From e2dfce24f4175e8ba183d5800f669fc89843df54 Mon Sep 17 00:00:00 2001 From: Zong Li Date: Mon, 28 Mar 2022 17:52:25 +0800 Subject: [PATCH] dmaengine: sf-pdma: Get number of channel by device tree It currently assumes that there are always four channels, it would cause the error if there is actually less than four channels. Change that by getting number of channel from device tree. For backwards-compatibility, it uses the default value (i.e. 4) when there is no 'dma-channels' information in dts. Signed-off-by: Zong Li Acked-by: Palmer Dabbelt Reviewed-by: Bin Meng Link: https://lore.kernel.org/r/f08a95b6582a51712c5b2c3cb859136d07bfa8b9.1648461096.git.zong.li@sifive.com Signed-off-by: Vinod Koul --- drivers/dma/sf-pdma/sf-pdma.c | 24 ++++++++++++++++-------- drivers/dma/sf-pdma/sf-pdma.h | 8 ++------ 2 files changed, 18 insertions(+), 14 deletions(-) diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c index f12606a..db5a4ef 100644 --- a/drivers/dma/sf-pdma/sf-pdma.c +++ b/drivers/dma/sf-pdma/sf-pdma.c @@ -482,23 +482,30 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma) static int sf_pdma_probe(struct platform_device *pdev) { struct sf_pdma *pdma; - struct sf_pdma_chan *chan; struct resource *res; - int len, chans; - int ret; + int ret, n_chans; const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES; - chans = PDMA_NR_CH; - len = sizeof(*pdma) + sizeof(*chan) * chans; - pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL); + ret = of_property_read_u32(pdev->dev.of_node, "dma-channels", &n_chans); + if (ret) { + /* backwards-compatibility for no dma-channels property */ + dev_dbg(&pdev->dev, "set number of channels to default value: 4\n"); + n_chans = PDMA_MAX_NR_CH; + } else if (n_chans > PDMA_MAX_NR_CH) { + dev_err(&pdev->dev, "the number of channels exceeds the maximum\n"); + return -EINVAL; + } + + pdma = devm_kzalloc(&pdev->dev, struct_size(pdma, chans, n_chans), + GFP_KERNEL); if (!pdma) return -ENOMEM; - pdma->n_chans = chans; + pdma->n_chans = n_chans; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pdma->membase = devm_ioremap_resource(&pdev->dev, res); @@ -556,7 +563,7 @@ static int sf_pdma_remove(struct platform_device *pdev) struct sf_pdma_chan *ch; int i; - for (i = 0; i < PDMA_NR_CH; i++) { + for (i = 0; i < pdma->n_chans; i++) { ch = &pdma->chans[i]; devm_free_irq(&pdev->dev, ch->txirq, ch); @@ -574,6 +581,7 @@ static int sf_pdma_remove(struct platform_device *pdev) static const struct of_device_id sf_pdma_dt_ids[] = { { .compatible = "sifive,fu540-c000-pdma" }, + { .compatible = "sifive,pdma0" }, {}, }; MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids); diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h index 0c20167..dcb3687 100644 --- a/drivers/dma/sf-pdma/sf-pdma.h +++ b/drivers/dma/sf-pdma/sf-pdma.h @@ -22,11 +22,7 @@ #include "../dmaengine.h" #include "../virt-dma.h" -#define PDMA_NR_CH 4 - -#if (PDMA_NR_CH != 4) -#error "Please define PDMA_NR_CH to 4" -#endif +#define PDMA_MAX_NR_CH 4 #define PDMA_BASE_ADDR 0x3000000 #define PDMA_CHAN_OFFSET 0x1000 @@ -118,7 +114,7 @@ struct sf_pdma { void __iomem *membase; void __iomem *mappedbase; u32 n_chans; - struct sf_pdma_chan chans[PDMA_NR_CH]; + struct sf_pdma_chan chans[]; }; #endif /* _SF_PDMA_H */ -- 2.7.4