From 907b2ad8c9acad39ac1f0ccdbbe66c63856055e3 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 19 Oct 2021 10:29:28 +0200 Subject: [PATCH] iio: at91-sama5d2: Fix incorrect cast to platform_device The at91-sama5d2 driver calls `to_platform_device()` on a struct device that is part of a IIO device. This is incorrect since `to_platform_device()` must only be called on a struct device that is part of a platform device. The code still works by accident because non of the struct platform_device specific fields are accessed. Refactor the code a bit so that it behaves identically, but does not use the incorrect cast. This avoids accidentally adding undefined behavior in the future by assuming the `struct platform_device` is actually valid. Signed-off-by: Lars-Peter Clausen Tested-by: Eugen Hristev Link: https://lore.kernel.org/r/20211019082929.30503-1-lars@metafoo.de Signed-off-by: Jonathan Cameron --- drivers/iio/adc/at91-sama5d2_adc.c | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 4c922ef..3841e7b 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1661,10 +1661,9 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, } } -static void at91_adc_dma_init(struct platform_device *pdev) +static void at91_adc_dma_init(struct at91_adc_state *st) { - struct iio_dev *indio_dev = platform_get_drvdata(pdev); - struct at91_adc_state *st = iio_priv(indio_dev); + struct device *dev = &st->indio_dev->dev; struct dma_slave_config config = {0}; /* we have 2 bytes for each channel */ unsigned int sample_size = st->soc_info.platform->nr_channels * 2; @@ -1679,9 +1678,9 @@ static void at91_adc_dma_init(struct platform_device *pdev) if (st->dma_st.dma_chan) return; - st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx"); + st->dma_st.dma_chan = dma_request_chan(dev, "rx"); if (IS_ERR(st->dma_st.dma_chan)) { - dev_info(&pdev->dev, "can't get DMA channel\n"); + dev_info(dev, "can't get DMA channel\n"); st->dma_st.dma_chan = NULL; goto dma_exit; } @@ -1691,7 +1690,7 @@ static void at91_adc_dma_init(struct platform_device *pdev) &st->dma_st.rx_dma_buf, GFP_KERNEL); if (!st->dma_st.rx_buf) { - dev_info(&pdev->dev, "can't allocate coherent DMA area\n"); + dev_info(dev, "can't allocate coherent DMA area\n"); goto dma_chan_disable; } @@ -1704,11 +1703,11 @@ static void at91_adc_dma_init(struct platform_device *pdev) config.dst_maxburst = 1; if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) { - dev_info(&pdev->dev, "can't configure DMA slave\n"); + dev_info(dev, "can't configure DMA slave\n"); goto dma_free_area; } - dev_info(&pdev->dev, "using %s for rx DMA transfers\n", + dev_info(dev, "using %s for rx DMA transfers\n", dma_chan_name(st->dma_st.dma_chan)); return; @@ -1720,13 +1719,12 @@ dma_chan_disable: dma_release_channel(st->dma_st.dma_chan); st->dma_st.dma_chan = NULL; dma_exit: - dev_info(&pdev->dev, "continuing without DMA support\n"); + dev_info(dev, "continuing without DMA support\n"); } -static void at91_adc_dma_disable(struct platform_device *pdev) +static void at91_adc_dma_disable(struct at91_adc_state *st) { - struct iio_dev *indio_dev = platform_get_drvdata(pdev); - struct at91_adc_state *st = iio_priv(indio_dev); + struct device *dev = &st->indio_dev->dev; /* we have 2 bytes for each channel */ unsigned int sample_size = st->soc_info.platform->nr_channels * 2; unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * @@ -1744,7 +1742,7 @@ static void at91_adc_dma_disable(struct platform_device *pdev) dma_release_channel(st->dma_st.dma_chan); st->dma_st.dma_chan = NULL; - dev_info(&pdev->dev, "continuing without DMA support\n"); + dev_info(dev, "continuing without DMA support\n"); } static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) @@ -1770,9 +1768,9 @@ static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) */ if (val == 1) - at91_adc_dma_disable(to_platform_device(&indio_dev->dev)); + at91_adc_dma_disable(st); else if (val > 1) - at91_adc_dma_init(to_platform_device(&indio_dev->dev)); + at91_adc_dma_init(st); /* * We can start the DMA only after setting the watermark and @@ -1780,7 +1778,7 @@ static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) */ ret = at91_adc_buffer_prepare(indio_dev); if (ret) - at91_adc_dma_disable(to_platform_device(&indio_dev->dev)); + at91_adc_dma_disable(st); return ret; } @@ -2077,7 +2075,7 @@ static int at91_adc_probe(struct platform_device *pdev) return 0; dma_disable: - at91_adc_dma_disable(pdev); + at91_adc_dma_disable(st); per_clk_disable_unprepare: clk_disable_unprepare(st->per_clk); vref_disable: @@ -2094,7 +2092,7 @@ static int at91_adc_remove(struct platform_device *pdev) iio_device_unregister(indio_dev); - at91_adc_dma_disable(pdev); + at91_adc_dma_disable(st); clk_disable_unprepare(st->per_clk); -- 2.7.4