blob: c1b708600e891e553884ddbe4d91910ffe0be2b4 [file] [log] [blame]
/*
* Copyright (c) 2013 Gerhard Sittig <gsi@denx.de>
* based on the U-Boot Asix driver as well as information
* from the Linux Moschip driver
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* MOSCHIP MCS7830 based (7730/7830/7832) USB 2.0 Ethernet Devices
*/
#include <common.h>
#include <errno.h>
#include <linux/mii.h>
#include <malloc.h>
#include <usb.h>
#include "usb_ether.h"
#define MCS7830_BASE_NAME "mcs"
#define USBCALL_TIMEOUT 1000
#define LINKSTATUS_TIMEOUT 5000 /* link status, connect timeout */
#define LINKSTATUS_TIMEOUT_RES 50 /* link status, resolution in msec */
#define MCS7830_RX_URB_SIZE 2048
/* command opcodes */
#define MCS7830_WR_BREQ 0x0d
#define MCS7830_RD_BREQ 0x0e
/* register layout, numerical offset specs for USB API calls */
struct mcs7830_regs {
uint8_t multicast_hashes[8];
uint8_t packet_gap[2];
uint8_t phy_data[2];
uint8_t phy_command[2];
uint8_t configuration;
uint8_t ether_address[6];
uint8_t frame_drop_count;
uint8_t pause_threshold;
};
#define REG_MULTICAST_HASH offsetof(struct mcs7830_regs, multicast_hashes)
#define REG_PHY_DATA offsetof(struct mcs7830_regs, phy_data)
#define REG_PHY_CMD offsetof(struct mcs7830_regs, phy_command)
#define REG_CONFIG offsetof(struct mcs7830_regs, configuration)
#define REG_ETHER_ADDR offsetof(struct mcs7830_regs, ether_address)
#define REG_FRAME_DROP_COUNTER offsetof(struct mcs7830_regs, frame_drop_count)
#define REG_PAUSE_THRESHOLD offsetof(struct mcs7830_regs, pause_threshold)
/* bit masks and default values for the above registers */
#define PHY_CMD1_READ 0x40
#define PHY_CMD1_WRITE 0x20
#define PHY_CMD1_PHYADDR 0x01
#define PHY_CMD2_PEND 0x80
#define PHY_CMD2_READY 0x40
#define CONF_CFG 0x80
#define CONF_SPEED100 0x40
#define CONF_FDX_ENABLE 0x20
#define CONF_RXENABLE 0x10
#define CONF_TXENABLE 0x08
#define CONF_SLEEPMODE 0x04
#define CONF_ALLMULTICAST 0x02
#define CONF_PROMISCUOUS 0x01
#define PAUSE_THRESHOLD_DEFAULT 0
/* bit masks for the status byte which follows received ethernet frames */
#define STAT_RX_FRAME_CORRECT 0x20
#define STAT_RX_LARGE_FRAME 0x10
#define STAT_RX_CRC_ERROR 0x08
#define STAT_RX_ALIGNMENT_ERROR 0x04
#define STAT_RX_LENGTH_ERROR 0x02
#define STAT_RX_SHORT_FRAME 0x01
/*
* struct mcs7830_private - private driver data for an individual adapter
* @config: shadow for the network adapter's configuration register
* @mchash: shadow for the network adapter's multicast hash registers
*/
struct mcs7830_private {
uint8_t config;
uint8_t mchash[8];
};
/*
* mcs7830_read_reg() - read a register of the network adapter
* @dev: network device to read from
* @idx: index of the register to start reading from
* @size: number of bytes to read
* @data: buffer to read into
* Return: zero upon success, negative upon error
*/
static int mcs7830_read_reg(struct ueth_data *dev, uint8_t idx,
uint16_t size, void *data)
{
int len;
ALLOC_CACHE_ALIGN_BUFFER(uint8_t, buf, size);
debug("%s() idx=0x%04X sz=%d\n", __func__, idx, size);
len = usb_control_msg(dev->pusb_dev,
usb_rcvctrlpipe(dev->pusb_dev, 0),
MCS7830_RD_BREQ,
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
0, idx, buf, size,
USBCALL_TIMEOUT);
if (len != size) {
debug("%s() len=%d != sz=%d\n", __func__, len, size);
return -EIO;
}
memcpy(data, buf, size);
return 0;
}
/*
* mcs7830_write_reg() - write a register of the network adapter
* @dev: network device to write to
* @idx: index of the register to start writing to
* @size: number of bytes to write
* @data: buffer holding the data to write
* Return: zero upon success, negative upon error
*/
static int mcs7830_write_reg(struct ueth_data *dev, uint8_t idx,
uint16_t size, void *data)
{
int len;
ALLOC_CACHE_ALIGN_BUFFER(uint8_t, buf, size);
debug("%s() idx=0x%04X sz=%d\n", __func__, idx, size);
memcpy(buf, data, size);
len = usb_control_msg(dev->pusb_dev,
usb_sndctrlpipe(dev->pusb_dev, 0),
MCS7830_WR_BREQ,
USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
0, idx, buf, size,
USBCALL_TIMEOUT);
if (len != size) {
debug("%s() len=%d != sz=%d\n", __func__, len, size);
return -EIO;
}
return 0;
}
/*
* mcs7830_phy_emit_wait() - emit PHY read/write access, wait for its execution
* @dev: network device to talk to
* @rwflag: PHY_CMD1_READ or PHY_CMD1_WRITE opcode
* @index: number of the PHY register to read or write
* Return: zero upon success, negative upon error
*/
static int mcs7830_phy_emit_wait(struct ueth_data *dev,
uint8_t rwflag, uint8_t index)
{
int rc;
int retry;
uint8_t cmd[2];
/* send the PHY read/write request */
cmd[0] = rwflag | PHY_CMD1_PHYADDR;
cmd[1] = PHY_CMD2_PEND | (index & 0x1f);
rc = mcs7830_write_reg(dev, REG_PHY_CMD, sizeof(cmd), cmd);
if (rc < 0)
return rc;
/* wait for the response to become available (usually < 1ms) */
retry = 10;
do {
rc = mcs7830_read_reg(dev, REG_PHY_CMD, sizeof(cmd), cmd);
if (rc < 0)
return rc;
if (cmd[1] & PHY_CMD2_READY)
return 0;
if (!retry--)
return -ETIMEDOUT;
mdelay(1);
} while (1);
/* UNREACH */
}
/*
* mcs7830_read_phy() - read a PHY register of the network adapter
* @dev: network device to read from
* @index: index of the PHY register to read from
* Return: non-negative 16bit register content, negative upon error
*/
static int mcs7830_read_phy(struct ueth_data *dev, uint8_t index)
{
int rc;
uint16_t val;
/* issue the PHY read request and wait for its execution */
rc = mcs7830_phy_emit_wait(dev, PHY_CMD1_READ, index);
if (rc < 0)
return rc;
/* fetch the PHY data which was read */
rc = mcs7830_read_reg(dev, REG_PHY_DATA, sizeof(val), &val);
if (rc < 0)
return rc;
rc = le16_to_cpu(val);
debug("%s(%s, %d) => 0x%04X\n", __func__, dev->eth_dev.name, index, rc);
return rc;
}
/*
* mcs7830_write_phy() - write a PHY register of the network adapter
* @dev: network device to write to
* @index: index of the PHY register to write to
* @val: value to write to the PHY register
* Return: zero upon success, negative upon error
*/
static int mcs7830_write_phy(struct ueth_data *dev, uint8_t index, uint16_t val)
{
int rc;
debug("%s(%s, %d, 0x%04X)\n", __func__, dev->eth_dev.name, index, val);
/* setup the PHY data which is to get written */
val = cpu_to_le16(val);
rc = mcs7830_write_reg(dev, REG_PHY_DATA, sizeof(val), &val);
if (rc < 0)
return rc;
/* issue the PHY write request and wait for its execution */
rc = mcs7830_phy_emit_wait(dev, PHY_CMD1_WRITE, index);
if (rc < 0)
return rc;
return 0;
}
/*
* mcs7830_write_config() - write to the network adapter's config register
* @eth: network device to write to
* Return: zero upon success, negative upon error
*
* the data which gets written is taken from the shadow config register
* within the device driver's private data
*/
static int mcs7830_write_config(struct ueth_data *dev)
{
struct mcs7830_private *priv;
int rc;
debug("%s()\n", __func__);
priv = dev->dev_priv;
rc = mcs7830_write_reg(dev, REG_CONFIG,
sizeof(priv->config), &priv->config);
if (rc < 0) {
debug("writing config to adapter failed\n");
return rc;
}
return 0;
}
/*
* mcs7830_write_mchash() - write the network adapter's multicast filter
* @eth: network device to write to
* Return: zero upon success, negative upon error
*
* the data which gets written is taken from the shadow multicast hashes
* within the device driver's private data
*/
static int mcs7830_write_mchash(struct ueth_data *dev)
{
struct mcs7830_private *priv;
int rc;
debug("%s()\n", __func__);
priv = dev->dev_priv;
rc = mcs7830_write_reg(dev, REG_MULTICAST_HASH,
sizeof(priv->mchash), &priv->mchash);
if (rc < 0) {
debug("writing multicast hash to adapter failed\n");
return rc;
}
return 0;
}
/*
* mcs7830_set_autoneg() - setup and trigger ethernet link autonegotiation
* @eth: network device to run link negotiation on
* Return: zero upon success, negative upon error
*
* the routine advertises available media and starts autonegotiation
*/
static int mcs7830_set_autoneg(struct ueth_data *dev)
{
int adv, flg;
int rc;
debug("%s()\n", __func__);
/*
* algorithm taken from the Linux driver, which took it from
* "the original mcs7830 version 1.4 driver":
*
* enable all media, reset BMCR, enable auto neg, restart
* auto neg while keeping the enable auto neg flag set
*/
adv = ADVERTISE_PAUSE_CAP | ADVERTISE_ALL | ADVERTISE_CSMA;
rc = mcs7830_write_phy(dev, MII_ADVERTISE, adv);
flg = 0;
if (!rc)
rc = mcs7830_write_phy(dev, MII_BMCR, flg);
flg |= BMCR_ANENABLE;
if (!rc)
rc = mcs7830_write_phy(dev, MII_BMCR, flg);
flg |= BMCR_ANRESTART;
if (!rc)
rc = mcs7830_write_phy(dev, MII_BMCR, flg);
return rc;
}
/*
* mcs7830_get_rev() - identify a network adapter's chip revision
* @eth: network device to identify
* Return: non-negative number, reflecting the revision number
*
* currently, only "rev C and higher" and "below rev C" are needed, so
* the return value is #1 for "below rev C", and #2 for "rev C and above"
*/
static int mcs7830_get_rev(struct ueth_data *dev)
{
uint8_t buf[2];
int rc;
int rev;
/* register 22 is readable in rev C and higher */
rc = mcs7830_read_reg(dev, REG_FRAME_DROP_COUNTER, sizeof(buf), buf);
if (rc < 0)
rev = 1;
else
rev = 2;
debug("%s() rc=%d, rev=%d\n", __func__, rc, rev);
return rev;
}
/*
* mcs7830_apply_fixup() - identify an adapter and potentially apply fixups
* @eth: network device to identify and apply fixups to
* Return: zero upon success (no errors emitted from here)
*
* this routine identifies the network adapter's chip revision, and applies
* fixups for known issues
*/
static int mcs7830_apply_fixup(struct ueth_data *dev)
{
int rev;
int i;
uint8_t thr;
rev = mcs7830_get_rev(dev);
debug("%s() rev=%d\n", __func__, rev);
/*
* rev C requires setting the pause threshold (the Linux driver
* is inconsistent, the implementation does it for "rev C
* exactly", the introductory comment says "rev C and above")
*/
if (rev == 2) {
debug("%s: applying rev C fixup\n", dev->eth_dev.name);
thr = PAUSE_THRESHOLD_DEFAULT;
for (i = 0; i < 2; i++) {
(void)mcs7830_write_reg(dev, REG_PAUSE_THRESHOLD,
sizeof(thr), &thr);
mdelay(1);
}
}
return 0;
}
/*
* mcs7830_basic_reset() - bring the network adapter into a known first state
* @eth: network device to act upon
* Return: zero upon success, negative upon error
*
* this routine initializes the network adapter such that subsequent invocations
* of the interface callbacks can exchange ethernet frames; link negotiation is
* triggered from here already and continues in background
*/
static int mcs7830_basic_reset(struct ueth_data *dev)
{
struct mcs7830_private *priv;
int rc;
debug("%s()\n", __func__);
priv = dev->dev_priv;
/*
* comment from the respective Linux driver, which
* unconditionally sets the ALLMULTICAST flag as well:
* should not be needed, but does not work otherwise
*/
priv->config = CONF_TXENABLE;
priv->config |= CONF_ALLMULTICAST;
rc = mcs7830_set_autoneg(dev);
if (rc < 0) {
error("setting autoneg failed\n");
return rc;
}
rc = mcs7830_write_mchash(dev);
if (rc < 0) {
error("failed to set multicast hash\n");
return rc;
}
rc = mcs7830_write_config(dev);
if (rc < 0) {
error("failed to set configuration\n");
return rc;
}
rc = mcs7830_apply_fixup(dev);
if (rc < 0) {
error("fixup application failed\n");
return rc;
}
return 0;
}
/*
* mcs7830_read_mac() - read an ethernet adapter's MAC address
* @eth: network device to read from
* Return: zero upon success, negative upon error
*
* this routine fetches the MAC address stored within the ethernet adapter,
* and stores it in the ethernet interface's data structure
*/
static int mcs7830_read_mac(struct eth_device *eth)
{
struct ueth_data *dev;
int rc;
uint8_t buf[ETH_ALEN];
debug("%s()\n", __func__);
dev = eth->priv;
rc = mcs7830_read_reg(dev, REG_ETHER_ADDR, ETH_ALEN, buf);
if (rc < 0) {
debug("reading MAC from adapter failed\n");
return rc;
}
memcpy(&eth->enetaddr[0], buf, ETH_ALEN);
return 0;
}
/*
* mcs7830_write_mac() - write an ethernet adapter's MAC address
* @eth: network device to write to
* Return: zero upon success, negative upon error
*
* this routine takes the MAC address from the ethernet interface's data
* structure, and writes it into the ethernet adapter such that subsequent
* exchange of ethernet frames uses this address
*/
static int mcs7830_write_mac(struct eth_device *eth)
{
struct ueth_data *dev;
int rc;
debug("%s()\n", __func__);
dev = eth->priv;
if (sizeof(eth->enetaddr) != ETH_ALEN)
return -EINVAL;
rc = mcs7830_write_reg(dev, REG_ETHER_ADDR, ETH_ALEN, eth->enetaddr);
if (rc < 0) {
debug("writing MAC to adapter failed\n");
return rc;
}
return 0;
}
/*
* mcs7830_init() - network interface's init callback
* @eth: network device to initialize
* @bd: board information
* Return: zero upon success, negative upon error
*
* after initial setup during probe() and get_info(), this init() callback
* ensures that the link is up and subsequent send() and recv() calls can
* exchange ethernet frames
*/
static int mcs7830_init(struct eth_device *eth, bd_t *bd)
{
struct ueth_data *dev;
int timeout;
int have_link;
debug("%s()\n", __func__);
dev = eth->priv;
timeout = 0;
do {
have_link = mcs7830_read_phy(dev, MII_BMSR) & BMSR_LSTATUS;
if (have_link)
break;
udelay(LINKSTATUS_TIMEOUT_RES * 1000);
timeout += LINKSTATUS_TIMEOUT_RES;
} while (timeout < LINKSTATUS_TIMEOUT);
if (!have_link) {
debug("ethernet link is down\n");
return -ETIMEDOUT;
}
return 0;
}
/*
* mcs7830_send() - network interface's send callback
* @eth: network device to send the frame from
* @packet: ethernet frame content
* @length: ethernet frame length
* Return: zero upon success, negative upon error
*
* this routine send an ethernet frame out of the network interface
*/
static int mcs7830_send(struct eth_device *eth, void *packet, int length)
{
struct ueth_data *dev;
int rc;
int gotlen;
/* there is a status byte after the ethernet frame */
ALLOC_CACHE_ALIGN_BUFFER(uint8_t, buf, PKTSIZE + sizeof(uint8_t));
dev = eth->priv;
memcpy(buf, packet, length);
rc = usb_bulk_msg(dev->pusb_dev,
usb_sndbulkpipe(dev->pusb_dev, dev->ep_out),
&buf[0], length, &gotlen,
USBCALL_TIMEOUT);
debug("%s() TX want len %d, got len %d, rc %d\n",
__func__, length, gotlen, rc);
return rc;
}
/*
* mcs7830_recv() - network interface's recv callback
* @eth: network device to receive frames from
* Return: zero upon success, negative upon error
*
* this routine checks for available ethernet frames that the network
* interface might have received, and notifies the network stack
*/
static int mcs7830_recv(struct eth_device *eth)
{
struct ueth_data *dev;
ALLOC_CACHE_ALIGN_BUFFER(uint8_t, buf, MCS7830_RX_URB_SIZE);
int rc, wantlen, gotlen;
uint8_t sts;
debug("%s()\n", __func__);
dev = eth->priv;
/* fetch input data from the adapter */
wantlen = MCS7830_RX_URB_SIZE;
rc = usb_bulk_msg(dev->pusb_dev,
usb_rcvbulkpipe(dev->pusb_dev, dev->ep_in),
&buf[0], wantlen, &gotlen,
USBCALL_TIMEOUT);
debug("%s() RX want len %d, got len %d, rc %d\n",
__func__, wantlen, gotlen, rc);
if (rc != 0) {
error("RX: failed to receive\n");
return rc;
}
if (gotlen > wantlen) {
error("RX: got too many bytes (%d)\n", gotlen);
return -EIO;
}
/*
* the bulk message that we received from USB contains exactly
* one ethernet frame and a trailing status byte
*/
if (gotlen < sizeof(sts))
return -EIO;
gotlen -= sizeof(sts);
sts = buf[gotlen];
if (sts == STAT_RX_FRAME_CORRECT) {
debug("%s() got a frame, len=%d\n", __func__, gotlen);
net_process_received_packet(buf, gotlen);
return 0;
}
debug("RX: frame error (sts 0x%02X, %s %s %s %s %s)\n",
sts,
(sts & STAT_RX_LARGE_FRAME) ? "large" : "-",
(sts & STAT_RX_LENGTH_ERROR) ? "length" : "-",
(sts & STAT_RX_SHORT_FRAME) ? "short" : "-",
(sts & STAT_RX_CRC_ERROR) ? "crc" : "-",
(sts & STAT_RX_ALIGNMENT_ERROR) ? "align" : "-");
return -EIO;
}
/*
* mcs7830_halt() - network interface's halt callback
* @eth: network device to cease operation of
* Return: none
*
* this routine is supposed to undo the effect of previous initialization and
* ethernet frames exchange; in this implementation it's a NOP
*/
static void mcs7830_halt(struct eth_device *eth)
{
debug("%s()\n", __func__);
}
/*
* mcs7830_iface_idx - index of detected network interfaces
*
* this counter keeps track of identified supported interfaces,
* to assign unique names as more interfaces are found
*/
static int mcs7830_iface_idx;
/*
* mcs7830_eth_before_probe() - network driver's before_probe callback
* Return: none
*
* this routine initializes driver's internal data in preparation of
* subsequent probe callbacks
*/
void mcs7830_eth_before_probe(void)
{
mcs7830_iface_idx = 0;
}
/*
* struct mcs7830_dongle - description of a supported Moschip ethernet dongle
* @vendor: 16bit USB vendor identification
* @product: 16bit USB product identification
*
* this structure describes a supported USB ethernet dongle by means of the
* vendor and product codes found during USB enumeration; no flags are held
* here since all supported dongles have identical behaviour, and required
* fixups get determined at runtime, such that no manual configuration is
* needed
*/
struct mcs7830_dongle {
uint16_t vendor;
uint16_t product;
};
/*
* mcs7830_dongles - the list of supported Moschip based USB ethernet dongles
*/
static const struct mcs7830_dongle mcs7830_dongles[] = {
{ 0x9710, 0x7832, }, /* Moschip 7832 */
{ 0x9710, 0x7830, }, /* Moschip 7830 */
{ 0x9710, 0x7730, }, /* Moschip 7730 */
{ 0x0df6, 0x0021, }, /* Sitecom LN 30 */
};
/*
* mcs7830_eth_probe() - network driver's probe callback
* @dev: detected USB device to check
* @ifnum: detected USB interface to check
* @ss: USB ethernet data structure to fill in upon match
* Return: #1 upon match, #0 upon mismatch or error
*
* this routine checks whether the found USB device is supported by
* this ethernet driver, and upon match fills in the USB ethernet
* data structure which later is passed to the get_info callback
*/
int mcs7830_eth_probe(struct usb_device *dev, unsigned int ifnum,
struct ueth_data *ss)
{
struct usb_interface *iface;
struct usb_interface_descriptor *iface_desc;
int i;
struct mcs7830_private *priv;
int ep_in_found, ep_out_found, ep_intr_found;
debug("%s()\n", __func__);
/* iterate the list of supported dongles */
iface = &dev->config.if_desc[ifnum];
iface_desc = &iface->desc;
for (i = 0; i < ARRAY_SIZE(mcs7830_dongles); i++) {
if (dev->descriptor.idVendor == mcs7830_dongles[i].vendor &&
dev->descriptor.idProduct == mcs7830_dongles[i].product)
break;
}
if (i == ARRAY_SIZE(mcs7830_dongles))
return 0;
debug("detected USB ethernet device: %04X:%04X\n",
dev->descriptor.idVendor, dev->descriptor.idProduct);
/* fill in driver private data */
priv = calloc(1, sizeof(*priv));
if (!priv)
return 0;
/* fill in the ueth_data structure, attach private data */
memset(ss, 0, sizeof(*ss));
ss->ifnum = ifnum;
ss->pusb_dev = dev;
ss->subclass = iface_desc->bInterfaceSubClass;
ss->protocol = iface_desc->bInterfaceProtocol;
ss->dev_priv = priv;
/*
* a minimum of three endpoints is expected: in (bulk),
* out (bulk), and interrupt; ignore all others
*/
ep_in_found = ep_out_found = ep_intr_found = 0;
for (i = 0; i < iface_desc->bNumEndpoints; i++) {
uint8_t eptype, epaddr;
bool is_input;
eptype = iface->ep_desc[i].bmAttributes;
eptype &= USB_ENDPOINT_XFERTYPE_MASK;
epaddr = iface->ep_desc[i].bEndpointAddress;
is_input = epaddr & USB_DIR_IN;
epaddr &= USB_ENDPOINT_NUMBER_MASK;
if (eptype == USB_ENDPOINT_XFER_BULK) {
if (is_input && !ep_in_found) {
ss->ep_in = epaddr;
ep_in_found++;
}
if (!is_input && !ep_out_found) {
ss->ep_out = epaddr;
ep_out_found++;
}
}
if (eptype == USB_ENDPOINT_XFER_INT) {
if (is_input && !ep_intr_found) {
ss->ep_int = epaddr;
ss->irqinterval = iface->ep_desc[i].bInterval;
ep_intr_found++;
}
}
}
debug("endpoints: in %d, out %d, intr %d\n",
ss->ep_in, ss->ep_out, ss->ep_int);
/* apply basic sanity checks */
if (usb_set_interface(dev, iface_desc->bInterfaceNumber, 0) ||
!ss->ep_in || !ss->ep_out || !ss->ep_int) {
debug("device probe incomplete\n");
return 0;
}
dev->privptr = ss;
return 1;
}
/*
* mcs7830_eth_get_info() - network driver's get_info callback
* @dev: detected USB device
* @ss: USB ethernet data structure filled in at probe()
* @eth: ethernet interface data structure to fill in
* Return: #1 upon success, #0 upon error
*
* this routine registers the mandatory init(), send(), recv(), and
* halt() callbacks with the ethernet interface, can register the
* optional write_hwaddr() callback with the ethernet interface,
* and initiates configuration of the interface such that subsequent
* calls to those callbacks results in network communication
*/
int mcs7830_eth_get_info(struct usb_device *dev, struct ueth_data *ss,
struct eth_device *eth)
{
debug("%s()\n", __func__);
if (!eth) {
debug("%s: missing parameter.\n", __func__);
return 0;
}
snprintf(eth->name, sizeof(eth->name), "%s%d",
MCS7830_BASE_NAME, mcs7830_iface_idx++);
eth->init = mcs7830_init;
eth->send = mcs7830_send;
eth->recv = mcs7830_recv;
eth->halt = mcs7830_halt;
eth->write_hwaddr = mcs7830_write_mac;
eth->priv = ss;
if (mcs7830_basic_reset(ss))
return 0;
if (mcs7830_read_mac(eth))
return 0;
debug("MAC %pM\n", eth->enetaddr);
return 1;
}