net: smmac: allow configuring lower pbl values

The driver currently always sets the PBLx8/PBLx4 bit, which means that
the pbl values configured via the pbl/txpbl/rxpbl DT properties are
always multiplied by 8/4 in the hardware.

In order to allow the DT to configure lower pbl values, while at the
same time not changing behavior of any existing device trees using the
pbl/txpbl/rxpbl settings, add a property to disable the multiplication
of the pbl by 8/4 in the hardware.

Suggested-by: Rabin Vincent <rabinv@axis.com>
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 15:20:08 +01:00 committed by David S. Miller
parent 89caaa2d80
commit 4022d039a3
7 changed files with 14 additions and 3 deletions

View file

@ -39,6 +39,8 @@ Optional properties:
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,no-pbl-x8 Don't multiply the pbl/txpbl/rxpbl values by 8.
For core rev < 3.50, don't multiply the values by 4.
- 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

View file

@ -152,8 +152,9 @@ Where:
o dma_cfg: internal DMA parameters
o pbl: the Programmable Burst Length is maximum number of beats to
be transferred in one DMA transaction.
GMAC also enables the 4xPBL by default.
GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer)
o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst/mixed_burst/aal
o clk_csr: fixed CSR Clock range selection.
o has_gmac: uses the GMAC core.
@ -208,6 +209,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;
@ -219,6 +221,7 @@ Where:
If set, DMA tx will use this value rather than pbl.
o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than pbl.
o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst: program the DMA to use the fixed burst mode
o mixed_burst: program the DMA to use the mixed burst mode
o aal: Address-Aligned Beats

View file

@ -98,7 +98,8 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
* Note: before stmmac core 3.50 this mode bit was 4xPBL, and
* post 3.5 mode bit acts as 8*PBL.
*/
value |= DMA_BUS_MODE_MAXPBL;
if (dma_cfg->pblx8)
value |= DMA_BUS_MODE_MAXPBL;
value |= DMA_BUS_MODE_USP;
value &= ~(DMA_BUS_MODE_PBL_MASK | DMA_BUS_MODE_RPBL_MASK);
value |= (txpbl << DMA_BUS_MODE_PBL_SHIFT);

View file

@ -84,7 +84,8 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr,
* on each channel
*/
value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
value = value | DMA_BUS_MODE_PBL;
if (dma_cfg->pblx8)
value = value | DMA_BUS_MODE_PBL;
writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));

View file

@ -81,6 +81,7 @@ static void stmmac_default_data(struct plat_stmmacenet_data *plat)
plat->mdio_bus_data->phy_mask = 0;
plat->dma_cfg->pbl = 32;
plat->dma_cfg->pblx8 = true;
/* TODO: AXI */
/* Set default value for multicast hash bins */
@ -115,6 +116,7 @@ static int quark_default_data(struct plat_stmmacenet_data *plat,
plat->mdio_bus_data->phy_mask = 0;
plat->dma_cfg->pbl = 16;
plat->dma_cfg->pblx8 = true;
plat->dma_cfg->fixed_burst = 1;
/* AXI (TODO) */

View file

@ -317,6 +317,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
dma_cfg->pbl = DEFAULT_DMA_PBL;
of_property_read_u32(np, "snps,txpbl", &dma_cfg->txpbl);
of_property_read_u32(np, "snps,rxpbl", &dma_cfg->rxpbl);
dma_cfg->pblx8 = !of_property_read_bool(np, "snps,no-pbl-x8");
dma_cfg->aal = of_property_read_bool(np, "snps,aal");
dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");

View file

@ -90,6 +90,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;