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-rw-r--r--Documentation/networking/stmmac.txt24
1 files changed, 21 insertions, 3 deletions
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index 61f40a3fa7ea..eacb640286b1 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -111,7 +111,7 @@ and detailed below as well:
int phy_addr;
int interface;
struct stmmac_mdio_bus_data *mdio_bus_data;
- int pbl;
+ struct stmmac_dma_cfg *dma_cfg;
int clk_csr;
int has_gmac;
int enh_desc;
@@ -163,7 +163,7 @@ Where:
o custom_cfg: this is a custom configuration that can be passed while
initialising the resources.
-The we have:
+For MDIO bus The we have:
struct stmmac_mdio_bus_data {
int bus_id;
@@ -180,10 +180,28 @@ Where:
o irqs: list of IRQs, one per PHY.
o probed_phy_irq: if irqs is NULL, use this for probed PHY.
+
+For DMA engine we have the following internal fields that should be
+tuned according to the HW capabilities.
+
+struct stmmac_dma_cfg {
+ int pbl;
+ int fixed_burst;
+ int burst_len_supported;
+};
+
+Where:
+ o pbl: Programmable Burst Length
+ o fixed_burst: program the DMA to use the fixed burst mode
+ o burst_len: this is the value we put in the register
+ supported values are provided as macros in
+ linux/stmmac.h header file.
+
+---
+
Below an example how the structures above are using on ST platforms.
static struct plat_stmmacenet_data stxYYY_ethernet_platform_data = {
- .pbl = 32,
.has_gmac = 0,
.enh_desc = 0,
.fix_mac_speed = stxYYY_ethernet_fix_mac_speed,