Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH 1/2] mtd: mtk-quadspi: add support for memory-mapped flash reading | From | Vignesh Raghavendra <> | Date | Thu, 7 Nov 2019 11:36:03 +0530 |
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Hi,
On 06/11/19 7:37 PM, Chuanhong Guo wrote: > PIO reading mode on this controller is ridiculously inefficient > (one cmd+addr+dummy sequence reads only one byte) > This patch adds support for reading from memory-mapped flash area > which increases reading speed from 1MB/s to 5.6MB/s > > Signed-off-by: Chuanhong Guo <gch981213@gmail.com> > --- > drivers/mtd/spi-nor/mtk-quadspi.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/mtd/spi-nor/mtk-quadspi.c b/drivers/mtd/spi-nor/mtk-quadspi.c > index 34db01ab6cab..ba8b3be39896 100644 > --- a/drivers/mtd/spi-nor/mtk-quadspi.c > +++ b/drivers/mtd/spi-nor/mtk-quadspi.c > @@ -106,6 +106,7 @@ struct mtk_nor { > struct spi_nor nor; > struct device *dev; > void __iomem *base; /* nor flash base address */ > + void __iomem *flash_base; > struct clk *spi_clk; > struct clk *nor_clk; > }; > @@ -272,6 +273,11 @@ static ssize_t mtk_nor_read(struct spi_nor *nor, loff_t from, size_t length, > mtk_nor_set_read_mode(mtk_nor); > mtk_nor_set_addr(mtk_nor, addr); > > + if (mtk_nor->flash_base) { > + memcpy_fromio(buffer, mtk_nor->flash_base + from, length); > + return length; > + } > +
Don't you need to check if access is still within valid memory mapped window?
> for (i = 0; i < length; i++) { > ret = mtk_nor_execute_cmd(mtk_nor, MTK_NOR_PIO_READ_CMD); > if (ret < 0) > @@ -475,6 +481,11 @@ static int mtk_nor_drv_probe(struct platform_device *pdev) > if (IS_ERR(mtk_nor->base)) > return PTR_ERR(mtk_nor->base); > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + mtk_nor->flash_base = devm_ioremap_resource(&pdev->dev, res);
There is a single API now: devm_platform_ioremap_resource().
> + if (IS_ERR(mtk_nor->flash_base)) > + mtk_nor->flash_base = NULL; > + > mtk_nor->spi_clk = devm_clk_get(&pdev->dev, "spi"); > if (IS_ERR(mtk_nor->spi_clk)) > return PTR_ERR(mtk_nor->spi_clk); >
-- Regards Vignesh
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