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author | Rafal Jaworowski <raj@semihalf.com> | 2007-07-27 14:43:59 +0200 |
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committer | Rafal Jaworowski <raj@semihalf.com> | 2007-07-27 14:43:59 +0200 |
commit | 8993e54b6f397973794f3d6f47d3b3c0c98dd4f6 (patch) | |
tree | c5ce1d56f002d132d527f66afc9a35adb077b56f /cpu/mpc512x/fec.c | |
parent | 1863cfb7b100ba0ee3401799457a01dc058745f8 (diff) | |
download | u-boot-imx-8993e54b6f397973794f3d6f47d3b3c0c98dd4f6.zip u-boot-imx-8993e54b6f397973794f3d6f47d3b3c0c98dd4f6.tar.gz u-boot-imx-8993e54b6f397973794f3d6f47d3b3c0c98dd4f6.tar.bz2 |
[ADS5121] Support for the ADS5121 board
The following MPC5121e subsystems are supported:
- low-level CPU init
- NOR Boot Flash (common CFI driver)
- DDR SDRAM
- FEC
- I2C
- Watchdog
Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
Signed-off-by: Rafal Jaworowski <raj@semihalf.com>
Signed-off-by: Jan Wrobel <wrr@semihalf.com>
Diffstat (limited to 'cpu/mpc512x/fec.c')
-rw-r--r-- | cpu/mpc512x/fec.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/cpu/mpc512x/fec.c b/cpu/mpc512x/fec.c new file mode 100644 index 0000000..f1b7a25 --- /dev/null +++ b/cpu/mpc512x/fec.c @@ -0,0 +1,801 @@ +/* + * (C) Copyright 2003-2007 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * Derived from the MPC8xx FEC driver. + * Adapted for MPC512x by Grzegorz Bernacki <gjb@semihalf.com> + */ + +#include <common.h> +#include <mpc512x.h> +#include <malloc.h> +#include <net.h> +#include <miiphy.h> +#include "fec.h" + +DECLARE_GLOBAL_DATA_PTR; + +#define DEBUG 0 + +#if (CONFIG_COMMANDS & CFG_CMD_NET) && defined(CONFIG_NET_MULTI) && \ + defined(CONFIG_MPC512x_FEC) + +#if !(defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII)) +#error "CONFIG_MII has to be defined!" +#endif + +#if (DEBUG & 0x40) +static uint32 local_crc32(char *string, unsigned int crc_value, int len); +#endif + +int fec512x_miiphy_read(char *devname, uint8 phyAddr, uint8 regAddr, uint16 * retVal); +int fec512x_miiphy_write(char *devname, uint8 phyAddr, uint8 regAddr, uint16 data); +int mpc512x_fec_init_phy(struct eth_device *dev, bd_t * bis); + +/********************************************************************/ +#if (DEBUG & 0x2) +static void mpc512x_fec_phydump (char *devname) +{ + uint16 phyStatus, i; + uint8 phyAddr = CONFIG_PHY_ADDR; + uint8 reg_mask[] = { + /* regs to print: 0...8, 21,27,31 */ + 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, + }; + + for (i = 0; i < 32; i++) { + if (reg_mask[i]) { + miiphy_read (devname, phyAddr, i, &phyStatus); + printf ("Mii reg %d: 0x%04x\n", i, phyStatus); + } + } +} +#endif + +/********************************************************************/ +static int mpc512x_fec_bd_init (mpc512x_fec_priv *fec) +{ + int ix; + + /* + * Receive BDs init + */ + for (ix = 0; ix < FEC_RBD_NUM; ix++) { + fec->bdBase->rbd[ix].dataPointer = (uint32)&fec->bdBase->recv_frames[ix]; + fec->bdBase->rbd[ix].status = FEC_RBD_EMPTY; + fec->bdBase->rbd[ix].dataLength = 0; + } + + /* + * have the last RBD to close the ring + */ + fec->bdBase->rbd[ix - 1].status |= FEC_RBD_WRAP; + fec->rbdIndex = 0; + + /* + * Trasmit BDs init + */ + for (ix = 0; ix < FEC_TBD_NUM; ix++) { + fec->bdBase->tbd[ix].status = 0; + } + + /* + * Have the last TBD to close the ring + */ + fec->bdBase->tbd[ix - 1].status |= FEC_TBD_WRAP; + + /* + * Initialize some indices + */ + fec->tbdIndex = 0; + fec->usedTbdIndex = 0; + fec->cleanTbdNum = FEC_TBD_NUM; + + return 0; +} + +/********************************************************************/ +static void mpc512x_fec_rbd_clean (mpc512x_fec_priv *fec, volatile FEC_RBD * pRbd) +{ + /* + * Reset buffer descriptor as empty + */ + if ((fec->rbdIndex) == (FEC_RBD_NUM - 1)) + pRbd->status = (FEC_RBD_WRAP | FEC_RBD_EMPTY); + else + pRbd->status = FEC_RBD_EMPTY; + + pRbd->dataLength = 0; + + /* + * Increment BD count + */ + fec->rbdIndex = (fec->rbdIndex + 1) % FEC_RBD_NUM; + + /* + * Now, we have an empty RxBD, notify FEC + */ + fec->eth->r_des_active = 0x01000000; /* Descriptor polling active */ +} + +/********************************************************************/ +static void mpc512x_fec_tbd_scrub (mpc512x_fec_priv *fec) +{ + volatile FEC_TBD *pUsedTbd; + +#if (DEBUG & 0x1) + printf ("tbd_scrub: fec->cleanTbdNum = %d, fec->usedTbdIndex = %d\n", + fec->cleanTbdNum, fec->usedTbdIndex); +#endif + + /* + * process all the consumed TBDs + */ + while (fec->cleanTbdNum < FEC_TBD_NUM) { + pUsedTbd = &fec->bdBase->tbd[fec->usedTbdIndex]; + if (pUsedTbd->status & FEC_TBD_READY) { +#if (DEBUG & 0x20) + printf ("Cannot clean TBD %d, in use\n", fec->usedTbdIndex); +#endif + return; + } + + /* + * clean this buffer descriptor + */ + if (fec->usedTbdIndex == (FEC_TBD_NUM - 1)) + pUsedTbd->status = FEC_TBD_WRAP; + else + pUsedTbd->status = 0; + + /* + * update some indeces for a correct handling of the TBD ring + */ + fec->cleanTbdNum++; + fec->usedTbdIndex = (fec->usedTbdIndex + 1) % FEC_TBD_NUM; + } +} + +/********************************************************************/ +static void mpc512x_fec_set_hwaddr (mpc512x_fec_priv *fec, char *mac) +{ + uint8 currByte; /* byte for which to compute the CRC */ + int byte; /* loop - counter */ + int bit; /* loop - counter */ + uint32 crc = 0xffffffff; /* initial value */ + + /* + * The algorithm used is the following: + * we loop on each of the six bytes of the provided address, + * and we compute the CRC by left-shifting the previous + * value by one position, so that each bit in the current + * byte of the address may contribute the calculation. If + * the latter and the MSB in the CRC are different, then + * the CRC value so computed is also ex-ored with the + * "polynomium generator". The current byte of the address + * is also shifted right by one bit at each iteration. + * This is because the CRC generatore in hardware is implemented + * as a shift-register with as many ex-ores as the radixes + * in the polynomium. This suggests that we represent the + * polynomiumm itself as a 32-bit constant. + */ + for (byte = 0; byte < 6; byte++) { + currByte = mac[byte]; + for (bit = 0; bit < 8; bit++) { + if ((currByte & 0x01) ^ (crc & 0x01)) { + crc >>= 1; + crc = crc ^ 0xedb88320; + } else { + crc >>= 1; + } + currByte >>= 1; + } + } + + crc = crc >> 26; + + /* + * Set individual hash table register + */ + if (crc >= 32) { + fec->eth->iaddr1 = (1 << (crc - 32)); + fec->eth->iaddr2 = 0; + } else { + fec->eth->iaddr1 = 0; + fec->eth->iaddr2 = (1 << crc); + } + + /* + * Set physical address + */ + fec->eth->paddr1 = (mac[0] << 24) + (mac[1] << 16) + (mac[2] << 8) + mac[3]; + fec->eth->paddr2 = (mac[4] << 24) + (mac[5] << 16) + 0x8808; +} + +/********************************************************************/ +static int mpc512x_fec_init (struct eth_device *dev, bd_t * bis) +{ + mpc512x_fec_priv *fec = (mpc512x_fec_priv *)dev->priv; + +#if (DEBUG & 0x1) + printf ("mpc512x_fec_init... Begin\n"); +#endif + + /* Set interrupt mask register */ + fec->eth->imask = 0x00000000; + + /* Clear FEC-Lite interrupt event register(IEVENT) */ + fec->eth->ievent = 0xffffffff; + + /* Set transmit fifo watermark register(X_WMRK), default = 64 */ + fec->eth->x_wmrk = 0x0; + + /* Set Opcode/Pause Duration Register */ + fec->eth->op_pause = 0x00010020; + + /* Frame length=1518; MII mode */ + fec->eth->r_cntrl = 0x05ee000c; + + /* Half-duplex, heartbeat disabled */ + fec->eth->x_cntrl = 0x00000000; + + /* Enable MIB counters */ + fec->eth->mib_control = 0x0; + + /* Setup recv fifo start and buff size */ + fec->eth->r_fstart = 0x500; + fec->eth->r_buff_size = 0x5e0; + + /* Setup BD base addresses */ + fec->eth->r_des_start = (uint32)fec->bdBase->rbd; + fec->eth->x_des_start = (uint32)fec->bdBase->tbd; + + /* DMA Control */ + fec->eth->dma_control = 0xc0000000; + + /* Enable FEC */ + fec->eth->ecntrl |= 0x00000006; + + /* Initilize addresses and status words of BDs */ + mpc512x_fec_bd_init (fec); + + /* Descriptor polling active */ + fec->eth->r_des_active = 0x01000000; + +#if (DEBUG & 0x1) + printf("mpc512x_fec_init... Done \n"); +#endif + return 1; +} + +/********************************************************************/ +int mpc512x_fec_init_phy (struct eth_device *dev, bd_t * bis) +{ + mpc512x_fec_priv *fec = (mpc512x_fec_priv *)dev->priv; + const uint8 phyAddr = CONFIG_PHY_ADDR; /* Only one PHY */ + int timeout = 1; + uint16 phyStatus; + +#if (DEBUG & 0x1) + printf ("mpc512x_fec_init_phy... Begin\n"); +#endif + + /* + * Clear FEC-Lite interrupt event register(IEVENT) + */ + fec->eth->ievent = 0xffffffff; + + /* + * Set interrupt mask register + */ + fec->eth->imask = 0x00000000; + + if (fec->xcv_type != SEVENWIRE) { + /* + * Set MII_SPEED = (1/(mii_speed * 2)) * System Clock + * and do not drop the Preamble. + */ + fec->eth->mii_speed = (((gd->ipb_clk / 1000000) / 5) + 1) << 1; + + /* + * Reset PHY, then delay 300ns + */ + miiphy_write (dev->name, phyAddr, 0x0, 0x8000); + udelay (1000); + + if (fec->xcv_type == MII10) { + /* + * Force 10Base-T, FDX operation + */ +#if (DEBUG & 0x2) + printf ("Forcing 10 Mbps ethernet link... "); +#endif + miiphy_read (dev->name, phyAddr, 0x1, &phyStatus); + + miiphy_write (dev->name, phyAddr, 0x0, 0x0180); + + timeout = 20; + do { /* wait for link status to go down */ + udelay (10000); + if ((timeout--) == 0) { +#if (DEBUG & 0x2) + printf ("hmmm, should not have waited..."); +#endif + break; + } + miiphy_read (dev->name, phyAddr, 0x1, &phyStatus); +#if (DEBUG & 0x2) + printf ("="); +#endif + } while ((phyStatus & 0x0004)); /* !link up */ + + timeout = 1000; + do { /* wait for link status to come back up */ + udelay (10000); + if ((timeout--) == 0) { + printf ("failed. Link is down.\n"); + break; + } + miiphy_read (dev->name, phyAddr, 0x1, &phyStatus); +#if (DEBUG & 0x2) + printf ("+"); +#endif + } while (!(phyStatus & 0x0004)); /* !link up */ + +#if (DEBUG & 0x2) + printf ("done.\n"); +#endif + } else { /* MII100 */ + /* + * Set the auto-negotiation advertisement register bits + */ + miiphy_write (dev->name, phyAddr, 0x4, 0x01e1); + + /* + * Set MDIO bit 0.12 = 1(&& bit 0.9=1?) to enable auto-negotiation + */ + miiphy_write (dev->name, phyAddr, 0x0, 0x1200); + + /* + * Wait for AN completion + */ + timeout = 50000; + do { + udelay (1000); + + if ((timeout--) == 0) { +#if (DEBUG & 0x2) + printf ("PHY auto neg 0 failed...\n"); +#endif + return -1; + } + + if (miiphy_read (dev->name, phyAddr, 0x1, &phyStatus) != 0) { +#if (DEBUG & 0x2) + printf ("PHY auto neg 1 failed 0x%04x...\n", phyStatus); +#endif + return -1; + } + } while (!(phyStatus & 0x0004)); + +#if (DEBUG & 0x2) + printf ("PHY auto neg complete! \n"); +#endif + } + } + +#if (DEBUG & 0x2) + if (fec->xcv_type != SEVENWIRE) + mpc512x_fec_phydump (dev->name); +#endif + +#if (DEBUG & 0x1) + printf ("mpc512x_fec_init_phy... Done \n"); +#endif + return 1; +} + +/********************************************************************/ +static void mpc512x_fec_halt (struct eth_device *dev) +{ + mpc512x_fec_priv *fec = (mpc512x_fec_priv *)dev->priv; + int counter = 0xffff; + +#if (DEBUG & 0x2) + if (fec->xcv_type != SEVENWIRE) + mpc512x_fec_phydump (dev->name); +#endif + + /* + * mask FEC chip interrupts + */ + fec->eth->imask = 0; + + /* + * issue graceful stop command to the FEC transmitter if necessary + */ + fec->eth->x_cntrl |= 0x00000001; + + /* + * wait for graceful stop to register + */ + while ((counter--) && (!(fec->eth->ievent & 0x10000000))) ; + + /* + * Disable the Ethernet Controller + */ + fec->eth->ecntrl &= 0xfffffffd; + + /* + * Issue a reset command to the FEC chip + */ + fec->eth->ecntrl |= 0x1; + + /* + * wait at least 16 clock cycles + */ + udelay (10); +#if (DEBUG & 0x3) + printf ("Ethernet task stopped\n"); +#endif +} + +/********************************************************************/ + +static int mpc512x_fec_send (struct eth_device *dev, volatile void *eth_data, + int data_length) +{ + /* + * This routine transmits one frame. This routine only accepts + * 6-byte Ethernet addresses. + */ + mpc512x_fec_priv *fec = (mpc512x_fec_priv *)dev->priv; + volatile FEC_TBD *pTbd; + +#if (DEBUG & 0x20) + printf("tbd status: 0x%04x\n", fec->tbdBase[fec->tbdIndex].status); +#endif + + /* + * Clear Tx BD ring at first + */ + mpc512x_fec_tbd_scrub (fec); + + /* + * Check for valid length of data. + */ + if ((data_length > 1500) || (data_length <= 0)) { + return -1; + } + + /* + * Check the number of vacant TxBDs. + */ + if (fec->cleanTbdNum < 1) { +#if (DEBUG & 0x20) + printf ("No available TxBDs ...\n"); +#endif + return -1; + } + + /* + * Get the first TxBD to send the mac header + */ + pTbd = &fec->bdBase->tbd[fec->tbdIndex]; + pTbd->dataLength = data_length; + pTbd->dataPointer = (uint32)eth_data; + pTbd->status |= FEC_TBD_LAST | FEC_TBD_TC | FEC_TBD_READY; + fec->tbdIndex = (fec->tbdIndex + 1) % FEC_TBD_NUM; + + /* Activate transmit Buffer Descriptor polling */ + fec->eth->x_des_active = 0x01000000; /* Descriptor polling active */ + +#if (DEBUG & 0x8) + printf ( "+" ); +#endif + + fec->cleanTbdNum -= 1; + + /* + * wait until frame is sent . + */ + while (pTbd->status & FEC_TBD_READY) { + udelay (10); +#if (DEBUG & 0x8) + printf ("TDB status = %04x\n", pTbd->status); +#endif + } + + return 0; +} + + +/********************************************************************/ +static int mpc512x_fec_recv (struct eth_device *dev) +{ + /* + * This command pulls one frame from the card + */ + mpc512x_fec_priv *fec = (mpc512x_fec_priv *)dev->priv; + volatile FEC_RBD *pRbd = &fec->bdBase->rbd[fec->rbdIndex]; + unsigned long ievent; + int frame_length, len = 0; + uchar buff[FEC_MAX_PKT_SIZE]; + +#if (DEBUG & 0x1) + printf ("mpc512x_fec_recv %d Start...\n", fec->rbdIndex); +#endif +#if (DEBUG & 0x8) + printf( "-" ); +#endif + + /* + * Check if any critical events have happened + */ + ievent = fec->eth->ievent; + fec->eth->ievent = ievent; + if (ievent & 0x20060000) { + /* BABT, Rx/Tx FIFO errors */ + mpc512x_fec_halt (dev); + mpc512x_fec_init (dev, NULL); + return 0; + } + if (ievent & 0x80000000) { + /* Heartbeat error */ + fec->eth->x_cntrl |= 0x00000001; + } + if (ievent & 0x10000000) { + /* Graceful stop complete */ + if (fec->eth->x_cntrl & 0x00000001) { + mpc512x_fec_halt (dev); + fec->eth->x_cntrl &= ~0x00000001; + mpc512x_fec_init (dev, NULL); + } + } + + if (!(pRbd->status & FEC_RBD_EMPTY)) { + if ((pRbd->status & FEC_RBD_LAST) && + !(pRbd->status & FEC_RBD_ERR) && + ((pRbd->dataLength - 4) > 14)) { + + /* + * Get buffer size + */ + frame_length = pRbd->dataLength - 4; + +#if (DEBUG & 0x20) + { + int i; + printf ("recv data hdr:"); + for (i = 0; i < 14; i++) + printf ("%x ", *((uint8*)pRbd->dataPointer + i)); + printf("\n"); + } +#endif + + /* + * Fill the buffer and pass it to upper layers + */ + memcpy (buff, (void*)pRbd->dataPointer, frame_length); + NetReceive ((uchar*)buff, frame_length); + len = frame_length; + } + + /* + * Reset buffer descriptor as empty + */ + mpc512x_fec_rbd_clean (fec, pRbd); + } + + /* Try to fill Buffer Descriptors */ + fec->eth->r_des_active = 0x01000000; /* Descriptor polling active */ + return len; +} + +/********************************************************************/ +int mpc512x_fec_initialize (bd_t * bis) +{ + + immap_t *im = (immap_t*) CFG_IMMR; + mpc512x_fec_priv *fec; + struct eth_device *dev; + int i; + char *tmp, *end, env_enetaddr[6]; + uint32 *reg; + void * bd; + + fec = (mpc512x_fec_priv *) malloc (sizeof(*fec)); + dev = (struct eth_device *) malloc (sizeof(*dev)); + memset (dev, 0, sizeof *dev); + + fec->eth = (ethernet_regs *) MPC512X_FEC; + +# ifndef CONFIG_FEC_10MBIT + fec->xcv_type = MII100; +# else + fec->xcv_type = MII10; +# endif + dev->priv = (void *)fec; + dev->iobase = MPC512X_FEC; + dev->init = mpc512x_fec_init; + dev->halt = mpc512x_fec_halt; + dev->send = mpc512x_fec_send; + dev->recv = mpc512x_fec_recv; + + sprintf (dev->name, "FEC ETHERNET"); + eth_register (dev); + +#if defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII) + miiphy_register (dev->name, + fec512x_miiphy_read, fec512x_miiphy_write); +#endif + + /* + * Initialize I\O pins + */ + reg = (uint32 *) &(im->io_ctrl.regs[PSC0_0_IDX]); + + for (i = 0; i < 15; i++) + reg[i] = IOCTRL_MUX_FEC | 0x00000001; + + im->io_ctrl.regs[SPDIF_TXCLOCK_IDX] = IOCTRL_MUX_FEC | 0x00000001; + im->io_ctrl.regs[SPDIF_TX_IDX] = IOCTRL_MUX_FEC | 0x00000001; + im->io_ctrl.regs[SPDIF_RX_IDX] = IOCTRL_MUX_FEC | 0x00000001; + + /* Clean up space FEC's MIB and FIFO RAM ...*/ + memset ((void *) MPC512X_FEC + 0x200, 0x00, 0x400); + + /* + * Malloc space for BDs (must be quad word-aligned) + * this pointer is lost, so cannot be freed + */ + bd = malloc (sizeof(mpc512x_buff_descs) + 0x1f); + fec->bdBase = (mpc512x_buff_descs*)((uint32)bd & 0xfffffff0); + memset ((void *) bd, 0x00, sizeof(mpc512x_buff_descs) + 0x1f); + + /* + * Set interrupt mask register + */ + fec->eth->imask = 0x00000000; + + /* + * Clear FEC-Lite interrupt event register(IEVENT) + */ + fec->eth->ievent = 0xffffffff; + + /* + * Try to set the mac address now. The fec mac address is + * a garbage after reset. When not using fec for booting + * the Linux fec driver will try to work with this garbage. + */ + tmp = getenv ("ethaddr"); + if (tmp) { + for (i=0; i<6; i++) { + env_enetaddr[i] = tmp ? simple_strtoul (tmp, &end, 16) : 0; + if (tmp) + tmp = (*end) ? end+1 : end; + } + mpc512x_fec_set_hwaddr (fec, env_enetaddr); + fec->eth->gaddr1 = 0x00000000; + fec->eth->gaddr2 = 0x00000000; + } + + mpc512x_fec_init_phy (dev, bis); + + return 1; +} + +/* MII-interface related functions */ +/********************************************************************/ +int fec512x_miiphy_read (char *devname, uint8 phyAddr, uint8 regAddr, uint16 * retVal) +{ + ethernet_regs *eth = (ethernet_regs *) MPC512X_FEC; + uint32 reg; /* convenient holder for the PHY register */ + uint32 phy; /* convenient holder for the PHY */ + int timeout = 0xffff; + + /* + * reading from any PHY's register is done by properly + * programming the FEC's MII data register. + */ + reg = regAddr << FEC_MII_DATA_RA_SHIFT; + phy = phyAddr << FEC_MII_DATA_PA_SHIFT; + + eth->mii_data = (FEC_MII_DATA_ST | FEC_MII_DATA_OP_RD | FEC_MII_DATA_TA | phy | reg); + + /* + * wait for the related interrupt + */ + while ((timeout--) && (!(eth->ievent & 0x00800000))) ; + + if (timeout == 0) { +#if (DEBUG & 0x2) + printf ("Read MDIO failed...\n"); +#endif + return -1; + } + + /* + * clear mii interrupt bit + */ + eth->ievent = 0x00800000; + + /* + * it's now safe to read the PHY's register + */ + *retVal = (uint16) eth->mii_data; + + return 0; +} + +/********************************************************************/ +int fec512x_miiphy_write (char *devname, uint8 phyAddr, uint8 regAddr, uint16 data) +{ + ethernet_regs *eth = (ethernet_regs *) MPC512X_FEC; + uint32 reg; /* convenient holder for the PHY register */ + uint32 phy; /* convenient holder for the PHY */ + int timeout = 0xffff; + + reg = regAddr << FEC_MII_DATA_RA_SHIFT; + phy = phyAddr << FEC_MII_DATA_PA_SHIFT; + + eth->mii_data = (FEC_MII_DATA_ST | FEC_MII_DATA_OP_WR | + FEC_MII_DATA_TA | phy | reg | data); + + /* + * wait for the MII interrupt + */ + while ((timeout--) && (!(eth->ievent & 0x00800000))) ; + + if (timeout == 0) { +#if (DEBUG & 0x2) + printf ("Write MDIO failed...\n"); +#endif + return -1; + } + + /* + * clear MII interrupt bit + */ + eth->ievent = 0x00800000; + + return 0; +} + +#if (DEBUG & 0x40) +static uint32 local_crc32 (char *string, unsigned int crc_value, int len) +{ + int i; + char c; + unsigned int crc, count; + + /* + * crc32 algorithm + */ + /* + * crc = 0xffffffff; * The initialized value should be 0xffffffff + */ + crc = crc_value; + + for (i = len; --i >= 0;) { + c = *string++; + for (count = 0; count < 8; count++) { + if ((c & 0x01) ^ (crc & 0x01)) { + crc >>= 1; + crc = crc ^ 0xedb88320; + } else { + crc >>= 1; + } + c >>= 1; + } + } + + /* + * In big endian system, do byte swaping for crc value + */ + /**/ return crc; +} +#endif /* DEBUG */ + +#endif /* CONFIG_MPC512x_FEC */ |