linux/linux-5.4.31/drivers/net/wan/hd64570.c

717 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Hitachi SCA HD64570 driver for Linux
*
* Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
*
* Source of information: Hitachi HD64570 SCA User's Manual
*
* We use the following SCA memory map:
*
* Packet buffer descriptor rings - starting from winbase or win0base:
* rx_ring_buffers * sizeof(pkt_desc) = logical channel #0 RX ring
* tx_ring_buffers * sizeof(pkt_desc) = logical channel #0 TX ring
* rx_ring_buffers * sizeof(pkt_desc) = logical channel #1 RX ring (if used)
* tx_ring_buffers * sizeof(pkt_desc) = logical channel #1 TX ring (if used)
*
* Packet data buffers - starting from winbase + buff_offset:
* rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers
* tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers
* rx_ring_buffers * HDLC_MAX_MRU = logical channel #0 RX buffers (if used)
* tx_ring_buffers * HDLC_MAX_MRU = logical channel #0 TX buffers (if used)
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/hdlc.h>
#include <linux/in.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include "hd64570.h"
#define get_msci(port) (phy_node(port) ? MSCI1_OFFSET : MSCI0_OFFSET)
#define get_dmac_rx(port) (phy_node(port) ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
#define get_dmac_tx(port) (phy_node(port) ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
#define SCA_INTR_MSCI(node) (node ? 0x10 : 0x01)
#define SCA_INTR_DMAC_RX(node) (node ? 0x20 : 0x02)
#define SCA_INTR_DMAC_TX(node) (node ? 0x40 : 0x04)
static inline struct net_device *port_to_dev(port_t *port)
{
return port->dev;
}
static inline int sca_intr_status(card_t *card)
{
u8 result = 0;
u8 isr0 = sca_in(ISR0, card);
u8 isr1 = sca_in(ISR1, card);
if (isr1 & 0x03) result |= SCA_INTR_DMAC_RX(0);
if (isr1 & 0x0C) result |= SCA_INTR_DMAC_TX(0);
if (isr1 & 0x30) result |= SCA_INTR_DMAC_RX(1);
if (isr1 & 0xC0) result |= SCA_INTR_DMAC_TX(1);
if (isr0 & 0x0F) result |= SCA_INTR_MSCI(0);
if (isr0 & 0xF0) result |= SCA_INTR_MSCI(1);
if (!(result & SCA_INTR_DMAC_TX(0)))
if (sca_in(DSR_TX(0), card) & DSR_EOM)
result |= SCA_INTR_DMAC_TX(0);
if (!(result & SCA_INTR_DMAC_TX(1)))
if (sca_in(DSR_TX(1), card) & DSR_EOM)
result |= SCA_INTR_DMAC_TX(1);
return result;
}
static inline port_t* dev_to_port(struct net_device *dev)
{
return dev_to_hdlc(dev)->priv;
}
static inline u16 next_desc(port_t *port, u16 desc, int transmit)
{
return (desc + 1) % (transmit ? port_to_card(port)->tx_ring_buffers
: port_to_card(port)->rx_ring_buffers);
}
static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
{
u16 rx_buffs = port_to_card(port)->rx_ring_buffers;
u16 tx_buffs = port_to_card(port)->tx_ring_buffers;
desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
return log_node(port) * (rx_buffs + tx_buffs) +
transmit * rx_buffs + desc;
}
static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
{
/* Descriptor offset always fits in 16 bits */
return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
}
static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
int transmit)
{
#ifdef PAGE0_ALWAYS_MAPPED
return (pkt_desc __iomem *)(win0base(port_to_card(port))
+ desc_offset(port, desc, transmit));
#else
return (pkt_desc __iomem *)(winbase(port_to_card(port))
+ desc_offset(port, desc, transmit));
#endif
}
static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
{
return port_to_card(port)->buff_offset +
desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
}
static inline void sca_set_carrier(port_t *port)
{
if (!(sca_in(get_msci(port) + ST3, port_to_card(port)) & ST3_DCD)) {
#ifdef DEBUG_LINK
printk(KERN_DEBUG "%s: sca_set_carrier on\n",
port_to_dev(port)->name);
#endif
netif_carrier_on(port_to_dev(port));
} else {
#ifdef DEBUG_LINK
printk(KERN_DEBUG "%s: sca_set_carrier off\n",
port_to_dev(port)->name);
#endif
netif_carrier_off(port_to_dev(port));
}
}
static void sca_init_port(port_t *port)
{
card_t *card = port_to_card(port);
int transmit, i;
port->rxin = 0;
port->txin = 0;
port->txlast = 0;
#ifndef PAGE0_ALWAYS_MAPPED
openwin(card, 0);
#endif
for (transmit = 0; transmit < 2; transmit++) {
u16 dmac = transmit ? get_dmac_tx(port) : get_dmac_rx(port);
u16 buffs = transmit ? card->tx_ring_buffers
: card->rx_ring_buffers;
for (i = 0; i < buffs; i++) {
pkt_desc __iomem *desc = desc_address(port, i, transmit);
u16 chain_off = desc_offset(port, i + 1, transmit);
u32 buff_off = buffer_offset(port, i, transmit);
writew(chain_off, &desc->cp);
writel(buff_off, &desc->bp);
writew(0, &desc->len);
writeb(0, &desc->stat);
}
/* DMA disable - to halt state */
sca_out(0, transmit ? DSR_TX(phy_node(port)) :
DSR_RX(phy_node(port)), card);
/* software ABORT - to initial state */
sca_out(DCR_ABORT, transmit ? DCR_TX(phy_node(port)) :
DCR_RX(phy_node(port)), card);
/* current desc addr */
sca_out(0, dmac + CPB, card); /* pointer base */
sca_outw(desc_offset(port, 0, transmit), dmac + CDAL, card);
if (!transmit)
sca_outw(desc_offset(port, buffs - 1, transmit),
dmac + EDAL, card);
else
sca_outw(desc_offset(port, 0, transmit), dmac + EDAL,
card);
/* clear frame end interrupt counter */
sca_out(DCR_CLEAR_EOF, transmit ? DCR_TX(phy_node(port)) :
DCR_RX(phy_node(port)), card);
if (!transmit) { /* Receive */
/* set buffer length */
sca_outw(HDLC_MAX_MRU, dmac + BFLL, card);
/* Chain mode, Multi-frame */
sca_out(0x14, DMR_RX(phy_node(port)), card);
sca_out(DIR_EOME | DIR_BOFE, DIR_RX(phy_node(port)),
card);
/* DMA enable */
sca_out(DSR_DE, DSR_RX(phy_node(port)), card);
} else { /* Transmit */
/* Chain mode, Multi-frame */
sca_out(0x14, DMR_TX(phy_node(port)), card);
/* enable underflow interrupts */
sca_out(DIR_BOFE, DIR_TX(phy_node(port)), card);
}
}
sca_set_carrier(port);
}
#ifdef NEED_SCA_MSCI_INTR
/* MSCI interrupt service */
static inline void sca_msci_intr(port_t *port)
{
u16 msci = get_msci(port);
card_t* card = port_to_card(port);
u8 stat = sca_in(msci + ST1, card); /* read MSCI ST1 status */
/* Reset MSCI TX underrun and CDCD status bit */
sca_out(stat & (ST1_UDRN | ST1_CDCD), msci + ST1, card);
if (stat & ST1_UDRN) {
/* TX Underrun error detected */
port_to_dev(port)->stats.tx_errors++;
port_to_dev(port)->stats.tx_fifo_errors++;
}
if (stat & ST1_CDCD)
sca_set_carrier(port);
}
#endif
static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
u16 rxin)
{
struct net_device *dev = port_to_dev(port);
struct sk_buff *skb;
u16 len;
u32 buff;
u32 maxlen;
u8 page;
len = readw(&desc->len);
skb = dev_alloc_skb(len);
if (!skb) {
dev->stats.rx_dropped++;
return;
}
buff = buffer_offset(port, rxin, 0);
page = buff / winsize(card);
buff = buff % winsize(card);
maxlen = winsize(card) - buff;
openwin(card, page);
if (len > maxlen) {
memcpy_fromio(skb->data, winbase(card) + buff, maxlen);
openwin(card, page + 1);
memcpy_fromio(skb->data + maxlen, winbase(card), len - maxlen);
} else
memcpy_fromio(skb->data, winbase(card) + buff, len);
#ifndef PAGE0_ALWAYS_MAPPED
openwin(card, 0); /* select pkt_desc table page back */
#endif
skb_put(skb, len);
#ifdef DEBUG_PKT
printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
debug_frame(skb);
#endif
dev->stats.rx_packets++;
dev->stats.rx_bytes += skb->len;
skb->protocol = hdlc_type_trans(skb, dev);
netif_rx(skb);
}
/* Receive DMA interrupt service */
static inline void sca_rx_intr(port_t *port)
{
struct net_device *dev = port_to_dev(port);
u16 dmac = get_dmac_rx(port);
card_t *card = port_to_card(port);
u8 stat = sca_in(DSR_RX(phy_node(port)), card); /* read DMA Status */
/* Reset DSR status bits */
sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
DSR_RX(phy_node(port)), card);
if (stat & DSR_BOF)
/* Dropped one or more frames */
dev->stats.rx_over_errors++;
while (1) {
u32 desc_off = desc_offset(port, port->rxin, 0);
pkt_desc __iomem *desc;
u32 cda = sca_inw(dmac + CDAL, card);
if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
break; /* No frame received */
desc = desc_address(port, port->rxin, 0);
stat = readb(&desc->stat);
if (!(stat & ST_RX_EOM))
port->rxpart = 1; /* partial frame received */
else if ((stat & ST_ERROR_MASK) || port->rxpart) {
dev->stats.rx_errors++;
if (stat & ST_RX_OVERRUN)
dev->stats.rx_fifo_errors++;
else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
ST_RX_RESBIT)) || port->rxpart)
dev->stats.rx_frame_errors++;
else if (stat & ST_RX_CRC)
dev->stats.rx_crc_errors++;
if (stat & ST_RX_EOM)
port->rxpart = 0; /* received last fragment */
} else
sca_rx(card, port, desc, port->rxin);
/* Set new error descriptor address */
sca_outw(desc_off, dmac + EDAL, card);
port->rxin = next_desc(port, port->rxin, 0);
}
/* make sure RX DMA is enabled */
sca_out(DSR_DE, DSR_RX(phy_node(port)), card);
}
/* Transmit DMA interrupt service */
static inline void sca_tx_intr(port_t *port)
{
struct net_device *dev = port_to_dev(port);
u16 dmac = get_dmac_tx(port);
card_t* card = port_to_card(port);
u8 stat;
spin_lock(&port->lock);
stat = sca_in(DSR_TX(phy_node(port)), card); /* read DMA Status */
/* Reset DSR status bits */
sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
DSR_TX(phy_node(port)), card);
while (1) {
pkt_desc __iomem *desc;
u32 desc_off = desc_offset(port, port->txlast, 1);
u32 cda = sca_inw(dmac + CDAL, card);
if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
break; /* Transmitter is/will_be sending this frame */
desc = desc_address(port, port->txlast, 1);
dev->stats.tx_packets++;
dev->stats.tx_bytes += readw(&desc->len);
writeb(0, &desc->stat); /* Free descriptor */
port->txlast = next_desc(port, port->txlast, 1);
}
netif_wake_queue(dev);
spin_unlock(&port->lock);
}
static irqreturn_t sca_intr(int irq, void* dev_id)
{
card_t *card = dev_id;
int i;
u8 stat;
int handled = 0;
u8 page = sca_get_page(card);
while((stat = sca_intr_status(card)) != 0) {
handled = 1;
for (i = 0; i < 2; i++) {
port_t *port = get_port(card, i);
if (port) {
if (stat & SCA_INTR_MSCI(i))
sca_msci_intr(port);
if (stat & SCA_INTR_DMAC_RX(i))
sca_rx_intr(port);
if (stat & SCA_INTR_DMAC_TX(i))
sca_tx_intr(port);
}
}
}
openwin(card, page); /* Restore original page */
return IRQ_RETVAL(handled);
}
static void sca_set_port(port_t *port)
{
card_t* card = port_to_card(port);
u16 msci = get_msci(port);
u8 md2 = sca_in(msci + MD2, card);
unsigned int tmc, br = 10, brv = 1024;
if (port->settings.clock_rate > 0) {
/* Try lower br for better accuracy*/
do {
br--;
brv >>= 1; /* brv = 2^9 = 512 max in specs */
/* Baud Rate = CLOCK_BASE / TMC / 2^BR */
tmc = CLOCK_BASE / brv / port->settings.clock_rate;
}while (br > 1 && tmc <= 128);
if (tmc < 1) {
tmc = 1;
br = 0; /* For baud=CLOCK_BASE we use tmc=1 br=0 */
brv = 1;
} else if (tmc > 255)
tmc = 256; /* tmc=0 means 256 - low baud rates */
port->settings.clock_rate = CLOCK_BASE / brv / tmc;
} else {
br = 9; /* Minimum clock rate */
tmc = 256; /* 8bit = 0 */
port->settings.clock_rate = CLOCK_BASE / (256 * 512);
}
port->rxs = (port->rxs & ~CLK_BRG_MASK) | br;
port->txs = (port->txs & ~CLK_BRG_MASK) | br;
port->tmc = tmc;
/* baud divisor - time constant*/
sca_out(port->tmc, msci + TMC, card);
/* Set BRG bits */
sca_out(port->rxs, msci + RXS, card);
sca_out(port->txs, msci + TXS, card);
if (port->settings.loopback)
md2 |= MD2_LOOPBACK;
else
md2 &= ~MD2_LOOPBACK;
sca_out(md2, msci + MD2, card);
}
static void sca_open(struct net_device *dev)
{
port_t *port = dev_to_port(dev);
card_t* card = port_to_card(port);
u16 msci = get_msci(port);
u8 md0, md2;
switch(port->encoding) {
case ENCODING_NRZ: md2 = MD2_NRZ; break;
case ENCODING_NRZI: md2 = MD2_NRZI; break;
case ENCODING_FM_MARK: md2 = MD2_FM_MARK; break;
case ENCODING_FM_SPACE: md2 = MD2_FM_SPACE; break;
default: md2 = MD2_MANCHESTER;
}
if (port->settings.loopback)
md2 |= MD2_LOOPBACK;
switch(port->parity) {
case PARITY_CRC16_PR0: md0 = MD0_HDLC | MD0_CRC_16_0; break;
case PARITY_CRC16_PR1: md0 = MD0_HDLC | MD0_CRC_16; break;
case PARITY_CRC16_PR0_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU_0; break;
case PARITY_CRC16_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU; break;
default: md0 = MD0_HDLC | MD0_CRC_NONE;
}
sca_out(CMD_RESET, msci + CMD, card);
sca_out(md0, msci + MD0, card);
sca_out(0x00, msci + MD1, card); /* no address field check */
sca_out(md2, msci + MD2, card);
sca_out(0x7E, msci + IDL, card); /* flag character 0x7E */
sca_out(CTL_IDLE, msci + CTL, card);
/* Allow at least 8 bytes before requesting RX DMA operation */
/* TX with higher priority and possibly with shorter transfers */
sca_out(0x07, msci + RRC, card); /* +1=RXRDY/DMA activation condition*/
sca_out(0x10, msci + TRC0, card); /* = TXRDY/DMA activation condition*/
sca_out(0x14, msci + TRC1, card); /* +1=TXRDY/DMA deactiv condition */
/* We're using the following interrupts:
- TXINT (DMAC completed all transmisions, underrun or DCD change)
- all DMA interrupts
*/
sca_set_carrier(port);
/* MSCI TX INT and RX INT A IRQ enable */
sca_out(IE0_TXINT | IE0_RXINTA, msci + IE0, card);
sca_out(IE1_UDRN | IE1_CDCD, msci + IE1, card);
sca_out(sca_in(IER0, card) | (phy_node(port) ? 0xC0 : 0x0C),
IER0, card); /* TXINT and RXINT */
/* enable DMA IRQ */
sca_out(sca_in(IER1, card) | (phy_node(port) ? 0xF0 : 0x0F),
IER1, card);
sca_out(port->tmc, msci + TMC, card); /* Restore registers */
sca_out(port->rxs, msci + RXS, card);
sca_out(port->txs, msci + TXS, card);
sca_out(CMD_TX_ENABLE, msci + CMD, card);
sca_out(CMD_RX_ENABLE, msci + CMD, card);
netif_start_queue(dev);
}
static void sca_close(struct net_device *dev)
{
port_t *port = dev_to_port(dev);
card_t* card = port_to_card(port);
/* reset channel */
sca_out(CMD_RESET, get_msci(port) + CMD, port_to_card(port));
/* disable MSCI interrupts */
sca_out(sca_in(IER0, card) & (phy_node(port) ? 0x0F : 0xF0),
IER0, card);
/* disable DMA interrupts */
sca_out(sca_in(IER1, card) & (phy_node(port) ? 0x0F : 0xF0),
IER1, card);
netif_stop_queue(dev);
}
static int sca_attach(struct net_device *dev, unsigned short encoding,
unsigned short parity)
{
if (encoding != ENCODING_NRZ &&
encoding != ENCODING_NRZI &&
encoding != ENCODING_FM_MARK &&
encoding != ENCODING_FM_SPACE &&
encoding != ENCODING_MANCHESTER)
return -EINVAL;
if (parity != PARITY_NONE &&
parity != PARITY_CRC16_PR0 &&
parity != PARITY_CRC16_PR1 &&
parity != PARITY_CRC16_PR0_CCITT &&
parity != PARITY_CRC16_PR1_CCITT)
return -EINVAL;
dev_to_port(dev)->encoding = encoding;
dev_to_port(dev)->parity = parity;
return 0;
}
#ifdef DEBUG_RINGS
static void sca_dump_rings(struct net_device *dev)
{
port_t *port = dev_to_port(dev);
card_t *card = port_to_card(port);
u16 cnt;
#ifndef PAGE0_ALWAYS_MAPPED
u8 page = sca_get_page(card);
openwin(card, 0);
#endif
printk(KERN_DEBUG "RX ring: CDA=%u EDA=%u DSR=%02X in=%u %sactive",
sca_inw(get_dmac_rx(port) + CDAL, card),
sca_inw(get_dmac_rx(port) + EDAL, card),
sca_in(DSR_RX(phy_node(port)), card), port->rxin,
sca_in(DSR_RX(phy_node(port)), card) & DSR_DE ? "" : "in");
for (cnt = 0; cnt < port_to_card(port)->rx_ring_buffers; cnt++)
pr_cont(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
pr_cont("\n");
printk(KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
"last=%u %sactive",
sca_inw(get_dmac_tx(port) + CDAL, card),
sca_inw(get_dmac_tx(port) + EDAL, card),
sca_in(DSR_TX(phy_node(port)), card), port->txin, port->txlast,
sca_in(DSR_TX(phy_node(port)), card) & DSR_DE ? "" : "in");
for (cnt = 0; cnt < port_to_card(port)->tx_ring_buffers; cnt++)
pr_cont(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
pr_cont("\n");
printk(KERN_DEBUG "MSCI: MD: %02x %02x %02x, ST: %02x %02x %02x %02x,"
" FST: %02x CST: %02x %02x\n",
sca_in(get_msci(port) + MD0, card),
sca_in(get_msci(port) + MD1, card),
sca_in(get_msci(port) + MD2, card),
sca_in(get_msci(port) + ST0, card),
sca_in(get_msci(port) + ST1, card),
sca_in(get_msci(port) + ST2, card),
sca_in(get_msci(port) + ST3, card),
sca_in(get_msci(port) + FST, card),
sca_in(get_msci(port) + CST0, card),
sca_in(get_msci(port) + CST1, card));
printk(KERN_DEBUG "ISR: %02x %02x %02x\n", sca_in(ISR0, card),
sca_in(ISR1, card), sca_in(ISR2, card));
#ifndef PAGE0_ALWAYS_MAPPED
openwin(card, page); /* Restore original page */
#endif
}
#endif /* DEBUG_RINGS */
static netdev_tx_t sca_xmit(struct sk_buff *skb, struct net_device *dev)
{
port_t *port = dev_to_port(dev);
card_t *card = port_to_card(port);
pkt_desc __iomem *desc;
u32 buff, len;
u8 page;
u32 maxlen;
spin_lock_irq(&port->lock);
desc = desc_address(port, port->txin + 1, 1);
BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
#ifdef DEBUG_PKT
printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
debug_frame(skb);
#endif
desc = desc_address(port, port->txin, 1);
buff = buffer_offset(port, port->txin, 1);
len = skb->len;
page = buff / winsize(card);
buff = buff % winsize(card);
maxlen = winsize(card) - buff;
openwin(card, page);
if (len > maxlen) {
memcpy_toio(winbase(card) + buff, skb->data, maxlen);
openwin(card, page + 1);
memcpy_toio(winbase(card), skb->data + maxlen, len - maxlen);
} else
memcpy_toio(winbase(card) + buff, skb->data, len);
#ifndef PAGE0_ALWAYS_MAPPED
openwin(card, 0); /* select pkt_desc table page back */
#endif
writew(len, &desc->len);
writeb(ST_TX_EOM, &desc->stat);
port->txin = next_desc(port, port->txin, 1);
sca_outw(desc_offset(port, port->txin, 1),
get_dmac_tx(port) + EDAL, card);
sca_out(DSR_DE, DSR_TX(phy_node(port)), card); /* Enable TX DMA */
desc = desc_address(port, port->txin + 1, 1);
if (readb(&desc->stat)) /* allow 1 packet gap */
netif_stop_queue(dev);
spin_unlock_irq(&port->lock);
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
#ifdef NEED_DETECT_RAM
static u32 sca_detect_ram(card_t *card, u8 __iomem *rambase, u32 ramsize)
{
/* Round RAM size to 32 bits, fill from end to start */
u32 i = ramsize &= ~3;
u32 size = winsize(card);
openwin(card, (i - 4) / size); /* select last window */
do {
i -= 4;
if ((i + 4) % size == 0)
openwin(card, i / size);
writel(i ^ 0x12345678, rambase + i % size);
} while (i > 0);
for (i = 0; i < ramsize ; i += 4) {
if (i % size == 0)
openwin(card, i / size);
if (readl(rambase + i % size) != (i ^ 0x12345678))
break;
}
return i;
}
#endif /* NEED_DETECT_RAM */
static void sca_init(card_t *card, int wait_states)
{
sca_out(wait_states, WCRL, card); /* Wait Control */
sca_out(wait_states, WCRM, card);
sca_out(wait_states, WCRH, card);
sca_out(0, DMER, card); /* DMA Master disable */
sca_out(0x03, PCR, card); /* DMA priority */
sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
sca_out(0, DSR_TX(0), card);
sca_out(0, DSR_RX(1), card);
sca_out(0, DSR_TX(1), card);
sca_out(DMER_DME, DMER, card); /* DMA Master enable */
}