xref: /openbmc/linux/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c (revision 356b7557)

/*
 * This is the driver for the GMAC on-chip Ethernet controller for ST SoCs.
 * DWC Ether MAC version 4.xx  has been used for  developing this code.
 *
 * This contains the functions to handle the dma.
 *
 * Copyright (C) 2015  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.
 *
 * Author: Alexandre Torgue <alexandre.torgue@st.com>
 */

#include <linux/io.h>
#include "dwmac4.h"
#include "dwmac4_dma.h"

static void dwmac4_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
{
	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
	int i;

	pr_info("dwmac4: Master AXI performs %s burst length\n",
		(value & DMA_SYS_BUS_FB) ? "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_OSR_MAX) <<
		 DMA_AXI_WR_OSR_LMT_SHIFT;

	value &= ~DMA_AXI_RD_OSR_LMT;
	value |= (axi->axi_rd_osr_lmt & DMA_AXI_OSR_MAX) <<
		 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_SYS_BUS_MODE);
}

static void dwmac4_dma_init_channel(void __iomem *ioaddr,
				    struct stmmac_dma_cfg *dma_cfg,
				    u32 dma_tx_phy, u32 dma_rx_phy,
				    u32 channel)
{
	u32 value;
	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;

	/* set PBL for each channels. Currently we affect same configuration
	 * on each channel
	 */
	value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
	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));
	value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT);
	writel(value, ioaddr + DMA_CHAN_TX_CONTROL(channel));

	value = readl(ioaddr + DMA_CHAN_RX_CONTROL(channel));
	value = value | (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
	writel(value, ioaddr + DMA_CHAN_RX_CONTROL(channel));

	/* Mask interrupts by writing to CSR7 */
	writel(DMA_CHAN_INTR_DEFAULT_MASK, ioaddr + DMA_CHAN_INTR_ENA(channel));

	writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(channel));
	writel(dma_rx_phy, ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
}

static void dwmac4_dma_init(void __iomem *ioaddr,
			    struct stmmac_dma_cfg *dma_cfg,
			    u32 dma_tx, u32 dma_rx, int atds)
{
	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
	int i;

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

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

	if (dma_cfg->aal)
		value |= DMA_SYS_BUS_AAL;

	writel(value, ioaddr + DMA_SYS_BUS_MODE);

	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
		dwmac4_dma_init_channel(ioaddr, dma_cfg, dma_tx, dma_rx, i);
}

static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel,
				  u32 *reg_space)
{
	reg_space[DMA_CHAN_CONTROL(channel) / 4] =
		readl(ioaddr + DMA_CHAN_CONTROL(channel));
	reg_space[DMA_CHAN_TX_CONTROL(channel) / 4] =
		readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
	reg_space[DMA_CHAN_RX_CONTROL(channel) / 4] =
		readl(ioaddr + DMA_CHAN_RX_CONTROL(channel));
	reg_space[DMA_CHAN_TX_BASE_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_TX_BASE_ADDR(channel));
	reg_space[DMA_CHAN_RX_BASE_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
	reg_space[DMA_CHAN_TX_END_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_TX_END_ADDR(channel));
	reg_space[DMA_CHAN_RX_END_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_RX_END_ADDR(channel));
	reg_space[DMA_CHAN_TX_RING_LEN(channel) / 4] =
		readl(ioaddr + DMA_CHAN_TX_RING_LEN(channel));
	reg_space[DMA_CHAN_RX_RING_LEN(channel) / 4] =
		readl(ioaddr + DMA_CHAN_RX_RING_LEN(channel));
	reg_space[DMA_CHAN_INTR_ENA(channel) / 4] =
		readl(ioaddr + DMA_CHAN_INTR_ENA(channel));
	reg_space[DMA_CHAN_RX_WATCHDOG(channel) / 4] =
		readl(ioaddr + DMA_CHAN_RX_WATCHDOG(channel));
	reg_space[DMA_CHAN_SLOT_CTRL_STATUS(channel) / 4] =
		readl(ioaddr + DMA_CHAN_SLOT_CTRL_STATUS(channel));
	reg_space[DMA_CHAN_CUR_TX_DESC(channel) / 4] =
		readl(ioaddr + DMA_CHAN_CUR_TX_DESC(channel));
	reg_space[DMA_CHAN_CUR_RX_DESC(channel) / 4] =
		readl(ioaddr + DMA_CHAN_CUR_RX_DESC(channel));
	reg_space[DMA_CHAN_CUR_TX_BUF_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_CUR_TX_BUF_ADDR(channel));
	reg_space[DMA_CHAN_CUR_RX_BUF_ADDR(channel) / 4] =
		readl(ioaddr + DMA_CHAN_CUR_RX_BUF_ADDR(channel));
	reg_space[DMA_CHAN_STATUS(channel) / 4] =
		readl(ioaddr + DMA_CHAN_STATUS(channel));
}

static void dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 *reg_space)
{
	int i;

	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
		_dwmac4_dump_dma_regs(ioaddr, i, reg_space);
}

static void dwmac4_rx_watchdog(void __iomem *ioaddr, u32 riwt)
{
	int i;

	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
		writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(i));
}

static void dwmac4_dma_chan_op_mode(void __iomem *ioaddr, int txmode,
				    int rxmode, u32 channel, int rxfifosz)
{
	unsigned int rqs = rxfifosz / 256 - 1;
	u32 mtl_tx_op, mtl_rx_op, mtl_rx_int;

	/* Following code only done for channel 0, other channels not yet
	 * supported.
	 */
	mtl_tx_op = readl(ioaddr + MTL_CHAN_TX_OP_MODE(channel));

	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. */
		mtl_tx_op |= MTL_OP_MODE_TSF;
	} else {
		pr_debug("GMAC: disabling TX SF (threshold %d)\n", txmode);
		mtl_tx_op &= ~MTL_OP_MODE_TSF;
		mtl_tx_op &= MTL_OP_MODE_TTC_MASK;
		/* Set the transmit threshold */
		if (txmode <= 32)
			mtl_tx_op |= MTL_OP_MODE_TTC_32;
		else if (txmode <= 64)
			mtl_tx_op |= MTL_OP_MODE_TTC_64;
		else if (txmode <= 96)
			mtl_tx_op |= MTL_OP_MODE_TTC_96;
		else if (txmode <= 128)
			mtl_tx_op |= MTL_OP_MODE_TTC_128;
		else if (txmode <= 192)
			mtl_tx_op |= MTL_OP_MODE_TTC_192;
		else if (txmode <= 256)
			mtl_tx_op |= MTL_OP_MODE_TTC_256;
		else if (txmode <= 384)
			mtl_tx_op |= MTL_OP_MODE_TTC_384;
		else
			mtl_tx_op |= MTL_OP_MODE_TTC_512;
	}
	/* For an IP with DWC_EQOS_NUM_TXQ == 1, the fields TXQEN and TQS are RO
	 * with reset values: TXQEN on, TQS == DWC_EQOS_TXFIFO_SIZE.
	 * For an IP with DWC_EQOS_NUM_TXQ > 1, the fields TXQEN and TQS are R/W
	 * with reset values: TXQEN off, TQS 256 bytes.
	 *
	 * Write the bits in both cases, since it will have no effect when RO.
	 * For DWC_EQOS_NUM_TXQ > 1, the top bits in MTL_OP_MODE_TQS_MASK might
	 * be RO, however, writing the whole TQS field will result in a value
	 * equal to DWC_EQOS_TXFIFO_SIZE, just like for DWC_EQOS_NUM_TXQ == 1.
	 */
	mtl_tx_op |= MTL_OP_MODE_TXQEN | MTL_OP_MODE_TQS_MASK;
	writel(mtl_tx_op, ioaddr +  MTL_CHAN_TX_OP_MODE(channel));

	mtl_rx_op = readl(ioaddr + MTL_CHAN_RX_OP_MODE(channel));

	if (rxmode == SF_DMA_MODE) {
		pr_debug("GMAC: enable RX store and forward mode\n");
		mtl_rx_op |= MTL_OP_MODE_RSF;
	} else {
		pr_debug("GMAC: disable RX SF mode (threshold %d)\n", rxmode);
		mtl_rx_op &= ~MTL_OP_MODE_RSF;
		mtl_rx_op &= MTL_OP_MODE_RTC_MASK;
		if (rxmode <= 32)
			mtl_rx_op |= MTL_OP_MODE_RTC_32;
		else if (rxmode <= 64)
			mtl_rx_op |= MTL_OP_MODE_RTC_64;
		else if (rxmode <= 96)
			mtl_rx_op |= MTL_OP_MODE_RTC_96;
		else
			mtl_rx_op |= MTL_OP_MODE_RTC_128;
	}

	mtl_rx_op &= ~MTL_OP_MODE_RQS_MASK;
	mtl_rx_op |= rqs << MTL_OP_MODE_RQS_SHIFT;

	/* enable flow control only if each channel gets 4 KiB or more FIFO */
	if (rxfifosz >= 4096) {
		unsigned int rfd, rfa;

		mtl_rx_op |= MTL_OP_MODE_EHFC;

		/* Set Threshold for Activating Flow Control to min 2 frames,
		 * i.e. 1500 * 2 = 3000 bytes.
		 *
		 * Set Threshold for Deactivating Flow Control to min 1 frame,
		 * i.e. 1500 bytes.
		 */
		switch (rxfifosz) {
		case 4096:
			/* This violates the above formula because of FIFO size
			 * limit therefore overflow may occur in spite of this.
			 */
			rfd = 0x03; /* Full-2.5K */
			rfa = 0x01; /* Full-1.5K */
			break;

		case 8192:
			rfd = 0x06; /* Full-4K */
			rfa = 0x0a; /* Full-6K */
			break;

		case 16384:
			rfd = 0x06; /* Full-4K */
			rfa = 0x12; /* Full-10K */
			break;

		default:
			rfd = 0x06; /* Full-4K */
			rfa = 0x1e; /* Full-16K */
			break;
		}

		mtl_rx_op &= ~MTL_OP_MODE_RFD_MASK;
		mtl_rx_op |= rfd << MTL_OP_MODE_RFD_SHIFT;

		mtl_rx_op &= ~MTL_OP_MODE_RFA_MASK;
		mtl_rx_op |= rfa << MTL_OP_MODE_RFA_SHIFT;
	}

	writel(mtl_rx_op, ioaddr + MTL_CHAN_RX_OP_MODE(channel));

	/* Enable MTL RX overflow */
	mtl_rx_int = readl(ioaddr + MTL_CHAN_INT_CTRL(channel));
	writel(mtl_rx_int | MTL_RX_OVERFLOW_INT_EN,
	       ioaddr + MTL_CHAN_INT_CTRL(channel));
}

static void dwmac4_dma_operation_mode(void __iomem *ioaddr, int txmode,
				      int rxmode, int rxfifosz)
{
	/* Only Channel 0 is actually configured and used */
	dwmac4_dma_chan_op_mode(ioaddr, txmode, rxmode, 0, rxfifosz);
}

static void dwmac4_get_hw_feature(void __iomem *ioaddr,
				  struct dma_features *dma_cap)
{
	u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0);

	/*  MAC HW feature0 */
	dma_cap->mbps_10_100 = (hw_cap & GMAC_HW_FEAT_MIISEL);
	dma_cap->mbps_1000 = (hw_cap & GMAC_HW_FEAT_GMIISEL) >> 1;
	dma_cap->half_duplex = (hw_cap & GMAC_HW_FEAT_HDSEL) >> 2;
	dma_cap->hash_filter = (hw_cap & GMAC_HW_FEAT_VLHASH) >> 4;
	dma_cap->multi_addr = (hw_cap & GMAC_HW_FEAT_ADDMAC) >> 18;
	dma_cap->pcs = (hw_cap & GMAC_HW_FEAT_PCSSEL) >> 3;
	dma_cap->sma_mdio = (hw_cap & GMAC_HW_FEAT_SMASEL) >> 5;
	dma_cap->pmt_remote_wake_up = (hw_cap & GMAC_HW_FEAT_RWKSEL) >> 6;
	dma_cap->pmt_magic_frame = (hw_cap & GMAC_HW_FEAT_MGKSEL) >> 7;
	/* MMC */
	dma_cap->rmon = (hw_cap & GMAC_HW_FEAT_MMCSEL) >> 8;
	/* IEEE 1588-2008 */
	dma_cap->atime_stamp = (hw_cap & GMAC_HW_FEAT_TSSEL) >> 12;
	/* 802.3az - Energy-Efficient Ethernet (EEE) */
	dma_cap->eee = (hw_cap & GMAC_HW_FEAT_EEESEL) >> 13;
	/* TX and RX csum */
	dma_cap->tx_coe = (hw_cap & GMAC_HW_FEAT_TXCOSEL) >> 14;
	dma_cap->rx_coe =  (hw_cap & GMAC_HW_FEAT_RXCOESEL) >> 16;

	/* MAC HW feature1 */
	hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);
	dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
	dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
	/* RX and TX FIFO sizes are encoded as log2(n / 128). Undo that by
	 * shifting and store the sizes in bytes.
	 */
	dma_cap->tx_fifo_size = 128 << ((hw_cap & GMAC_HW_TXFIFOSIZE) >> 6);
	dma_cap->rx_fifo_size = 128 << ((hw_cap & GMAC_HW_RXFIFOSIZE) >> 0);
	/* MAC HW feature2 */
	hw_cap = readl(ioaddr + GMAC_HW_FEATURE2);
	/* TX and RX number of channels */
	dma_cap->number_rx_channel =
		((hw_cap & GMAC_HW_FEAT_RXCHCNT) >> 12) + 1;
	dma_cap->number_tx_channel =
		((hw_cap & GMAC_HW_FEAT_TXCHCNT) >> 18) + 1;
	/* TX and RX number of queues */
	dma_cap->number_rx_queues =
		((hw_cap & GMAC_HW_FEAT_RXQCNT) >> 0) + 1;
	dma_cap->number_tx_queues =
		((hw_cap & GMAC_HW_FEAT_TXQCNT) >> 6) + 1;

	/* IEEE 1588-2002 */
	dma_cap->time_stamp = 0;
}

/* Enable/disable TSO feature and set MSS */
static void dwmac4_enable_tso(void __iomem *ioaddr, bool en, u32 chan)
{
	u32 value;

	if (en) {
		/* enable TSO */
		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
		writel(value | DMA_CONTROL_TSE,
		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
	} else {
		/* enable TSO */
		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
		writel(value & ~DMA_CONTROL_TSE,
		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
	}
}

const struct stmmac_dma_ops dwmac4_dma_ops = {
	.reset = dwmac4_dma_reset,
	.init = dwmac4_dma_init,
	.axi = dwmac4_dma_axi,
	.dump_regs = dwmac4_dump_dma_regs,
	.dma_mode = dwmac4_dma_operation_mode,
	.enable_dma_irq = dwmac4_enable_dma_irq,
	.disable_dma_irq = dwmac4_disable_dma_irq,
	.start_tx = dwmac4_dma_start_tx,
	.stop_tx = dwmac4_dma_stop_tx,
	.start_rx = dwmac4_dma_start_rx,
	.stop_rx = dwmac4_dma_stop_rx,
	.dma_interrupt = dwmac4_dma_interrupt,
	.get_hw_feature = dwmac4_get_hw_feature,
	.rx_watchdog = dwmac4_rx_watchdog,
	.set_rx_ring_len = dwmac4_set_rx_ring_len,
	.set_tx_ring_len = dwmac4_set_tx_ring_len,
	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
	.enable_tso = dwmac4_enable_tso,
};

const struct stmmac_dma_ops dwmac410_dma_ops = {
	.reset = dwmac4_dma_reset,
	.init = dwmac4_dma_init,
	.axi = dwmac4_dma_axi,
	.dump_regs = dwmac4_dump_dma_regs,
	.dma_mode = dwmac4_dma_operation_mode,
	.enable_dma_irq = dwmac410_enable_dma_irq,
	.disable_dma_irq = dwmac4_disable_dma_irq,
	.start_tx = dwmac4_dma_start_tx,
	.stop_tx = dwmac4_dma_stop_tx,
	.start_rx = dwmac4_dma_start_rx,
	.stop_rx = dwmac4_dma_stop_rx,
	.dma_interrupt = dwmac4_dma_interrupt,
	.get_hw_feature = dwmac4_get_hw_feature,
	.rx_watchdog = dwmac4_rx_watchdog,
	.set_rx_ring_len = dwmac4_set_rx_ring_len,
	.set_tx_ring_len = dwmac4_set_tx_ring_len,
	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
	.enable_tso = dwmac4_enable_tso,
};