From 0430a7c753744af746679a96026916b50908aafa Mon Sep 17 00:00:00 2001 From: Icenowy Zheng Date: Tue, 29 Aug 2017 12:51:26 +0800 Subject: dmaengine: sun6i: make gate bit in sun8i's DMA engines a common quirk Originally we enable a special gate bit when the compatible indicates A23/33. But according to BSP sources and user manuals, more SoCs will need this gate bit. So make it a common quirk configured in the config struct. Signed-off-by: Icenowy Zheng Reviewed-by: Chen-Yu Tsai Signed-off-by: Vinod Koul --- drivers/dma/sun6i-dma.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'drivers/dma/sun6i-dma.c') diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index a2358780ab2c..252b59c1d1d5 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -101,6 +101,17 @@ struct sun6i_dma_config { u32 nr_max_channels; u32 nr_max_requests; u32 nr_max_vchans; + /* + * In the datasheets/user manuals of newer Allwinner SoCs, a special + * bit (bit 2 at register 0x20) is present. + * It's named "DMA MCLK interface circuit auto gating bit" in the + * documents, and the footnote of this register says that this bit + * should be set up when initializing the DMA controller. + * Allwinner A23/A33 user manuals do not have this bit documented, + * however these SoCs really have and need this bit, as seen in the + * BSP kernel source code. + */ + bool gate_needed; }; /* @@ -1009,6 +1020,7 @@ static struct sun6i_dma_config sun8i_a23_dma_cfg = { .nr_max_channels = 8, .nr_max_requests = 24, .nr_max_vchans = 37, + .gate_needed = true, }; static struct sun6i_dma_config sun8i_a83t_dma_cfg = { @@ -1174,13 +1186,7 @@ static int sun6i_dma_probe(struct platform_device *pdev) goto err_dma_unregister; } - /* - * sun8i variant requires us to toggle a dma gating register, - * as seen in Allwinner's SDK. This register is not documented - * in the A23 user manual. - */ - if (of_device_is_compatible(pdev->dev.of_node, - "allwinner,sun8i-a23-dma")) + if (sdc->cfg->gate_needed) writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE); return 0; -- cgit v1.2.3