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  • /***********************************************************************
     *
     * Copyright (c) 2005 Freescale Semiconductor, Inc.
     *
     * See file CREDITS for list of people who contributed to this
     * project.
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License as
     * published by the Free Software Foundation; either version 2 of
     * the License, or (at your option) any later version.
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program; if not, write to the Free Software
     * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     *
     * Description:
     *   Ethernet interface for Tundra TSI108 bridge chip
     *
     ***********************************************************************/
    
    #include <config.h>
    
    #if !defined(CONFIG_TSI108_ETH_NUM_PORTS) || (CONFIG_TSI108_ETH_NUM_PORTS > 2)
    #error "CONFIG_TSI108_ETH_NUM_PORTS must be defined as 1 or 2"
    #endif
    
    #include <common.h>
    #include <malloc.h>
    #include <net.h>
    
    #include <asm/cache.h>
    
    #ifdef DEBUG
    #define TSI108_ETH_DEBUG 7
    #else
    #define TSI108_ETH_DEBUG 0
    #endif
    
    #if TSI108_ETH_DEBUG > 0
    
    #define debug_lev(lev, fmt, args...) \
    if (lev <= TSI108_ETH_DEBUG) \
    printf ("%s %d: " fmt, __FUNCTION__, __LINE__, ##args)
    
    #else
    #define debug_lev(lev, fmt, args...) do{}while(0)
    #endif
    
    #define RX_PRINT_ERRORS
    #define TX_PRINT_ERRORS
    
    
    #define ETH_BASE	(CONFIG_SYS_TSI108_CSR_BASE + 0x6000)
    
    #define ETH_PORT_OFFSET	0x400
    
    
    #define __REG32(base, offset) (*((volatile u32 *)((char *)(base) + (offset))))
    
    
    #define reg_MAC_CONFIG_1(base)		__REG32(base, 0x00000000)
    #define MAC_CONFIG_1_TX_ENABLE		(0x00000001)
    #define MAC_CONFIG_1_SYNC_TX_ENABLE	(0x00000002)
    #define MAC_CONFIG_1_RX_ENABLE		(0x00000004)
    #define MAC_CONFIG_1_SYNC_RX_ENABLE	(0x00000008)
    #define MAC_CONFIG_1_TX_FLOW_CONTROL	(0x00000010)
    #define MAC_CONFIG_1_RX_FLOW_CONTROL	(0x00000020)
    #define MAC_CONFIG_1_LOOP_BACK		(0x00000100)
    #define MAC_CONFIG_1_RESET_TX_FUNCTION	(0x00010000)
    #define MAC_CONFIG_1_RESET_RX_FUNCTION	(0x00020000)
    #define MAC_CONFIG_1_RESET_TX_MAC	(0x00040000)
    #define MAC_CONFIG_1_RESET_RX_MAC	(0x00080000)
    #define MAC_CONFIG_1_SIM_RESET		(0x40000000)
    #define MAC_CONFIG_1_SOFT_RESET		(0x80000000)
    
    #define reg_MAC_CONFIG_2(base)		__REG32(base, 0x00000004)
    #define MAC_CONFIG_2_FULL_DUPLEX	(0x00000001)
    #define MAC_CONFIG_2_CRC_ENABLE		(0x00000002)
    #define MAC_CONFIG_2_PAD_CRC		(0x00000004)
    #define MAC_CONFIG_2_LENGTH_CHECK	(0x00000010)
    #define MAC_CONFIG_2_HUGE_FRAME		(0x00000020)
    #define MAC_CONFIG_2_INTERFACE_MODE(val)	(((val) & 0x3) << 8)
    #define MAC_CONFIG_2_PREAMBLE_LENGTH(val)	(((val) & 0xf) << 12)
    #define INTERFACE_MODE_NIBBLE		1	/* 10/100 Mb/s MII) */
    #define INTERFACE_MODE_BYTE		2	/* 1000 Mb/s GMII/TBI */
    
    #define reg_MAXIMUM_FRAME_LENGTH(base)		__REG32(base, 0x00000010)
    
    #define reg_MII_MGMT_CONFIG(base)		__REG32(base, 0x00000020)
    #define MII_MGMT_CONFIG_MGMT_CLOCK_SELECT(val)	((val) & 0x7)
    #define MII_MGMT_CONFIG_NO_PREAMBLE		(0x00000010)
    #define MII_MGMT_CONFIG_SCAN_INCREMENT		(0x00000020)
    #define MII_MGMT_CONFIG_RESET_MGMT		(0x80000000)
    
    #define reg_MII_MGMT_COMMAND(base)		__REG32(base, 0x00000024)
    #define MII_MGMT_COMMAND_READ_CYCLE		(0x00000001)
    #define MII_MGMT_COMMAND_SCAN_CYCLE		(0x00000002)
    
    #define reg_MII_MGMT_ADDRESS(base)		__REG32(base, 0x00000028)
    #define reg_MII_MGMT_CONTROL(base)		__REG32(base, 0x0000002c)
    #define reg_MII_MGMT_STATUS(base)		__REG32(base, 0x00000030)
    
    #define reg_MII_MGMT_INDICATORS(base)		__REG32(base, 0x00000034)
    #define MII_MGMT_INDICATORS_BUSY		(0x00000001)
    #define MII_MGMT_INDICATORS_SCAN		(0x00000002)
    #define MII_MGMT_INDICATORS_NOT_VALID		(0x00000004)
    
    #define reg_INTERFACE_STATUS(base)		__REG32(base, 0x0000003c)
    #define INTERFACE_STATUS_LINK_FAIL		(0x00000008)
    #define INTERFACE_STATUS_EXCESS_DEFER		(0x00000200)
    
    #define reg_STATION_ADDRESS_1(base)		__REG32(base, 0x00000040)
    #define reg_STATION_ADDRESS_2(base)		__REG32(base, 0x00000044)
    
    #define reg_PORT_CONTROL(base)			__REG32(base, 0x00000200)
    #define PORT_CONTROL_PRI		(0x00000001)
    #define PORT_CONTROL_BPT		(0x00010000)
    #define PORT_CONTROL_SPD		(0x00040000)
    #define PORT_CONTROL_RBC		(0x00080000)
    #define PORT_CONTROL_PRB		(0x00200000)
    #define PORT_CONTROL_DIS		(0x00400000)
    #define PORT_CONTROL_TBI		(0x00800000)
    #define PORT_CONTROL_STE		(0x10000000)
    #define PORT_CONTROL_ZOR		(0x20000000)
    #define PORT_CONTROL_CLR		(0x40000000)
    #define PORT_CONTROL_SRT		(0x80000000)
    
    #define reg_TX_CONFIG(base)		__REG32(base, 0x00000220)
    #define TX_CONFIG_START_Q		(0x00000003)
    #define TX_CONFIG_EHP			(0x00400000)
    #define TX_CONFIG_CHP			(0x00800000)
    #define TX_CONFIG_RST			(0x80000000)
    
    #define reg_TX_CONTROL(base)		__REG32(base, 0x00000224)
    #define TX_CONTROL_GO			(0x00008000)
    #define TX_CONTROL_MP			(0x01000000)
    #define TX_CONTROL_EAI			(0x20000000)
    #define TX_CONTROL_ABT			(0x40000000)
    #define TX_CONTROL_EII			(0x80000000)
    
    #define reg_TX_STATUS(base)		__REG32(base, 0x00000228)
    #define TX_STATUS_QUEUE_USABLE		(0x0000000f)
    #define TX_STATUS_CURR_Q		(0x00000300)
    #define TX_STATUS_ACT			(0x00008000)
    #define TX_STATUS_QUEUE_IDLE		(0x000f0000)
    #define TX_STATUS_EOQ_PENDING		(0x0f000000)
    
    #define reg_TX_EXTENDED_STATUS(base)		__REG32(base, 0x0000022c)
    #define TX_EXTENDED_STATUS_END_OF_QUEUE_CONDITION		(0x0000000f)
    #define TX_EXTENDED_STATUS_END_OF_FRAME_CONDITION		(0x00000f00)
    #define TX_EXTENDED_STATUS_DESCRIPTOR_INTERRUPT_CONDITION	(0x000f0000)
    #define TX_EXTENDED_STATUS_ERROR_FLAG				(0x0f000000)
    
    #define reg_TX_THRESHOLDS(base)			__REG32(base, 0x00000230)
    
    
    #define reg_TX_DIAGNOSTIC_ADDR(base)           __REG32(base, 0x00000270)
    
    #define TX_DIAGNOSTIC_ADDR_INDEX		(0x0000007f)
    #define TX_DIAGNOSTIC_ADDR_DFR			(0x40000000)
    #define TX_DIAGNOSTIC_ADDR_AI			(0x80000000)
    
    #define reg_TX_DIAGNOSTIC_DATA(base)		__REG32(base, 0x00000274)
    
    #define reg_TX_ERROR_STATUS(base)		__REG32(base, 0x00000278)
    #define TX_ERROR_STATUS				(0x00000278)
    #define TX_ERROR_STATUS_QUEUE_0_ERROR_RESPONSE	(0x0000000f)
    #define TX_ERROR_STATUS_TEA_ON_QUEUE_0		(0x00000010)
    #define TX_ERROR_STATUS_RER_ON_QUEUE_0		(0x00000020)
    #define TX_ERROR_STATUS_TER_ON_QUEUE_0		(0x00000040)
    #define TX_ERROR_STATUS_DER_ON_QUEUE_0		(0x00000080)
    #define TX_ERROR_STATUS_QUEUE_1_ERROR_RESPONSE	(0x00000f00)
    #define TX_ERROR_STATUS_TEA_ON_QUEUE_1		(0x00001000)
    #define TX_ERROR_STATUS_RER_ON_QUEUE_1		(0x00002000)
    #define TX_ERROR_STATUS_TER_ON_QUEUE_1		(0x00004000)
    #define TX_ERROR_STATUS_DER_ON_QUEUE_1		(0x00008000)
    #define TX_ERROR_STATUS_QUEUE_2_ERROR_RESPONSE	(0x000f0000)
    #define TX_ERROR_STATUS_TEA_ON_QUEUE_2		(0x00100000)
    #define TX_ERROR_STATUS_RER_ON_QUEUE_2		(0x00200000)
    #define TX_ERROR_STATUS_TER_ON_QUEUE_2		(0x00400000)
    #define TX_ERROR_STATUS_DER_ON_QUEUE_2		(0x00800000)
    #define TX_ERROR_STATUS_QUEUE_3_ERROR_RESPONSE	(0x0f000000)
    #define TX_ERROR_STATUS_TEA_ON_QUEUE_3		(0x10000000)
    #define TX_ERROR_STATUS_RER_ON_QUEUE_3		(0x20000000)
    #define TX_ERROR_STATUS_TER_ON_QUEUE_3		(0x40000000)
    #define TX_ERROR_STATUS_DER_ON_QUEUE_3		(0x80000000)
    
    #define reg_TX_QUEUE_0_CONFIG(base)		__REG32(base, 0x00000280)
    #define TX_QUEUE_0_CONFIG_OCN_PORT		(0x0000003f)
    #define TX_QUEUE_0_CONFIG_BSWP			(0x00000400)
    #define TX_QUEUE_0_CONFIG_WSWP			(0x00000800)
    #define TX_QUEUE_0_CONFIG_AM			(0x00004000)
    #define TX_QUEUE_0_CONFIG_GVI			(0x00008000)
    #define TX_QUEUE_0_CONFIG_EEI			(0x00010000)
    #define TX_QUEUE_0_CONFIG_ELI			(0x00020000)
    #define TX_QUEUE_0_CONFIG_ENI			(0x00040000)
    #define TX_QUEUE_0_CONFIG_ESI			(0x00080000)
    #define TX_QUEUE_0_CONFIG_EDI			(0x00100000)
    
    #define reg_TX_QUEUE_0_BUF_CONFIG(base)		__REG32(base, 0x00000284)
    #define TX_QUEUE_0_BUF_CONFIG_OCN_PORT		(0x0000003f)
    #define TX_QUEUE_0_BUF_CONFIG_BURST		(0x00000300)
    #define TX_QUEUE_0_BUF_CONFIG_BSWP		(0x00000400)
    #define TX_QUEUE_0_BUF_CONFIG_WSWP		(0x00000800)
    
    #define OCN_PORT_HLP			0	/* HLP Interface */
    #define OCN_PORT_PCI_X			1	/* PCI-X Interface */
    
    #define OCN_PORT_PROCESSOR_MASTER	2	/* Processor Interface (master) */
    
    #define OCN_PORT_PROCESSOR_SLAVE	3	/* Processor Interface (slave) */
    #define OCN_PORT_MEMORY			4	/* Memory Controller */
    #define OCN_PORT_DMA			5	/* DMA Controller */
    #define OCN_PORT_ETHERNET		6	/* Ethernet Controller */
    #define OCN_PORT_PRINT			7	/* Print Engine Interface */
    
    #define reg_TX_QUEUE_0_PTR_LOW(base)		__REG32(base, 0x00000288)
    
    #define reg_TX_QUEUE_0_PTR_HIGH(base)		__REG32(base, 0x0000028c)
    #define TX_QUEUE_0_PTR_HIGH_VALID		(0x80000000)
    
    #define reg_RX_CONFIG(base)			__REG32(base, 0x00000320)
    #define RX_CONFIG_DEF_Q				(0x00000003)
    #define RX_CONFIG_EMF				(0x00000100)
    #define RX_CONFIG_EUF				(0x00000200)
    #define RX_CONFIG_BFE				(0x00000400)
    #define RX_CONFIG_MFE				(0x00000800)
    #define RX_CONFIG_UFE				(0x00001000)
    #define RX_CONFIG_SE				(0x00002000)
    #define RX_CONFIG_ABF				(0x00200000)
    #define RX_CONFIG_APE				(0x00400000)
    #define RX_CONFIG_CHP				(0x00800000)
    #define RX_CONFIG_RST				(0x80000000)
    
    #define reg_RX_CONTROL(base)			__REG32(base, 0x00000324)
    #define GE_E0_RX_CONTROL_QUEUE_ENABLES		(0x0000000f)
    #define GE_E0_RX_CONTROL_GO			(0x00008000)
    #define GE_E0_RX_CONTROL_EAI			(0x20000000)
    #define GE_E0_RX_CONTROL_ABT			(0x40000000)
    #define GE_E0_RX_CONTROL_EII			(0x80000000)
    
    #define reg_RX_EXTENDED_STATUS(base)		__REG32(base, 0x0000032c)
    #define RX_EXTENDED_STATUS			(0x0000032c)
    #define RX_EXTENDED_STATUS_EOQ			(0x0000000f)
    #define RX_EXTENDED_STATUS_EOQ_0		(0x00000001)
    #define RX_EXTENDED_STATUS_EOF			(0x00000f00)
    #define RX_EXTENDED_STATUS_DESCRIPTOR_INTERRUPT_CONDITION	(0x000f0000)
    #define RX_EXTENDED_STATUS_ERROR_FLAG				(0x0f000000)
    
    #define reg_RX_THRESHOLDS(base)			__REG32(base, 0x00000330)
    
    #define reg_RX_DIAGNOSTIC_ADDR(base)		__REG32(base, 0x00000370)
    #define RX_DIAGNOSTIC_ADDR_INDEX		(0x0000007f)
    #define RX_DIAGNOSTIC_ADDR_DFR			(0x40000000)
    #define RX_DIAGNOSTIC_ADDR_AI			(0x80000000)
    
    #define reg_RX_DIAGNOSTIC_DATA(base)		__REG32(base, 0x00000374)
    
    #define reg_RX_QUEUE_0_CONFIG(base)		__REG32(base, 0x00000380)
    #define RX_QUEUE_0_CONFIG_OCN_PORT		(0x0000003f)
    #define RX_QUEUE_0_CONFIG_BSWP			(0x00000400)
    #define RX_QUEUE_0_CONFIG_WSWP			(0x00000800)
    #define RX_QUEUE_0_CONFIG_AM			(0x00004000)
    #define RX_QUEUE_0_CONFIG_EEI			(0x00010000)
    #define RX_QUEUE_0_CONFIG_ELI			(0x00020000)
    #define RX_QUEUE_0_CONFIG_ENI			(0x00040000)
    #define RX_QUEUE_0_CONFIG_ESI			(0x00080000)
    #define RX_QUEUE_0_CONFIG_EDI			(0x00100000)
    
    #define reg_RX_QUEUE_0_BUF_CONFIG(base)		__REG32(base, 0x00000384)
    #define RX_QUEUE_0_BUF_CONFIG_OCN_PORT		(0x0000003f)
    #define RX_QUEUE_0_BUF_CONFIG_BURST		(0x00000300)
    #define RX_QUEUE_0_BUF_CONFIG_BSWP		(0x00000400)
    #define RX_QUEUE_0_BUF_CONFIG_WSWP		(0x00000800)
    
    #define reg_RX_QUEUE_0_PTR_LOW(base)		__REG32(base, 0x00000388)
    
    #define reg_RX_QUEUE_0_PTR_HIGH(base)		__REG32(base, 0x0000038c)
    #define RX_QUEUE_0_PTR_HIGH_VALID		(0x80000000)
    
    
    /*
     *  PHY register definitions
     */
    /* the first 15 PHY registers are standard. */
    
    #define PHY_CTRL_REG		0	/* Control Register */
    #define PHY_STATUS_REG		1	/* Status Regiser */
    #define PHY_ID1_REG		2	/* Phy Id Reg (word 1) */
    #define PHY_ID2_REG		3	/* Phy Id Reg (word 2) */
    #define PHY_AN_ADV_REG		4	/* Autoneg Advertisement */
    #define PHY_LP_ABILITY_REG	5	/* Link Partner Ability (Base Page) */
    #define PHY_AUTONEG_EXP_REG	6	/* Autoneg Expansion Reg */
    #define PHY_NEXT_PAGE_TX_REG	7	/* Next Page TX */
    #define PHY_LP_NEXT_PAGE_REG	8	/* Link Partner Next Page */
    #define PHY_1000T_CTRL_REG	9	/* 1000Base-T Control Reg */
    #define PHY_1000T_STATUS_REG	10	/* 1000Base-T Status Reg */
    #define PHY_EXT_STATUS_REG	11	/* Extended Status Reg */
    
    
    /*
     * PHY Register bit masks.
     */
    
    #define PHY_CTRL_RESET		(1 << 15)
    #define PHY_CTRL_LOOPBACK	(1 << 14)
    #define PHY_CTRL_SPEED0		(1 << 13)
    #define PHY_CTRL_AN_EN		(1 << 12)
    #define PHY_CTRL_PWR_DN		(1 << 11)
    #define PHY_CTRL_ISOLATE	(1 << 10)
    #define PHY_CTRL_RESTART_AN	(1 << 9)
    #define PHY_CTRL_FULL_DUPLEX	(1 << 8)
    #define PHY_CTRL_CT_EN		(1 << 7)
    #define PHY_CTRL_SPEED1		(1 << 6)
    
    #define PHY_STAT_100BASE_T4	(1 << 15)
    #define PHY_STAT_100BASE_X_FD	(1 << 14)
    #define PHY_STAT_100BASE_X_HD	(1 << 13)
    #define PHY_STAT_10BASE_T_FD	(1 << 12)
    #define PHY_STAT_10BASE_T_HD	(1 << 11)
    #define PHY_STAT_100BASE_T2_FD	(1 << 10)
    #define PHY_STAT_100BASE_T2_HD	(1 << 9)
    #define PHY_STAT_EXT_STAT	(1 << 8)
    #define PHY_STAT_RESERVED	(1 << 7)
    #define PHY_STAT_MFPS		(1 << 6)	/* Management Frames Preamble Suppression */
    #define PHY_STAT_AN_COMPLETE	(1 << 5)
    #define PHY_STAT_REM_FAULT	(1 << 4)
    #define PHY_STAT_AN_CAP		(1 << 3)
    #define PHY_STAT_LINK_UP	(1 << 2)
    #define PHY_STAT_JABBER		(1 << 1)
    #define PHY_STAT_EXT_CAP	(1 << 0)
    
    #define TBI_CONTROL_2					0x11
    #define TBI_CONTROL_2_ENABLE_COMMA_DETECT		0x0001
    #define TBI_CONTROL_2_ENABLE_WRAP			0x0002
    #define TBI_CONTROL_2_G_MII_MODE			0x0010
    #define TBI_CONTROL_2_RECEIVE_CLOCK_SELECT		0x0020
    #define TBI_CONTROL_2_AUTO_NEGOTIATION_SENSE		0x0100
    #define TBI_CONTROL_2_DISABLE_TRANSMIT_RUNNING_DISPARITY	0x1000
    #define TBI_CONTROL_2_DISABLE_RECEIVE_RUNNING_DISPARITY		0x2000
    #define TBI_CONTROL_2_SHORTCUT_LINK_TIMER			0x4000
    #define TBI_CONTROL_2_SOFT_RESET				0x8000
    
    
    /* marvel specific */
    
    #define MV1111_EXT_CTRL1_REG	16	/* PHY Specific Control Reg */
    #define MV1111_SPEC_STAT_REG	17	/* PHY Specific Status Reg */
    #define MV1111_EXT_CTRL2_REG	20	/* Extended PHY Specific Control Reg */
    
    
    /*
     * MARVELL 88E1111 PHY register bit masks
     */
    /* PHY Specific Status Register (MV1111_EXT_CTRL1_REG) */
    
    
    #define SPEC_STAT_SPEED_MASK	(3 << 14)
    #define SPEC_STAT_FULL_DUP	(1 << 13)
    #define SPEC_STAT_PAGE_RCVD	(1 << 12)
    #define SPEC_STAT_RESOLVED	(1 << 11)	/* Speed and Duplex Resolved */
    #define SPEC_STAT_LINK_UP	(1 << 10)
    #define SPEC_STAT_CABLE_LEN_MASK	(7 << 7)/* Cable Length (100/1000 modes only) */
    #define SPEC_STAT_MDIX		(1 << 6)
    #define SPEC_STAT_POLARITY	(1 << 1)
    #define SPEC_STAT_JABBER	(1 << 0)
    
    #define SPEED_1000		(2 << 14)
    #define SPEED_100		(1 << 14)
    #define SPEED_10		(0 << 14)
    
    #define TBI_ADDR	0x1E	/* Ten Bit Interface address */
    
    
    /* negotiated link parameters */
    
    #define LINK_SPEED_UNKNOWN	0
    #define LINK_SPEED_10		1
    #define LINK_SPEED_100		2
    #define LINK_SPEED_1000		3
    
    #define LINK_DUPLEX_UNKNOWN	0
    #define LINK_DUPLEX_HALF	1
    #define LINK_DUPLEX_FULL	2
    
    
    static unsigned int phy_address[] = { 8, 9 };
    
    #define vuint32 volatile u32
    
    /* TX/RX buffer descriptors. MUST be cache line aligned in memory. (32 byte)
     * This structure is accessed by the ethernet DMA engine which means it
     * MUST be in LITTLE ENDIAN format */
    struct dma_descriptor {
    	vuint32 start_addr0;	/* buffer address, least significant bytes. */
    	vuint32 start_addr1;	/* buffer address, most significant bytes. */
    	vuint32 next_descr_addr0;/* next descriptor address, least significant bytes.  Must be 64-bit aligned. */
    	vuint32 next_descr_addr1;/* next descriptor address, most significant bytes. */
    	vuint32 vlan_byte_count;/* VLAN tag(top 2 bytes) and byte countt (bottom 2 bytes). */
    	vuint32 config_status;	/* Configuration/Status. */
    	vuint32 reserved1;	/* reserved to make the descriptor cache line aligned. */
    	vuint32 reserved2;	/* reserved to make the descriptor cache line aligned. */
    };
    
    /* last next descriptor address flag */
    
    #define DMA_DESCR_LAST		(1 << 31)
    
    
    /* TX DMA descriptor config status bits */
    
    #define DMA_DESCR_TX_EOF	(1 <<  0)	/* end of frame */
    #define DMA_DESCR_TX_SOF	(1 <<  1)	/* start of frame */
    #define DMA_DESCR_TX_PFVLAN	(1 <<  2)
    #define DMA_DESCR_TX_HUGE	(1 <<  3)
    #define DMA_DESCR_TX_PAD	(1 <<  4)
    #define DMA_DESCR_TX_CRC	(1 <<  5)
    #define DMA_DESCR_TX_DESCR_INT	(1 << 14)
    #define DMA_DESCR_TX_RETRY_COUNT	0x000F0000
    #define DMA_DESCR_TX_ONE_COLLISION	(1 << 20)
    #define DMA_DESCR_TX_LATE_COLLISION	(1 << 24)
    #define DMA_DESCR_TX_UNDERRUN		(1 << 25)
    #define DMA_DESCR_TX_RETRY_LIMIT	(1 << 26)
    #define DMA_DESCR_TX_OK			(1 << 30)
    #define DMA_DESCR_TX_OWNER		(1 << 31)
    
    
    /* RX DMA descriptor status bits */
    
    #define DMA_DESCR_RX_EOF		(1 <<  0)
    #define DMA_DESCR_RX_SOF		(1 <<  1)
    #define DMA_DESCR_RX_VTF		(1 <<  2)
    #define DMA_DESCR_RX_FRAME_IS_TYPE	(1 <<  3)
    #define DMA_DESCR_RX_SHORT_FRAME	(1 <<  4)
    #define DMA_DESCR_RX_HASH_MATCH		(1 <<  7)
    #define DMA_DESCR_RX_BAD_FRAME		(1 <<  8)
    #define DMA_DESCR_RX_OVERRUN		(1 <<  9)
    #define DMA_DESCR_RX_MAX_FRAME_LEN	(1 << 11)
    #define DMA_DESCR_RX_CRC_ERROR		(1 << 12)
    #define DMA_DESCR_RX_DESCR_INT		(1 << 13)
    #define DMA_DESCR_RX_OWNER		(1 << 15)
    
    #define RX_BUFFER_SIZE	PKTSIZE
    #define NUM_RX_DESC	PKTBUFSRX
    
    
    static struct dma_descriptor tx_descriptor __attribute__ ((aligned(32)));
    
    static struct dma_descriptor rx_descr_array[NUM_RX_DESC]
    
    	__attribute__ ((aligned(32)));
    
    
    static struct dma_descriptor *rx_descr_current;
    
    
    static int tsi108_eth_probe (struct eth_device *dev, bd_t * bis);
    
    static int tsi108_eth_send(struct eth_device *dev, void *packet, int length);
    
    static int tsi108_eth_recv (struct eth_device *dev);
    static void tsi108_eth_halt (struct eth_device *dev);
    static unsigned int read_phy (unsigned int base,
    
    			     unsigned int phy_addr, unsigned int phy_reg);
    
    static void write_phy (unsigned int base,
    
    		      unsigned int phy_addr,
    		      unsigned int phy_reg, unsigned int phy_data);
    
    #if TSI108_ETH_DEBUG > 100
    /*
     * print phy debug infomation
     */
    
    static void dump_phy_regs (unsigned int phy_addr)
    
    	printf ("PHY %d registers\n", phy_addr);
    
    	for (i = 0; i <= 30; i++) {
    
    		printf ("%2d  0x%04x\n", i, read_phy (ETH_BASE, phy_addr, i));
    
    	printf ("\n");
    
    
    }
    #else
    #define dump_phy_regs(base) do{}while(0)
    #endif
    
    #if TSI108_ETH_DEBUG > 100
    /*
     * print debug infomation
     */
    
    static void tx_diag_regs (unsigned int base)
    
    {
    	int i;
    	unsigned long dummy;
    
    
    	printf ("TX diagnostics registers\n");
    
    	reg_TX_DIAGNOSTIC_ADDR(base) = 0x00 | TX_DIAGNOSTIC_ADDR_AI;
    
    	udelay (1000);
    
    	dummy = reg_TX_DIAGNOSTIC_DATA(base);
    	for (i = 0x00; i <= 0x05; i++) {
    
    		udelay (1000);
    		printf ("0x%02x  0x%08x\n", i, reg_TX_DIAGNOSTIC_DATA(base));
    
    	}
    	reg_TX_DIAGNOSTIC_ADDR(base) = 0x40 | TX_DIAGNOSTIC_ADDR_AI;
    
    	udelay (1000);
    
    	dummy = reg_TX_DIAGNOSTIC_DATA(base);
    	for (i = 0x40; i <= 0x47; i++) {
    
    		udelay (1000);
    		printf ("0x%02x  0x%08x\n", i, reg_TX_DIAGNOSTIC_DATA(base));
    
    	printf ("\n");
    
    
    }
    #else
    #define tx_diag_regs(base) do{}while(0)
    #endif
    
    #if TSI108_ETH_DEBUG > 100
    /*
     * print debug infomation
     */
    
    static void rx_diag_regs (unsigned int base)
    
    {
    	int i;
    	unsigned long dummy;
    
    
    	printf ("RX diagnostics registers\n");
    
    	reg_RX_DIAGNOSTIC_ADDR(base) = 0x00 | RX_DIAGNOSTIC_ADDR_AI;
    
    	udelay (1000);
    
    	dummy = reg_RX_DIAGNOSTIC_DATA(base);
    	for (i = 0x00; i <= 0x05; i++) {
    
    		udelay (1000);
    		printf ("0x%02x  0x%08x\n", i, reg_RX_DIAGNOSTIC_DATA(base));
    
    	}
    	reg_RX_DIAGNOSTIC_ADDR(base) = 0x40 | RX_DIAGNOSTIC_ADDR_AI;
    
    	udelay (1000);
    
    	dummy = reg_RX_DIAGNOSTIC_DATA(base);
    	for (i = 0x08; i <= 0x0a; i++) {
    
    		udelay (1000);
    		printf ("0x%02x  0x%08x\n", i, reg_RX_DIAGNOSTIC_DATA(base));
    
    	printf ("\n");
    
    
    }
    #else
    #define rx_diag_regs(base) do{}while(0)
    #endif
    
    #if TSI108_ETH_DEBUG > 100
    /*
     * print debug infomation
     */
    
    static void debug_mii_regs (unsigned int base)
    
    	printf ("MII_MGMT_CONFIG     0x%08x\n", reg_MII_MGMT_CONFIG(base));
    	printf ("MII_MGMT_COMMAND    0x%08x\n", reg_MII_MGMT_COMMAND(base));
    	printf ("MII_MGMT_ADDRESS    0x%08x\n", reg_MII_MGMT_ADDRESS(base));
    	printf ("MII_MGMT_CONTROL    0x%08x\n", reg_MII_MGMT_CONTROL(base));
    	printf ("MII_MGMT_STATUS     0x%08x\n", reg_MII_MGMT_STATUS(base));
    	printf ("MII_MGMT_INDICATORS 0x%08x\n", reg_MII_MGMT_INDICATORS(base));
    	printf ("\n");
    
    
    }
    #else
    #define debug_mii_regs(base) do{}while(0)
    #endif
    
    /*
     * Wait until the phy bus is non-busy
     */
    
    static void phy_wait (unsigned int base, unsigned int condition)
    
    {
    	int timeout;
    
    	timeout = 0;
    	while (reg_MII_MGMT_INDICATORS(base) & condition) {
    
    		udelay (10);
    
    		if (++timeout > 10000) {
    
    			printf ("ERROR: timeout waiting for phy bus (%d)\n",
    
    static unsigned int read_phy (unsigned int base,
    
    			     unsigned int phy_addr, unsigned int phy_reg)
    {
    	unsigned int value;
    
    
    	phy_wait (base, MII_MGMT_INDICATORS_BUSY);
    
    
    	reg_MII_MGMT_ADDRESS(base) = (phy_addr << 8) | phy_reg;
    
    	/* Ensure that the Read Cycle bit is cleared prior to next read cycle */
    	reg_MII_MGMT_COMMAND(base) = 0;
    
    	/* start the read */
    	reg_MII_MGMT_COMMAND(base) = MII_MGMT_COMMAND_READ_CYCLE;
    
    	/* wait for the read to complete */
    
    	phy_wait (base,
    
    		 MII_MGMT_INDICATORS_NOT_VALID | MII_MGMT_INDICATORS_BUSY);
    
    	value = reg_MII_MGMT_STATUS(base);
    
    	reg_MII_MGMT_COMMAND(base) = 0;
    
    	return value;
    }
    
    /*
     * write phy register
     */
    
    static void write_phy (unsigned int base,
    
    		      unsigned int phy_addr,
    		      unsigned int phy_reg, unsigned int phy_data)
    {
    
    	phy_wait (base, MII_MGMT_INDICATORS_BUSY);
    
    
    	reg_MII_MGMT_ADDRESS(base) = (phy_addr << 8) | phy_reg;
    
    	/* Ensure that the Read Cycle bit is cleared prior to next cycle */
    	reg_MII_MGMT_COMMAND(base) = 0;
    
    	/* start the write */
    	reg_MII_MGMT_CONTROL(base) = phy_data;
    }
    
    /*
     * configure the marvell 88e1111 phy
     */
    
    static int marvell_88e_phy_config (struct eth_device *dev, int *speed,
    
    				  int *duplex)
    {
    	unsigned long base;
    	unsigned long phy_addr;
    	unsigned int phy_status;
    	unsigned int phy_spec_status;
    	int timeout;
    	int phy_speed;
    	int phy_duplex;
    	unsigned int value;
    
    	phy_speed = LINK_SPEED_UNKNOWN;
    	phy_duplex = LINK_DUPLEX_UNKNOWN;
    
    	base = dev->iobase;
    	phy_addr = (unsigned long)dev->priv;
    
    	/* Take the PHY out of reset. */
    
    	write_phy (ETH_BASE, phy_addr, PHY_CTRL_REG, PHY_CTRL_RESET);
    
    
    	/* Wait for the reset process to complete. */
    
    	udelay (10);
    
    	timeout = 0;
    	while ((phy_status =
    
    		read_phy (ETH_BASE, phy_addr, PHY_CTRL_REG)) & PHY_CTRL_RESET) {
    		udelay (10);
    
    		if (++timeout > 10000) {
    
    			printf ("ERROR: timeout waiting for phy reset\n");
    
    			break;
    		}
    	}
    
    	/* TBI Configuration. */
    
    	write_phy (base, TBI_ADDR, TBI_CONTROL_2, TBI_CONTROL_2_G_MII_MODE |
    
    		  TBI_CONTROL_2_RECEIVE_CLOCK_SELECT);
    	/* Wait for the link to be established. */
    	timeout = 0;
    	do {
    
    		udelay (20000);
    		phy_status = read_phy (ETH_BASE, phy_addr, PHY_STATUS_REG);
    
    		if (++timeout > 100) {
    			debug_lev(1, "ERROR: unable to establish link!!!\n");
    			break;
    		}
    	} while ((phy_status & PHY_STAT_LINK_UP) == 0);
    
    
    	if ((phy_status & PHY_STAT_LINK_UP) == 0)
    
    	phy_spec_status = read_phy (ETH_BASE, phy_addr, MV1111_SPEC_STAT_REG);
    
    	if (phy_spec_status & SPEC_STAT_RESOLVED) {
    		switch (phy_spec_status & SPEC_STAT_SPEED_MASK) {
    		case SPEED_1000:
    			phy_speed = LINK_SPEED_1000;
    			value |= PHY_CTRL_SPEED1;
    			break;
    		case SPEED_100:
    			phy_speed = LINK_SPEED_100;
    			value |= PHY_CTRL_SPEED0;
    			break;
    		case SPEED_10:
    			phy_speed = LINK_SPEED_10;
    			break;
    		}
    		if (phy_spec_status & SPEC_STAT_FULL_DUP) {
    			phy_duplex = LINK_DUPLEX_FULL;
    			value |= PHY_CTRL_FULL_DUPLEX;
    
    			phy_duplex = LINK_DUPLEX_HALF;
    	}
    	/* set TBI speed */
    
    	write_phy (base, TBI_ADDR, PHY_CTRL_REG, value);
    	write_phy (base, TBI_ADDR, PHY_AN_ADV_REG, 0x0060);
    
    
    #if TSI108_ETH_DEBUG > 0
    
    	printf ("%s link is up", dev->name);
    	phy_spec_status = read_phy (ETH_BASE, phy_addr, MV1111_SPEC_STAT_REG);
    
    	if (phy_spec_status & SPEC_STAT_RESOLVED) {
    		switch (phy_speed) {
    		case LINK_SPEED_1000:
    
    			printf (", 1000 Mbps");
    
    			break;
    		case LINK_SPEED_100:
    
    			printf (", 100 Mbps");
    
    			break;
    		case LINK_SPEED_10:
    
    			printf (", 10 Mbps");
    
    		if (phy_duplex == LINK_DUPLEX_FULL)
    			printf (", Full duplex");
    		else
    			printf (", Half duplex");
    
    	printf ("\n");
    
    	dump_phy_regs (TBI_ADDR);
    	if (speed)
    
    		*speed = phy_speed;
    
    	if (duplex)
    
    		*duplex = phy_duplex;
    
    	return 1;
    }
    
    /*
     * External interface
     *
     * register the tsi108 ethernet controllers with the multi-ethernet system
     */
    
    int tsi108_eth_initialize (bd_t * bis)
    
    {
    	struct eth_device *dev;
    	int index;
    
    	for (index = 0; index < CONFIG_TSI108_ETH_NUM_PORTS; index++) {
    		dev = (struct eth_device *)malloc(sizeof(struct eth_device));
    
    		if (!dev) {
    			printf("tsi108: Can not allocate memory\n");
    			break;
    		}
    		memset(dev, 0, sizeof(*dev));
    
    		sprintf (dev->name, "TSI108_eth%d", index);
    
    
    		dev->iobase = ETH_BASE + (index * ETH_PORT_OFFSET);
    		dev->priv = (void *)(phy_address[index]);
    		dev->init = tsi108_eth_probe;
    		dev->halt = tsi108_eth_halt;
    		dev->send = tsi108_eth_send;
    		dev->recv = tsi108_eth_recv;
    
    		eth_register(dev);
    	}
    	return index;
    }
    
    /*
     * probe for and initialize a single ethernet interface
     */
    
    static int tsi108_eth_probe (struct eth_device *dev, bd_t * bis)
    
    {
    	unsigned long base;
    	unsigned long value;
    	int index;
    	struct dma_descriptor *tx_descr;
    	struct dma_descriptor *rx_descr;
    	int speed;
    	int duplex;
    
    	base = dev->iobase;
    
    	reg_PORT_CONTROL(base) = PORT_CONTROL_STE | PORT_CONTROL_BPT;
    
    	/* Bring DMA/FIFO out of reset. */
    	reg_TX_CONFIG(base) = 0x00000000;
    	reg_RX_CONFIG(base) = 0x00000000;
    
    	reg_TX_THRESHOLDS(base) = (192 << 16) | 192;
    	reg_RX_THRESHOLDS(base) = (192 << 16) | 112;
    
    	/* Bring MAC out of reset. */
    	reg_MAC_CONFIG_1(base) = 0x00000000;
    
    	/* DMA MAC configuration. */
    	reg_MAC_CONFIG_1(base) =
    	    MAC_CONFIG_1_RX_ENABLE | MAC_CONFIG_1_TX_ENABLE;
    
    	reg_MII_MGMT_CONFIG(base) = MII_MGMT_CONFIG_NO_PREAMBLE;
    	reg_MAXIMUM_FRAME_LENGTH(base) = RX_BUFFER_SIZE;
    
    	/* Note: Early tsi108 manual did not have correct byte order
    	 * for the station address.*/
    	reg_STATION_ADDRESS_1(base) = (dev->enetaddr[5] << 24) |
    	    (dev->enetaddr[4] << 16) |
    	    (dev->enetaddr[3] << 8) | (dev->enetaddr[2] << 0);
    
    	reg_STATION_ADDRESS_2(base) = (dev->enetaddr[1] << 24) |
    	    (dev->enetaddr[0] << 16);
    
    
    	if (marvell_88e_phy_config(dev, &speed, &duplex) == 0)
    
    		return -1;
    
    
    	value =
    	    MAC_CONFIG_2_PREAMBLE_LENGTH(7) | MAC_CONFIG_2_PAD_CRC |
    	    MAC_CONFIG_2_CRC_ENABLE;
    
    	if (speed == LINK_SPEED_1000)
    
    		value |= MAC_CONFIG_2_INTERFACE_MODE(INTERFACE_MODE_BYTE);
    
    		value |= MAC_CONFIG_2_INTERFACE_MODE(INTERFACE_MODE_NIBBLE);
    		reg_PORT_CONTROL(base) |= PORT_CONTROL_SPD;
    	}
    	if (duplex == LINK_DUPLEX_FULL) {
    		value |= MAC_CONFIG_2_FULL_DUPLEX;
    		reg_PORT_CONTROL(base) &= ~PORT_CONTROL_BPT;
    
    		reg_PORT_CONTROL(base) |= PORT_CONTROL_BPT;
    	reg_MAC_CONFIG_2(base) = value;
    
    	reg_RX_CONFIG(base) = RX_CONFIG_SE;
    	reg_RX_QUEUE_0_CONFIG(base) = OCN_PORT_MEMORY;
    	reg_RX_QUEUE_0_BUF_CONFIG(base) = OCN_PORT_MEMORY;
    
    	/* initialize the RX DMA descriptors */
    	rx_descr = &rx_descr_array[0];
    	rx_descr_current = rx_descr;
    	for (index = 0; index < NUM_RX_DESC; index++) {
    		/* make sure the receive buffers are not in cache */
    		invalidate_dcache_range((unsigned long)NetRxPackets[index],
    					(unsigned long)NetRxPackets[index] +
    					RX_BUFFER_SIZE);
    		rx_descr->start_addr0 =
    		    cpu_to_le32((vuint32) NetRxPackets[index]);
    		rx_descr->start_addr1 = 0;
    		rx_descr->next_descr_addr0 =
    		    cpu_to_le32((vuint32) (rx_descr + 1));
    		rx_descr->next_descr_addr1 = 0;
    		rx_descr->vlan_byte_count = 0;
    		rx_descr->config_status = cpu_to_le32((RX_BUFFER_SIZE << 16) |
    						      DMA_DESCR_RX_OWNER);
    		rx_descr++;
    	}
    	rx_descr--;
    	rx_descr->next_descr_addr0 = 0;
    	rx_descr->next_descr_addr1 = cpu_to_le32(DMA_DESCR_LAST);
    	/* Push the descriptors to RAM so the ethernet DMA can see them */
    	invalidate_dcache_range((unsigned long)rx_descr_array,
    				(unsigned long)rx_descr_array +
    				sizeof(rx_descr_array));
    
    	/* enable RX queue */
    	reg_RX_CONTROL(base) = TX_CONTROL_GO | 0x01;
    	reg_RX_QUEUE_0_PTR_LOW(base) = (u32) rx_descr_current;
    	/* enable receive DMA */
    	reg_RX_QUEUE_0_PTR_HIGH(base) = RX_QUEUE_0_PTR_HIGH_VALID;
    
    	reg_TX_QUEUE_0_CONFIG(base) = OCN_PORT_MEMORY;
    	reg_TX_QUEUE_0_BUF_CONFIG(base) = OCN_PORT_MEMORY;
    
    	/* initialize the TX DMA descriptor */
    	tx_descr = &tx_descriptor;
    
    	tx_descr->start_addr0 = 0;
    	tx_descr->start_addr1 = 0;
    	tx_descr->next_descr_addr0 = 0;
    	tx_descr->next_descr_addr1 = cpu_to_le32(DMA_DESCR_LAST);
    	tx_descr->vlan_byte_count = 0;
    	tx_descr->config_status = cpu_to_le32(DMA_DESCR_TX_OK |
    					      DMA_DESCR_TX_SOF |
    					      DMA_DESCR_TX_EOF);
    	/* enable TX queue */
    	reg_TX_CONTROL(base) = TX_CONTROL_GO | 0x01;
    
    
    	return 0;
    
    static int tsi108_eth_send(struct eth_device *dev, void *packet, int length)
    
    {
    	unsigned long base;
    	int timeout;
    	struct dma_descriptor *tx_descr;
    	unsigned long status;
    
    	base = dev->iobase;
    	tx_descr = &tx_descriptor;
    
    	/* Wait until the last packet has been transmitted. */
    	timeout = 0;
    	do {
    		/* make sure we see the changes made by the DMA engine */
    		invalidate_dcache_range((unsigned long)tx_descr,
    					(unsigned long)tx_descr +
    					sizeof(struct dma_descriptor));
    
    
    		if (timeout != 0)
    			udelay (15);
    
    		if (++timeout > 10000) {
    			tx_diag_regs(base);
    			debug_lev(1,
    				  "ERROR: timeout waiting for last transmit packet to be sent\n");
    			return 0;
    		}
    	} while (tx_descr->config_status & cpu_to_le32(DMA_DESCR_TX_OWNER));
    
    	status = le32_to_cpu(tx_descr->config_status);
    	if ((status & DMA_DESCR_TX_OK) == 0) {
    #ifdef TX_PRINT_ERRORS
    
    		printf ("TX packet error: 0x%08lx\n    %s%s%s%s\n", status,
    
    		       status & DMA_DESCR_TX_OK ? "tx error, " : "",
    		       status & DMA_DESCR_TX_RETRY_LIMIT ?
    		       "retry limit reached, " : "",
    		       status & DMA_DESCR_TX_UNDERRUN ? "underrun, " : "",
    		       status & DMA_DESCR_TX_LATE_COLLISION ? "late collision, "
    		       : "");
    #endif
    	}
    
    
    	debug_lev (9, "sending packet %d\n", length);
    
    	tx_descr->start_addr0 = cpu_to_le32((vuint32) packet);
    	tx_descr->start_addr1 = 0;
    	tx_descr->next_descr_addr0 = 0;
    	tx_descr->next_descr_addr1 = cpu_to_le32(DMA_DESCR_LAST);
    	tx_descr->vlan_byte_count = cpu_to_le32(length);
    	tx_descr->config_status = cpu_to_le32(DMA_DESCR_TX_OWNER |
    					      DMA_DESCR_TX_CRC |
    					      DMA_DESCR_TX_PAD |
    					      DMA_DESCR_TX_SOF |
    					      DMA_DESCR_TX_EOF);
    
    	invalidate_dcache_range((unsigned long)tx_descr,
    				(unsigned long)tx_descr +
    				sizeof(struct dma_descriptor));
    
    	invalidate_dcache_range((unsigned long)packet,
    				(unsigned long)packet + length);
    
    	reg_TX_QUEUE_0_PTR_LOW(base) = (u32) tx_descr;
    	reg_TX_QUEUE_0_PTR_HIGH(base) = TX_QUEUE_0_PTR_HIGH_VALID;
    
    	return length;
    }
    
    /*
     * Check for received packets and send them up the protocal stack
     */
    
    static int tsi108_eth_recv (struct eth_device *dev)
    
    {
    	struct dma_descriptor *rx_descr;
    	unsigned long base;
    	int length = 0;
    	unsigned long status;
    
    
    	base = dev->iobase;
    
    	/* make sure we see the changes made by the DMA engine */
    
    	invalidate_dcache_range ((unsigned long)rx_descr_array,
    
    				(unsigned long)rx_descr_array +
    				sizeof(rx_descr_array));
    
    	/* process all of the received packets */
    	rx_descr = rx_descr_current;
    	while ((rx_descr->config_status & cpu_to_le32(DMA_DESCR_RX_OWNER)) == 0) {
    		/* check for error */
    		status = le32_to_cpu(rx_descr->config_status);
    		if (status & DMA_DESCR_RX_BAD_FRAME) {
    #ifdef RX_PRINT_ERRORS
    
    			printf ("RX packet error: 0x%08lx\n    %s%s%s%s%s%s\n",
    
    			       status,
    			       status & DMA_DESCR_RX_FRAME_IS_TYPE ? "too big, "
    			       : "",
    			       status & DMA_DESCR_RX_SHORT_FRAME ? "too short, "
    			       : "",
    			       status & DMA_DESCR_RX_BAD_FRAME ? "bad frame, " :
    			       "",
    			       status & DMA_DESCR_RX_OVERRUN ? "overrun, " : "",
    			       status & DMA_DESCR_RX_MAX_FRAME_LEN ?
    			       "max length, " : "",
    			       status & DMA_DESCR_RX_CRC_ERROR ? "CRC error, " :
    			       "");
    #endif
    		} else {
    			length =
    			    le32_to_cpu(rx_descr->vlan_byte_count) & 0xFFFF;
    
    			/*** process packet ***/
    
    			buffer = (uchar *)(le32_to_cpu(rx_descr->start_addr0));
    			NetReceive(buffer, length);
    
    			invalidate_dcache_range ((unsigned long)buffer,
    
    						(unsigned long)buffer +
    						RX_BUFFER_SIZE);
    		}
    		/* Give this buffer back to the DMA engine */
    		rx_descr->vlan_byte_count = 0;
    
    		rx_descr->config_status = cpu_to_le32 ((RX_BUFFER_SIZE << 16) |
    
    						      DMA_DESCR_RX_OWNER);
    		/* move descriptor pointer forward */
    		rx_descr =
    		    (struct dma_descriptor
    
    		     *)(le32_to_cpu (rx_descr->next_descr_addr0));
    		if (rx_descr == 0)
    
    			rx_descr = &rx_descr_array[0];