stmmac: re-work the internal GMAC DMA platf parameters

[deliverable/linux.git] / Documentation / networking / stmmac.txt

diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index 61f40a3fa7ea42a5bb6253213888d5953ac0c56c..eacb640286b171c6b6432849d104a64e27898cbf 100644 (file)
--- 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,