xref: /openbmc/linux/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c (revision 1ac731c529cd4d6adbce134754b51ff7d822b145)

// SPDX-License-Identifier: GPL-2.0-only
/*******************************************************************************
  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


  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 &= ~DMA_AXI_WR_OSR_LMT;
	value |= (axi->axi_wr_osr_lmt & DMA_AXI_WR_OSR_LMT_MASK) <<
		 DMA_AXI_WR_OSR_LMT_SHIFT;

	value &= ~DMA_AXI_RD_OSR_LMT;
	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,
			       struct stmmac_dma_cfg *dma_cfg, int atds)
{
	u32 value = readl(ioaddr + DMA_BUS_MODE);
	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;

	/*
	 * 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.
	 */
	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);
	value |= (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);

	/* Set the Fixed burst mode */
	if (dma_cfg->fixed_burst)
		value |= DMA_BUS_MODE_FB;

	/* Mixed Burst has no effect when fb is set */
	if (dma_cfg->mixed_burst)
		value |= DMA_BUS_MODE_MB;

	if (atds)
		value |= DMA_BUS_MODE_ATDS;

	if (dma_cfg->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);
}

static void dwmac1000_dma_init_rx(struct stmmac_priv *priv,
				  void __iomem *ioaddr,
				  struct stmmac_dma_cfg *dma_cfg,
				  dma_addr_t dma_rx_phy, u32 chan)
{
	/* RX descriptor base address list must be written into DMA CSR3 */
	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
}

static void dwmac1000_dma_init_tx(struct stmmac_priv *priv,
				  void __iomem *ioaddr,
				  struct stmmac_dma_cfg *dma_cfg,
				  dma_addr_t dma_tx_phy, u32 chan)
{
	/* TX descriptor base address list must be written into DMA CSR4 */
	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_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_rx(struct stmmac_priv *priv,
					    void __iomem *ioaddr, int mode,
					    u32 channel, int fifosz, u8 qmode)
{
	u32 csr6 = readl(ioaddr + DMA_CONTROL);

	if (mode == 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", mode);
		csr6 &= ~DMA_CONTROL_RSF;
		csr6 &= DMA_CONTROL_TC_RX_MASK;
		if (mode <= 32)
			csr6 |= DMA_CONTROL_RTC_32;
		else if (mode <= 64)
			csr6 |= DMA_CONTROL_RTC_64;
		else if (mode <= 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, fifosz);

	writel(csr6, ioaddr + DMA_CONTROL);
}

static void dwmac1000_dma_operation_mode_tx(struct stmmac_priv *priv,
					    void __iomem *ioaddr, int mode,
					    u32 channel, int fifosz, u8 qmode)
{
	u32 csr6 = readl(ioaddr + DMA_CONTROL);

	if (mode == 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", mode);
		csr6 &= ~DMA_CONTROL_TSF;
		csr6 &= DMA_CONTROL_TC_TX_MASK;
		/* Set the transmit threshold */
		if (mode <= 32)
			csr6 |= DMA_CONTROL_TTC_32;
		else if (mode <= 64)
			csr6 |= DMA_CONTROL_TTC_64;
		else if (mode <= 128)
			csr6 |= DMA_CONTROL_TTC_128;
		else if (mode <= 192)
			csr6 |= DMA_CONTROL_TTC_192;
		else
			csr6 |= DMA_CONTROL_TTC_256;
	}

	writel(csr6, ioaddr + DMA_CONTROL);
}

static void dwmac1000_dump_dma_regs(struct stmmac_priv *priv,
				    void __iomem *ioaddr, u32 *reg_space)
{
	int i;

	for (i = 0; i < NUM_DWMAC1000_DMA_REGS; i++)
		if ((i < 12) || (i > 17))
			reg_space[DMA_BUS_MODE / 4 + i] =
				readl(ioaddr + DMA_BUS_MODE + i * 4);
}

static int dwmac1000_get_hw_feature(void __iomem *ioaddr,
				    struct dma_features *dma_cap)
{
	u32 hw_cap = readl(ioaddr + DMA_HW_FEATURE);

	if (!hw_cap) {
		/* 0x00000000 is the value read on old hardware that does not
		 * implement this register
		 */
		return -EOPNOTSUPP;
	}

	dma_cap->mbps_10_100 = (hw_cap & DMA_HW_FEAT_MIISEL);
	dma_cap->mbps_1000 = (hw_cap & DMA_HW_FEAT_GMIISEL) >> 1;
	dma_cap->half_duplex = (hw_cap & DMA_HW_FEAT_HDSEL) >> 2;
	dma_cap->hash_filter = (hw_cap & DMA_HW_FEAT_HASHSEL) >> 4;
	dma_cap->multi_addr = (hw_cap & DMA_HW_FEAT_ADDMAC) >> 5;
	dma_cap->pcs = (hw_cap & DMA_HW_FEAT_PCSSEL) >> 6;
	dma_cap->sma_mdio = (hw_cap & DMA_HW_FEAT_SMASEL) >> 8;
	dma_cap->pmt_remote_wake_up = (hw_cap & DMA_HW_FEAT_RWKSEL) >> 9;
	dma_cap->pmt_magic_frame = (hw_cap & DMA_HW_FEAT_MGKSEL) >> 10;
	/* MMC */
	dma_cap->rmon = (hw_cap & DMA_HW_FEAT_MMCSEL) >> 11;
	/* IEEE 1588-2002 */
	dma_cap->time_stamp =
	    (hw_cap & DMA_HW_FEAT_TSVER1SEL) >> 12;
	/* IEEE 1588-2008 */
	dma_cap->atime_stamp = (hw_cap & DMA_HW_FEAT_TSVER2SEL) >> 13;
	/* 802.3az - Energy-Efficient Ethernet (EEE) */
	dma_cap->eee = (hw_cap & DMA_HW_FEAT_EEESEL) >> 14;
	dma_cap->av = (hw_cap & DMA_HW_FEAT_AVSEL) >> 15;
	/* TX and RX csum */
	dma_cap->tx_coe = (hw_cap & DMA_HW_FEAT_TXCOESEL) >> 16;
	dma_cap->rx_coe_type1 = (hw_cap & DMA_HW_FEAT_RXTYP1COE) >> 17;
	dma_cap->rx_coe_type2 = (hw_cap & DMA_HW_FEAT_RXTYP2COE) >> 18;
	dma_cap->rxfifo_over_2048 = (hw_cap & DMA_HW_FEAT_RXFIFOSIZE) >> 19;
	/* TX and RX number of channels */
	dma_cap->number_rx_channel = (hw_cap & DMA_HW_FEAT_RXCHCNT) >> 20;
	dma_cap->number_tx_channel = (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22;
	/* Alternate (enhanced) DESC mode */
	dma_cap->enh_desc = (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;

	return 0;
}

static void dwmac1000_rx_watchdog(struct stmmac_priv *priv,
				  void __iomem *ioaddr, u32 riwt, u32 queue)
{
	writel(riwt, ioaddr + DMA_RX_WATCHDOG);
}

const struct stmmac_dma_ops dwmac1000_dma_ops = {
	.reset = dwmac_dma_reset,
	.init = dwmac1000_dma_init,
	.init_rx_chan = dwmac1000_dma_init_rx,
	.init_tx_chan = dwmac1000_dma_init_tx,
	.axi = dwmac1000_dma_axi,
	.dump_regs = dwmac1000_dump_dma_regs,
	.dma_rx_mode = dwmac1000_dma_operation_mode_rx,
	.dma_tx_mode = dwmac1000_dma_operation_mode_tx,
	.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,
};