[U-Boot] [PATCH v5] net: Add MT7628 ethernet driver

Stefan Roese sr at denx.de
Fri Oct 26 11:31:20 UTC 2018


On 25.10.18 01:01, Joe Hershberger wrote:
> On Wed, Oct 24, 2018 at 1:36 AM Stefan Roese <sr at denx.de> wrote:
>>
>> This patch adds ethernet support for the MIPS based Mediatek MT76xx SoCs
>> (e.g. MT7628 and MT7688), including a minimum setup of the integrated
>> switch. This driver is loosly based on the driver version included in
>> this MediaTek github repository:
>>
>> https://github.com/MediaTek-Labs/linkit-smart-uboot.git
>>
>> Tested on the MT7688 LinkIt smart-gateway and on the
>> Gardena-smart-gateway.
>>
>> Signed-off-by: Stefan Roese <sr at denx.de>
>> Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
>> Cc: Joe Hershberger <joe.hershberger at ni.com>
>> Cc: Frank Wunderlich <frankwu at gmx.de>
>> Cc: Weijie Gao <hackpascal at gmail.com>
>> ---
>> v5:
>> - Rename driver and Kconfig and functions names again to avoid mix-up
>>    with the MT76xx ARM SoCs
>>
>> v4:
>> - Rename driver and Kconfig to avoid mix-up with the MT76xx ARM SoCs
>>
>> v3:
>> - Add Reviewed-by from Daniel
>> - Address review comments from Joe:
>>    - Use more macros / defines instead of magic values, especially
>>      in the MDIO functions
>>    - Use FIELD_xxx from include/linux/bitfield.h whereever possible
>>    - Remove some unreferenced defines
>>    - Remove some unnecessary casts
>>    - Spelling fixes
>>    - Add documentation in doc/device-tree-bindings/net/
>>
>> v2:
>> - Use wait_for_bit_le32() in more places
>> - Use syscon / regmap to access the system-controller registers
>>    needed in this driver instead of finding and mapping this
>>    area
>>
>>   .../net/mediatek,mt7628-eth.txt               |  17 +
>>   drivers/net/Kconfig                           |   7 +
>>   drivers/net/Makefile                          |   1 +
>>   drivers/net/mt7628-eth.c                      | 635 ++++++++++++++++++
>>   4 files changed, 660 insertions(+)
>>   create mode 100644 doc/device-tree-bindings/net/mediatek,mt7628-eth.txt
>>   create mode 100644 drivers/net/mt7628-eth.c
>>
>> diff --git a/doc/device-tree-bindings/net/mediatek,mt7628-eth.txt b/doc/device-tree-bindings/net/mediatek,mt7628-eth.txt
>> new file mode 100644
>> index 0000000000..ec97504a3f
>> --- /dev/null
>> +++ b/doc/device-tree-bindings/net/mediatek,mt7628-eth.txt
>> @@ -0,0 +1,17 @@
>> +* MediaTek Frame Engine Ethernet controller
>> +
>> +Required properties:
>> +- compatible: should be "mediatek,mt7628-eth"
>> +- reg: address and length of the register set for the frame
>> +       engine ethernet controller and the internal switch.
>> +- syscon: phandle to the system controller
>> +
>> +Example:
>> +
>> +eth at 10100000 {
>> +       compatible = "mediatek,mt7628-eth";
>> +       reg = <0x10100000 0x10000
>> +              0x10110000 0x8000>;
>> +
>> +       syscon = <&sysc>;
>> +};
>> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
>> index f1f0e2d94e..fba9d7c31c 100644
>> --- a/drivers/net/Kconfig
>> +++ b/drivers/net/Kconfig
>> @@ -227,6 +227,13 @@ config MACB_ZYNQ
>>            The Cadence MACB ethernet interface was used on Zynq platform.
>>            Say Y to enable support for the MACB/GEM in Zynq chip.
>>
>> +config MT7628_ETH
>> +       bool "MediaTek MT7628 Ethernet Interface"
>> +       depends on ARCH_MT7620
>> +       help
>> +         The MediaTek MT7628 ethernet interface is used on MT7628 and
>> +         MT7688 based boards.
>> +
>>   config PCH_GBE
>>          bool "Intel Platform Controller Hub EG20T GMAC driver"
>>          depends on DM_ETH && DM_PCI
>> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
>> index 48a2878071..cc0971c614 100644
>> --- a/drivers/net/Makefile
>> +++ b/drivers/net/Makefile
>> @@ -37,6 +37,7 @@ obj-$(CONFIG_LPC32XX_ETH) += lpc32xx_eth.o
>>   obj-$(CONFIG_MACB) += macb.o
>>   obj-$(CONFIG_MCFFEC) += mcffec.o mcfmii.o
>>   obj-$(CONFIG_MPC8XX_FEC) += mpc8xx_fec.o
>> +obj-$(CONFIG_MT7628_ETH) += mt7628-eth.o
>>   obj-$(CONFIG_MVGBE) += mvgbe.o
>>   obj-$(CONFIG_MVNETA) += mvneta.o
>>   obj-$(CONFIG_MVPP2) += mvpp2.o
>> diff --git a/drivers/net/mt7628-eth.c b/drivers/net/mt7628-eth.c
>> new file mode 100644
>> index 0000000000..93efea395b
>> --- /dev/null
>> +++ b/drivers/net/mt7628-eth.c
>> @@ -0,0 +1,635 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * MediaTek ethernet IP driver for U-Boot
>> + *
>> + * Copyright (C) 2018 Stefan Roese <sr at denx.de>
>> + *
>> + * This code is mostly based on the code extracted from this MediaTek
>> + * github repository:
>> + *
>> + * https://github.com/MediaTek-Labs/linkit-smart-uboot.git
>> + *
>> + * I was not able to find a specific license or other developers
>> + * copyrights here, so I can't add them here.
>> + */
>> +
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <malloc.h>
>> +#include <miiphy.h>
>> +#include <net.h>
>> +#include <regmap.h>
>> +#include <syscon.h>
>> +#include <wait_bit.h>
>> +#include <asm/io.h>
>> +#include <linux/bitfield.h>
>> +#include <linux/err.h>
>> +
>> +/* System controller register */
>> +#define MT7628_RSTCTRL_REG     0x34
>> +#define RSTCTRL_EPHY_RST       BIT(24)
>> +
>> +#define MT7628_AGPIO_CFG_REG   0x3c
>> +#define MT7628_EPHY_GPIO_AIO_EN        GENMASK(20, 17)
>> +#define MT7628_EPHY_P0_DIS     BIT(16)
>> +
>> +#define MT7628_GPIO2_MODE_REG  0x64
>> +
>> +/* Ethernet frame engine register */
>> +#define PDMA_RELATED           0x0800
>> +
>> +#define TX_BASE_PTR0           (PDMA_RELATED + 0x000)
>> +#define TX_MAX_CNT0            (PDMA_RELATED + 0x004)
>> +#define TX_CTX_IDX0            (PDMA_RELATED + 0x008)
>> +#define TX_DTX_IDX0            (PDMA_RELATED + 0x00c)
>> +
>> +#define RX_BASE_PTR0           (PDMA_RELATED + 0x100)
>> +#define RX_MAX_CNT0            (PDMA_RELATED + 0x104)
>> +#define RX_CALC_IDX0           (PDMA_RELATED + 0x108)
>> +
>> +#define PDMA_GLO_CFG           (PDMA_RELATED + 0x204)
>> +#define PDMA_RST_IDX           (PDMA_RELATED + 0x208)
>> +#define DLY_INT_CFG            (PDMA_RELATED + 0x20c)
>> +
>> +#define SDM_RELATED            0x0c00
>> +
>> +#define SDM_MAC_ADRL           (SDM_RELATED + 0x0c)    /* MAC address LSB */
>> +#define SDM_MAC_ADRH           (SDM_RELATED + 0x10)    /* MAC Address MSB */
>> +
>> +#define RST_DTX_IDX0           BIT(0)
>> +#define RST_DRX_IDX0           BIT(16)
>> +
>> +#define TX_DMA_EN              BIT(0)
>> +#define TX_DMA_BUSY            BIT(1)
>> +#define RX_DMA_EN              BIT(2)
>> +#define RX_DMA_BUSY            BIT(3)
>> +#define TX_WB_DDONE            BIT(6)
>> +
>> +/* Ethernet switch register */
>> +#define MT7628_SWITCH_FCT0     0x0008
>> +#define MT7628_SWITCH_PFC1     0x0014
>> +#define MT7628_SWITCH_FPA      0x0084
>> +#define MT7628_SWITCH_SOCPC    0x008c
>> +#define MT7628_SWITCH_POC0     0x0090
>> +#define MT7628_SWITCH_POC2     0x0098
>> +#define MT7628_SWITCH_SGC      0x009c
>> +#define MT7628_SWITCH_PCR0     0x00c0
>> +#define PCR0_PHY_ADDR          GENMASK(4, 0)
>> +#define PCR0_PHY_REG           GENMASK(12, 8)
>> +#define PCR0_WT_PHY_CMD                BIT(13)
>> +#define PCR0_RD_PHY_CMD                BIT(14)
>> +#define PCR0_WT_DATA           GENMASK(31, 16)
>> +
>> +#define MT7628_SWITCH_PCR1     0x00c4
>> +#define PCR1_WT_DONE           BIT(0)
>> +#define PCR1_RD_RDY            BIT(1)
>> +#define PCR1_RD_DATA           GENMASK(31, 16)
>> +
>> +#define MT7628_SWITCH_FPA1     0x00c8
>> +#define MT7628_SWITCH_FCT2     0x00cc
>> +#define MT7628_SWITCH_SGC2     0x00e4
>> +#define MT7628_SWITCH_BMU_CTRL 0x0110
>> +
>> +/* rxd2 */
>> +#define RX_DMA_DONE            BIT(31)
>> +#define RX_DMA_LSO             BIT(30)
>> +#define RX_DMA_PLEN0           GENMASK(29, 16)
>> +#define RX_DMA_TAG             BIT(15)
>> +
>> +struct fe_rx_dma {
>> +       unsigned int rxd1;
>> +       unsigned int rxd2;
>> +       unsigned int rxd3;
>> +       unsigned int rxd4;
>> +} __packed __aligned(4);
>> +
>> +#define TX_DMA_PLEN0           GENMASK(29, 16)
>> +#define TX_DMA_LS1             BIT(14)
>> +#define TX_DMA_LS0             BIT(30)
>> +#define TX_DMA_DONE            BIT(31)
>> +
>> +#define TX_DMA_INS_VLAN_MT7621 BIT(16)
>> +#define TX_DMA_INS_VLAN                BIT(7)
>> +#define TX_DMA_INS_PPPOE       BIT(12)
>> +#define TX_DMA_PN              GENMASK(26, 24)
>> +
>> +struct fe_tx_dma {
>> +       unsigned int txd1;
>> +       unsigned int txd2;
>> +       unsigned int txd3;
>> +       unsigned int txd4;
>> +} __packed __aligned(4);
>> +
>> +#define NUM_RX_DESC            256
>> +#define NUM_TX_DESC            4
>> +
>> +#define PADDING_LENGTH         60
>> +
>> +#define MTK_QDMA_PAGE_SIZE     2048
>> +
>> +#define CONFIG_MDIO_TIMEOUT    100
>> +#define CONFIG_DMA_STOP_TIMEOUT        100
>> +#define CONFIG_TX_DMA_TIMEOUT  100
>> +
>> +#define LINK_DELAY_TIME                500             /* 500 ms */
>> +#define LINK_TIMEOUT           10000           /* 10 seconds */
>> +
>> +struct mt7628_eth_dev {
>> +       void __iomem *base;             /* frame engine base address */
>> +       void __iomem *eth_sw_base;      /* switch base address */
>> +       struct regmap *sysctrl_regmap;  /* system-controller reg-map */
>> +
>> +       struct mii_dev *bus;
>> +
>> +       struct fe_tx_dma *tx_ring;
>> +       struct fe_rx_dma *rx_ring;
>> +
>> +       u8 *rx_buf[NUM_RX_DESC];
>> +
>> +       /* Point to the next RXD DMA wants to use in RXD Ring0 */
>> +       int rx_dma_idx;
>> +       /* Point to the next TXD in TXD Ring0 CPU wants to use */
>> +       int tx_dma_idx;
>> +};
>> +
>> +static int mdio_wait_read(struct mt7628_eth_dev *priv, u32 mask, bool mask_set)
>> +{
>> +       void __iomem *base = priv->eth_sw_base;
>> +       int ret;
>> +
>> +       ret = wait_for_bit_le32(base + MT7628_SWITCH_PCR1, mask, mask_set,
>> +                               CONFIG_MDIO_TIMEOUT, false);
>> +       if (ret) {
>> +               printf("MDIO operation timeout!\n");
>> +               return -ETIMEDOUT;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int mii_mgr_read(struct mt7628_eth_dev *priv,
>> +                       u32 phy_addr, u32 phy_register, u32 *read_data)
>> +{
>> +       void __iomem *base = priv->eth_sw_base;
>> +       u32 status = 0;
>> +       u32 ret;
>> +
>> +       *read_data = 0xffff;
>> +       /* Make sure previous read operation is complete */
>> +       ret = mdio_wait_read(priv, PCR1_RD_RDY, false);
>> +       if (ret)
>> +               return ret;
>> +
>> +       writel(PCR0_RD_PHY_CMD |
>> +              FIELD_PREP(PCR0_PHY_REG, phy_register) |
>> +              FIELD_PREP(PCR0_PHY_ADDR, phy_addr),
>> +              base + MT7628_SWITCH_PCR0);
>> +
>> +       /* Make sure previous read operation is complete */
>> +       ret = mdio_wait_read(priv, PCR1_RD_RDY, true);
>> +       if (ret)
>> +               return ret;
>> +
>> +       status = readl(base + MT7628_SWITCH_PCR1);
>> +       *read_data = FIELD_GET(PCR1_RD_DATA, status);
>> +
>> +       return 0;
>> +}
>> +
>> +static int mii_mgr_write(struct mt7628_eth_dev *priv,
>> +                        u32 phy_addr, u32 phy_register, u32 write_data)
>> +{
>> +       void __iomem *base = priv->eth_sw_base;
>> +       u32 data;
>> +       int ret;
>> +
>> +       /* Make sure previous write operation is complete */
>> +       ret = mdio_wait_read(priv, PCR1_WT_DONE, false);
>> +       if (ret)
>> +               return ret;
>> +
>> +       data = FIELD_PREP(PCR0_WT_DATA, write_data) |
>> +               FIELD_PREP(PCR0_PHY_REG, phy_register) |
>> +               FIELD_PREP(PCR0_PHY_ADDR, phy_addr) |
>> +               PCR0_WT_PHY_CMD;
>> +       writel(data, base + MT7628_SWITCH_PCR0);
>> +
>> +       return mdio_wait_read(priv, PCR1_WT_DONE, true);
>> +}
>> +
>> +static int mt7628_mdio_read(struct mii_dev *bus, int addr, int devad, int reg)
>> +{
>> +       u32 val;
>> +       int ret;
>> +
>> +       ret = mii_mgr_read(bus->priv, addr, reg, &val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       return val;
>> +}
>> +
>> +static int mt7628_mdio_write(struct mii_dev *bus, int addr, int devad, int reg,
>> +                            u16 value)
>> +{
>> +       return mii_mgr_write(bus->priv, addr, reg, value);
>> +}
>> +
>> +static void mt7628_ephy_init(struct mt7628_eth_dev *priv)
>> +{
>> +       int i;
>> +
>> +       mii_mgr_write(priv, 0, 31, 0x2000);     /* change G2 page */
>> +       mii_mgr_write(priv, 0, 26, 0x0000);
>> +
>> +       for (i = 0; i < 5; i++) {
>> +               mii_mgr_write(priv, i, 31, 0x8000);     /* change L0 page */
>> +               mii_mgr_write(priv, i,  0, 0x3100);
>> +
>> +               /* EEE disable */
>> +               mii_mgr_write(priv, i, 30, 0xa000);
>> +               mii_mgr_write(priv, i, 31, 0xa000);     /* change L2 page */
>> +               mii_mgr_write(priv, i, 16, 0x0606);
>> +               mii_mgr_write(priv, i, 23, 0x0f0e);
>> +               mii_mgr_write(priv, i, 24, 0x1610);
>> +               mii_mgr_write(priv, i, 30, 0x1f15);
>> +               mii_mgr_write(priv, i, 28, 0x6111);
>> +       }
>> +
>> +       /* 100Base AOI setting */
>> +       mii_mgr_write(priv, 0, 31, 0x5000);     /* change G5 page */
>> +       mii_mgr_write(priv, 0, 19, 0x004a);
>> +       mii_mgr_write(priv, 0, 20, 0x015a);
>> +       mii_mgr_write(priv, 0, 21, 0x00ee);
>> +       mii_mgr_write(priv, 0, 22, 0x0033);
>> +       mii_mgr_write(priv, 0, 23, 0x020a);
>> +       mii_mgr_write(priv, 0, 24, 0x0000);
>> +       mii_mgr_write(priv, 0, 25, 0x024a);
>> +       mii_mgr_write(priv, 0, 26, 0x035a);
>> +       mii_mgr_write(priv, 0, 27, 0x02ee);
>> +       mii_mgr_write(priv, 0, 28, 0x0233);
>> +       mii_mgr_write(priv, 0, 29, 0x000a);
>> +       mii_mgr_write(priv, 0, 30, 0x0000);
>> +
>> +       /* Fix EPHY idle state abnormal behavior */
>> +       mii_mgr_write(priv, 0, 31, 0x4000);     /* change G4 page */
>> +       mii_mgr_write(priv, 0, 29, 0x000d);
>> +       mii_mgr_write(priv, 0, 30, 0x0500);
>> +}
>> +
>> +static void rt305x_esw_init(struct mt7628_eth_dev *priv)
>> +{
>> +       void __iomem *base = priv->eth_sw_base;
>> +
>> +       /*
>> +        * FC_RLS_TH=200, FC_SET_TH=160
>> +        * DROP_RLS=120, DROP_SET_TH=80
>> +        */
>> +       writel(0xc8a07850, base + MT7628_SWITCH_FCT0);
>> +       writel(0x00000000, base + MT7628_SWITCH_SGC2);
>> +       writel(0x00405555, base + MT7628_SWITCH_PFC1);
>> +       writel(0x00007f7f, base + MT7628_SWITCH_POC0);
>> +       writel(0x00007f7f, base + MT7628_SWITCH_POC2);  /* disable VLAN */
>> +       writel(0x0002500c, base + MT7628_SWITCH_FCT2);
>> +       /* hashing algorithm=XOR48, aging interval=300sec */
>> +       writel(0x0008a301, base + MT7628_SWITCH_SGC);
>> +       writel(0x02404040, base + MT7628_SWITCH_SOCPC);
>> +
>> +       /* Ext PHY Addr=0x1f */
>> +       writel(0x3f502b28, base + MT7628_SWITCH_FPA1);
>> +       writel(0x00000000, base + MT7628_SWITCH_FPA);
>> +       /* 1us cycle number=125 (FE's clock=125Mhz) */
>> +       writel(0x7d000000, base + MT7628_SWITCH_BMU_CTRL);
>> +
>> +       /* Configure analog GPIO setup */
>> +       regmap_update_bits(priv->sysctrl_regmap, MT7628_AGPIO_CFG_REG,
>> +                          MT7628_EPHY_P0_DIS, MT7628_EPHY_GPIO_AIO_EN);
>> +
>> +       /* Reset PHY */
>> +       regmap_update_bits(priv->sysctrl_regmap, MT7628_RSTCTRL_REG,
>> +                          0, RSTCTRL_EPHY_RST);
>> +       regmap_update_bits(priv->sysctrl_regmap, MT7628_RSTCTRL_REG,
>> +                          RSTCTRL_EPHY_RST, 0);
>> +       mdelay(10);
>> +
>> +       /* Set P0 EPHY LED mode */
>> +       regmap_update_bits(priv->sysctrl_regmap, MT7628_GPIO2_MODE_REG,
>> +                          0x0ffc0ffc, 0x05540554);
>> +       mdelay(10);
>> +
>> +       mt7628_ephy_init(priv);
>> +}
>> +
>> +static void eth_dma_start(struct mt7628_eth_dev *priv)
>> +{
>> +       void __iomem *base = priv->base;
>> +
>> +       setbits_le32(base + PDMA_GLO_CFG, TX_WB_DDONE | RX_DMA_EN | TX_DMA_EN);
>> +}
>> +
>> +static void eth_dma_stop(struct mt7628_eth_dev *priv)
>> +{
>> +       void __iomem *base = priv->base;
>> +       int ret;
>> +
>> +       clrbits_le32(base + PDMA_GLO_CFG, TX_WB_DDONE | RX_DMA_EN | TX_DMA_EN);
>> +
>> +       /* Wait for DMA to stop */
>> +       ret = wait_for_bit_le32(base + PDMA_GLO_CFG,
>> +                               RX_DMA_BUSY | TX_DMA_BUSY, false,
>> +                               CONFIG_DMA_STOP_TIMEOUT, false);
>> +       if (ret)
>> +               printf("DMA stop timeout error!\n");
>> +}
>> +
>> +static int mt7628_eth_write_hwaddr(struct udevice *dev)
>> +{
>> +       struct mt7628_eth_dev *priv = dev_get_priv(dev);
>> +       void __iomem *base = priv->base;
>> +       u8 *addr = ((struct eth_pdata *)dev_get_platdata(dev))->enetaddr;
>> +       u32 val;
>> +       u16 tmp;
>> +
>> +       /* Set MAC address. */
>> +       tmp = addr[0];
>> +       val = (tmp << 8) | addr[1];
>> +       writel(val, base + SDM_MAC_ADRH);
>> +
>> +       tmp = addr[2];
>> +       val = (tmp << 8) | addr[3];
>> +       val = val << 16;
>> +       tmp = addr[4];
>> +       val |= (tmp << 8) | addr[5];
> 
> Kind of peculiar way to handle this, but sure.
> 
> I would have expected something like:
> 
>         val = addr[2];
>         val = (val << 8) | addr[3];
>         val = (val << 8) | addr[4];
>         val = (val << 8) | addr[5];

Looks better, thanks. Will update in next version.
  
>> +       writel(val, base + SDM_MAC_ADRL);
>> +
>> +       return 0;
>> +}
>> +
>> +static int mt7628_eth_send(struct udevice *dev, void *packet, int length)
>> +{
>> +       struct mt7628_eth_dev *priv = dev_get_priv(dev);
>> +       void __iomem *base = priv->base;
>> +       int ret;
>> +       int idx;
>> +       int i;
>> +
>> +       idx = priv->tx_dma_idx;
>> +
>> +       /* Pad message to a minimum length */
>> +       if (length < PADDING_LENGTH) {
>> +               char *p = (char *)packet;
>> +
>> +               for (i = 0; i < PADDING_LENGTH - length; i++)
>> +                       p[length + i] = 0;
>> +               length = PADDING_LENGTH;
>> +       }
>> +
>> +       /* Check if buffer is ready for next TX DMA */
>> +       ret = wait_for_bit_le32(&priv->tx_ring[idx].txd2, TX_DMA_DONE, true,
>> +                               CONFIG_TX_DMA_TIMEOUT, false);
>> +       if (ret) {
>> +               printf("TX: DMA still busy on buffer %d\n", idx);
>> +               return ret;
>> +       }
>> +
>> +       flush_dcache_range((u32)packet, (u32)packet + length);
>> +
>> +       priv->tx_ring[idx].txd1 = CPHYSADDR(packet);
>> +       priv->tx_ring[idx].txd2 &= ~TX_DMA_PLEN0;
>> +       priv->tx_ring[idx].txd2 |= FIELD_PREP(TX_DMA_PLEN0, length);
>> +       priv->tx_ring[idx].txd2 &= ~TX_DMA_DONE;
>> +
>> +       idx = (idx + 1) % NUM_TX_DESC;
>> +
>> +       /* Make sure the writes executed at this place */
>> +       wmb();
>> +       writel(idx, base + TX_CTX_IDX0);
>> +
>> +       priv->tx_dma_idx = idx;
>> +
>> +       return 0;
>> +}
>> +
>> +static int mt7628_eth_recv(struct udevice *dev, int flags, uchar **packetp)
>> +{
>> +       struct mt7628_eth_dev *priv = dev_get_priv(dev);
>> +       void __iomem *base = priv->base;
>> +       u32 rxd_info;
>> +       int length;
>> +       int idx;
>> +
>> +       idx = priv->rx_dma_idx;
>> +
>> +       rxd_info = priv->rx_ring[idx].rxd2;
>> +       if ((rxd_info & RX_DMA_DONE) == 0)
>> +               return -EAGAIN;
>> +
>> +       length = FIELD_GET(RX_DMA_PLEN0, priv->rx_ring[idx].rxd2);
>> +       if (length == 0 || length > MTK_QDMA_PAGE_SIZE) {
>> +               printf("%s: invalid length (%d bytes)\n", __func__, length);
>> +               return -EIO;
>> +       }
>> +
>> +       *packetp = priv->rx_buf[idx];
>> +       invalidate_dcache_range((u32)*packetp, (u32)*packetp + length);
>> +
>> +       priv->rx_ring[idx].rxd4 = 0;
>> +       priv->rx_ring[idx].rxd2 = RX_DMA_LSO;
>> +
>> +       /* Make sure the writes executed at this place */
>> +       wmb();
>> +
> 
> Seems like everything after this point belongs in a .free_pkt
> function. Am I misreading it?

Yes, you are correct.

Frankly, I've not been using free_pkt in my driver ports yet.
I'll update this in the next patch version.

Thanks,
Stefan


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