linux/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
Giuseppe Cavallaro afea03656a stmmac: rework DMA bus setting and introduce new platform AXI structure
This patch restructures the DMA bus settings and this is done
by introducing a new platform structure used for programming
the AXI Bus Mode Register inside the DMA module.
This structure can be populated from device-tree as documented in the
binding txt file.

After initializing the DMA, the AXI register can be optionally tuned
for platform drivers based.
This patch also reworks some parameters to make coherent the DMA
configuration now that AXI register is introduced.
For example, the burst_len is managed by using the mentioned axi
support above; so the snps,burst-len parameter has been removed.
It makes sense to provide the AAL parameter from DT to Address-Aligned
Beats inside the Register0 and review the PBL settings when initialize
the engine.

For PCI glue, rebuilding the story of this setting, it
was added to align a configuration so not for fixing some
known problem. No issue raised after this patch.
It is safe to use the default burst length instead of
tuning it to the maximum value

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-02 14:21:30 -05:00

245 lines
6.7 KiB
C

/*******************************************************************************
This is the driver for the GMAC on-chip Ethernet controller for ST SoCs.
DWC Ether MAC 10/100/1000 Universal version 3.41a has been used for
developing this code.
This contains the functions to handle the dma.
Copyright (C) 2007-2009 STMicroelectronics Ltd
This program is free software; you can redistribute it and/or modify it
under the terms and conditions of the GNU General Public License,
version 2, as published by the Free Software Foundation.
This program is distributed in the hope it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
The full GNU General Public License is included in this distribution in
the file called "COPYING".
Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
*******************************************************************************/
#include <asm/io.h>
#include "dwmac1000.h"
#include "dwmac_dma.h"
static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
{
u32 value = readl(ioaddr + DMA_AXI_BUS_MODE);
int i;
pr_info("dwmac1000: Master AXI performs %s burst length\n",
!(value & DMA_AXI_UNDEF) ? "fixed" : "any");
if (axi->axi_lpi_en)
value |= DMA_AXI_EN_LPI;
if (axi->axi_xit_frm)
value |= DMA_AXI_LPI_XIT_FRM;
value |= (axi->axi_wr_osr_lmt & DMA_AXI_WR_OSR_LMT_MASK) <<
DMA_AXI_WR_OSR_LMT_SHIFT;
value |= (axi->axi_rd_osr_lmt & DMA_AXI_RD_OSR_LMT_MASK) <<
DMA_AXI_RD_OSR_LMT_SHIFT;
/* Depending on the UNDEF bit the Master AXI will perform any burst
* length according to the BLEN programmed (by default all BLEN are
* set).
*/
for (i = 0; i < AXI_BLEN; i++) {
switch (axi->axi_blen[i]) {
case 256:
value |= DMA_AXI_BLEN256;
break;
case 128:
value |= DMA_AXI_BLEN128;
break;
case 64:
value |= DMA_AXI_BLEN64;
break;
case 32:
value |= DMA_AXI_BLEN32;
break;
case 16:
value |= DMA_AXI_BLEN16;
break;
case 8:
value |= DMA_AXI_BLEN8;
break;
case 4:
value |= DMA_AXI_BLEN4;
break;
}
}
writel(value, ioaddr + DMA_AXI_BUS_MODE);
}
static void dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
int aal, u32 dma_tx, u32 dma_rx, int atds)
{
u32 value = readl(ioaddr + DMA_BUS_MODE);
/*
* Set the DMA PBL (Programmable Burst Length) mode.
*
* Note: before stmmac core 3.50 this mode bit was 4xPBL, and
* post 3.5 mode bit acts as 8*PBL.
*
* This configuration doesn't take care about the Separate PBL
* so only the bits: 13-8 are programmed with the PBL passed from the
* platform.
*/
value |= DMA_BUS_MODE_MAXPBL;
value &= ~DMA_BUS_MODE_PBL_MASK;
value |= (pbl << DMA_BUS_MODE_PBL_SHIFT);
/* Set the Fixed burst mode */
if (fb)
value |= DMA_BUS_MODE_FB;
/* Mixed Burst has no effect when fb is set */
if (mb)
value |= DMA_BUS_MODE_MB;
if (atds)
value |= DMA_BUS_MODE_ATDS;
if (aal)
value |= DMA_BUS_MODE_AAL;
writel(value, ioaddr + DMA_BUS_MODE);
/* Mask interrupts by writing to CSR7 */
writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
/* RX/TX descriptor base address lists must be written into
* DMA CSR3 and CSR4, respectively
*/
writel(dma_tx, ioaddr + DMA_TX_BASE_ADDR);
writel(dma_rx, ioaddr + DMA_RCV_BASE_ADDR);
}
static u32 dwmac1000_configure_fc(u32 csr6, int rxfifosz)
{
csr6 &= ~DMA_CONTROL_RFA_MASK;
csr6 &= ~DMA_CONTROL_RFD_MASK;
/* Leave flow control disabled if receive fifo size is less than
* 4K or 0. Otherwise, send XOFF when fifo is 1K less than full,
* and send XON when 2K less than full.
*/
if (rxfifosz < 4096) {
csr6 &= ~DMA_CONTROL_EFC;
pr_debug("GMAC: disabling flow control, rxfifo too small(%d)\n",
rxfifosz);
} else {
csr6 |= DMA_CONTROL_EFC;
csr6 |= RFA_FULL_MINUS_1K;
csr6 |= RFD_FULL_MINUS_2K;
}
return csr6;
}
static void dwmac1000_dma_operation_mode(void __iomem *ioaddr, int txmode,
int rxmode, int rxfifosz)
{
u32 csr6 = readl(ioaddr + DMA_CONTROL);
if (txmode == SF_DMA_MODE) {
pr_debug("GMAC: enable TX store and forward mode\n");
/* Transmit COE type 2 cannot be done in cut-through mode. */
csr6 |= DMA_CONTROL_TSF;
/* Operating on second frame increase the performance
* especially when transmit store-and-forward is used.
*/
csr6 |= DMA_CONTROL_OSF;
} else {
pr_debug("GMAC: disabling TX SF (threshold %d)\n", txmode);
csr6 &= ~DMA_CONTROL_TSF;
csr6 &= DMA_CONTROL_TC_TX_MASK;
/* Set the transmit threshold */
if (txmode <= 32)
csr6 |= DMA_CONTROL_TTC_32;
else if (txmode <= 64)
csr6 |= DMA_CONTROL_TTC_64;
else if (txmode <= 128)
csr6 |= DMA_CONTROL_TTC_128;
else if (txmode <= 192)
csr6 |= DMA_CONTROL_TTC_192;
else
csr6 |= DMA_CONTROL_TTC_256;
}
if (rxmode == SF_DMA_MODE) {
pr_debug("GMAC: enable RX store and forward mode\n");
csr6 |= DMA_CONTROL_RSF;
} else {
pr_debug("GMAC: disable RX SF mode (threshold %d)\n", rxmode);
csr6 &= ~DMA_CONTROL_RSF;
csr6 &= DMA_CONTROL_TC_RX_MASK;
if (rxmode <= 32)
csr6 |= DMA_CONTROL_RTC_32;
else if (rxmode <= 64)
csr6 |= DMA_CONTROL_RTC_64;
else if (rxmode <= 96)
csr6 |= DMA_CONTROL_RTC_96;
else
csr6 |= DMA_CONTROL_RTC_128;
}
/* Configure flow control based on rx fifo size */
csr6 = dwmac1000_configure_fc(csr6, rxfifosz);
writel(csr6, ioaddr + DMA_CONTROL);
}
static void dwmac1000_dump_dma_regs(void __iomem *ioaddr)
{
int i;
pr_info(" DMA registers\n");
for (i = 0; i < 22; i++) {
if ((i < 9) || (i > 17)) {
int offset = i * 4;
pr_err("\t Reg No. %d (offset 0x%x): 0x%08x\n", i,
(DMA_BUS_MODE + offset),
readl(ioaddr + DMA_BUS_MODE + offset));
}
}
}
static unsigned int dwmac1000_get_hw_feature(void __iomem *ioaddr)
{
return readl(ioaddr + DMA_HW_FEATURE);
}
static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt)
{
writel(riwt, ioaddr + DMA_RX_WATCHDOG);
}
const struct stmmac_dma_ops dwmac1000_dma_ops = {
.reset = dwmac_dma_reset,
.init = dwmac1000_dma_init,
.axi = dwmac1000_dma_axi,
.dump_regs = dwmac1000_dump_dma_regs,
.dma_mode = dwmac1000_dma_operation_mode,
.enable_dma_transmission = dwmac_enable_dma_transmission,
.enable_dma_irq = dwmac_enable_dma_irq,
.disable_dma_irq = dwmac_disable_dma_irq,
.start_tx = dwmac_dma_start_tx,
.stop_tx = dwmac_dma_stop_tx,
.start_rx = dwmac_dma_start_rx,
.stop_rx = dwmac_dma_stop_rx,
.dma_interrupt = dwmac_dma_interrupt,
.get_hw_feature = dwmac1000_get_hw_feature,
.rx_watchdog = dwmac1000_rx_watchdog,
};