The IEEE 802.3 standard guarantees operation of the MDIO signals at up to 2.5MHz (anything above this is a vendor-specific feature, although most PHYs work at higher frequencies). With the EMAC being fed by a (typically) 300MHz clock (e.g. on the A64 this is AHB2, which should be kept at 300MHz according to the CCU documentation), we need to use the divide-by-128 setting to get us below 2.5MHz.

The ~2.34MHz clock signal (i.e. assuring that the MDC clock is indeed derived from the AHB2 clock) has been verified using a A64-uQ7.

Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com --- drivers/net/sun8i_emac.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)

diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c index b87210b..5ae17b7 100644 --- a/drivers/net/sun8i_emac.c +++ b/drivers/net/sun8i_emac.c @@ -1,92 +1,98 @@ /* * (C) Copyright 2016 * Author: Amit Singh Tomar, amittomer25@gmail.com * * SPDX-License-Identifier: GPL-2.0+ * * Ethernet driver for H3/A64/A83T based SoC's * * It is derived from the work done by * LABBE Corentin & Chen-Yu Tsai for Linux, THANKS! * */

#include <asm/io.h> #include <asm/arch/clock.h> #include <asm/arch/gpio.h> #include <common.h> #include <dm.h> #include <fdt_support.h> #include <linux/err.h> #include <malloc.h> #include <miiphy.h> #include <net.h>

#define MDIO_CMD_MII_BUSY BIT(0) #define MDIO_CMD_MII_WRITE BIT(1)

#define MDIO_CMD_MII_PHY_REG_ADDR_MASK 0x000001f0 #define MDIO_CMD_MII_PHY_REG_ADDR_SHIFT 4 #define MDIO_CMD_MII_PHY_ADDR_MASK 0x0001f000 #define MDIO_CMD_MII_PHY_ADDR_SHIFT 12

+#define MDIO_CMD_MDC_DIV_RATIO_M_SHIFT 20 +#define MDIO_CMD_MDC_DIV_16 (0 << MDIO_CMD_MDC_DIV_RATIO_M_SHIFT) +#define MDIO_CMD_MDC_DIV_32 (1 << MDIO_CMD_MDC_DIV_RATIO_M_SHIFT) +#define MDIO_CMD_MDC_DIV_64 (2 << MDIO_CMD_MDC_DIV_RATIO_M_SHIFT) +#define MDIO_CMD_MDC_DIV_128 (3 << MDIO_CMD_MDC_DIV_RATIO_M_SHIFT) + #define CONFIG_TX_DESCR_NUM 32 #define CONFIG_RX_DESCR_NUM 32 #define CONFIG_ETH_BUFSIZE 2048 /* Note must be dma aligned */

/* * The datasheet says that each descriptor can transfers up to 4096 bytes * But later, the register documentation reduces that value to 2048, * using 2048 cause strange behaviours and even BSP driver use 2047 */ #define CONFIG_ETH_RXSIZE 2044 /* Note must fit in ETH_BUFSIZE */

#define TX_TOTAL_BUFSIZE (CONFIG_ETH_BUFSIZE * CONFIG_TX_DESCR_NUM) #define RX_TOTAL_BUFSIZE (CONFIG_ETH_BUFSIZE * CONFIG_RX_DESCR_NUM)

#define H3_EPHY_DEFAULT_VALUE 0x58000 #define H3_EPHY_DEFAULT_MASK GENMASK(31, 15) #define H3_EPHY_ADDR_SHIFT 20 #define REG_PHY_ADDR_MASK GENMASK(4, 0) #define H3_EPHY_LED_POL BIT(17) /* 1: active low, 0: active high */ #define H3_EPHY_SHUTDOWN BIT(16) /* 1: shutdown, 0: power up */ #define H3_EPHY_SELECT BIT(15) /* 1: internal PHY, 0: external PHY */

#define SC_RMII_EN BIT(13) #define SC_EPIT BIT(2) /* 1: RGMII, 0: MII */ #define SC_ETCS_MASK GENMASK(1, 0) #define SC_ETCS_EXT_GMII 0x1 #define SC_ETCS_INT_GMII 0x2

#define CONFIG_MDIO_TIMEOUT (3 * CONFIG_SYS_HZ)

#define AHB_GATE_OFFSET_EPHY 0

#if defined(CONFIG_MACH_SUN8I_H3) #define SUN8I_GPD8_GMAC 2 #else #define SUN8I_GPD8_GMAC 4 #endif

/* H3/A64 EMAC Register's offset */ #define EMAC_CTL0 0x00 #define EMAC_CTL1 0x04 #define EMAC_INT_STA 0x08 #define EMAC_INT_EN 0x0c #define EMAC_TX_CTL0 0x10 #define EMAC_TX_CTL1 0x14 #define EMAC_TX_FLOW_CTL 0x1c #define EMAC_TX_DMA_DESC 0x20 #define EMAC_RX_CTL0 0x24 #define EMAC_RX_CTL1 0x28 #define EMAC_RX_DMA_DESC 0x34 #define EMAC_MII_CMD 0x48 #define EMAC_MII_DATA 0x4c #define EMAC_ADDR0_HIGH 0x50 #define EMAC_ADDR0_LOW 0x54 #define EMAC_TX_DMA_STA 0xb0 #define EMAC_TX_CUR_DESC 0xb4 #define EMAC_TX_CUR_BUF 0xb8 #define EMAC_RX_DMA_STA 0xc0 #define EMAC_RX_CUR_DESC 0xc4

@@ -133,66 +139,74 @@ struct emac_eth_dev { static int sun8i_mdio_read(struct mii_dev *bus, int addr, int devad, int reg) { struct emac_eth_dev *priv = bus->priv; ulong start; u32 miiaddr = 0; int timeout = CONFIG_MDIO_TIMEOUT;

miiaddr &= ~MDIO_CMD_MII_WRITE; miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK; miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) & MDIO_CMD_MII_PHY_REG_ADDR_MASK;

miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK;

miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) & MDIO_CMD_MII_PHY_ADDR_MASK;

+ /* The MAC block is fed by a 300MHz clock, so we need to divide by 128 + to bring the MDC into the range permissible by the IEEE standard. */ + miiaddr |= MDIO_CMD_MDC_DIV_128; + miiaddr |= MDIO_CMD_MII_BUSY;

writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);

start = get_timer(0); while (get_timer(start) < timeout) { if (!(readl(priv->mac_reg + EMAC_MII_CMD) & MDIO_CMD_MII_BUSY)) return readl(priv->mac_reg + EMAC_MII_DATA); udelay(10); };

return -1; }

static int sun8i_mdio_write(struct mii_dev *bus, int addr, int devad, int reg, u16 val) { struct emac_eth_dev *priv = bus->priv; ulong start; u32 miiaddr = 0; int ret = -1, timeout = CONFIG_MDIO_TIMEOUT;

miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK; miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) & MDIO_CMD_MII_PHY_REG_ADDR_MASK;

miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK; miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) & MDIO_CMD_MII_PHY_ADDR_MASK;

miiaddr |= MDIO_CMD_MII_WRITE; miiaddr |= MDIO_CMD_MII_BUSY;

+ /* The MAC block is fed by a 300MHz clock, so we need to divide by 128 + to bring the MDC into the range permissible by the IEEE standard. */ + miiaddr |= MDIO_CMD_MDC_DIV_128; + writel(val, priv->mac_reg + EMAC_MII_DATA); writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);

start = get_timer(0); while (get_timer(start) < timeout) { if (!(readl(priv->mac_reg + EMAC_MII_CMD) & MDIO_CMD_MII_BUSY)) { ret = 0; break; } udelay(10); };

return ret; }