[PATCH 3/3] stmmac: Add an optional device tree property "snps,burst_len"

[Sonic Zhang <sonic.adi@gmail.com>]

From: Sonic Zhang <sonic.zhang@analog.com>

This property define the AXI bug lenth.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
---
 Documentation/devicetree/bindings/net/stmmac.txt   |    1 +
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |    3 +++
 2 files changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index c41afd9..8ca65ce 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -43,6 +43,7 @@ Optional properties:
   available this clock is used for programming the Timestamp Addend Register.
   If not passed then the system clock will be used and this is fine on some
   platforms.
+- snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
 
 Examples:
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 3039de2..a20cf0d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -234,6 +234,9 @@ static int stmmac_probe_config_dt(struct platform_device *pdev,
 			of_property_read_bool(np, "snps,fixed-burst");
 		dma_cfg->mixed_burst =
 			of_property_read_bool(np, "snps,mixed-burst");
+		of_property_read_u32(np, "snps,burst_len", &dma_cfg->burst_len);
+		if (dma_cfg->burst_len < 0 || dma_cfg->burst_len > 256)
+			dma_cfg->burst_len = 0;
 	}
 	plat->force_thresh_dma_mode = of_property_read_bool(np, "snps,force_thresh_dma_mode");
 	if (plat->force_thresh_dma_mode) {
-- 
1.7.9.5