net: stmmac: add support for independent DMA pbl for tx/rx

GMAC and newer supports independent programmable burst lengths for
DMA tx/rx. Add new optional devicetree properties representing this.

To be backwards compatible, snps,pbl will still be valid, but
snps,txpbl/snps,rxpbl will override the value in snps,pbl if set.

If the IP is synthesized to use the AXI interface, there is a register
and a matching DT property inside the optional stmmac-axi-config DT node
for controlling burst lengths, named snps,blen.
However, using this register, it is not possible to control tx and rx
independently. Also, this register is not available if the IP was
synthesized with, e.g., the AHB interface.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Niklas Cassel
2016-12-07 15:20:07 +01:00
committed by David S. Miller
parent 825658a273
commit 89caaa2d80
6 changed files with 35 additions and 18 deletions

View File

@@ -34,7 +34,11 @@ Optional properties:
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,pbl Programmable Burst Length (tx and rx)
- snps,txpbl Tx Programmable Burst Length. Only for GMAC and newer.
If set, DMA tx will use this value rather than snps,pbl.
- snps,rxpbl Rx Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than snps,pbl.
- 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