From: Icenowy Zheng <icenowy@xxxxxxxx>
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 <icenowy@xxxxxxxx>
---
Changes since original codec patchset v3:
- Refactored comments to cover some words found in official documents.
- Removed the comments when toggling the gate bit.
drivers/dma/sun6i-dma.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
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;
--
2.12.2
--
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