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;
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;
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,
struct stmmac_dma_ops {
/* DMA core initialization */
- int (*init) (void __iomem *ioaddr, int pbl, u32 dma_tx, u32 dma_rx);
+ int (*init) (void __iomem *ioaddr, int pbl, int fb, int burst_len,
+ u32 dma_tx, u32 dma_rx);
/* Dump DMA registers */
void (*dump_regs) (void __iomem *ioaddr);
/* Set tx/rx threshold in the csr6 register
#define DMA_BUS_MODE_RPBL_MASK 0x003e0000 /* Rx-Programmable Burst Len */
#define DMA_BUS_MODE_RPBL_SHIFT 17
#define DMA_BUS_MODE_USP 0x00800000
-#define DMA_BUS_MODE_4PBL 0x01000000
+#define DMA_BUS_MODE_PBL 0x01000000
#define DMA_BUS_MODE_AAL 0x02000000
/* DMA CRS Control and Status Register Mapping */
#include "dwmac1000.h"
#include "dwmac_dma.h"
-static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, u32 dma_tx,
- u32 dma_rx)
+static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb,
+ int burst_len, u32 dma_tx, u32 dma_rx)
{
u32 value = readl(ioaddr + DMA_BUS_MODE);
int limit;
if (limit < 0)
return -EBUSY;
- value = /* DMA_BUS_MODE_FB | */ DMA_BUS_MODE_4PBL |
- ((pbl << DMA_BUS_MODE_PBL_SHIFT) |
- (pbl << DMA_BUS_MODE_RPBL_SHIFT));
+ /*
+ * Set the DMA PBL (Programmable Burst Length) mode
+ * Before stmmac core 3.50 this mode bit was 4xPBL, and
+ * post 3.5 mode bit acts as 8*PBL.
+ * For core rev < 3.5, when the core is set for 4xPBL mode, the
+ * DMA transfers the data in 4, 8, 16, 32, 64 & 128 beats
+ * depending on pbl value.
+ * For core rev > 3.5, when the core is set for 8xPBL mode, the
+ * DMA transfers the data in 8, 16, 32, 64, 128 & 256 beats
+ * depending on pbl value.
+ */
+ value = DMA_BUS_MODE_PBL | ((pbl << DMA_BUS_MODE_PBL_SHIFT) |
+ (pbl << DMA_BUS_MODE_RPBL_SHIFT));
+
+ /* Set the Fixed burst mode */
+ if (fb)
+ value |= DMA_BUS_MODE_FB;
#ifdef CONFIG_STMMAC_DA
value |= DMA_BUS_MODE_DA; /* Rx has priority over tx */
#endif
writel(value, ioaddr + DMA_BUS_MODE);
+ /* In case of GMAC AXI configuration, program the DMA_AXI_BUS_MODE
+ * for supported bursts.
+ *
+ * Note: This is applicable only for revision GMACv3.61a. For
+ * older version this register is reserved and shall have no
+ * effect.
+ *
+ * Note:
+ * For Fixed Burst Mode: if we directly write 0xFF to this
+ * register using the configurations pass from platform code,
+ * this would ensure that all bursts supported by core are set
+ * and those which are not supported would remain ineffective.
+ *
+ * For Non Fixed Burst Mode: provide the maximum value of the
+ * burst length. Any burst equal or below the provided burst
+ * length would be allowed to perform. */
+ writel(burst_len, ioaddr + DMA_AXI_BUS_MODE);
+
/* Mask interrupts by writing to CSR7 */
writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
#include "dwmac100.h"
#include "dwmac_dma.h"
-static int dwmac100_dma_init(void __iomem *ioaddr, int pbl, u32 dma_tx,
- u32 dma_rx)
+static int dwmac100_dma_init(void __iomem *ioaddr, int pbl, int fb,
+ int burst_len, u32 dma_tx, u32 dma_rx)
{
u32 value = readl(ioaddr + DMA_BUS_MODE);
int limit;
/* Enable Application Access by writing to DMA CSR0 */
writel(DMA_BUS_MODE_DEFAULT | (pbl << DMA_BUS_MODE_PBL_SHIFT),
- ioaddr + DMA_BUS_MODE);
+ ioaddr + DMA_BUS_MODE);
/* Mask interrupts by writing to CSR7 */
writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
#define DMA_CONTROL 0x00001018 /* Ctrl (Operational Mode) */
#define DMA_INTR_ENA 0x0000101c /* Interrupt Enable */
#define DMA_MISSED_FRAME_CTR 0x00001020 /* Missed Frame Counter */
+#define DMA_AXI_BUS_MODE 0x00001028 /* AXI Bus Mode */
#define DMA_CUR_TX_BUF_ADDR 0x00001050 /* Current Host Tx Buffer */
#define DMA_CUR_RX_BUF_ADDR 0x00001054 /* Current Host Rx Buffer */
#define DMA_HW_FEATURE 0x00001058 /* HW Feature Register */
init_dma_desc_rings(dev);
/* DMA initialization and SW reset */
- ret = priv->hw->dma->init(priv->ioaddr, priv->plat->pbl,
+ ret = priv->hw->dma->init(priv->ioaddr, priv->plat->dma_cfg->pbl,
+ priv->plat->dma_cfg->fixed_burst,
+ priv->plat->dma_cfg->burst_len,
priv->dma_tx_phy, priv->dma_rx_phy);
if (ret < 0) {
pr_err("%s: DMA initialization failed\n", __func__);
plat_dat.bus_id = 1;
plat_dat.phy_addr = 0;
plat_dat.interface = PHY_INTERFACE_MODE_GMII;
- plat_dat.pbl = 32;
+ plat_dat.dma_cfg->pbl = 32;
+ plat_dat.dma_cfg->burst_len = DMA_AXI_BLEN_256;
plat_dat.clk_csr = 2; /* clk_csr_i = 20-35MHz & MDC = clk_csr_i/16 */
plat_dat.has_gmac = 1;
plat_dat.force_sf_dma_mode = 1;
* 1110 clk_csr_i/16
* 1111 clk_csr_i/18 */
+/* AXI DMA Burst length suported */
+#define DMA_AXI_BLEN_4 (1 << 1)
+#define DMA_AXI_BLEN_8 (1 << 2)
+#define DMA_AXI_BLEN_16 (1 << 3)
+#define DMA_AXI_BLEN_32 (1 << 4)
+#define DMA_AXI_BLEN_64 (1 << 5)
+#define DMA_AXI_BLEN_128 (1 << 6)
+#define DMA_AXI_BLEN_256 (1 << 7)
+#define DMA_AXI_BLEN_ALL (DMA_AXI_BLEN_4 | DMA_AXI_BLEN_8 | DMA_AXI_BLEN_16 \
+ | DMA_AXI_BLEN_32 | DMA_AXI_BLEN_64 \
+ | DMA_AXI_BLEN_128 | DMA_AXI_BLEN_256)
+
/* Platfrom data for platform device structure's platform_data field */
struct stmmac_mdio_bus_data {
int probed_phy_irq;
};
+struct stmmac_dma_cfg {
+ int pbl;
+ int fixed_burst;
+ int burst_len;
+};
+
struct plat_stmmacenet_data {
char *phy_bus_name;
int bus_id;
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;