[PATCH 01/10] dmaengine: sun6i: Correct setting of clock autogating register for A83T/H3

Stefan Brüns
2017-09-03T22:44:37Z

The H83T uses a compatible string different from the A23, but requires
the same clock autogating register setting.

The H3 also requires setting the clock autogating register, but has
the register at a different offset.

Some currently available SoCs not yet supported by the sun6i-dma driver
will require new compatible strings. These SoCs either follow the A23
register model (e.g. V3s) or the H3 register model (A64, R40), so a new
variable is added to the config struct to group SoCs with common register
models.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
---
drivers/dma/sun6i-dma.c | 34 +++++++++++++++++++++++++++++++---
1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index a2358780ab2c..1d9b3be30d22 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -48,6 +48,9 @@
#define SUN8I_DMA_GATE 0x20
#define SUN8I_DMA_GATE_ENABLE 0x4

+#define SUNXI_H3_SECURITE_REG 0x20
+#define SUNXI_H3_DMA_GATE 0x28
+#define SUNXI_H3_DMA_GATE_ENABLE 0x4
/*
* Channels specific registers
*/
@@ -90,6 +93,21 @@
#define NORMAL_WAIT 8
#define DRQ_SDRAM 1

+/*
+ * DMA Controller generations
+ *
+ * Newer SoC generations changed or added some register definitions:
+ * - A23 added a clock gate register
+ * - H3 has a different offset for the clock gating register,
+ * the burst length field has a different offset in the channel
+ * configuration register, also additional burst lengths/widths.
+ */
+enum dmac_variant {
+ DMAC_VARIANT_A31,
+ DMAC_VARIANT_A23,
+ DMAC_VARIANT_H3,
+};
+
/*
* Hardware channels / ports representation
*
@@ -101,6 +119,7 @@ struct sun6i_dma_config {
u32 nr_max_channels;
u32 nr_max_requests;
u32 nr_max_vchans;
+ enum dmac_variant dmac_variant;
};

/*
@@ -998,6 +1017,7 @@ static struct sun6i_dma_config sun6i_a31_dma_cfg = {
.nr_max_channels = 16,
.nr_max_requests = 30,
.nr_max_vchans = 53,
+ .dmac_variant = DMAC_VARIANT_A31,
};

/*
@@ -1009,23 +1029,29 @@ static struct sun6i_dma_config sun8i_a23_dma_cfg = {
.nr_max_channels = 8,
.nr_max_requests = 24,
.nr_max_vchans = 37,
+ .dmac_variant = DMAC_VARIANT_A23,
};

static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
.nr_max_channels = 8,
.nr_max_requests = 28,
.nr_max_vchans = 39,
+ .dmac_variant = DMAC_VARIANT_A23,
};

/*
* The H3 has 12 physical channels, a maximum DRQ port id of 27,
* and a total of 34 usable source and destination endpoints.
+ * It also supports additional burst lengths and bus widths,
+ * and the burst length fields have different offsets.
*/

static struct sun6i_dma_config sun8i_h3_dma_cfg = {
.nr_max_channels = 12,
.nr_max_requests = 27,
.nr_max_vchans = 34,
+ .dmac_variant = DMAC_VARIANT_H3,
+};
};

static const struct of_device_id sun6i_dma_match[] = {
@@ -1177,11 +1203,13 @@ static int sun6i_dma_probe(struct platform_device *pdev)
/*
* 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.
+ * in the A23 user manual, but appears in e.g. the H83T manual.
+ * For the H3, H5 and A64, the register has a different location
*/
- if (of_device_is_compatible(pdev->dev.of_node,
- "allwinner,sun8i-a23-dma"))
+ if (sdc->cfg->dmac_variant == DMAC_VARIANT_A23)
writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE);
+ else if (sdc->cfg->dmac_variant == DMAC_VARIANT_H3)
+ writel(SUNXI_H3_DMA_GATE_ENABLE, sdc->base + SUNXI_H3_DMA_GATE);

return 0;

--
2.14.1