--- /dev/null
+/*
+ * Driver for Zilog serial chips found on SGI workstations and
+ * servers. This driver could actually be made more generic.
+ *
+ * This is based on the drivers/serial/sunzilog.c code as of 2.6.0-test7 and the
+ * old drivers/sgi/char/sgiserial.c code which itself is based of the original
+ * drivers/sbus/char/zs.c code. A lot of code has been simply moved over
+ * directly from there but much has been rewritten. Credits therefore go out
+ * to David S. Miller, Eddie C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell
+ * for their work there.
+ *
+ * Copyright (C) 2002 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+#if defined(CONFIG_SERIAL_IP22_ZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/serial_core.h>
+
+#include "ip22zilog.h"
+
+/*
+ * On IP22 we need to delay after register accesses but we do not need to
+ * flush writes.
+ */
+#define ZSDELAY() udelay(5)
+#define ZSDELAY_LONG() udelay(20)
+#define ZS_WSYNC(channel) do { } while (0)
+
+#define NUM_IP22ZILOG 1
+#define NUM_CHANNELS (NUM_IP22ZILOG * 2)
+
+#define ZS_CLOCK 3672000 /* Zilog input clock rate. */
+#define ZS_CLOCK_DIVISOR 16 /* Divisor this driver uses. */
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_ip22zilog_port {
+ struct uart_port port;
+
+ /* IRQ servicing chain. */
+ struct uart_ip22zilog_port *next;
+
+ /* Current values of Zilog write registers. */
+ unsigned char curregs[NUM_ZSREGS];
+
+ unsigned int flags;
+#define IP22ZILOG_FLAG_IS_CONS 0x00000004
+#define IP22ZILOG_FLAG_IS_KGDB 0x00000008
+#define IP22ZILOG_FLAG_MODEM_STATUS 0x00000010
+#define IP22ZILOG_FLAG_IS_CHANNEL_A 0x00000020
+#define IP22ZILOG_FLAG_REGS_HELD 0x00000040
+#define IP22ZILOG_FLAG_TX_STOPPED 0x00000080
+#define IP22ZILOG_FLAG_TX_ACTIVE 0x00000100
+#define IP22ZILOG_FLAG_RESET_DONE 0x00000200
+
+ unsigned int tty_break;
+
+ unsigned char parity_mask;
+ unsigned char prev_status;
+};
+
+#define ZILOG_CHANNEL_FROM_PORT(PORT) ((struct zilog_channel *)((PORT)->membase))
+#define UART_ZILOG(PORT) ((struct uart_ip22zilog_port *)(PORT))
+#define IP22ZILOG_GET_CURR_REG(PORT, REGNUM) \
+ (UART_ZILOG(PORT)->curregs[REGNUM])
+#define IP22ZILOG_SET_CURR_REG(PORT, REGNUM, REGVAL) \
+ ((UART_ZILOG(PORT)->curregs[REGNUM]) = (REGVAL))
+#define ZS_IS_CONS(UP) ((UP)->flags & IP22ZILOG_FLAG_IS_CONS)
+#define ZS_IS_KGDB(UP) ((UP)->flags & IP22ZILOG_FLAG_IS_KGDB)
+#define ZS_WANTS_MODEM_STATUS(UP) ((UP)->flags & IP22ZILOG_FLAG_MODEM_STATUS)
+#define ZS_IS_CHANNEL_A(UP) ((UP)->flags & IP22ZILOG_FLAG_IS_CHANNEL_A)
+#define ZS_REGS_HELD(UP) ((UP)->flags & IP22ZILOG_FLAG_REGS_HELD)
+#define ZS_TX_STOPPED(UP) ((UP)->flags & IP22ZILOG_FLAG_TX_STOPPED)
+#define ZS_TX_ACTIVE(UP) ((UP)->flags & IP22ZILOG_FLAG_TX_ACTIVE)
+
+/* Reading and writing Zilog8530 registers. The delays are to make this
+ * driver work on the IP22 which needs a settling delay after each chip
+ * register access, other machines handle this in hardware via auxiliary
+ * flip-flops which implement the settle time we do in software.
+ *
+ * The port lock must be held and local IRQs must be disabled
+ * when {read,write}_zsreg is invoked.
+ */
+static unsigned char read_zsreg(struct zilog_channel *channel,
+ unsigned char reg)
+{
+ unsigned char retval;
+
+ writeb(reg, &channel->control);
+ ZSDELAY();
+ retval = readb(&channel->control);
+ ZSDELAY();
+
+ return retval;
+}
+
+static void write_zsreg(struct zilog_channel *channel,
+ unsigned char reg, unsigned char value)
+{
+ writeb(reg, &channel->control);
+ ZSDELAY();
+ writeb(value, &channel->control);
+ ZSDELAY();
+}
+
+static void ip22zilog_clear_fifo(struct zilog_channel *channel)
+{
+ int i;
+
+ for (i = 0; i < 32; i++) {
+ unsigned char regval;
+
+ regval = readb(&channel->control);
+ ZSDELAY();
+ if (regval & Rx_CH_AV)
+ break;
+
+ regval = read_zsreg(channel, R1);
+ readb(&channel->data);
+ ZSDELAY();
+
+ if (regval & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+ writeb(ERR_RES, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+ }
+ }
+}
+
+/* This function must only be called when the TX is not busy. The UART
+ * port lock must be held and local interrupts disabled.
+ */
+static void __load_zsregs(struct zilog_channel *channel, unsigned char *regs)
+{
+ int i;
+
+ /* Let pending transmits finish. */
+ for (i = 0; i < 1000; i++) {
+ unsigned char stat = read_zsreg(channel, R1);
+ if (stat & ALL_SNT)
+ break;
+ udelay(100);
+ }
+
+ writeb(ERR_RES, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ ip22zilog_clear_fifo(channel);
+
+ /* Disable all interrupts. */
+ write_zsreg(channel, R1,
+ regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
+
+ /* Set parity, sync config, stop bits, and clock divisor. */
+ write_zsreg(channel, R4, regs[R4]);
+
+ /* Set misc. TX/RX control bits. */
+ write_zsreg(channel, R10, regs[R10]);
+
+ /* Set TX/RX controls sans the enable bits. */
+ write_zsreg(channel, R3, regs[R3] & ~RxENAB);
+ write_zsreg(channel, R5, regs[R5] & ~TxENAB);
+
+ /* Synchronous mode config. */
+ write_zsreg(channel, R6, regs[R6]);
+ write_zsreg(channel, R7, regs[R7]);
+
+ /* Don't mess with the interrupt vector (R2, unused by us) and
+ * master interrupt control (R9). We make sure this is setup
+ * properly at probe time then never touch it again.
+ */
+
+ /* Disable baud generator. */
+ write_zsreg(channel, R14, regs[R14] & ~BRENAB);
+
+ /* Clock mode control. */
+ write_zsreg(channel, R11, regs[R11]);
+
+ /* Lower and upper byte of baud rate generator divisor. */
+ write_zsreg(channel, R12, regs[R12]);
+ write_zsreg(channel, R13, regs[R13]);
+
+ /* Now rewrite R14, with BRENAB (if set). */
+ write_zsreg(channel, R14, regs[R14]);
+
+ /* External status interrupt control. */
+ write_zsreg(channel, R15, regs[R15]);
+
+ /* Reset external status interrupts. */
+ write_zsreg(channel, R0, RES_EXT_INT);
+ write_zsreg(channel, R0, RES_EXT_INT);
+
+ /* Rewrite R3/R5, this time without enables masked. */
+ write_zsreg(channel, R3, regs[R3]);
+ write_zsreg(channel, R5, regs[R5]);
+
+ /* Rewrite R1, this time without IRQ enabled masked. */
+ write_zsreg(channel, R1, regs[R1]);
+}
+
+/* Reprogram the Zilog channel HW registers with the copies found in the
+ * software state struct. If the transmitter is busy, we defer this update
+ * until the next TX complete interrupt. Else, we do it right now.
+ *
+ * The UART port lock must be held and local interrupts disabled.
+ */
+static void ip22zilog_maybe_update_regs(struct uart_ip22zilog_port *up,
+ struct zilog_channel *channel)
+{
+ if (!ZS_REGS_HELD(up)) {
+ if (ZS_TX_ACTIVE(up)) {
+ up->flags |= IP22ZILOG_FLAG_REGS_HELD;
+ } else {
+ __load_zsregs(channel, up->curregs);
+ }
+ }
+}
+
+#define Rx_BRK 0x0100 /* BREAK event software flag. */
+#define Rx_SYS 0x0200 /* SysRq event software flag. */
+
+static bool ip22zilog_receive_chars(struct uart_ip22zilog_port *up,
+ struct zilog_channel *channel)
+{
+ unsigned char ch, flag;
+ unsigned int r1;
+ bool push = up->port.state != NULL;
+
+ for (;;) {
+ ch = readb(&channel->control);
+ ZSDELAY();
+ if (!(ch & Rx_CH_AV))
+ break;
+
+ r1 = read_zsreg(channel, R1);
+ if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+ writeb(ERR_RES, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+ }
+
+ ch = readb(&channel->data);
+ ZSDELAY();
+
+ ch &= up->parity_mask;
+
+ /* Handle the null char got when BREAK is removed. */
+ if (!ch)
+ r1 |= up->tty_break;
+
+ /* A real serial line, record the character and status. */
+ flag = TTY_NORMAL;
+ up->port.icount.rx++;
+ if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | Rx_SYS | Rx_BRK)) {
+ up->tty_break = 0;
+
+ if (r1 & (Rx_SYS | Rx_BRK)) {
+ up->port.icount.brk++;
+ if (r1 & Rx_SYS)
+ continue;
+ r1 &= ~(PAR_ERR | CRC_ERR);
+ }
+ else if (r1 & PAR_ERR)
+ up->port.icount.parity++;
+ else if (r1 & CRC_ERR)
+ up->port.icount.frame++;
+ if (r1 & Rx_OVR)
+ up->port.icount.overrun++;
+ r1 &= up->port.read_status_mask;
+ if (r1 & Rx_BRK)
+ flag = TTY_BREAK;
+ else if (r1 & PAR_ERR)
+ flag = TTY_PARITY;
+ else if (r1 & CRC_ERR)
+ flag = TTY_FRAME;
+ }
+
+ if (uart_handle_sysrq_char(&up->port, ch))
+ continue;
+
+ if (push)
+ uart_insert_char(&up->port, r1, Rx_OVR, ch, flag);
+ }
+ return push;
+}
+
+static void ip22zilog_status_handle(struct uart_ip22zilog_port *up,
+ struct zilog_channel *channel)
+{
+ unsigned char status;
+
+ status = readb(&channel->control);
+ ZSDELAY();
+
+ writeb(RES_EXT_INT, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ if (up->curregs[R15] & BRKIE) {
+ if ((status & BRK_ABRT) && !(up->prev_status & BRK_ABRT)) {
+ if (uart_handle_break(&up->port))
+ up->tty_break = Rx_SYS;
+ else
+ up->tty_break = Rx_BRK;
+ }
+ }
+
+ if (ZS_WANTS_MODEM_STATUS(up)) {
+ if (status & SYNC)
+ up->port.icount.dsr++;
+
+ /* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
+ * But it does not tell us which bit has changed, we have to keep
+ * track of this ourselves.
+ */
+ if ((status ^ up->prev_status) ^ DCD)
+ uart_handle_dcd_change(&up->port,
+ (status & DCD));
+ if ((status ^ up->prev_status) ^ CTS)
+ uart_handle_cts_change(&up->port,
+ (status & CTS));
+
+ wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+ }
+
+ up->prev_status = status;
+}
+
+static void ip22zilog_transmit_chars(struct uart_ip22zilog_port *up,
+ struct zilog_channel *channel)
+{
+ struct circ_buf *xmit;
+
+ if (ZS_IS_CONS(up)) {
+ unsigned char status = readb(&channel->control);
+ ZSDELAY();
+
+ /* TX still busy? Just wait for the next TX done interrupt.
+ *
+ * It can occur because of how we do serial console writes. It would
+ * be nice to transmit console writes just like we normally would for
+ * a TTY line. (ie. buffered and TX interrupt driven). That is not
+ * easy because console writes cannot sleep. One solution might be
+ * to poll on enough port->xmit space becoming free. -DaveM
+ */
+ if (!(status & Tx_BUF_EMP))
+ return;
+ }
+
+ up->flags &= ~IP22ZILOG_FLAG_TX_ACTIVE;
+
+ if (ZS_REGS_HELD(up)) {
+ __load_zsregs(channel, up->curregs);
+ up->flags &= ~IP22ZILOG_FLAG_REGS_HELD;
+ }
+
+ if (ZS_TX_STOPPED(up)) {
+ up->flags &= ~IP22ZILOG_FLAG_TX_STOPPED;
+ goto ack_tx_int;
+ }
+
+ if (up->port.x_char) {
+ up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+ writeb(up->port.x_char, &channel->data);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ up->port.icount.tx++;
+ up->port.x_char = 0;
+ return;
+ }
+
+ if (up->port.state == NULL)
+ goto ack_tx_int;
+ xmit = &up->port.state->xmit;
+ if (uart_circ_empty(xmit))
+ goto ack_tx_int;
+ if (uart_tx_stopped(&up->port))
+ goto ack_tx_int;
+
+ up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+ writeb(xmit->buf[xmit->tail], &channel->data);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ up->port.icount.tx++;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&up->port);
+
+ return;
+
+ack_tx_int:
+ writeb(RES_Tx_P, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+}
+
+static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
+{
+ struct uart_ip22zilog_port *up = dev_id;
+
+ while (up) {
+ struct zilog_channel *channel
+ = ZILOG_CHANNEL_FROM_PORT(&up->port);
+ unsigned char r3;
+ bool push = false;
+
+ spin_lock(&up->port.lock);
+ r3 = read_zsreg(channel, R3);
+
+ /* Channel A */
+ if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
+ writeb(RES_H_IUS, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ if (r3 & CHARxIP)
+ push = ip22zilog_receive_chars(up, channel);
+ if (r3 & CHAEXT)
+ ip22zilog_status_handle(up, channel);
+ if (r3 & CHATxIP)
+ ip22zilog_transmit_chars(up, channel);
+ }
+ spin_unlock(&up->port.lock);
+
+ if (push)
+ tty_flip_buffer_push(&up->port.state->port);
+
+ /* Channel B */
+ up = up->next;
+ channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+ push = false;
+
+ spin_lock(&up->port.lock);
+ if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
+ writeb(RES_H_IUS, &channel->control);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ if (r3 & CHBRxIP)
+ push = ip22zilog_receive_chars(up, channel);
+ if (r3 & CHBEXT)
+ ip22zilog_status_handle(up, channel);
+ if (r3 & CHBTxIP)
+ ip22zilog_transmit_chars(up, channel);
+ }
+ spin_unlock(&up->port.lock);
+
+ if (push)
+ tty_flip_buffer_push(&up->port.state->port);
+
+ up = up->next;
+ }
+
+ return IRQ_HANDLED;
+}
+
+/* A convenient way to quickly get R0 status. The caller must _not_ hold the
+ * port lock, it is acquired here.
+ */
+static __inline__ unsigned char ip22zilog_read_channel_status(struct uart_port *port)
+{
+ struct zilog_channel *channel;
+ unsigned char status;
+
+ channel = ZILOG_CHANNEL_FROM_PORT(port);
+ status = readb(&channel->control);
+ ZSDELAY();
+
+ return status;
+}
+
+/* The port lock is not held. */
+static unsigned int ip22zilog_tx_empty(struct uart_port *port)
+{
+ unsigned long flags;
+ unsigned char status;
+ unsigned int ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ status = ip22zilog_read_channel_status(port);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (status & Tx_BUF_EMP)
+ ret = TIOCSER_TEMT;
+ else
+ ret = 0;
+
+ return ret;
+}
+
+/* The port lock is held and interrupts are disabled. */
+static unsigned int ip22zilog_get_mctrl(struct uart_port *port)
+{
+ unsigned char status;
+ unsigned int ret;
+
+ status = ip22zilog_read_channel_status(port);
+
+ ret = 0;
+ if (status & DCD)
+ ret |= TIOCM_CAR;
+ if (status & SYNC)
+ ret |= TIOCM_DSR;
+ if (status & CTS)
+ ret |= TIOCM_CTS;
+
+ return ret;
+}
+
+/* The port lock is held and interrupts are disabled. */
+static void ip22zilog_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+ struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+ unsigned char set_bits, clear_bits;
+
+ set_bits = clear_bits = 0;
+
+ if (mctrl & TIOCM_RTS)
+ set_bits |= RTS;
+ else
+ clear_bits |= RTS;
+ if (mctrl & TIOCM_DTR)
+ set_bits |= DTR;
+ else
+ clear_bits |= DTR;
+
+ /* NOTE: Not subject to 'transmitter active' rule. */
+ up->curregs[R5] |= set_bits;
+ up->curregs[R5] &= ~clear_bits;
+ write_zsreg(channel, R5, up->curregs[R5]);
+}
+
+/* The port lock is held and interrupts are disabled. */
+static void ip22zilog_stop_tx(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+
+ up->flags |= IP22ZILOG_FLAG_TX_STOPPED;
+}
+
+/* The port lock is held and interrupts are disabled. */
+static void ip22zilog_start_tx(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+ struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+ unsigned char status;
+
+ up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+ up->flags &= ~IP22ZILOG_FLAG_TX_STOPPED;
+
+ status = readb(&channel->control);
+ ZSDELAY();
+
+ /* TX busy? Just wait for the TX done interrupt. */
+ if (!(status & Tx_BUF_EMP))
+ return;
+
+ /* Send the first character to jump-start the TX done
+ * IRQ sending engine.
+ */
+ if (port->x_char) {
+ writeb(port->x_char, &channel->data);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ port->icount.tx++;
+ port->x_char = 0;
+ } else {
+ struct circ_buf *xmit = &port->state->xmit;
+
+ if (uart_circ_empty(xmit))
+ return;
+ writeb(xmit->buf[xmit->tail], &channel->data);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&up->port);
+ }
+}
+
+/* The port lock is held and interrupts are disabled. */
+static void ip22zilog_stop_rx(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up = UART_ZILOG(port);
+ struct zilog_channel *channel;
+
+ if (ZS_IS_CONS(up))
+ return;
+
+ channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+ /* Disable all RX interrupts. */
+ up->curregs[R1] &= ~RxINT_MASK;
+ ip22zilog_maybe_update_regs(up, channel);
+}
+
+/* The port lock is held. */
+static void ip22zilog_enable_ms(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+ struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+ unsigned char new_reg;
+
+ new_reg = up->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
+ if (new_reg != up->curregs[R15]) {
+ up->curregs[R15] = new_reg;
+
+ /* NOTE: Not subject to 'transmitter active' rule. */
+ write_zsreg(channel, R15, up->curregs[R15]);
+ }
+}
+
+/* The port lock is not held. */
+static void ip22zilog_break_ctl(struct uart_port *port, int break_state)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+ struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+ unsigned char set_bits, clear_bits, new_reg;
+ unsigned long flags;
+
+ set_bits = clear_bits = 0;
+
+ if (break_state)
+ set_bits |= SND_BRK;
+ else
+ clear_bits |= SND_BRK;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
+ if (new_reg != up->curregs[R5]) {
+ up->curregs[R5] = new_reg;
+
+ /* NOTE: Not subject to 'transmitter active' rule. */
+ write_zsreg(channel, R5, up->curregs[R5]);
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void __ip22zilog_reset(struct uart_ip22zilog_port *up)
+{
+ struct zilog_channel *channel;
+ int i;
+
+ if (up->flags & IP22ZILOG_FLAG_RESET_DONE)
+ return;
+
+ /* Let pending transmits finish. */
+ channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+ for (i = 0; i < 1000; i++) {
+ unsigned char stat = read_zsreg(channel, R1);
+ if (stat & ALL_SNT)
+ break;
+ udelay(100);
+ }
+
+ if (!ZS_IS_CHANNEL_A(up)) {
+ up++;
+ channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+ }
+ write_zsreg(channel, R9, FHWRES);
+ ZSDELAY_LONG();
+ (void) read_zsreg(channel, R0);
+
+ up->flags |= IP22ZILOG_FLAG_RESET_DONE;
+ up->next->flags |= IP22ZILOG_FLAG_RESET_DONE;
+}
+
+static void __ip22zilog_startup(struct uart_ip22zilog_port *up)
+{
+ struct zilog_channel *channel;
+
+ channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+
+ __ip22zilog_reset(up);
+
+ __load_zsregs(channel, up->curregs);
+ /* set master interrupt enable */
+ write_zsreg(channel, R9, up->curregs[R9]);
+ up->prev_status = readb(&channel->control);
+
+ /* Enable receiver and transmitter. */
+ up->curregs[R3] |= RxENAB;
+ up->curregs[R5] |= TxENAB;
+
+ up->curregs[R1] |= EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+ ip22zilog_maybe_update_regs(up, channel);
+}
+
+static int ip22zilog_startup(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up = UART_ZILOG(port);
+ unsigned long flags;
+
+ if (ZS_IS_CONS(up))
+ return 0;
+
+ spin_lock_irqsave(&port->lock, flags);
+ __ip22zilog_startup(up);
+ spin_unlock_irqrestore(&port->lock, flags);
+ return 0;
+}
+
+/*
+ * The test for ZS_IS_CONS is explained by the following e-mail:
+ *****
+ * From: Russell King <rmk@arm.linux.org.uk>
+ * Date: Sun, 8 Dec 2002 10:18:38 +0000
+ *
+ * On Sun, Dec 08, 2002 at 02:43:36AM -0500, Pete Zaitcev wrote:
+ * > I boot my 2.5 boxes using "console=ttyS0,9600" argument,
+ * > and I noticed that something is not right with reference
+ * > counting in this case. It seems that when the console
+ * > is open by kernel initially, this is not accounted
+ * > as an open, and uart_startup is not called.
+ *
+ * That is correct. We are unable to call uart_startup when the serial
+ * console is initialised because it may need to allocate memory (as
+ * request_irq does) and the memory allocators may not have been
+ * initialised.
+ *
+ * 1. initialise the port into a state where it can send characters in the
+ * console write method.
+ *
+ * 2. don't do the actual hardware shutdown in your shutdown() method (but
+ * do the normal software shutdown - ie, free irqs etc)
+ *****
+ */
+static void ip22zilog_shutdown(struct uart_port *port)
+{
+ struct uart_ip22zilog_port *up = UART_ZILOG(port);
+ struct zilog_channel *channel;
+ unsigned long flags;
+
+ if (ZS_IS_CONS(up))
+ return;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+ /* Disable receiver and transmitter. */
+ up->curregs[R3] &= ~RxENAB;
+ up->curregs[R5] &= ~TxENAB;
+
+ /* Disable all interrupts and BRK assertion. */
+ up->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
+ up->curregs[R5] &= ~SND_BRK;
+ ip22zilog_maybe_update_regs(up, channel);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Shared by TTY driver and serial console setup. The port lock is held
+ * and local interrupts are disabled.
+ */
+static void
+ip22zilog_convert_to_zs(struct uart_ip22zilog_port *up, unsigned int cflag,
+ unsigned int iflag, int brg)
+{
+
+ up->curregs[R10] = NRZ;
+ up->curregs[R11] = TCBR | RCBR;
+
+ /* Program BAUD and clock source. */
+ up->curregs[R4] &= ~XCLK_MASK;
+ up->curregs[R4] |= X16CLK;
+ up->curregs[R12] = brg & 0xff;
+ up->curregs[R13] = (brg >> 8) & 0xff;
+ up->curregs[R14] = BRENAB;
+
+ /* Character size, stop bits, and parity. */
+ up->curregs[3] &= ~RxN_MASK;
+ up->curregs[5] &= ~TxN_MASK;
+ switch (cflag & CSIZE) {
+ case CS5:
+ up->curregs[3] |= Rx5;
+ up->curregs[5] |= Tx5;
+ up->parity_mask = 0x1f;
+ break;
+ case CS6:
+ up->curregs[3] |= Rx6;
+ up->curregs[5] |= Tx6;
+ up->parity_mask = 0x3f;
+ break;
+ case CS7:
+ up->curregs[3] |= Rx7;
+ up->curregs[5] |= Tx7;
+ up->parity_mask = 0x7f;
+ break;
+ case CS8:
+ default:
+ up->curregs[3] |= Rx8;
+ up->curregs[5] |= Tx8;
+ up->parity_mask = 0xff;
+ break;
+ }
+ up->curregs[4] &= ~0x0c;
+ if (cflag & CSTOPB)
+ up->curregs[4] |= SB2;
+ else
+ up->curregs[4] |= SB1;
+ if (cflag & PARENB)
+ up->curregs[4] |= PAR_ENAB;
+ else
+ up->curregs[4] &= ~PAR_ENAB;
+ if (!(cflag & PARODD))
+ up->curregs[4] |= PAR_EVEN;
+ else
+ up->curregs[4] &= ~PAR_EVEN;
+
+ up->port.read_status_mask = Rx_OVR;
+ if (iflag & INPCK)
+ up->port.read_status_mask |= CRC_ERR | PAR_ERR;
+ if (iflag & (IGNBRK | BRKINT | PARMRK))
+ up->port.read_status_mask |= BRK_ABRT;
+
+ up->port.ignore_status_mask = 0;
+ if (iflag & IGNPAR)
+ up->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
+ if (iflag & IGNBRK) {
+ up->port.ignore_status_mask |= BRK_ABRT;
+ if (iflag & IGNPAR)
+ up->port.ignore_status_mask |= Rx_OVR;
+ }
+
+ if ((cflag & CREAD) == 0)
+ up->port.ignore_status_mask = 0xff;
+}
+
+/* The port lock is not held. */
+static void
+ip22zilog_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct uart_ip22zilog_port *up =
+ container_of(port, struct uart_ip22zilog_port, port);
+ unsigned long flags;
+ int baud, brg;
+
+ baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
+
+ spin_lock_irqsave(&up->port.lock, flags);
+
+ brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+
+ ip22zilog_convert_to_zs(up, termios->c_cflag, termios->c_iflag, brg);
+
+ if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+ up->flags |= IP22ZILOG_FLAG_MODEM_STATUS;
+ else
+ up->flags &= ~IP22ZILOG_FLAG_MODEM_STATUS;
+
+ ip22zilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ip22zilog_type(struct uart_port *port)
+{
+ return "IP22-Zilog";
+}
+
+/* We do not request/release mappings of the registers here, this
+ * happens at early serial probe time.
+ */
+static void ip22zilog_release_port(struct uart_port *port)
+{
+}
+
+static int ip22zilog_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+/* These do not need to do anything interesting either. */
+static void ip22zilog_config_port(struct uart_port *port, int flags)
+{
+}
+
+/* We do not support letting the user mess with the divisor, IRQ, etc. */
+static int ip22zilog_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ return -EINVAL;
+}
+
+static struct uart_ops ip22zilog_pops = {
+ .tx_empty = ip22zilog_tx_empty,
+ .set_mctrl = ip22zilog_set_mctrl,
+ .get_mctrl = ip22zilog_get_mctrl,
+ .stop_tx = ip22zilog_stop_tx,
+ .start_tx = ip22zilog_start_tx,
+ .stop_rx = ip22zilog_stop_rx,
+ .enable_ms = ip22zilog_enable_ms,
+ .break_ctl = ip22zilog_break_ctl,
+ .startup = ip22zilog_startup,
+ .shutdown = ip22zilog_shutdown,
+ .set_termios = ip22zilog_set_termios,
+ .type = ip22zilog_type,
+ .release_port = ip22zilog_release_port,
+ .request_port = ip22zilog_request_port,
+ .config_port = ip22zilog_config_port,
+ .verify_port = ip22zilog_verify_port,
+};
+
+static struct uart_ip22zilog_port *ip22zilog_port_table;
+static struct zilog_layout **ip22zilog_chip_regs;
+
+static struct uart_ip22zilog_port *ip22zilog_irq_chain;
+static int zilog_irq = -1;
+
+static void * __init alloc_one_table(unsigned long size)
+{
+ return kzalloc(size, GFP_KERNEL);
+}
+
+static void __init ip22zilog_alloc_tables(void)
+{
+ ip22zilog_port_table = (struct uart_ip22zilog_port *)
+ alloc_one_table(NUM_CHANNELS * sizeof(struct uart_ip22zilog_port));
+ ip22zilog_chip_regs = (struct zilog_layout **)
+ alloc_one_table(NUM_IP22ZILOG * sizeof(struct zilog_layout *));
+
+ if (ip22zilog_port_table == NULL || ip22zilog_chip_regs == NULL) {
+ panic("IP22-Zilog: Cannot allocate IP22-Zilog tables.");
+ }
+}
+
+/* Get the address of the registers for IP22-Zilog instance CHIP. */
+static struct zilog_layout * __init get_zs(int chip)
+{
+ unsigned long base;
+
+ if (chip < 0 || chip >= NUM_IP22ZILOG) {
+ panic("IP22-Zilog: Illegal chip number %d in get_zs.", chip);
+ }
+
+ /* Not probe-able, hard code it. */
+ base = (unsigned long) &sgioc->uart;
+
+ zilog_irq = SGI_SERIAL_IRQ;
+ request_mem_region(base, 8, "IP22-Zilog");
+
+ return (struct zilog_layout *) base;
+}
+
+#define ZS_PUT_CHAR_MAX_DELAY 2000 /* 10 ms */
+
+#ifdef CONFIG_SERIAL_IP22_ZILOG_CONSOLE
+static void ip22zilog_put_char(struct uart_port *port, int ch)
+{
+ struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+ int loops = ZS_PUT_CHAR_MAX_DELAY;
+
+ /* This is a timed polling loop so do not switch the explicit
+ * udelay with ZSDELAY as that is a NOP on some platforms. -DaveM
+ */
+ do {
+ unsigned char val = readb(&channel->control);
+ if (val & Tx_BUF_EMP) {
+ ZSDELAY();
+ break;
+ }
+ udelay(5);
+ } while (--loops);
+
+ writeb(ch, &channel->data);
+ ZSDELAY();
+ ZS_WSYNC(channel);
+}
+
+static void
+ip22zilog_console_write(struct console *con, const char *s, unsigned int count)
+{
+ struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
+ unsigned long flags;
+
+ spin_lock_irqsave(&up->port.lock, flags);
+ uart_console_write(&up->port, s, count, ip22zilog_put_char);
+ udelay(2);
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ip22zilog_console_setup(struct console *con, char *options)
+{
+ struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
+ unsigned long flags;
+ int baud = 9600, bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ up->flags |= IP22ZILOG_FLAG_IS_CONS;
+
+ printk(KERN_INFO "Console: ttyS%d (IP22-Zilog)\n", con->index);
+
+ spin_lock_irqsave(&up->port.lock, flags);
+
+ up->curregs[R15] |= BRKIE;
+
+ __ip22zilog_startup(up);
+
+ spin_unlock_irqrestore(&up->port.lock, flags);
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ return uart_set_options(&up->port, con, baud, parity, bits, flow);
+}
+
+static struct uart_driver ip22zilog_reg;
+
+static struct console ip22zilog_console = {
+ .name = "ttyS",
+ .write = ip22zilog_console_write,
+ .device = uart_console_device,
+ .setup = ip22zilog_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &ip22zilog_reg,
+};
+#endif /* CONFIG_SERIAL_IP22_ZILOG_CONSOLE */
+
+static struct uart_driver ip22zilog_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = "serial",
+ .dev_name = "ttyS",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .nr = NUM_CHANNELS,
+#ifdef CONFIG_SERIAL_IP22_ZILOG_CONSOLE
+ .cons = &ip22zilog_console,
+#endif
+};
+
+static void __init ip22zilog_prepare(void)
+{
+ struct uart_ip22zilog_port *up;
+ struct zilog_layout *rp;
+ int channel, chip;
+
+ /*
+ * Temporary fix.
+ */
+ for (channel = 0; channel < NUM_CHANNELS; channel++)
+ spin_lock_init(&ip22zilog_port_table[channel].port.lock);
+
+ ip22zilog_irq_chain = &ip22zilog_port_table[NUM_CHANNELS - 1];
+ up = &ip22zilog_port_table[0];
+ for (channel = NUM_CHANNELS - 1 ; channel > 0; channel--)
+ up[channel].next = &up[channel - 1];
+ up[channel].next = NULL;
+
+ for (chip = 0; chip < NUM_IP22ZILOG; chip++) {
+ if (!ip22zilog_chip_regs[chip]) {
+ ip22zilog_chip_regs[chip] = rp = get_zs(chip);
+
+ up[(chip * 2) + 0].port.membase = (char *) &rp->channelB;
+ up[(chip * 2) + 1].port.membase = (char *) &rp->channelA;
+
+ /* In theory mapbase is the physical address ... */
+ up[(chip * 2) + 0].port.mapbase =
+ (unsigned long) ioremap((unsigned long) &rp->channelB, 8);
+ up[(chip * 2) + 1].port.mapbase =
+ (unsigned long) ioremap((unsigned long) &rp->channelA, 8);
+ }
+
+ /* Channel A */
+ up[(chip * 2) + 0].port.iotype = UPIO_MEM;
+ up[(chip * 2) + 0].port.irq = zilog_irq;
+ up[(chip * 2) + 0].port.uartclk = ZS_CLOCK;
+ up[(chip * 2) + 0].port.fifosize = 1;
+ up[(chip * 2) + 0].port.ops = &ip22zilog_pops;
+ up[(chip * 2) + 0].port.type = PORT_IP22ZILOG;
+ up[(chip * 2) + 0].port.flags = 0;
+ up[(chip * 2) + 0].port.line = (chip * 2) + 0;
+ up[(chip * 2) + 0].flags = 0;
+
+ /* Channel B */
+ up[(chip * 2) + 1].port.iotype = UPIO_MEM;
+ up[(chip * 2) + 1].port.irq = zilog_irq;
+ up[(chip * 2) + 1].port.uartclk = ZS_CLOCK;
+ up[(chip * 2) + 1].port.fifosize = 1;
+ up[(chip * 2) + 1].port.ops = &ip22zilog_pops;
+ up[(chip * 2) + 1].port.type = PORT_IP22ZILOG;
+ up[(chip * 2) + 1].port.line = (chip * 2) + 1;
+ up[(chip * 2) + 1].flags |= IP22ZILOG_FLAG_IS_CHANNEL_A;
+ }
+
+ for (channel = 0; channel < NUM_CHANNELS; channel++) {
+ struct uart_ip22zilog_port *up = &ip22zilog_port_table[channel];
+ int brg;
+
+ /* Normal serial TTY. */
+ up->parity_mask = 0xff;
+ up->curregs[R1] = EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+ up->curregs[R4] = PAR_EVEN | X16CLK | SB1;
+ up->curregs[R3] = RxENAB | Rx8;
+ up->curregs[R5] = TxENAB | Tx8;
+ up->curregs[R9] = NV | MIE;
+ up->curregs[R10] = NRZ;
+ up->curregs[R11] = TCBR | RCBR;
+ brg = BPS_TO_BRG(9600, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+ up->curregs[R12] = (brg & 0xff);
+ up->curregs[R13] = (brg >> 8) & 0xff;
+ up->curregs[R14] = BRENAB;
+ }
+}
+
+static int __init ip22zilog_ports_init(void)
+{
+ int ret;
+
+ printk(KERN_INFO "Serial: IP22 Zilog driver (%d chips).\n", NUM_IP22ZILOG);
+
+ ip22zilog_prepare();
+
+ if (request_irq(zilog_irq, ip22zilog_interrupt, 0,
+ "IP22-Zilog", ip22zilog_irq_chain)) {
+ panic("IP22-Zilog: Unable to register zs interrupt handler.\n");
+ }
+
+ ret = uart_register_driver(&ip22zilog_reg);
+ if (ret == 0) {
+ int i;
+
+ for (i = 0; i < NUM_CHANNELS; i++) {
+ struct uart_ip22zilog_port *up = &ip22zilog_port_table[i];
+
+ uart_add_one_port(&ip22zilog_reg, &up->port);
+ }
+ }
+
+ return ret;
+}
+
+static int __init ip22zilog_init(void)
+{
+ /* IP22 Zilog setup is hard coded, no probing to do. */
+ ip22zilog_alloc_tables();
+ ip22zilog_ports_init();
+
+ return 0;
+}
+
+static void __exit ip22zilog_exit(void)
+{
+ int i;
+ struct uart_ip22zilog_port *up;
+
+ for (i = 0; i < NUM_CHANNELS; i++) {
+ up = &ip22zilog_port_table[i];
+
+ uart_remove_one_port(&ip22zilog_reg, &up->port);
+ }
+
+ /* Free IO mem */
+ up = &ip22zilog_port_table[0];
+ for (i = 0; i < NUM_IP22ZILOG; i++) {
+ if (up[(i * 2) + 0].port.mapbase) {
+ iounmap((void*)up[(i * 2) + 0].port.mapbase);
+ up[(i * 2) + 0].port.mapbase = 0;
+ }
+ if (up[(i * 2) + 1].port.mapbase) {
+ iounmap((void*)up[(i * 2) + 1].port.mapbase);
+ up[(i * 2) + 1].port.mapbase = 0;
+ }
+ }
+
+ uart_unregister_driver(&ip22zilog_reg);
+}
+
+module_init(ip22zilog_init);
+module_exit(ip22zilog_exit);
+
+/* David wrote it but I'm to blame for the bugs ... */
+MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
+MODULE_DESCRIPTION("SGI Zilog serial port driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff