drivers/net/stmmac/dwmac1000_dma.c

   1 /*******************************************************************************
   2   This is the driver for the GMAC on-chip Ethernet controller for ST SoCs.
   3   DWC Ether MAC 10/100/1000 Universal version 3.41a  has been used for
   4   developing this code.
   5
   6   This contains the functions to handle the dma.
   7
   8   Copyright (C) 2007-2009  STMicroelectronics Ltd
   9
  10   This program is free software; you can redistribute it and/or modify it
  11   under the terms and conditions of the GNU General Public License,
  12   version 2, as published by the Free Software Foundation.
  13
  14   This program is distributed in the hope it will be useful, but WITHOUT
  15   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17   more details.
  18
  19   You should have received a copy of the GNU General Public License along with
  20   this program; if not, write to the Free Software Foundation, Inc.,
  21   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  22
  23   The full GNU General Public License is included in this distribution in
  24   the file called "COPYING".
  25
  26   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  27 *******************************************************************************/
  28
  29 #include "dwmac1000.h"
  30 #include "dwmac_dma.h"
  31
  32 static int dwmac1000_dma_init(void __iomem *ioaddr, int pbl, u32 dma_tx,
  33                               u32 dma_rx)
  34 {
  35         u32 value = readl(ioaddr + DMA_BUS_MODE);
  36         int limit;
  37
  38         /* DMA SW reset */
  39         value |= DMA_BUS_MODE_SFT_RESET;
  40         writel(value, ioaddr + DMA_BUS_MODE);
  41         limit = 15000;
  42         while (limit--) {
  43                 if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
  44                         break;
  45         }
  46         if (limit < 0)
  47                 return -EBUSY;
  48
  49         value = /* DMA_BUS_MODE_FB | */ DMA_BUS_MODE_4PBL |
  50             ((pbl << DMA_BUS_MODE_PBL_SHIFT) |
  51              (pbl << DMA_BUS_MODE_RPBL_SHIFT));
  52
  53 #ifdef CONFIG_STMMAC_DA
  54         value |= DMA_BUS_MODE_DA;       /* Rx has priority over tx */
  55 #endif
  56         writel(value, ioaddr + DMA_BUS_MODE);
  57
  58         /* Mask interrupts by writing to CSR7 */
  59         writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
  60
  61         /* The base address of the RX/TX descriptor lists must be written into
  62          * DMA CSR3 and CSR4, respectively. */
  63         writel(dma_tx, ioaddr + DMA_TX_BASE_ADDR);
  64         writel(dma_rx, ioaddr + DMA_RCV_BASE_ADDR);
  65
  66         return 0;
  67 }
  68
  69 static void dwmac1000_dma_operation_mode(void __iomem *ioaddr, int txmode,
  70                                     int rxmode)
  71 {
  72         u32 csr6 = readl(ioaddr + DMA_CONTROL);
  73
  74         if (txmode == SF_DMA_MODE) {
  75                 CHIP_DBG(KERN_DEBUG "GMAC: enable TX store and forward mode\n");
  76                 /* Transmit COE type 2 cannot be done in cut-through mode. */
  77                 csr6 |= DMA_CONTROL_TSF;
  78                 /* Operating on second frame increase the performance
  79                  * especially when transmit store-and-forward is used.*/
  80                 csr6 |= DMA_CONTROL_OSF;
  81         } else {
  82                 CHIP_DBG(KERN_DEBUG "GMAC: disabling TX store and forward mode"
  83                               " (threshold = %d)\n", txmode);
  84                 csr6 &= ~DMA_CONTROL_TSF;
  85                 csr6 &= DMA_CONTROL_TC_TX_MASK;
  86                 /* Set the transmit threshold */
  87                 if (txmode <= 32)
  88                         csr6 |= DMA_CONTROL_TTC_32;
  89                 else if (txmode <= 64)
  90                         csr6 |= DMA_CONTROL_TTC_64;
  91                 else if (txmode <= 128)
  92                         csr6 |= DMA_CONTROL_TTC_128;
  93                 else if (txmode <= 192)
  94                         csr6 |= DMA_CONTROL_TTC_192;
  95                 else
  96                         csr6 |= DMA_CONTROL_TTC_256;
  97         }
  98
  99         if (rxmode == SF_DMA_MODE) {
 100                 CHIP_DBG(KERN_DEBUG "GMAC: enable RX store and forward mode\n");
 101                 csr6 |= DMA_CONTROL_RSF;
 102         } else {
 103                 CHIP_DBG(KERN_DEBUG "GMAC: disabling RX store and forward mode"
 104                               " (threshold = %d)\n", rxmode);
 105                 csr6 &= ~DMA_CONTROL_RSF;
 106                 csr6 &= DMA_CONTROL_TC_RX_MASK;
 107                 if (rxmode <= 32)
 108                         csr6 |= DMA_CONTROL_RTC_32;
 109                 else if (rxmode <= 64)
 110                         csr6 |= DMA_CONTROL_RTC_64;
 111                 else if (rxmode <= 96)
 112                         csr6 |= DMA_CONTROL_RTC_96;
 113                 else
 114                         csr6 |= DMA_CONTROL_RTC_128;
 115         }
 116
 117         writel(csr6, ioaddr + DMA_CONTROL);
 118 }
 119
 120 /* Not yet implemented --- no RMON module */
 121 static void dwmac1000_dma_diagnostic_fr(void *data,
 122                   struct stmmac_extra_stats *x, void __iomem *ioaddr)
 123 {
 124         return;
 125 }
 126
 127 static void dwmac1000_dump_dma_regs(void __iomem *ioaddr)
 128 {
 129         int i;
 130         pr_info(" DMA registers\n");
 131         for (i = 0; i < 22; i++) {
 132                 if ((i < 9) || (i > 17)) {
 133                         int offset = i * 4;
 134                         pr_err("\t Reg No. %d (offset 0x%x): 0x%08x\n", i,
 135                                (DMA_BUS_MODE + offset),
 136                                readl(ioaddr + DMA_BUS_MODE + offset));
 137                 }
 138         }
 139 }
 140
 141 const struct stmmac_dma_ops dwmac1000_dma_ops = {
 142         .init = dwmac1000_dma_init,
 143         .dump_regs = dwmac1000_dump_dma_regs,
 144         .dma_mode = dwmac1000_dma_operation_mode,
 145         .dma_diagnostic_fr = dwmac1000_dma_diagnostic_fr,
 146         .enable_dma_transmission = dwmac_enable_dma_transmission,
 147         .enable_dma_irq = dwmac_enable_dma_irq,
 148         .disable_dma_irq = dwmac_disable_dma_irq,
 149         .start_tx = dwmac_dma_start_tx,
 150         .stop_tx = dwmac_dma_stop_tx,
 151         .start_rx = dwmac_dma_start_rx,
 152         .stop_rx = dwmac_dma_stop_rx,
 153         .dma_interrupt = dwmac_dma_interrupt,
 154 };