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, 37 insertions, 17 deletions

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index e862a922bd3f..6605d19601c2 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -17,7 +17,25 @@ Required properties:
 	The 1st cell is reset pre-delay in micro seconds.
 	The 2nd cell is reset pulse in micro seconds.
 	The 3rd cell is reset post-delay in micro seconds.
+
+Optional properties:
+- resets: Should contain a phandle to the STMMAC reset signal, if any
+- reset-names: Should contain the reset signal name "stmmaceth", if a
+	reset phandle is given
+- max-frame-size: See ethernet.txt file in the same directory
+- clocks: If present, the first clock should be the GMAC main clock and
+  the second clock should be peripheral's register interface clock. Further
+  clocks may be specified in derived bindings.
+- clock-names: One name for each entry in the clocks property, the
+  first one should be "stmmaceth" and the second one should be "pclk".
+- clk_ptp_ref: this is the PTP reference clock; in case of the PTP is
+  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.
+- tx-fifo-depth: See ethernet.txt file in the same directory
+- rx-fifo-depth: See ethernet.txt file in the same directory
 - snps,pbl		Programmable Burst Length
+- snps,aal		Address-Aligned Beats
 - snps,fixed-burst	Program the DMA to use the fixed burst mode
 - snps,mixed-burst	Program the DMA to use the mixed burst mode
 - snps,force_thresh_dma_mode	Force DMA to use the threshold mode for
@@ -29,27 +47,28 @@ Required properties:
 				supported by this device instance
 - snps,perfect-filter-entries:	Number of perfect filter entries supported
 				by this device instance
-
-Optional properties:
-- resets: Should contain a phandle to the STMMAC reset signal, if any
-- reset-names: Should contain the reset signal name "stmmaceth", if a
-	reset phandle is given
-- max-frame-size: See ethernet.txt file in the same directory
-- clocks: If present, the first clock should be the GMAC main clock
-  The optional second clock should be peripheral's register interface clock.
-  The third optional clock should be the ptp reference clock.
-  Further clocks may be specified in derived bindings.
-- clock-names: One name for each entry in the clocks property.
-  The first one should be "stmmaceth".
-  The optional second one should be "pclk".
-  The optional third one should be "clk_ptp_ref".
-- snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
-- tx-fifo-depth: See ethernet.txt file in the same directory
-- rx-fifo-depth: See ethernet.txt file in the same directory
+- AXI BUS Mode parameters: below the list of all the parameters to program the
+			   AXI register inside the DMA module:
+	- snps,lpi_en: enable Low Power Interface
+	- snps,xit_frm: unlock on WoL
+	- snps,wr_osr_lmt: max write oustanding req. limit
+	- snps,rd_osr_lmt: max read oustanding req. limit
+	- snps,kbbe: do not cross 1KiB boundary.
+	- snps,axi_all: align address
+	- snps,blen: this is a vector of supported burst length.
+	- snps,fb: fixed-burst
+	- snps,mb: mixed-burst
+	- snps,rb: rebuild INCRx Burst
 - mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
 
 Examples:
 
+	stmmac_axi_setup: stmmac-axi-config {
+		snps,wr_osr_lmt = <0xf>;
+		snps,rd_osr_lmt = <0xf>;
+		snps,blen = <256 128 64 32 0 0 0>;
+	};
+
 	gmac0: ethernet@e0800000 {
 		compatible = "st,spear600-gmac";
 		reg = <0xe0800000 0x8000>;
@@ -65,6 +84,7 @@ Examples:
 		tx-fifo-depth = <16384>;
 		clocks = <&clock>;
 		clock-names = "stmmaceth";
+		snps,axi-config = <&stmmac_axi_setup>;
 		mdio0 {
 			#address-cells = <1>;
 			#size-cells = <0>;