--- /dev/null
+/*
+ * Driver for high-speed SCC boards (those with DMA support)
+ * Copyright (C) 1997-2000 Klaus Kudielka
+ *
+ * S5SCC/DMA support by Janko Koleznik S52HI
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/if_arp.h>
+#include <linux/in.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/rtnetlink.h>
+#include <linux/sockios.h>
+#include <linux/workqueue.h>
+#include <linux/atomic.h>
+#include <asm/dma.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <net/ax25.h>
+#include "z8530.h"
+
+
+/* Number of buffers per channel */
+
+#define NUM_TX_BUF 2 /* NUM_TX_BUF >= 1 (min. 2 recommended) */
+#define NUM_RX_BUF 6 /* NUM_RX_BUF >= 1 (min. 2 recommended) */
+#define BUF_SIZE 1576 /* BUF_SIZE >= mtu + hard_header_len */
+
+
+/* Cards supported */
+
+#define HW_PI { "Ottawa PI", 0x300, 0x20, 0x10, 8, \
+ 0, 8, 1843200, 3686400 }
+#define HW_PI2 { "Ottawa PI2", 0x300, 0x20, 0x10, 8, \
+ 0, 8, 3686400, 7372800 }
+#define HW_TWIN { "Gracilis PackeTwin", 0x200, 0x10, 0x10, 32, \
+ 0, 4, 6144000, 6144000 }
+#define HW_S5 { "S5SCC/DMA", 0x200, 0x10, 0x10, 32, \
+ 0, 8, 4915200, 9830400 }
+
+#define HARDWARE { HW_PI, HW_PI2, HW_TWIN, HW_S5 }
+
+#define TMR_0_HZ 25600 /* Frequency of timer 0 */
+
+#define TYPE_PI 0
+#define TYPE_PI2 1
+#define TYPE_TWIN 2
+#define TYPE_S5 3
+#define NUM_TYPES 4
+
+#define MAX_NUM_DEVS 32
+
+
+/* SCC chips supported */
+
+#define Z8530 0
+#define Z85C30 1
+#define Z85230 2
+
+#define CHIPNAMES { "Z8530", "Z85C30", "Z85230" }
+
+
+/* I/O registers */
+
+/* 8530 registers relative to card base */
+#define SCCB_CMD 0x00
+#define SCCB_DATA 0x01
+#define SCCA_CMD 0x02
+#define SCCA_DATA 0x03
+
+/* 8253/8254 registers relative to card base */
+#define TMR_CNT0 0x00
+#define TMR_CNT1 0x01
+#define TMR_CNT2 0x02
+#define TMR_CTRL 0x03
+
+/* Additional PI/PI2 registers relative to card base */
+#define PI_DREQ_MASK 0x04
+
+/* Additional PackeTwin registers relative to card base */
+#define TWIN_INT_REG 0x08
+#define TWIN_CLR_TMR1 0x09
+#define TWIN_CLR_TMR2 0x0a
+#define TWIN_SPARE_1 0x0b
+#define TWIN_DMA_CFG 0x08
+#define TWIN_SERIAL_CFG 0x09
+#define TWIN_DMA_CLR_FF 0x0a
+#define TWIN_SPARE_2 0x0b
+
+
+/* PackeTwin I/O register values */
+
+/* INT_REG */
+#define TWIN_SCC_MSK 0x01
+#define TWIN_TMR1_MSK 0x02
+#define TWIN_TMR2_MSK 0x04
+#define TWIN_INT_MSK 0x07
+
+/* SERIAL_CFG */
+#define TWIN_DTRA_ON 0x01
+#define TWIN_DTRB_ON 0x02
+#define TWIN_EXTCLKA 0x04
+#define TWIN_EXTCLKB 0x08
+#define TWIN_LOOPA_ON 0x10
+#define TWIN_LOOPB_ON 0x20
+#define TWIN_EI 0x80
+
+/* DMA_CFG */
+#define TWIN_DMA_HDX_T1 0x08
+#define TWIN_DMA_HDX_R1 0x0a
+#define TWIN_DMA_HDX_T3 0x14
+#define TWIN_DMA_HDX_R3 0x16
+#define TWIN_DMA_FDX_T3R1 0x1b
+#define TWIN_DMA_FDX_T1R3 0x1d
+
+
+/* Status values */
+
+#define IDLE 0
+#define TX_HEAD 1
+#define TX_DATA 2
+#define TX_PAUSE 3
+#define TX_TAIL 4
+#define RTS_OFF 5
+#define WAIT 6
+#define DCD_ON 7
+#define RX_ON 8
+#define DCD_OFF 9
+
+
+/* Ioctls */
+
+#define SIOCGSCCPARAM SIOCDEVPRIVATE
+#define SIOCSSCCPARAM (SIOCDEVPRIVATE+1)
+
+
+/* Data types */
+
+struct scc_param {
+ int pclk_hz; /* frequency of BRG input (don't change) */
+ int brg_tc; /* BRG terminal count; BRG disabled if < 0 */
+ int nrzi; /* 0 (nrz), 1 (nrzi) */
+ int clocks; /* see dmascc_cfg documentation */
+ int txdelay; /* [1/TMR_0_HZ] */
+ int txtimeout; /* [1/HZ] */
+ int txtail; /* [1/TMR_0_HZ] */
+ int waittime; /* [1/TMR_0_HZ] */
+ int slottime; /* [1/TMR_0_HZ] */
+ int persist; /* 1 ... 256 */
+ int dma; /* -1 (disable), 0, 1, 3 */
+ int txpause; /* [1/TMR_0_HZ] */
+ int rtsoff; /* [1/TMR_0_HZ] */
+ int dcdon; /* [1/TMR_0_HZ] */
+ int dcdoff; /* [1/TMR_0_HZ] */
+};
+
+struct scc_hardware {
+ char *name;
+ int io_region;
+ int io_delta;
+ int io_size;
+ int num_devs;
+ int scc_offset;
+ int tmr_offset;
+ int tmr_hz;
+ int pclk_hz;
+};
+
+struct scc_priv {
+ int type;
+ int chip;
+ struct net_device *dev;
+ struct scc_info *info;
+
+ int channel;
+ int card_base, scc_cmd, scc_data;
+ int tmr_cnt, tmr_ctrl, tmr_mode;
+ struct scc_param param;
+ char rx_buf[NUM_RX_BUF][BUF_SIZE];
+ int rx_len[NUM_RX_BUF];
+ int rx_ptr;
+ struct work_struct rx_work;
+ int rx_head, rx_tail, rx_count;
+ int rx_over;
+ char tx_buf[NUM_TX_BUF][BUF_SIZE];
+ int tx_len[NUM_TX_BUF];
+ int tx_ptr;
+ int tx_head, tx_tail, tx_count;
+ int state;
+ unsigned long tx_start;
+ int rr0;
+ spinlock_t *register_lock; /* Per scc_info */
+ spinlock_t ring_lock;
+};
+
+struct scc_info {
+ int irq_used;
+ int twin_serial_cfg;
+ struct net_device *dev[2];
+ struct scc_priv priv[2];
+ struct scc_info *next;
+ spinlock_t register_lock; /* Per device register lock */
+};
+
+
+/* Function declarations */
+static int setup_adapter(int card_base, int type, int n) __init;
+
+static void write_scc(struct scc_priv *priv, int reg, int val);
+static void write_scc_data(struct scc_priv *priv, int val, int fast);
+static int read_scc(struct scc_priv *priv, int reg);
+static int read_scc_data(struct scc_priv *priv);
+
+static int scc_open(struct net_device *dev);
+static int scc_close(struct net_device *dev);
+static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
+static int scc_send_packet(struct sk_buff *skb, struct net_device *dev);
+static int scc_set_mac_address(struct net_device *dev, void *sa);
+
+static inline void tx_on(struct scc_priv *priv);
+static inline void rx_on(struct scc_priv *priv);
+static inline void rx_off(struct scc_priv *priv);
+static void start_timer(struct scc_priv *priv, int t, int r15);
+static inline unsigned char random(void);
+
+static inline void z8530_isr(struct scc_info *info);
+static irqreturn_t scc_isr(int irq, void *dev_id);
+static void rx_isr(struct scc_priv *priv);
+static void special_condition(struct scc_priv *priv, int rc);
+static void rx_bh(struct work_struct *);
+static void tx_isr(struct scc_priv *priv);
+static void es_isr(struct scc_priv *priv);
+static void tm_isr(struct scc_priv *priv);
+
+
+/* Initialization variables */
+
+static int io[MAX_NUM_DEVS] __initdata = { 0, };
+
+/* Beware! hw[] is also used in dmascc_exit(). */
+static struct scc_hardware hw[NUM_TYPES] = HARDWARE;
+
+
+/* Global variables */
+
+static struct scc_info *first;
+static unsigned long rand;
+
+
+MODULE_AUTHOR("Klaus Kudielka");
+MODULE_DESCRIPTION("Driver for high-speed SCC boards");
+module_param_array(io, int, NULL, 0);
+MODULE_LICENSE("GPL");
+
+static void __exit dmascc_exit(void)
+{
+ int i;
+ struct scc_info *info;
+
+ while (first) {
+ info = first;
+
+ /* Unregister devices */
+ for (i = 0; i < 2; i++)
+ unregister_netdev(info->dev[i]);
+
+ /* Reset board */
+ if (info->priv[0].type == TYPE_TWIN)
+ outb(0, info->dev[0]->base_addr + TWIN_SERIAL_CFG);
+ write_scc(&info->priv[0], R9, FHWRES);
+ release_region(info->dev[0]->base_addr,
+ hw[info->priv[0].type].io_size);
+
+ for (i = 0; i < 2; i++)
+ free_netdev(info->dev[i]);
+
+ /* Free memory */
+ first = info->next;
+ kfree(info);
+ }
+}
+
+static int __init dmascc_init(void)
+{
+ int h, i, j, n;
+ int base[MAX_NUM_DEVS], tcmd[MAX_NUM_DEVS], t0[MAX_NUM_DEVS],
+ t1[MAX_NUM_DEVS];
+ unsigned t_val;
+ unsigned long time, start[MAX_NUM_DEVS], delay[MAX_NUM_DEVS],
+ counting[MAX_NUM_DEVS];
+
+ /* Initialize random number generator */
+ rand = jiffies;
+ /* Cards found = 0 */
+ n = 0;
+ /* Warning message */
+ if (!io[0])
+ printk(KERN_INFO "dmascc: autoprobing (dangerous)\n");
+
+ /* Run autodetection for each card type */
+ for (h = 0; h < NUM_TYPES; h++) {
+
+ if (io[0]) {
+ /* User-specified I/O address regions */
+ for (i = 0; i < hw[h].num_devs; i++)
+ base[i] = 0;
+ for (i = 0; i < MAX_NUM_DEVS && io[i]; i++) {
+ j = (io[i] -
+ hw[h].io_region) / hw[h].io_delta;
+ if (j >= 0 && j < hw[h].num_devs &&
+ hw[h].io_region +
+ j * hw[h].io_delta == io[i]) {
+ base[j] = io[i];
+ }
+ }
+ } else {
+ /* Default I/O address regions */
+ for (i = 0; i < hw[h].num_devs; i++) {
+ base[i] =
+ hw[h].io_region + i * hw[h].io_delta;
+ }
+ }
+
+ /* Check valid I/O address regions */
+ for (i = 0; i < hw[h].num_devs; i++)
+ if (base[i]) {
+ if (!request_region
+ (base[i], hw[h].io_size, "dmascc"))
+ base[i] = 0;
+ else {
+ tcmd[i] =
+ base[i] + hw[h].tmr_offset +
+ TMR_CTRL;
+ t0[i] =
+ base[i] + hw[h].tmr_offset +
+ TMR_CNT0;
+ t1[i] =
+ base[i] + hw[h].tmr_offset +
+ TMR_CNT1;
+ }
+ }
+
+ /* Start timers */
+ for (i = 0; i < hw[h].num_devs; i++)
+ if (base[i]) {
+ /* Timer 0: LSB+MSB, Mode 3, TMR_0_HZ */
+ outb(0x36, tcmd[i]);
+ outb((hw[h].tmr_hz / TMR_0_HZ) & 0xFF,
+ t0[i]);
+ outb((hw[h].tmr_hz / TMR_0_HZ) >> 8,
+ t0[i]);
+ /* Timer 1: LSB+MSB, Mode 0, HZ/10 */
+ outb(0x70, tcmd[i]);
+ outb((TMR_0_HZ / HZ * 10) & 0xFF, t1[i]);
+ outb((TMR_0_HZ / HZ * 10) >> 8, t1[i]);
+ start[i] = jiffies;
+ delay[i] = 0;
+ counting[i] = 1;
+ /* Timer 2: LSB+MSB, Mode 0 */
+ outb(0xb0, tcmd[i]);
+ }
+ time = jiffies;
+ /* Wait until counter registers are loaded */
+ udelay(2000000 / TMR_0_HZ);
+
+ /* Timing loop */
+ while (jiffies - time < 13) {
+ for (i = 0; i < hw[h].num_devs; i++)
+ if (base[i] && counting[i]) {
+ /* Read back Timer 1: latch; read LSB; read MSB */
+ outb(0x40, tcmd[i]);
+ t_val =
+ inb(t1[i]) + (inb(t1[i]) << 8);
+ /* Also check whether counter did wrap */
+ if (t_val == 0 ||
+ t_val > TMR_0_HZ / HZ * 10)
+ counting[i] = 0;
+ delay[i] = jiffies - start[i];
+ }
+ }
+
+ /* Evaluate measurements */
+ for (i = 0; i < hw[h].num_devs; i++)
+ if (base[i]) {
+ if ((delay[i] >= 9 && delay[i] <= 11) &&
+ /* Ok, we have found an adapter */
+ (setup_adapter(base[i], h, n) == 0))
+ n++;
+ else
+ release_region(base[i],
+ hw[h].io_size);
+ }
+
+ } /* NUM_TYPES */
+
+ /* If any adapter was successfully initialized, return ok */
+ if (n)
+ return 0;
+
+ /* If no adapter found, return error */
+ printk(KERN_INFO "dmascc: no adapters found\n");
+ return -EIO;
+}
+
+module_init(dmascc_init);
+module_exit(dmascc_exit);
+
+static void __init dev_setup(struct net_device *dev)
+{
+ dev->type = ARPHRD_AX25;
+ dev->hard_header_len = AX25_MAX_HEADER_LEN;
+ dev->mtu = 1500;
+ dev->addr_len = AX25_ADDR_LEN;
+ dev->tx_queue_len = 64;
+ memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
+ memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
+}
+
+static const struct net_device_ops scc_netdev_ops = {
+ .ndo_open = scc_open,
+ .ndo_stop = scc_close,
+ .ndo_start_xmit = scc_send_packet,
+ .ndo_do_ioctl = scc_ioctl,
+ .ndo_set_mac_address = scc_set_mac_address,
+};
+
+static int __init setup_adapter(int card_base, int type, int n)
+{
+ int i, irq, chip;
+ struct scc_info *info;
+ struct net_device *dev;
+ struct scc_priv *priv;
+ unsigned long time;
+ unsigned int irqs;
+ int tmr_base = card_base + hw[type].tmr_offset;
+ int scc_base = card_base + hw[type].scc_offset;
+ char *chipnames[] = CHIPNAMES;
+
+ /* Initialize what is necessary for write_scc and write_scc_data */
+ info = kzalloc(sizeof(struct scc_info), GFP_KERNEL | GFP_DMA);
+ if (!info)
+ goto out;
+
+ info->dev[0] = alloc_netdev(0, "", NET_NAME_UNKNOWN, dev_setup);
+ if (!info->dev[0]) {
+ printk(KERN_ERR "dmascc: "
+ "could not allocate memory for %s at %#3x\n",
+ hw[type].name, card_base);
+ goto out1;
+ }
+
+ info->dev[1] = alloc_netdev(0, "", NET_NAME_UNKNOWN, dev_setup);
+ if (!info->dev[1]) {
+ printk(KERN_ERR "dmascc: "
+ "could not allocate memory for %s at %#3x\n",
+ hw[type].name, card_base);
+ goto out2;
+ }
+ spin_lock_init(&info->register_lock);
+
+ priv = &info->priv[0];
+ priv->type = type;
+ priv->card_base = card_base;
+ priv->scc_cmd = scc_base + SCCA_CMD;
+ priv->scc_data = scc_base + SCCA_DATA;
+ priv->register_lock = &info->register_lock;
+
+ /* Reset SCC */
+ write_scc(priv, R9, FHWRES | MIE | NV);
+
+ /* Determine type of chip by enabling SDLC/HDLC enhancements */
+ write_scc(priv, R15, SHDLCE);
+ if (!read_scc(priv, R15)) {
+ /* WR7' not present. This is an ordinary Z8530 SCC. */
+ chip = Z8530;
+ } else {
+ /* Put one character in TX FIFO */
+ write_scc_data(priv, 0, 0);
+ if (read_scc(priv, R0) & Tx_BUF_EMP) {
+ /* TX FIFO not full. This is a Z85230 ESCC with a 4-byte FIFO. */
+ chip = Z85230;
+ } else {
+ /* TX FIFO full. This is a Z85C30 SCC with a 1-byte FIFO. */
+ chip = Z85C30;
+ }
+ }
+ write_scc(priv, R15, 0);
+
+ /* Start IRQ auto-detection */
+ irqs = probe_irq_on();
+
+ /* Enable interrupts */
+ if (type == TYPE_TWIN) {
+ outb(0, card_base + TWIN_DMA_CFG);
+ inb(card_base + TWIN_CLR_TMR1);
+ inb(card_base + TWIN_CLR_TMR2);
+ info->twin_serial_cfg = TWIN_EI;
+ outb(info->twin_serial_cfg, card_base + TWIN_SERIAL_CFG);
+ } else {
+ write_scc(priv, R15, CTSIE);
+ write_scc(priv, R0, RES_EXT_INT);
+ write_scc(priv, R1, EXT_INT_ENAB);
+ }
+
+ /* Start timer */
+ outb(1, tmr_base + TMR_CNT1);
+ outb(0, tmr_base + TMR_CNT1);
+
+ /* Wait and detect IRQ */
+ time = jiffies;
+ while (jiffies - time < 2 + HZ / TMR_0_HZ);
+ irq = probe_irq_off(irqs);
+
+ /* Clear pending interrupt, disable interrupts */
+ if (type == TYPE_TWIN) {
+ inb(card_base + TWIN_CLR_TMR1);
+ } else {
+ write_scc(priv, R1, 0);
+ write_scc(priv, R15, 0);
+ write_scc(priv, R0, RES_EXT_INT);
+ }
+
+ if (irq <= 0) {
+ printk(KERN_ERR
+ "dmascc: could not find irq of %s at %#3x (irq=%d)\n",
+ hw[type].name, card_base, irq);
+ goto out3;
+ }
+
+ /* Set up data structures */
+ for (i = 0; i < 2; i++) {
+ dev = info->dev[i];
+ priv = &info->priv[i];
+ priv->type = type;
+ priv->chip = chip;
+ priv->dev = dev;
+ priv->info = info;
+ priv->channel = i;
+ spin_lock_init(&priv->ring_lock);
+ priv->register_lock = &info->register_lock;
+ priv->card_base = card_base;
+ priv->scc_cmd = scc_base + (i ? SCCB_CMD : SCCA_CMD);
+ priv->scc_data = scc_base + (i ? SCCB_DATA : SCCA_DATA);
+ priv->tmr_cnt = tmr_base + (i ? TMR_CNT2 : TMR_CNT1);
+ priv->tmr_ctrl = tmr_base + TMR_CTRL;
+ priv->tmr_mode = i ? 0xb0 : 0x70;
+ priv->param.pclk_hz = hw[type].pclk_hz;
+ priv->param.brg_tc = -1;
+ priv->param.clocks = TCTRxCP | RCRTxCP;
+ priv->param.persist = 256;
+ priv->param.dma = -1;
+ INIT_WORK(&priv->rx_work, rx_bh);
+ dev->ml_priv = priv;
+ sprintf(dev->name, "dmascc%i", 2 * n + i);
+ dev->base_addr = card_base;
+ dev->irq = irq;
+ dev->netdev_ops = &scc_netdev_ops;
+ dev->header_ops = &ax25_header_ops;
+ }
+ if (register_netdev(info->dev[0])) {
+ printk(KERN_ERR "dmascc: could not register %s\n",
+ info->dev[0]->name);
+ goto out3;
+ }
+ if (register_netdev(info->dev[1])) {
+ printk(KERN_ERR "dmascc: could not register %s\n",
+ info->dev[1]->name);
+ goto out4;
+ }
+
+
+ info->next = first;
+ first = info;
+ printk(KERN_INFO "dmascc: found %s (%s) at %#3x, irq %d\n",
+ hw[type].name, chipnames[chip], card_base, irq);
+ return 0;
+
+ out4:
+ unregister_netdev(info->dev[0]);
+ out3:
+ if (info->priv[0].type == TYPE_TWIN)
+ outb(0, info->dev[0]->base_addr + TWIN_SERIAL_CFG);
+ write_scc(&info->priv[0], R9, FHWRES);
+ free_netdev(info->dev[1]);
+ out2:
+ free_netdev(info->dev[0]);
+ out1:
+ kfree(info);
+ out:
+ return -1;
+}
+
+
+/* Driver functions */
+
+static void write_scc(struct scc_priv *priv, int reg, int val)
+{
+ unsigned long flags;
+ switch (priv->type) {
+ case TYPE_S5:
+ if (reg)
+ outb(reg, priv->scc_cmd);
+ outb(val, priv->scc_cmd);
+ return;
+ case TYPE_TWIN:
+ if (reg)
+ outb_p(reg, priv->scc_cmd);
+ outb_p(val, priv->scc_cmd);
+ return;
+ default:
+ spin_lock_irqsave(priv->register_lock, flags);
+ outb_p(0, priv->card_base + PI_DREQ_MASK);
+ if (reg)
+ outb_p(reg, priv->scc_cmd);
+ outb_p(val, priv->scc_cmd);
+ outb(1, priv->card_base + PI_DREQ_MASK);
+ spin_unlock_irqrestore(priv->register_lock, flags);
+ return;
+ }
+}
+
+
+static void write_scc_data(struct scc_priv *priv, int val, int fast)
+{
+ unsigned long flags;
+ switch (priv->type) {
+ case TYPE_S5:
+ outb(val, priv->scc_data);
+ return;
+ case TYPE_TWIN:
+ outb_p(val, priv->scc_data);
+ return;
+ default:
+ if (fast)
+ outb_p(val, priv->scc_data);
+ else {
+ spin_lock_irqsave(priv->register_lock, flags);
+ outb_p(0, priv->card_base + PI_DREQ_MASK);
+ outb_p(val, priv->scc_data);
+ outb(1, priv->card_base + PI_DREQ_MASK);
+ spin_unlock_irqrestore(priv->register_lock, flags);
+ }
+ return;
+ }
+}
+
+
+static int read_scc(struct scc_priv *priv, int reg)
+{
+ int rc;
+ unsigned long flags;
+ switch (priv->type) {
+ case TYPE_S5:
+ if (reg)
+ outb(reg, priv->scc_cmd);
+ return inb(priv->scc_cmd);
+ case TYPE_TWIN:
+ if (reg)
+ outb_p(reg, priv->scc_cmd);
+ return inb_p(priv->scc_cmd);
+ default:
+ spin_lock_irqsave(priv->register_lock, flags);
+ outb_p(0, priv->card_base + PI_DREQ_MASK);
+ if (reg)
+ outb_p(reg, priv->scc_cmd);
+ rc = inb_p(priv->scc_cmd);
+ outb(1, priv->card_base + PI_DREQ_MASK);
+ spin_unlock_irqrestore(priv->register_lock, flags);
+ return rc;
+ }
+}
+
+
+static int read_scc_data(struct scc_priv *priv)
+{
+ int rc;
+ unsigned long flags;
+ switch (priv->type) {
+ case TYPE_S5:
+ return inb(priv->scc_data);
+ case TYPE_TWIN:
+ return inb_p(priv->scc_data);
+ default:
+ spin_lock_irqsave(priv->register_lock, flags);
+ outb_p(0, priv->card_base + PI_DREQ_MASK);
+ rc = inb_p(priv->scc_data);
+ outb(1, priv->card_base + PI_DREQ_MASK);
+ spin_unlock_irqrestore(priv->register_lock, flags);
+ return rc;
+ }
+}
+
+
+static int scc_open(struct net_device *dev)
+{
+ struct scc_priv *priv = dev->ml_priv;
+ struct scc_info *info = priv->info;
+ int card_base = priv->card_base;
+
+ /* Request IRQ if not already used by other channel */
+ if (!info->irq_used) {
+ if (request_irq(dev->irq, scc_isr, 0, "dmascc", info)) {
+ return -EAGAIN;
+ }
+ }
+ info->irq_used++;
+
+ /* Request DMA if required */
+ if (priv->param.dma >= 0) {
+ if (request_dma(priv->param.dma, "dmascc")) {
+ if (--info->irq_used == 0)
+ free_irq(dev->irq, info);
+ return -EAGAIN;
+ } else {
+ unsigned long flags = claim_dma_lock();
+ clear_dma_ff(priv->param.dma);
+ release_dma_lock(flags);
+ }
+ }
+
+ /* Initialize local variables */
+ priv->rx_ptr = 0;
+ priv->rx_over = 0;
+ priv->rx_head = priv->rx_tail = priv->rx_count = 0;
+ priv->state = IDLE;
+ priv->tx_head = priv->tx_tail = priv->tx_count = 0;
+ priv->tx_ptr = 0;
+
+ /* Reset channel */
+ write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
+ /* X1 clock, SDLC mode */
+ write_scc(priv, R4, SDLC | X1CLK);
+ /* DMA */
+ write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
+ /* 8 bit RX char, RX disable */
+ write_scc(priv, R3, Rx8);
+ /* 8 bit TX char, TX disable */
+ write_scc(priv, R5, Tx8);
+ /* SDLC address field */
+ write_scc(priv, R6, 0);
+ /* SDLC flag */
+ write_scc(priv, R7, FLAG);
+ switch (priv->chip) {
+ case Z85C30:
+ /* Select WR7' */
+ write_scc(priv, R15, SHDLCE);
+ /* Auto EOM reset */
+ write_scc(priv, R7, AUTOEOM);
+ write_scc(priv, R15, 0);
+ break;
+ case Z85230:
+ /* Select WR7' */
+ write_scc(priv, R15, SHDLCE);
+ /* The following bits are set (see 2.5.2.1):
+ - Automatic EOM reset
+ - Interrupt request if RX FIFO is half full
+ This bit should be ignored in DMA mode (according to the
+ documentation), but actually isn't. The receiver doesn't work if
+ it is set. Thus, we have to clear it in DMA mode.
+ - Interrupt/DMA request if TX FIFO is completely empty
+ a) If set, the ESCC behaves as if it had no TX FIFO (Z85C30
+ compatibility).
+ b) If cleared, DMA requests may follow each other very quickly,
+ filling up the TX FIFO.
+ Advantage: TX works even in case of high bus latency.
+ Disadvantage: Edge-triggered DMA request circuitry may miss
+ a request. No more data is delivered, resulting
+ in a TX FIFO underrun.
+ Both PI2 and S5SCC/DMA seem to work fine with TXFIFOE cleared.
+ The PackeTwin doesn't. I don't know about the PI, but let's
+ assume it behaves like the PI2.
+ */
+ if (priv->param.dma >= 0) {
+ if (priv->type == TYPE_TWIN)
+ write_scc(priv, R7, AUTOEOM | TXFIFOE);
+ else
+ write_scc(priv, R7, AUTOEOM);
+ } else {
+ write_scc(priv, R7, AUTOEOM | RXFIFOH);
+ }
+ write_scc(priv, R15, 0);
+ break;
+ }
+ /* Preset CRC, NRZ(I) encoding */
+ write_scc(priv, R10, CRCPS | (priv->param.nrzi ? NRZI : NRZ));
+
+ /* Configure baud rate generator */
+ if (priv->param.brg_tc >= 0) {
+ /* Program BR generator */
+ write_scc(priv, R12, priv->param.brg_tc & 0xFF);
+ write_scc(priv, R13, (priv->param.brg_tc >> 8) & 0xFF);
+ /* BRG source = SYS CLK; enable BRG; DTR REQ function (required by
+ PackeTwin, not connected on the PI2); set DPLL source to BRG */
+ write_scc(priv, R14, SSBR | DTRREQ | BRSRC | BRENABL);
+ /* Enable DPLL */
+ write_scc(priv, R14, SEARCH | DTRREQ | BRSRC | BRENABL);
+ } else {
+ /* Disable BR generator */
+ write_scc(priv, R14, DTRREQ | BRSRC);
+ }
+
+ /* Configure clocks */
+ if (priv->type == TYPE_TWIN) {
+ /* Disable external TX clock receiver */
+ outb((info->twin_serial_cfg &=
+ ~(priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
+ card_base + TWIN_SERIAL_CFG);
+ }
+ write_scc(priv, R11, priv->param.clocks);
+ if ((priv->type == TYPE_TWIN) && !(priv->param.clocks & TRxCOI)) {
+ /* Enable external TX clock receiver */
+ outb((info->twin_serial_cfg |=
+ (priv->channel ? TWIN_EXTCLKB : TWIN_EXTCLKA)),
+ card_base + TWIN_SERIAL_CFG);
+ }
+
+ /* Configure PackeTwin */
+ if (priv->type == TYPE_TWIN) {
+ /* Assert DTR, enable interrupts */
+ outb((info->twin_serial_cfg |= TWIN_EI |
+ (priv->channel ? TWIN_DTRB_ON : TWIN_DTRA_ON)),
+ card_base + TWIN_SERIAL_CFG);
+ }
+
+ /* Read current status */
+ priv->rr0 = read_scc(priv, R0);
+ /* Enable DCD interrupt */
+ write_scc(priv, R15, DCDIE);
+
+ netif_start_queue(dev);
+
+ return 0;
+}
+
+
+static int scc_close(struct net_device *dev)
+{
+ struct scc_priv *priv = dev->ml_priv;
+ struct scc_info *info = priv->info;
+ int card_base = priv->card_base;
+
+ netif_stop_queue(dev);
+
+ if (priv->type == TYPE_TWIN) {
+ /* Drop DTR */
+ outb((info->twin_serial_cfg &=
+ (priv->channel ? ~TWIN_DTRB_ON : ~TWIN_DTRA_ON)),
+ card_base + TWIN_SERIAL_CFG);
+ }
+
+ /* Reset channel, free DMA and IRQ */
+ write_scc(priv, R9, (priv->channel ? CHRB : CHRA) | MIE | NV);
+ if (priv->param.dma >= 0) {
+ if (priv->type == TYPE_TWIN)
+ outb(0, card_base + TWIN_DMA_CFG);
+ free_dma(priv->param.dma);
+ }
+ if (--info->irq_used == 0)
+ free_irq(dev->irq, info);
+
+ return 0;
+}
+
+
+static int scc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ struct scc_priv *priv = dev->ml_priv;
+
+ switch (cmd) {
+ case SIOCGSCCPARAM:
+ if (copy_to_user
+ (ifr->ifr_data, &priv->param,
+ sizeof(struct scc_param)))
+ return -EFAULT;
+ return 0;
+ case SIOCSSCCPARAM:
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+ if (netif_running(dev))
+ return -EAGAIN;
+ if (copy_from_user
+ (&priv->param, ifr->ifr_data,
+ sizeof(struct scc_param)))
+ return -EFAULT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+
+static int scc_send_packet(struct sk_buff *skb, struct net_device *dev)
+{
+ struct scc_priv *priv = dev->ml_priv;
+ unsigned long flags;
+ int i;
+
+ if (skb->protocol == htons(ETH_P_IP))
+ return ax25_ip_xmit(skb);
+
+ /* Temporarily stop the scheduler feeding us packets */
+ netif_stop_queue(dev);
+
+ /* Transfer data to DMA buffer */
+ i = priv->tx_head;
+ skb_copy_from_linear_data_offset(skb, 1, priv->tx_buf[i], skb->len - 1);
+ priv->tx_len[i] = skb->len - 1;
+
+ /* Clear interrupts while we touch our circular buffers */
+
+ spin_lock_irqsave(&priv->ring_lock, flags);
+ /* Move the ring buffer's head */
+ priv->tx_head = (i + 1) % NUM_TX_BUF;
+ priv->tx_count++;
+
+ /* If we just filled up the last buffer, leave queue stopped.
+ The higher layers must wait until we have a DMA buffer
+ to accept the data. */
+ if (priv->tx_count < NUM_TX_BUF)
+ netif_wake_queue(dev);
+
+ /* Set new TX state */
+ if (priv->state == IDLE) {
+ /* Assert RTS, start timer */
+ priv->state = TX_HEAD;
+ priv->tx_start = jiffies;
+ write_scc(priv, R5, TxCRC_ENAB | RTS | TxENAB | Tx8);
+ write_scc(priv, R15, 0);
+ start_timer(priv, priv->param.txdelay, 0);
+ }
+
+ /* Turn interrupts back on and free buffer */
+ spin_unlock_irqrestore(&priv->ring_lock, flags);
+ dev_kfree_skb(skb);
+
+ return NETDEV_TX_OK;
+}
+
+
+static int scc_set_mac_address(struct net_device *dev, void *sa)
+{
+ memcpy(dev->dev_addr, ((struct sockaddr *) sa)->sa_data,
+ dev->addr_len);
+ return 0;
+}
+
+
+static inline void tx_on(struct scc_priv *priv)
+{
+ int i, n;
+ unsigned long flags;
+
+ if (priv->param.dma >= 0) {
+ n = (priv->chip == Z85230) ? 3 : 1;
+ /* Program DMA controller */
+ flags = claim_dma_lock();
+ set_dma_mode(priv->param.dma, DMA_MODE_WRITE);
+ set_dma_addr(priv->param.dma,
+ (int) priv->tx_buf[priv->tx_tail] + n);
+ set_dma_count(priv->param.dma,
+ priv->tx_len[priv->tx_tail] - n);
+ release_dma_lock(flags);
+ /* Enable TX underrun interrupt */
+ write_scc(priv, R15, TxUIE);
+ /* Configure DREQ */
+ if (priv->type == TYPE_TWIN)
+ outb((priv->param.dma ==
+ 1) ? TWIN_DMA_HDX_T1 : TWIN_DMA_HDX_T3,
+ priv->card_base + TWIN_DMA_CFG);
+ else
+ write_scc(priv, R1,
+ EXT_INT_ENAB | WT_FN_RDYFN |
+ WT_RDY_ENAB);
+ /* Write first byte(s) */
+ spin_lock_irqsave(priv->register_lock, flags);
+ for (i = 0; i < n; i++)
+ write_scc_data(priv,
+ priv->tx_buf[priv->tx_tail][i], 1);
+ enable_dma(priv->param.dma);
+ spin_unlock_irqrestore(priv->register_lock, flags);
+ } else {
+ write_scc(priv, R15, TxUIE);
+ write_scc(priv, R1,
+ EXT_INT_ENAB | WT_FN_RDYFN | TxINT_ENAB);
+ tx_isr(priv);
+ }
+ /* Reset EOM latch if we do not have the AUTOEOM feature */
+ if (priv->chip == Z8530)
+ write_scc(priv, R0, RES_EOM_L);
+}
+
+
+static inline void rx_on(struct scc_priv *priv)
+{
+ unsigned long flags;
+
+ /* Clear RX FIFO */
+ while (read_scc(priv, R0) & Rx_CH_AV)
+ read_scc_data(priv);
+ priv->rx_over = 0;
+ if (priv->param.dma >= 0) {
+ /* Program DMA controller */
+ flags = claim_dma_lock();
+ set_dma_mode(priv->param.dma, DMA_MODE_READ);
+ set_dma_addr(priv->param.dma,
+ (int) priv->rx_buf[priv->rx_head]);
+ set_dma_count(priv->param.dma, BUF_SIZE);
+ release_dma_lock(flags);
+ enable_dma(priv->param.dma);
+ /* Configure PackeTwin DMA */
+ if (priv->type == TYPE_TWIN) {
+ outb((priv->param.dma ==
+ 1) ? TWIN_DMA_HDX_R1 : TWIN_DMA_HDX_R3,
+ priv->card_base + TWIN_DMA_CFG);
+ }
+ /* Sp. cond. intr. only, ext int enable, RX DMA enable */
+ write_scc(priv, R1, EXT_INT_ENAB | INT_ERR_Rx |
+ WT_RDY_RT | WT_FN_RDYFN | WT_RDY_ENAB);
+ } else {
+ /* Reset current frame */
+ priv->rx_ptr = 0;
+ /* Intr. on all Rx characters and Sp. cond., ext int enable */
+ write_scc(priv, R1, EXT_INT_ENAB | INT_ALL_Rx | WT_RDY_RT |
+ WT_FN_RDYFN);
+ }
+ write_scc(priv, R0, ERR_RES);
+ write_scc(priv, R3, RxENABLE | Rx8 | RxCRC_ENAB);
+}
+
+
+static inline void rx_off(struct scc_priv *priv)
+{
+ /* Disable receiver */
+ write_scc(priv, R3, Rx8);
+ /* Disable DREQ / RX interrupt */
+ if (priv->param.dma >= 0 && priv->type == TYPE_TWIN)
+ outb(0, priv->card_base + TWIN_DMA_CFG);
+ else
+ write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
+ /* Disable DMA */
+ if (priv->param.dma >= 0)
+ disable_dma(priv->param.dma);
+}
+
+
+static void start_timer(struct scc_priv *priv, int t, int r15)
+{
+ outb(priv->tmr_mode, priv->tmr_ctrl);
+ if (t == 0) {
+ tm_isr(priv);
+ } else if (t > 0) {
+ outb(t & 0xFF, priv->tmr_cnt);
+ outb((t >> 8) & 0xFF, priv->tmr_cnt);
+ if (priv->type != TYPE_TWIN) {
+ write_scc(priv, R15, r15 | CTSIE);
+ priv->rr0 |= CTS;
+ }
+ }
+}
+
+
+static inline unsigned char random(void)
+{
+ /* See "Numerical Recipes in C", second edition, p. 284 */
+ rand = rand * 1664525L + 1013904223L;
+ return (unsigned char) (rand >> 24);
+}
+
+static inline void z8530_isr(struct scc_info *info)
+{
+ int is, i = 100;
+
+ while ((is = read_scc(&info->priv[0], R3)) && i--) {
+ if (is & CHARxIP) {
+ rx_isr(&info->priv[0]);
+ } else if (is & CHATxIP) {
+ tx_isr(&info->priv[0]);
+ } else if (is & CHAEXT) {
+ es_isr(&info->priv[0]);
+ } else if (is & CHBRxIP) {
+ rx_isr(&info->priv[1]);
+ } else if (is & CHBTxIP) {
+ tx_isr(&info->priv[1]);
+ } else {
+ es_isr(&info->priv[1]);
+ }
+ write_scc(&info->priv[0], R0, RES_H_IUS);
+ i++;
+ }
+ if (i < 0) {
+ printk(KERN_ERR "dmascc: stuck in ISR with RR3=0x%02x.\n",
+ is);
+ }
+ /* Ok, no interrupts pending from this 8530. The INT line should
+ be inactive now. */
+}
+
+
+static irqreturn_t scc_isr(int irq, void *dev_id)
+{
+ struct scc_info *info = dev_id;
+
+ spin_lock(info->priv[0].register_lock);
+ /* At this point interrupts are enabled, and the interrupt under service
+ is already acknowledged, but masked off.
+
+ Interrupt processing: We loop until we know that the IRQ line is
+ low. If another positive edge occurs afterwards during the ISR,
+ another interrupt will be triggered by the interrupt controller
+ as soon as the IRQ level is enabled again (see asm/irq.h).
+
+ Bottom-half handlers will be processed after scc_isr(). This is
+ important, since we only have small ringbuffers and want new data
+ to be fetched/delivered immediately. */
+
+ if (info->priv[0].type == TYPE_TWIN) {
+ int is, card_base = info->priv[0].card_base;
+ while ((is = ~inb(card_base + TWIN_INT_REG)) &
+ TWIN_INT_MSK) {
+ if (is & TWIN_SCC_MSK) {
+ z8530_isr(info);
+ } else if (is & TWIN_TMR1_MSK) {
+ inb(card_base + TWIN_CLR_TMR1);
+ tm_isr(&info->priv[0]);
+ } else {
+ inb(card_base + TWIN_CLR_TMR2);
+ tm_isr(&info->priv[1]);
+ }
+ }
+ } else
+ z8530_isr(info);
+ spin_unlock(info->priv[0].register_lock);
+ return IRQ_HANDLED;
+}
+
+
+static void rx_isr(struct scc_priv *priv)
+{
+ if (priv->param.dma >= 0) {
+ /* Check special condition and perform error reset. See 2.4.7.5. */
+ special_condition(priv, read_scc(priv, R1));
+ write_scc(priv, R0, ERR_RES);
+ } else {
+ /* Check special condition for each character. Error reset not necessary.
+ Same algorithm for SCC and ESCC. See 2.4.7.1 and 2.4.7.4. */
+ int rc;
+ while (read_scc(priv, R0) & Rx_CH_AV) {
+ rc = read_scc(priv, R1);
+ if (priv->rx_ptr < BUF_SIZE)
+ priv->rx_buf[priv->rx_head][priv->
+ rx_ptr++] =
+ read_scc_data(priv);
+ else {
+ priv->rx_over = 2;
+ read_scc_data(priv);
+ }
+ special_condition(priv, rc);
+ }
+ }
+}
+
+
+static void special_condition(struct scc_priv *priv, int rc)
+{
+ int cb;
+ unsigned long flags;
+
+ /* See Figure 2-15. Only overrun and EOF need to be checked. */
+
+ if (rc & Rx_OVR) {
+ /* Receiver overrun */
+ priv->rx_over = 1;
+ if (priv->param.dma < 0)
+ write_scc(priv, R0, ERR_RES);
+ } else if (rc & END_FR) {
+ /* End of frame. Get byte count */
+ if (priv->param.dma >= 0) {
+ flags = claim_dma_lock();
+ cb = BUF_SIZE - get_dma_residue(priv->param.dma) -
+ 2;
+ release_dma_lock(flags);
+ } else {
+ cb = priv->rx_ptr - 2;
+ }
+ if (priv->rx_over) {
+ /* We had an overrun */
+ priv->dev->stats.rx_errors++;
+ if (priv->rx_over == 2)
+ priv->dev->stats.rx_length_errors++;
+ else
+ priv->dev->stats.rx_fifo_errors++;
+ priv->rx_over = 0;
+ } else if (rc & CRC_ERR) {
+ /* Count invalid CRC only if packet length >= minimum */
+ if (cb >= 15) {
+ priv->dev->stats.rx_errors++;
+ priv->dev->stats.rx_crc_errors++;
+ }
+ } else {
+ if (cb >= 15) {
+ if (priv->rx_count < NUM_RX_BUF - 1) {
+ /* Put good frame in FIFO */
+ priv->rx_len[priv->rx_head] = cb;
+ priv->rx_head =
+ (priv->rx_head +
+ 1) % NUM_RX_BUF;
+ priv->rx_count++;
+ schedule_work(&priv->rx_work);
+ } else {
+ priv->dev->stats.rx_errors++;
+ priv->dev->stats.rx_over_errors++;
+ }
+ }
+ }
+ /* Get ready for new frame */
+ if (priv->param.dma >= 0) {
+ flags = claim_dma_lock();
+ set_dma_addr(priv->param.dma,
+ (int) priv->rx_buf[priv->rx_head]);
+ set_dma_count(priv->param.dma, BUF_SIZE);
+ release_dma_lock(flags);
+ } else {
+ priv->rx_ptr = 0;
+ }
+ }
+}
+
+
+static void rx_bh(struct work_struct *ugli_api)
+{
+ struct scc_priv *priv = container_of(ugli_api, struct scc_priv, rx_work);
+ int i = priv->rx_tail;
+ int cb;
+ unsigned long flags;
+ struct sk_buff *skb;
+ unsigned char *data;
+
+ spin_lock_irqsave(&priv->ring_lock, flags);
+ while (priv->rx_count) {
+ spin_unlock_irqrestore(&priv->ring_lock, flags);
+ cb = priv->rx_len[i];
+ /* Allocate buffer */
+ skb = dev_alloc_skb(cb + 1);
+ if (skb == NULL) {
+ /* Drop packet */
+ priv->dev->stats.rx_dropped++;
+ } else {
+ /* Fill buffer */
+ data = skb_put(skb, cb + 1);
+ data[0] = 0;
+ memcpy(&data[1], priv->rx_buf[i], cb);
+ skb->protocol = ax25_type_trans(skb, priv->dev);
+ netif_rx(skb);
+ priv->dev->stats.rx_packets++;
+ priv->dev->stats.rx_bytes += cb;
+ }
+ spin_lock_irqsave(&priv->ring_lock, flags);
+ /* Move tail */
+ priv->rx_tail = i = (i + 1) % NUM_RX_BUF;
+ priv->rx_count--;
+ }
+ spin_unlock_irqrestore(&priv->ring_lock, flags);
+}
+
+
+static void tx_isr(struct scc_priv *priv)
+{
+ int i = priv->tx_tail, p = priv->tx_ptr;
+
+ /* Suspend TX interrupts if we don't want to send anything.
+ See Figure 2-22. */
+ if (p == priv->tx_len[i]) {
+ write_scc(priv, R0, RES_Tx_P);
+ return;
+ }
+
+ /* Write characters */
+ while ((read_scc(priv, R0) & Tx_BUF_EMP) && p < priv->tx_len[i]) {
+ write_scc_data(priv, priv->tx_buf[i][p++], 0);
+ }
+
+ /* Reset EOM latch of Z8530 */
+ if (!priv->tx_ptr && p && priv->chip == Z8530)
+ write_scc(priv, R0, RES_EOM_L);
+
+ priv->tx_ptr = p;
+}
+
+
+static void es_isr(struct scc_priv *priv)
+{
+ int i, rr0, drr0, res;
+ unsigned long flags;
+
+ /* Read status, reset interrupt bit (open latches) */
+ rr0 = read_scc(priv, R0);
+ write_scc(priv, R0, RES_EXT_INT);
+ drr0 = priv->rr0 ^ rr0;
+ priv->rr0 = rr0;
+
+ /* Transmit underrun (2.4.9.6). We can't check the TxEOM flag, since
+ it might have already been cleared again by AUTOEOM. */
+ if (priv->state == TX_DATA) {
+ /* Get remaining bytes */
+ i = priv->tx_tail;
+ if (priv->param.dma >= 0) {
+ disable_dma(priv->param.dma);
+ flags = claim_dma_lock();
+ res = get_dma_residue(priv->param.dma);
+ release_dma_lock(flags);
+ } else {
+ res = priv->tx_len[i] - priv->tx_ptr;
+ priv->tx_ptr = 0;
+ }
+ /* Disable DREQ / TX interrupt */
+ if (priv->param.dma >= 0 && priv->type == TYPE_TWIN)
+ outb(0, priv->card_base + TWIN_DMA_CFG);
+ else
+ write_scc(priv, R1, EXT_INT_ENAB | WT_FN_RDYFN);
+ if (res) {
+ /* Update packet statistics */
+ priv->dev->stats.tx_errors++;
+ priv->dev->stats.tx_fifo_errors++;
+ /* Other underrun interrupts may already be waiting */
+ write_scc(priv, R0, RES_EXT_INT);
+ write_scc(priv, R0, RES_EXT_INT);
+ } else {
+ /* Update packet statistics */
+ priv->dev->stats.tx_packets++;
+ priv->dev->stats.tx_bytes += priv->tx_len[i];
+ /* Remove frame from FIFO */
+ priv->tx_tail = (i + 1) % NUM_TX_BUF;
+ priv->tx_count--;
+ /* Inform upper layers */
+ netif_wake_queue(priv->dev);
+ }
+ /* Switch state */
+ write_scc(priv, R15, 0);
+ if (priv->tx_count &&
+ (jiffies - priv->tx_start) < priv->param.txtimeout) {
+ priv->state = TX_PAUSE;
+ start_timer(priv, priv->param.txpause, 0);
+ } else {
+ priv->state = TX_TAIL;
+ start_timer(priv, priv->param.txtail, 0);
+ }
+ }
+
+ /* DCD transition */
+ if (drr0 & DCD) {
+ if (rr0 & DCD) {
+ switch (priv->state) {
+ case IDLE:
+ case WAIT:
+ priv->state = DCD_ON;
+ write_scc(priv, R15, 0);
+ start_timer(priv, priv->param.dcdon, 0);
+ }
+ } else {
+ switch (priv->state) {
+ case RX_ON:
+ rx_off(priv);
+ priv->state = DCD_OFF;
+ write_scc(priv, R15, 0);
+ start_timer(priv, priv->param.dcdoff, 0);
+ }
+ }
+ }
+
+ /* CTS transition */
+ if ((drr0 & CTS) && (~rr0 & CTS) && priv->type != TYPE_TWIN)
+ tm_isr(priv);
+
+}
+
+
+static void tm_isr(struct scc_priv *priv)
+{
+ switch (priv->state) {
+ case TX_HEAD:
+ case TX_PAUSE:
+ tx_on(priv);
+ priv->state = TX_DATA;
+ break;
+ case TX_TAIL:
+ write_scc(priv, R5, TxCRC_ENAB | Tx8);
+ priv->state = RTS_OFF;
+ if (priv->type != TYPE_TWIN)
+ write_scc(priv, R15, 0);
+ start_timer(priv, priv->param.rtsoff, 0);
+ break;
+ case RTS_OFF:
+ write_scc(priv, R15, DCDIE);
+ priv->rr0 = read_scc(priv, R0);
+ if (priv->rr0 & DCD) {
+ priv->dev->stats.collisions++;
+ rx_on(priv);
+ priv->state = RX_ON;
+ } else {
+ priv->state = WAIT;
+ start_timer(priv, priv->param.waittime, DCDIE);
+ }
+ break;
+ case WAIT:
+ if (priv->tx_count) {
+ priv->state = TX_HEAD;
+ priv->tx_start = jiffies;
+ write_scc(priv, R5,
+ TxCRC_ENAB | RTS | TxENAB | Tx8);
+ write_scc(priv, R15, 0);
+ start_timer(priv, priv->param.txdelay, 0);
+ } else {
+ priv->state = IDLE;
+ if (priv->type != TYPE_TWIN)
+ write_scc(priv, R15, DCDIE);
+ }
+ break;
+ case DCD_ON:
+ case DCD_OFF:
+ write_scc(priv, R15, DCDIE);
+ priv->rr0 = read_scc(priv, R0);
+ if (priv->rr0 & DCD) {
+ rx_on(priv);
+ priv->state = RX_ON;
+ } else {
+ priv->state = WAIT;
+ start_timer(priv,
+ random() / priv->param.persist *
+ priv->param.slottime, DCDIE);
+ }
+ break;
+ }
+}
Code Review / kvmfornfv.git / blobdiff