> > {
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > +
> > stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
> >
> > if (dma)
> > @@ -605,8 +609,10 @@ static void stm32f4_adc_start_conv(struct
> > stm32_adc *adc, bool dma)
> > stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART);
> > }
> >
> > -static void stm32f4_adc_stop_conv(struct stm32_adc *adc)
> > +static void stm32f4_adc_stop_conv(struct iio_dev *indio_dev)
> > {
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > +
> > stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK);
> > stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT);
> >
> > @@ -615,8 +621,9 @@ static void stm32f4_adc_stop_conv(struct stm32_adc
> > *adc)
> > STM32F4_ADON | STM32F4_DMA | STM32F4_DDS);
> > }
> >
> > -static void stm32h7_adc_start_conv(struct stm32_adc *adc, bool dma)
> > +static void stm32h7_adc_start_conv(struct iio_dev *indio_dev, bool
> > dma)
> > {
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > enum stm32h7_adc_dmngt dmngt;
> > unsigned long flags;
> > u32 val;
> > @@ -635,9 +642,9 @@ static void stm32h7_adc_start_conv(struct stm32_adc
> > *adc, bool dma)
> > stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART);
> > }
> >
> > -static void stm32h7_adc_stop_conv(struct stm32_adc *adc)
> > +static void stm32h7_adc_stop_conv(struct iio_dev *indio_dev)
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> > u32 val;
> >
> > @@ -652,9 +659,9 @@ static void stm32h7_adc_stop_conv(struct stm32_adc
> > *adc)
> > stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK);
> > }
> >
> > -static int stm32h7_adc_exit_pwr_down(struct stm32_adc *adc)
> > +static int stm32h7_adc_exit_pwr_down(struct iio_dev *indio_dev)
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> > u32 val;
> >
> > @@ -690,9 +697,9 @@ static void stm32h7_adc_enter_pwr_down(struct
> > stm32_adc *adc)
> > stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
> > }
> >
> > -static int stm32h7_adc_enable(struct stm32_adc *adc)
> > +static int stm32h7_adc_enable(struct iio_dev *indio_dev)
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> > u32 val;
> >
> > @@ -713,9 +720,9 @@ static int stm32h7_adc_enable(struct stm32_adc
> > *adc)
> > return ret;
> > }
> >
> > -static void stm32h7_adc_disable(struct stm32_adc *adc)
> > +static void stm32h7_adc_disable(struct iio_dev *indio_dev)
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> > u32 val;
> >
> > @@ -733,9 +740,9 @@ static void stm32h7_adc_disable(struct stm32_adc
> > *adc)
> > * @adc: stm32 adc instance
> > * Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are
> > writable
> > */
> > -static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
> > +static int stm32h7_adc_read_selfcalib(struct iio_dev *indio_dev)
>
> Same here.
>
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int i, ret;
> > u32 lincalrdyw_mask, val;
> >
> > @@ -777,9 +784,9 @@ static int stm32h7_adc_read_selfcalib(struct
> > stm32_adc *adc)
> > * @adc: stm32 adc instance
> > * Note: ADC must be enabled, with no on-going conversions.
> > */
> > -static int stm32h7_adc_restore_selfcalib(struct stm32_adc *adc)
> > +static int stm32h7_adc_restore_selfcalib(struct iio_dev *indio_dev)
>
> Same here.
>
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int i, ret;
> > u32 lincalrdyw_mask, val;
> >
> > @@ -850,9 +857,9 @@ static int stm32h7_adc_restore_selfcalib(struct
> > stm32_adc *adc)
> > * @adc: stm32 adc instance
> > * Note: Must be called once ADC is out of power down.
> > */
> > -static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
> > +static int stm32h7_adc_selfcalib(struct iio_dev *indio_dev)
>
> Same here
>
> > {
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int ret;
> > u32 val;
> >
> > @@ -912,30 +919,31 @@ static int stm32h7_adc_selfcalib(struct stm32_adc
> > *adc)
> > * - Only one input is selected for single ended (e.g. 'vinp')
> > * - Two inputs are selected for differential channels (e.g. 'vinp' &
> > 'vinn')
> > */
> > -static int stm32h7_adc_prepare(struct stm32_adc *adc)
> > +static int stm32h7_adc_prepare(struct iio_dev *indio_dev)
>
> Same here.
>
> With the comments updated, you can add my:
>
> Acked-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
>
> Thanks for the patch,
> Fabrice
>
> > {
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > int calib, ret;
> >
> > - ret = stm32h7_adc_exit_pwr_down(adc);
> > + ret = stm32h7_adc_exit_pwr_down(indio_dev);
> > if (ret)
> > return ret;
> >
> > - ret = stm32h7_adc_selfcalib(adc);
> > + ret = stm32h7_adc_selfcalib(indio_dev);
> > if (ret < 0)
> > goto pwr_dwn;
> > calib = ret;
> >
> > stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
> >
> > - ret = stm32h7_adc_enable(adc);
> > + ret = stm32h7_adc_enable(indio_dev);
> > if (ret)
> > goto pwr_dwn;
> >
> > /* Either restore or read calibration result for future reference
> > */
> > if (calib)
> > - ret = stm32h7_adc_restore_selfcalib(adc);
> > + ret = stm32h7_adc_restore_selfcalib(indio_dev);
> > else
> > - ret = stm32h7_adc_read_selfcalib(adc);
> > + ret = stm32h7_adc_read_selfcalib(indio_dev);
> > if (ret)
> > goto disable;
> >
> > @@ -944,16 +952,18 @@ static int stm32h7_adc_prepare(struct stm32_adc
> > *adc)
> > return 0;
> >
> > disable:
> > - stm32h7_adc_disable(adc);
> > + stm32h7_adc_disable(indio_dev);
> > pwr_dwn:
> > stm32h7_adc_enter_pwr_down(adc);
> >
> > return ret;
> > }
> >
> > -static void stm32h7_adc_unprepare(struct stm32_adc *adc)
> > +static void stm32h7_adc_unprepare(struct iio_dev *indio_dev)
> > {
> > - stm32h7_adc_disable(adc);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > +
> > + stm32h7_adc_disable(indio_dev);
> > stm32h7_adc_enter_pwr_down(adc);
> > }
> >
> > @@ -1160,7 +1170,7 @@ static int stm32_adc_single_conv(struct iio_dev
> > *indio_dev,
> >
> > stm32_adc_conv_irq_enable(adc);
> >
> > - adc->cfg->start_conv(adc, false);
> > + adc->cfg->start_conv(indio_dev, false);
> >
> > timeout = wait_for_completion_interruptible_timeout(
> > &adc->completion,
> > STM32_ADC_TIMEOUT);
> > @@ -1173,7 +1183,7 @@ static int stm32_adc_single_conv(struct iio_dev
> > *indio_dev,
> > ret = IIO_VAL_INT;
> > }
> >
> > - adc->cfg->stop_conv(adc);
> > + adc->cfg->stop_conv(indio_dev);
> >
> > stm32_adc_conv_irq_disable(adc);
> >
> > @@ -1227,8 +1237,8 @@ static int stm32_adc_read_raw(struct iio_dev
> > *indio_dev,
> >
> > static irqreturn_t stm32_adc_threaded_isr(int irq, void *data)
> > {
> > - struct stm32_adc *adc = data;
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct iio_dev *indio_dev = data;
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > const struct stm32_adc_regspec *regs = adc->cfg->regs;
> > u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
> >
> > @@ -1240,8 +1250,8 @@ static irqreturn_t stm32_adc_threaded_isr(int
> > irq, void *data)
> >
> > static irqreturn_t stm32_adc_isr(int irq, void *data)
> > {
> > - struct stm32_adc *adc = data;
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct iio_dev *indio_dev = data;
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> > const struct stm32_adc_regspec *regs = adc->cfg->regs;
> > u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
> >
> > @@ -1514,7 +1524,7 @@ static int __stm32_adc_buffer_postenable(struct
> > iio_dev *indio_dev)
> > if (!adc->dma_chan)
> > stm32_adc_conv_irq_enable(adc);
> >
> > - adc->cfg->start_conv(adc, !!adc->dma_chan);
> > + adc->cfg->start_conv(indio_dev, !!adc->dma_chan);
> >
> > return 0;
> >
> > @@ -1547,7 +1557,7 @@ static void __stm32_adc_buffer_predisable(struct
> > iio_dev *indio_dev)
> > struct stm32_adc *adc = iio_priv(indio_dev);
> > struct device *dev = indio_dev->dev.parent;
> >
> > - adc->cfg->stop_conv(adc);
> > + adc->cfg->stop_conv(indio_dev);
> > if (!adc->dma_chan)
> > stm32_adc_conv_irq_disable(adc);
> >
> > @@ -1891,7 +1901,7 @@ static int stm32_adc_probe(struct platform_device
> > *pdev)
> > indio_dev->info = &stm32_adc_iio_info;
> > indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
> >
> > - platform_set_drvdata(pdev, adc);
> > + platform_set_drvdata(pdev, indio_dev);
> >
> > ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
> > if (ret != 0) {
> > @@ -1905,7 +1915,7 @@ static int stm32_adc_probe(struct platform_device
> > *pdev)
> >
> > ret = devm_request_threaded_irq(&pdev->dev, adc->irq,
> > stm32_adc_isr,
> > stm32_adc_threaded_isr,
> > - 0, pdev->name, adc);
> > + 0, pdev->name, indio_dev);
> > if (ret) {
> > dev_err(&pdev->dev, "failed to request IRQ\n");
> > return ret;
> > @@ -1989,8 +1999,8 @@ static int stm32_adc_probe(struct platform_device
> > *pdev)
> >
> > static int stm32_adc_remove(struct platform_device *pdev)
> > {
> > - struct stm32_adc *adc = platform_get_drvdata(pdev);
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > + struct stm32_adc *adc = iio_priv(indio_dev);
> >
> > pm_runtime_get_sync(&pdev->dev);
> > iio_device_unregister(indio_dev);
> > @@ -2012,8 +2022,7 @@ static int stm32_adc_remove(struct
> > platform_device *pdev)
> > #if defined(CONFIG_PM_SLEEP)
> > static int stm32_adc_suspend(struct device *dev)
> > {
> > - struct stm32_adc *adc = dev_get_drvdata(dev);
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> >
> > if (iio_buffer_enabled(indio_dev))
> > __stm32_adc_buffer_predisable(indio_dev);
> > @@ -2023,8 +2032,7 @@ static int stm32_adc_suspend(struct device *dev)
> >
> > static int stm32_adc_resume(struct device *dev)
> > {
> > - struct stm32_adc *adc = dev_get_drvdata(dev);
> > - struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > int ret;
> >
> > ret = pm_runtime_force_resume(dev);
> >