From: maxime.ripard@bootlin.com (Maxime Ripard) Date: Mon, 5 Mar 2018 10:35:28 +0100 Subject: [PATCH 1/7] media: sun6i: Fill dma_pfn_offset to accomodate for the RAM offset In-Reply-To: <20180305093535.11801-1-maxime.ripard@bootlin.com> References: <1519697113-32202-1-git-send-email-yong.deng@magewell.com> <20180305093535.11801-1-maxime.ripard@bootlin.com> Message-ID: <20180305093535.11801-2-maxime.ripard@bootlin.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The CSI controller does its DMA accesses through a DMA bus that has the RAM mapped at the address 0. The current code removes from the dma_addr_t PHYS_OFFSET, and while it works, this is an abuse of the DMA API. Instead, fill the dma_pfn_offset field in the struct device that should be used to express such an offset, and the use the dma_addr_t directly as we should. Signed-off-by: Maxime Ripard --- drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c index 1aaaae238d57..2ec33fb04632 100644 --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c @@ -563,20 +563,15 @@ int sun6i_csi_update_config(struct sun6i_csi *csi, void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr) { struct sun6i_csi_dev *sdev = sun6i_csi_to_dev(csi); - /* transform physical address to bus address */ -#if defined(CONFIG_COMPILE_TEST) && !defined(PHYS_OFFSET) -#define PHYS_OFFSET 0 -#endif - dma_addr_t bus_addr = addr - PHYS_OFFSET; regmap_write(sdev->regmap, CSI_CH_F0_BUFA_REG, - (bus_addr + sdev->planar_offset[0]) >> 2); + (addr + sdev->planar_offset[0]) >> 2); if (sdev->planar_offset[1] != -1) regmap_write(sdev->regmap, CSI_CH_F1_BUFA_REG, - (bus_addr + sdev->planar_offset[1]) >> 2); + (addr + sdev->planar_offset[1]) >> 2); if (sdev->planar_offset[2] != -1) regmap_write(sdev->regmap, CSI_CH_F2_BUFA_REG, - (bus_addr + sdev->planar_offset[2]) >> 2); + (addr + sdev->planar_offset[2]) >> 2); } void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable) @@ -856,6 +851,14 @@ static int sun6i_csi_resource_request(struct sun6i_csi_dev *sdev, return 0; } +/* + * PHYS_OFFSET isn't available on all architectures. In order to + * accomodate for COMPILE_TEST, let's define it to something dumb. + */ +#ifndef PHYS_OFFSET +#define PHYS_OFFSET 0 +#endif + static int sun6i_csi_probe(struct platform_device *pdev) { struct sun6i_csi_dev *sdev; @@ -866,6 +869,8 @@ static int sun6i_csi_probe(struct platform_device *pdev) return -ENOMEM; sdev->dev = &pdev->dev; + /* The DMA bus has the memory mapped at 0 */ + sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT; ret = sun6i_csi_resource_request(sdev, pdev); if (ret) -- 2.14.3