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linux-stable-rt/drivers/serial/sunzilog.c

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/* sunzilog.c: Zilog serial driver for Sparc systems.
*
* Driver for Zilog serial chips found on Sun workstations and
* servers. This driver could actually be made more generic.
*
* This is based on the old 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 Eddie
* C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell for their
* work there.
*
* Copyright (C) 2002, 2006 David S. Miller (davem@davemloft.net)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.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>
#ifdef CONFIG_SERIO
#include <linux/serio.h>
#endif
#include <linux/init.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/prom.h>
#include <asm/of_device.h>
#if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#include "suncore.h"
#include "sunzilog.h"
/* On 32-bit sparcs we need to delay after register accesses
* to accommodate sun4 systems, but we do not need to flush writes.
* On 64-bit sparc we only need to flush single writes to ensure
* completion.
*/
#ifndef CONFIG_SPARC64
#define ZSDELAY() udelay(5)
#define ZSDELAY_LONG() udelay(20)
#define ZS_WSYNC(channel) do { } while (0)
#else
#define ZSDELAY()
#define ZSDELAY_LONG()
#define ZS_WSYNC(__channel) \
readb(&((__channel)->control))
#endif
static int num_sunzilog;
#define NUM_SUNZILOG num_sunzilog
#define NUM_CHANNELS (NUM_SUNZILOG * 2)
#define ZS_CLOCK 4915200 /* 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_sunzilog_port {
struct uart_port port;
/* IRQ servicing chain. */
struct uart_sunzilog_port *next;
/* Current values of Zilog write registers. */
unsigned char curregs[NUM_ZSREGS];
unsigned int flags;
#define SUNZILOG_FLAG_CONS_KEYB 0x00000001
#define SUNZILOG_FLAG_CONS_MOUSE 0x00000002
#define SUNZILOG_FLAG_IS_CONS 0x00000004
#define SUNZILOG_FLAG_IS_KGDB 0x00000008
#define SUNZILOG_FLAG_MODEM_STATUS 0x00000010
#define SUNZILOG_FLAG_IS_CHANNEL_A 0x00000020
#define SUNZILOG_FLAG_REGS_HELD 0x00000040
#define SUNZILOG_FLAG_TX_STOPPED 0x00000080
#define SUNZILOG_FLAG_TX_ACTIVE 0x00000100
unsigned int cflag;
unsigned char parity_mask;
unsigned char prev_status;
#ifdef CONFIG_SERIO
struct serio serio;
int serio_open;
#endif
};
#define ZILOG_CHANNEL_FROM_PORT(PORT) ((struct zilog_channel __iomem *)((PORT)->membase))
#define UART_ZILOG(PORT) ((struct uart_sunzilog_port *)(PORT))
#define ZS_IS_KEYB(UP) ((UP)->flags & SUNZILOG_FLAG_CONS_KEYB)
#define ZS_IS_MOUSE(UP) ((UP)->flags & SUNZILOG_FLAG_CONS_MOUSE)
#define ZS_IS_CONS(UP) ((UP)->flags & SUNZILOG_FLAG_IS_CONS)
#define ZS_IS_KGDB(UP) ((UP)->flags & SUNZILOG_FLAG_IS_KGDB)
#define ZS_WANTS_MODEM_STATUS(UP) ((UP)->flags & SUNZILOG_FLAG_MODEM_STATUS)
#define ZS_IS_CHANNEL_A(UP) ((UP)->flags & SUNZILOG_FLAG_IS_CHANNEL_A)
#define ZS_REGS_HELD(UP) ((UP)->flags & SUNZILOG_FLAG_REGS_HELD)
#define ZS_TX_STOPPED(UP) ((UP)->flags & SUNZILOG_FLAG_TX_STOPPED)
#define ZS_TX_ACTIVE(UP) ((UP)->flags & SUNZILOG_FLAG_TX_ACTIVE)
/* Reading and writing Zilog8530 registers. The delays are to make this
* driver work on the Sun4 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 __iomem *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 __iomem *channel,
unsigned char reg, unsigned char value)
{
writeb(reg, &channel->control);
ZSDELAY();
writeb(value, &channel->control);
ZSDELAY();
}
static void sunzilog_clear_fifo(struct zilog_channel __iomem *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 __iomem *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);
sunzilog_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 sunzilog_maybe_update_regs(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel)
{
if (!ZS_REGS_HELD(up)) {
if (ZS_TX_ACTIVE(up)) {
up->flags |= SUNZILOG_FLAG_REGS_HELD;
} else {
__load_zsregs(channel, up->curregs);
}
}
}
static void sunzilog_change_mouse_baud(struct uart_sunzilog_port *up)
{
unsigned int cur_cflag = up->cflag;
int brg, new_baud;
up->cflag &= ~CBAUD;
up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);
brg = BPS_TO_BRG(new_baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
up->curregs[R12] = (brg & 0xff);
up->curregs[R13] = (brg >> 8) & 0xff;
sunzilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(&up->port));
}
static void sunzilog_kbdms_receive_chars(struct uart_sunzilog_port *up,
unsigned char ch, int is_break,
struct pt_regs *regs)
{
if (ZS_IS_KEYB(up)) {
/* Stop-A is handled by drivers/char/keyboard.c now. */
#ifdef CONFIG_SERIO
if (up->serio_open)
serio_interrupt(&up->serio, ch, 0, regs);
#endif
} else if (ZS_IS_MOUSE(up)) {
int ret = suncore_mouse_baud_detection(ch, is_break);
switch (ret) {
case 2:
sunzilog_change_mouse_baud(up);
/* fallthru */
case 1:
break;
case 0:
#ifdef CONFIG_SERIO
if (up->serio_open)
serio_interrupt(&up->serio, ch, 0, regs);
#endif
break;
};
}
}
static struct tty_struct *
sunzilog_receive_chars(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel,
struct pt_regs *regs)
{
struct tty_struct *tty;
unsigned char ch, r1, flag;
tty = NULL;
if (up->port.info != NULL && /* Unopened serial console */
up->port.info->tty != NULL) /* Keyboard || mouse */
tty = up->port.info->tty;
for (;;) {
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->control);
ZSDELAY();
/* This funny hack depends upon BRK_ABRT not interfering
* with the other bits we care about in R1.
*/
if (ch & BRK_ABRT)
r1 |= BRK_ABRT;
if (!(ch & Rx_CH_AV))
break;
ch = readb(&channel->data);
ZSDELAY();
ch &= up->parity_mask;
if (unlikely(ZS_IS_KEYB(up)) || unlikely(ZS_IS_MOUSE(up))) {
sunzilog_kbdms_receive_chars(up, ch, 0, regs);
continue;
}
if (tty == NULL) {
uart_handle_sysrq_char(&up->port, ch, regs);
continue;
}
/* A real serial line, record the character and status. */
flag = TTY_NORMAL;
up->port.icount.rx++;
if (r1 & (BRK_ABRT | PAR_ERR | Rx_OVR | CRC_ERR)) {
if (r1 & BRK_ABRT) {
r1 &= ~(PAR_ERR | CRC_ERR);
up->port.icount.brk++;
if (uart_handle_break(&up->port))
continue;
}
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 & BRK_ABRT)
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, regs))
continue;
if (up->port.ignore_status_mask == 0xff ||
(r1 & up->port.ignore_status_mask) == 0) {
tty_insert_flip_char(tty, ch, flag);
}
if (r1 & Rx_OVR)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
return tty;
}
static void sunzilog_status_handle(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel,
struct pt_regs *regs)
{
unsigned char status;
status = readb(&channel->control);
ZSDELAY();
writeb(RES_EXT_INT, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (status & BRK_ABRT) {
if (ZS_IS_MOUSE(up))
sunzilog_kbdms_receive_chars(up, 0, 1, regs);
if (ZS_IS_CONS(up)) {
/* Wait for BREAK to deassert to avoid potentially
* confusing the PROM.
*/
while (1) {
status = readb(&channel->control);
ZSDELAY();
if (!(status & BRK_ABRT))
break;
}
sun_do_break();
return;
}
}
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.info->delta_msr_wait);
}
up->prev_status = status;
}
static void sunzilog_transmit_chars(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *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 becomming free. -DaveM
*/
if (!(status & Tx_BUF_EMP))
return;
}
up->flags &= ~SUNZILOG_FLAG_TX_ACTIVE;
if (ZS_REGS_HELD(up)) {
__load_zsregs(channel, up->curregs);
up->flags &= ~SUNZILOG_FLAG_REGS_HELD;
}
if (ZS_TX_STOPPED(up)) {
up->flags &= ~SUNZILOG_FLAG_TX_STOPPED;
goto ack_tx_int;
}
if (up->port.x_char) {
up->flags |= SUNZILOG_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.info == NULL)
goto ack_tx_int;
xmit = &up->port.info->xmit;
if (uart_circ_empty(xmit))
goto ack_tx_int;
if (uart_tx_stopped(&up->port))
goto ack_tx_int;
up->flags |= SUNZILOG_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 sunzilog_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_sunzilog_port *up = dev_id;
while (up) {
struct zilog_channel __iomem *channel
= ZILOG_CHANNEL_FROM_PORT(&up->port);
struct tty_struct *tty;
unsigned char r3;
spin_lock(&up->port.lock);
r3 = read_zsreg(channel, R3);
/* Channel A */
tty = NULL;
if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
writeb(RES_H_IUS, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (r3 & CHARxIP)
tty = sunzilog_receive_chars(up, channel, regs);
if (r3 & CHAEXT)
sunzilog_status_handle(up, channel, regs);
if (r3 & CHATxIP)
sunzilog_transmit_chars(up, channel);
}
spin_unlock(&up->port.lock);
if (tty)
tty_flip_buffer_push(tty);
/* Channel B */
up = up->next;
channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
spin_lock(&up->port.lock);
tty = NULL;
if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
writeb(RES_H_IUS, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (r3 & CHBRxIP)
tty = sunzilog_receive_chars(up, channel, regs);
if (r3 & CHBEXT)
sunzilog_status_handle(up, channel, regs);
if (r3 & CHBTxIP)
sunzilog_transmit_chars(up, channel);
}
spin_unlock(&up->port.lock);
if (tty)
tty_flip_buffer_push(tty);
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 sunzilog_read_channel_status(struct uart_port *port)
{
struct zilog_channel __iomem *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 sunzilog_tx_empty(struct uart_port *port)
{
unsigned long flags;
unsigned char status;
unsigned int ret;
spin_lock_irqsave(&port->lock, flags);
status = sunzilog_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 sunzilog_get_mctrl(struct uart_port *port)
{
unsigned char status;
unsigned int ret;
status = sunzilog_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 sunzilog_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *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 sunzilog_stop_tx(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
up->flags |= SUNZILOG_FLAG_TX_STOPPED;
}
/* The port lock is held and interrupts are disabled. */
static void sunzilog_start_tx(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
unsigned char status;
up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
up->flags &= ~SUNZILOG_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->info->xmit;
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. */
static void sunzilog_stop_rx(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
struct zilog_channel __iomem *channel;
if (ZS_IS_CONS(up))
return;
channel = ZILOG_CHANNEL_FROM_PORT(port);
/* Disable all RX interrupts. */
up->curregs[R1] &= ~RxINT_MASK;
sunzilog_maybe_update_regs(up, channel);
}
/* The port lock is held. */
static void sunzilog_enable_ms(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *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 sunzilog_break_ctl(struct uart_port *port, int break_state)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *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 __sunzilog_startup(struct uart_sunzilog_port *up)
{
struct zilog_channel __iomem *channel;
channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
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;
sunzilog_maybe_update_regs(up, channel);
}
static int sunzilog_startup(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
unsigned long flags;
if (ZS_IS_CONS(up))
return 0;
spin_lock_irqsave(&port->lock, flags);
__sunzilog_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 sunzilog_shutdown(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
struct zilog_channel __iomem *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;
sunzilog_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
sunzilog_convert_to_zs(struct uart_sunzilog_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] = BRSRC | 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 & (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
sunzilog_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_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);
sunzilog_convert_to_zs(up, termios->c_cflag, termios->c_iflag, brg);
if (UART_ENABLE_MS(&up->port, termios->c_cflag))
up->flags |= SUNZILOG_FLAG_MODEM_STATUS;
else
up->flags &= ~SUNZILOG_FLAG_MODEM_STATUS;
up->cflag = termios->c_cflag;
sunzilog_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 *sunzilog_type(struct uart_port *port)
{
return "zs";
}
/* We do not request/release mappings of the registers here, this
* happens at early serial probe time.
*/
static void sunzilog_release_port(struct uart_port *port)
{
}
static int sunzilog_request_port(struct uart_port *port)
{
return 0;
}
/* These do not need to do anything interesting either. */
static void sunzilog_config_port(struct uart_port *port, int flags)
{
}
/* We do not support letting the user mess with the divisor, IRQ, etc. */
static int sunzilog_verify_port(struct uart_port *port, struct serial_struct *ser)
{
return -EINVAL;
}
static struct uart_ops sunzilog_pops = {
.tx_empty = sunzilog_tx_empty,
.set_mctrl = sunzilog_set_mctrl,
.get_mctrl = sunzilog_get_mctrl,
.stop_tx = sunzilog_stop_tx,
.start_tx = sunzilog_start_tx,
.stop_rx = sunzilog_stop_rx,
.enable_ms = sunzilog_enable_ms,
.break_ctl = sunzilog_break_ctl,
.startup = sunzilog_startup,
.shutdown = sunzilog_shutdown,
.set_termios = sunzilog_set_termios,
.type = sunzilog_type,
.release_port = sunzilog_release_port,
.request_port = sunzilog_request_port,
.config_port = sunzilog_config_port,
.verify_port = sunzilog_verify_port,
};
static struct uart_sunzilog_port *sunzilog_port_table;
static struct zilog_layout __iomem **sunzilog_chip_regs;
static struct uart_sunzilog_port *sunzilog_irq_chain;
static struct uart_driver sunzilog_reg = {
.owner = THIS_MODULE,
.driver_name = "ttyS",
.dev_name = "ttyS",
.major = TTY_MAJOR,
};
static int __init sunzilog_alloc_tables(void)
{
struct uart_sunzilog_port *up;
unsigned long size;
int i;
size = NUM_CHANNELS * sizeof(struct uart_sunzilog_port);
sunzilog_port_table = kzalloc(size, GFP_KERNEL);
if (!sunzilog_port_table)
return -ENOMEM;
for (i = 0; i < NUM_CHANNELS; i++) {
up = &sunzilog_port_table[i];
spin_lock_init(&up->port.lock);
if (i == 0)
sunzilog_irq_chain = up;
if (i < NUM_CHANNELS - 1)
up->next = up + 1;
else
up->next = NULL;
}
size = NUM_SUNZILOG * sizeof(struct zilog_layout __iomem *);
sunzilog_chip_regs = kzalloc(size, GFP_KERNEL);
if (!sunzilog_chip_regs) {
kfree(sunzilog_port_table);
sunzilog_irq_chain = NULL;
return -ENOMEM;
}
return 0;
}
static void sunzilog_free_tables(void)
{
kfree(sunzilog_port_table);
sunzilog_irq_chain = NULL;
kfree(sunzilog_chip_regs);
}
#define ZS_PUT_CHAR_MAX_DELAY 2000 /* 10 ms */
static void sunzilog_putchar(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);
}
#ifdef CONFIG_SERIO
static DEFINE_SPINLOCK(sunzilog_serio_lock);
static int sunzilog_serio_write(struct serio *serio, unsigned char ch)
{
struct uart_sunzilog_port *up = serio->port_data;
unsigned long flags;
spin_lock_irqsave(&sunzilog_serio_lock, flags);
sunzilog_putchar(&up->port, ch);
spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
return 0;
}
static int sunzilog_serio_open(struct serio *serio)
{
struct uart_sunzilog_port *up = serio->port_data;
unsigned long flags;
int ret;
spin_lock_irqsave(&sunzilog_serio_lock, flags);
if (!up->serio_open) {
up->serio_open = 1;
ret = 0;
} else
ret = -EBUSY;
spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
return ret;
}
static void sunzilog_serio_close(struct serio *serio)
{
struct uart_sunzilog_port *up = serio->port_data;
unsigned long flags;
spin_lock_irqsave(&sunzilog_serio_lock, flags);
up->serio_open = 0;
spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
}
#endif /* CONFIG_SERIO */
#ifdef CONFIG_SERIAL_SUNZILOG_CONSOLE
static void
sunzilog_console_write(struct console *con, const char *s, unsigned int count)
{
struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, count, sunzilog_putchar);
udelay(2);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init sunzilog_console_setup(struct console *con, char *options)
{
struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
unsigned long flags;
int baud, brg;
printk(KERN_INFO "Console: ttyS%d (SunZilog zs%d)\n",
(sunzilog_reg.minor - 64) + con->index, con->index);
/* Get firmware console settings. */
sunserial_console_termios(con);
/* Firmware console speed is limited to 150-->38400 baud so
* this hackish cflag thing is OK.
*/
switch (con->cflag & CBAUD) {
case B150: baud = 150; break;
case B300: baud = 300; break;
case B600: baud = 600; break;
case B1200: baud = 1200; break;
case B2400: baud = 2400; break;
case B4800: baud = 4800; break;
default: case B9600: baud = 9600; break;
case B19200: baud = 19200; break;
case B38400: baud = 38400; break;
};
brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
spin_lock_irqsave(&up->port.lock, flags);
up->curregs[R15] = BRKIE;
sunzilog_convert_to_zs(up, con->cflag, 0, brg);
sunzilog_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
__sunzilog_startup(up);
spin_unlock_irqrestore(&up->port.lock, flags);
return 0;
}
static struct console sunzilog_console = {
.name = "ttyS",
.write = sunzilog_console_write,
.device = uart_console_device,
.setup = sunzilog_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sunzilog_reg,
};
static inline struct console *SUNZILOG_CONSOLE(void)
{
int i;
if (con_is_present())
return NULL;
for (i = 0; i < NUM_CHANNELS; i++) {
int this_minor = sunzilog_reg.minor + i;
if ((this_minor - 64) == (serial_console - 1))
break;
}
if (i == NUM_CHANNELS)
return NULL;
sunzilog_console.index = i;
sunzilog_port_table[i].flags |= SUNZILOG_FLAG_IS_CONS;
return &sunzilog_console;
}
#else
#define SUNZILOG_CONSOLE() (NULL)
#endif
static void __init sunzilog_init_kbdms(struct uart_sunzilog_port *up, int channel)
{
int baud, brg;
if (up->flags & SUNZILOG_FLAG_CONS_KEYB) {
up->cflag = B1200 | CS8 | CLOCAL | CREAD;
baud = 1200;
} else {
up->cflag = B4800 | CS8 | CLOCAL | CREAD;
baud = 4800;
}
up->curregs[R15] = BRKIE;
brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
sunzilog_convert_to_zs(up, up->cflag, 0, brg);
sunzilog_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
__sunzilog_startup(up);
}
#ifdef CONFIG_SERIO
static void __init sunzilog_register_serio(struct uart_sunzilog_port *up)
{
struct serio *serio = &up->serio;
serio->port_data = up;
serio->id.type = SERIO_RS232;
if (up->flags & SUNZILOG_FLAG_CONS_KEYB) {
serio->id.proto = SERIO_SUNKBD;
strlcpy(serio->name, "zskbd", sizeof(serio->name));
} else {
serio->id.proto = SERIO_SUN;
serio->id.extra = 1;
strlcpy(serio->name, "zsms", sizeof(serio->name));
}
strlcpy(serio->phys,
((up->flags & SUNZILOG_FLAG_CONS_KEYB) ?
"zs/serio0" : "zs/serio1"),
sizeof(serio->phys));
serio->write = sunzilog_serio_write;
serio->open = sunzilog_serio_open;
serio->close = sunzilog_serio_close;
serio->dev.parent = up->port.dev;
serio_register_port(serio);
}
#endif
static void __init sunzilog_init_hw(struct uart_sunzilog_port *up)
{
struct zilog_channel __iomem *channel;
unsigned long flags;
int baud, brg;
channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
spin_lock_irqsave(&up->port.lock, flags);
if (ZS_IS_CHANNEL_A(up)) {
write_zsreg(channel, R9, FHWRES);
ZSDELAY_LONG();
(void) read_zsreg(channel, R0);
}
if (up->flags & (SUNZILOG_FLAG_CONS_KEYB |
SUNZILOG_FLAG_CONS_MOUSE)) {
sunzilog_init_kbdms(up, up->port.line);
up->curregs[R9] |= (NV | MIE);
write_zsreg(channel, R9, up->curregs[R9]);
} else {
/* 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;
baud = 9600;
brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
up->curregs[R12] = (brg & 0xff);
up->curregs[R13] = (brg >> 8) & 0xff;
up->curregs[R14] = BRSRC | BRENAB;
__load_zsregs(channel, up->curregs);
write_zsreg(channel, R9, up->curregs[R9]);
}
spin_unlock_irqrestore(&up->port.lock, flags);
#ifdef CONFIG_SERIO
if (up->flags & (SUNZILOG_FLAG_CONS_KEYB |
SUNZILOG_FLAG_CONS_MOUSE))
sunzilog_register_serio(up);
#endif
}
static int zilog_irq = -1;
static int __devinit zs_probe(struct of_device *op, const struct of_device_id *match)
{
static int inst;
struct uart_sunzilog_port *up;
struct zilog_layout __iomem *rp;
int keyboard_mouse;
int err;
keyboard_mouse = 0;
if (of_find_property(op->node, "keyboard", NULL))
keyboard_mouse = 1;
sunzilog_chip_regs[inst] = of_ioremap(&op->resource[0], 0,
sizeof(struct zilog_layout),
"zs");
if (!sunzilog_chip_regs[inst])
return -ENOMEM;
rp = sunzilog_chip_regs[inst];
if (zilog_irq == -1)
zilog_irq = op->irqs[0];
up = &sunzilog_port_table[inst * 2];
/* Channel A */
up[0].port.mapbase = op->resource[0].start + 0x00;
up[0].port.membase = (void __iomem *) &rp->channelA;
up[0].port.iotype = UPIO_MEM;
up[0].port.irq = op->irqs[0];
up[0].port.uartclk = ZS_CLOCK;
up[0].port.fifosize = 1;
up[0].port.ops = &sunzilog_pops;
up[0].port.type = PORT_SUNZILOG;
up[0].port.flags = 0;
up[0].port.line = (inst * 2) + 0;
up[0].port.dev = &op->dev;
up[0].flags |= SUNZILOG_FLAG_IS_CHANNEL_A;
if (keyboard_mouse)
up[0].flags |= SUNZILOG_FLAG_CONS_KEYB;
sunzilog_init_hw(&up[0]);
/* Channel B */
up[1].port.mapbase = op->resource[0].start + 0x04;
up[1].port.membase = (void __iomem *) &rp->channelB;
up[1].port.iotype = UPIO_MEM;
up[1].port.irq = op->irqs[0];
up[1].port.uartclk = ZS_CLOCK;
up[1].port.fifosize = 1;
up[1].port.ops = &sunzilog_pops;
up[1].port.type = PORT_SUNZILOG;
up[1].port.flags = 0;
up[1].port.line = (inst * 2) + 1;
up[1].port.dev = &op->dev;
up[1].flags |= 0;
if (keyboard_mouse)
up[1].flags |= SUNZILOG_FLAG_CONS_MOUSE;
sunzilog_init_hw(&up[1]);
if (!keyboard_mouse) {
err = uart_add_one_port(&sunzilog_reg, &up[0].port);
if (err) {
of_iounmap(rp, sizeof(struct zilog_layout));
return err;
}
err = uart_add_one_port(&sunzilog_reg, &up[1].port);
if (err) {
uart_remove_one_port(&sunzilog_reg, &up[0].port);
of_iounmap(rp, sizeof(struct zilog_layout));
return err;
}
} else {
printk(KERN_INFO "%s: Keyboard at MMIO %lx (irq = %d) "
"is a zs\n",
op->dev.bus_id, up[0].port.mapbase, op->irqs[0]);
printk(KERN_INFO "%s: Mouse at MMIO %lx (irq = %d) "
"is a zs\n",
op->dev.bus_id, up[1].port.mapbase, op->irqs[0]);
}
dev_set_drvdata(&op->dev, &up[0]);
inst++;
return 0;
}
static void __devexit zs_remove_one(struct uart_sunzilog_port *up)
{
if (ZS_IS_KEYB(up) || ZS_IS_MOUSE(up)) {
#ifdef CONFIG_SERIO
serio_unregister_port(&up->serio);
#endif
} else
uart_remove_one_port(&sunzilog_reg, &up->port);
}
static int __devexit zs_remove(struct of_device *dev)
{
struct uart_sunzilog_port *up = dev_get_drvdata(&dev->dev);
struct zilog_layout __iomem *regs;
zs_remove_one(&up[0]);
zs_remove_one(&up[1]);
regs = sunzilog_chip_regs[up[0].port.line / 2];
of_iounmap(regs, sizeof(struct zilog_layout));
dev_set_drvdata(&dev->dev, NULL);
return 0;
}
static struct of_device_id zs_match[] = {
{
.name = "zs",
},
{},
};
MODULE_DEVICE_TABLE(of, zs_match);
static struct of_platform_driver zs_driver = {
.name = "zs",
.match_table = zs_match,
.probe = zs_probe,
.remove = __devexit_p(zs_remove),
};
static int __init sunzilog_init(void)
{
struct device_node *dp;
int err, uart_count;
int num_keybms;
NUM_SUNZILOG = 0;
num_keybms = 0;
for_each_node_by_name(dp, "zs") {
NUM_SUNZILOG++;
if (of_find_property(dp, "keyboard", NULL))
num_keybms++;
}
uart_count = 0;
if (NUM_SUNZILOG) {
int uart_count;
err = sunzilog_alloc_tables();
if (err)
goto out;
uart_count = (NUM_SUNZILOG * 2) - (2 * num_keybms);
sunzilog_reg.nr = uart_count;
sunzilog_reg.minor = sunserial_current_minor;
err = uart_register_driver(&sunzilog_reg);
if (err)
goto out_free_tables;
sunzilog_reg.tty_driver->name_base = sunzilog_reg.minor - 64;
sunzilog_reg.cons = SUNZILOG_CONSOLE();
sunserial_current_minor += uart_count;
}
err = of_register_driver(&zs_driver, &of_bus_type);
if (err)
goto out_unregister_uart;
if (zilog_irq != -1) {
err = request_irq(zilog_irq, sunzilog_interrupt, IRQF_SHARED,
"zs", sunzilog_irq_chain);
if (err)
goto out_unregister_driver;
}
out:
return err;
out_unregister_driver:
of_unregister_driver(&zs_driver);
out_unregister_uart:
if (NUM_SUNZILOG) {
uart_unregister_driver(&sunzilog_reg);
sunzilog_reg.cons = NULL;
}
out_free_tables:
sunzilog_free_tables();
goto out;
}
static void __exit sunzilog_exit(void)
{
of_unregister_driver(&zs_driver);
if (zilog_irq != -1) {
free_irq(zilog_irq, sunzilog_irq_chain);
zilog_irq = -1;
}
if (NUM_SUNZILOG) {
uart_unregister_driver(&sunzilog_reg);
sunzilog_free_tables();
}
}
module_init(sunzilog_init);
module_exit(sunzilog_exit);
MODULE_AUTHOR("David S. Miller");
MODULE_DESCRIPTION("Sun Zilog serial port driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");
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