stmmac: rework DMA bus setting and introduce new platform AXI structure

This patch restructures the DMA bus settings and this is done
by introducing a new platform structure used for programming
the AXI Bus Mode Register inside the DMA module.
This structure can be populated from device-tree as documented in the
binding txt file.

After initializing the DMA, the AXI register can be optionally tuned
for platform drivers based.
This patch also reworks some parameters to make coherent the DMA
configuration now that AXI register is introduced.
For example, the burst_len is managed by using the mentioned axi
support above; so the snps,burst-len parameter has been removed.
It makes sense to provide the AAL parameter from DT to Address-Aligned
Beats inside the Register0 and review the PBL settings when initialize
the engine.

For PCI glue, rebuilding the story of this setting, it
was added to align a configuration so not for fixing some
known problem. No issue raised after this patch.
It is safe to use the default burst length instead of
tuning it to the maximum value

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 1 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
index 13ca90e23479..726d9d9aaf83 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
@@ -41,8 +41,40 @@
 
 /* Rx watchdog register */
 #define DMA_RX_WATCHDOG		0x00001024
-/* AXI Bus Mode */
+
+/* AXI Master Bus Mode */
 #define DMA_AXI_BUS_MODE	0x00001028
+
+#define DMA_AXI_EN_LPI		BIT(31)
+#define DMA_AXI_LPI_XIT_FRM	BIT(30)
+#define DMA_AXI_WR_OSR_LMT	GENMASK(23, 20)
+#define DMA_AXI_WR_OSR_LMT_SHIFT	20
+#define DMA_AXI_WR_OSR_LMT_MASK	0xf
+#define DMA_AXI_RD_OSR_LMT	GENMASK(19, 16)
+#define DMA_AXI_RD_OSR_LMT_SHIFT	16
+#define DMA_AXI_RD_OSR_LMT_MASK	0xf
+
+#define DMA_AXI_OSR_MAX		0xf
+#define DMA_AXI_MAX_OSR_LIMIT ((DMA_AXI_OSR_MAX << DMA_AXI_WR_OSR_LMT_SHIFT) | \
+			       (DMA_AXI_OSR_MAX << DMA_AXI_RD_OSR_LMT_SHIFT))
+#define	DMA_AXI_1KBBE		BIT(13)
+#define DMA_AXI_AAL		BIT(12)
+#define DMA_AXI_BLEN256		BIT(7)
+#define DMA_AXI_BLEN128		BIT(6)
+#define DMA_AXI_BLEN64		BIT(5)
+#define DMA_AXI_BLEN32		BIT(4)
+#define DMA_AXI_BLEN16		BIT(3)
+#define DMA_AXI_BLEN8		BIT(2)
+#define DMA_AXI_BLEN4		BIT(1)
+#define DMA_BURST_LEN_DEFAULT	(DMA_AXI_BLEN256 | DMA_AXI_BLEN128 | \
+				 DMA_AXI_BLEN64 | DMA_AXI_BLEN32 | \
+				 DMA_AXI_BLEN16 | DMA_AXI_BLEN8 | \
+				 DMA_AXI_BLEN4)
+
+#define DMA_AXI_UNDEF		BIT(0)
+
+#define DMA_AXI_BURST_LEN_MASK	0x000000FE
+
 #define DMA_CUR_TX_BUF_ADDR	0x00001050	/* Current Host Tx Buffer */
 #define DMA_CUR_RX_BUF_ADDR	0x00001054	/* Current Host Rx Buffer */
 #define DMA_HW_FEATURE		0x00001058	/* HW Feature Register */