drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c

// SPDX-License-Identifier: GPL-2.0-only
/*******************************************************************************
  This is the driver for the MAC 10/100 on-chip Ethernet controller
  currently tested on all the ST boards based on STb7109 and stx7200 SoCs.

  DWC Ether MAC 10/100 Universal version 4.0 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 <linux/io.h>
#include "dwmac100.h"
#include "dwmac_dma.h"

static void dwmac100_dma_init(void __iomem *ioaddr,
			      struct stmmac_dma_cfg *dma_cfg)
{
	/* Enable Application Access by writing to DMA CSR0 */
	writel(DMA_BUS_MODE_DEFAULT | (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT),
	       ioaddr + DMA_BUS_MODE);

	/* Mask interrupts by writing to CSR7 */
	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
}

static void dwmac100_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 addr lists must be written into DMA CSR3 */
	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
}

static void dwmac100_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 addr lists must be written into DMA CSR4 */
	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_BASE_ADDR);
}

/* Store and Forward capability is not used at all.
 *
 * The transmit threshold can be programmed by setting the TTC bits in the DMA
 * control register.
 */
static void dwmac100_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 <= 32)
		csr6 |= DMA_CONTROL_TTC_32;
	else if (mode <= 64)
		csr6 |= DMA_CONTROL_TTC_64;
	else
		csr6 |= DMA_CONTROL_TTC_128;

	writel(csr6, ioaddr + DMA_CONTROL);
}

static void dwmac100_dump_dma_regs(struct stmmac_priv *priv,
				   void __iomem *ioaddr, u32 *reg_space)
{
	int i;

	for (i = 0; i < NUM_DWMAC100_DMA_REGS; i++)
		reg_space[DMA_BUS_MODE / 4 + i] =
			readl(ioaddr + DMA_BUS_MODE + i * 4);

	reg_space[DMA_CUR_TX_BUF_ADDR / 4] =
		readl(ioaddr + DMA_CUR_TX_BUF_ADDR);
	reg_space[DMA_CUR_RX_BUF_ADDR / 4] =
		readl(ioaddr + DMA_CUR_RX_BUF_ADDR);
}

/* DMA controller has two counters to track the number of the missed frames. */
static void dwmac100_dma_diagnostic_fr(struct stmmac_extra_stats *x,
				       void __iomem *ioaddr)
{
	u32 csr8 = readl(ioaddr + DMA_MISSED_FRAME_CTR);

	if (unlikely(csr8)) {
		if (csr8 & DMA_MISSED_FRAME_OVE) {
			x->rx_overflow_cntr += 0x800;
		} else {
			unsigned int ove_cntr;
			ove_cntr = ((csr8 & DMA_MISSED_FRAME_OVE_CNTR) >> 17);
			x->rx_overflow_cntr += ove_cntr;
		}

		if (csr8 & DMA_MISSED_FRAME_OVE_M) {
			x->rx_missed_cntr += 0xffff;
		} else {
			unsigned int miss_f = (csr8 & DMA_MISSED_FRAME_M_CNTR);
			x->rx_missed_cntr += miss_f;
		}
	}
}

const struct stmmac_dma_ops dwmac100_dma_ops = {
	.reset = dwmac_dma_reset,
	.init = dwmac100_dma_init,
	.init_rx_chan = dwmac100_dma_init_rx,
	.init_tx_chan = dwmac100_dma_init_tx,
	.dump_regs = dwmac100_dump_dma_regs,
	.dma_tx_mode = dwmac100_dma_operation_mode_tx,
	.dma_diagnostic_fr = dwmac100_dma_diagnostic_fr,
	.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,
};