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linux/drivers/char/vme_scc.c
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp 
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00

1044 lines
28 KiB
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/*
* drivers/char/vme_scc.c: MVME147, MVME162, BVME6000 SCC serial ports
* implementation.
* Copyright 1999 Richard Hirst <richard@sleepie.demon.co.uk>
*
* Based on atari_SCC.c which was
* Copyright 1994-95 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
* Partially based on PC-Linux serial.c by Linus Torvalds and Theodore Ts'o
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*
*/
#include <linux/module.h>
#include <linux/config.h>
#include <linux/kdev_t.h>
#include <asm/io.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/mm.h>
#include <linux/serial.h>
#include <linux/fcntl.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/console.h>
#include <linux/init.h>
#include <asm/setup.h>
#include <asm/bootinfo.h>
#ifdef CONFIG_MVME147_SCC
#include <asm/mvme147hw.h>
#endif
#ifdef CONFIG_MVME162_SCC
#include <asm/mvme16xhw.h>
#endif
#ifdef CONFIG_BVME6000_SCC
#include <asm/bvme6000hw.h>
#endif
#include <linux/generic_serial.h>
#include "scc.h"
#define CHANNEL_A 0
#define CHANNEL_B 1
#define SCC_MINOR_BASE 64
/* Shadows for all SCC write registers */
static unsigned char scc_shadow[2][16];
/* Location to access for SCC register access delay */
static volatile unsigned char *scc_del = NULL;
/* To keep track of STATUS_REG state for detection of Ext/Status int source */
static unsigned char scc_last_status_reg[2];
/***************************** Prototypes *****************************/
/* Function prototypes */
static void scc_disable_tx_interrupts(void * ptr);
static void scc_enable_tx_interrupts(void * ptr);
static void scc_disable_rx_interrupts(void * ptr);
static void scc_enable_rx_interrupts(void * ptr);
static int scc_get_CD(void * ptr);
static void scc_shutdown_port(void * ptr);
static int scc_set_real_termios(void *ptr);
static void scc_hungup(void *ptr);
static void scc_close(void *ptr);
static int scc_chars_in_buffer(void * ptr);
static int scc_open(struct tty_struct * tty, struct file * filp);
static int scc_ioctl(struct tty_struct * tty, struct file * filp,
unsigned int cmd, unsigned long arg);
static void scc_throttle(struct tty_struct *tty);
static void scc_unthrottle(struct tty_struct *tty);
static irqreturn_t scc_tx_int(int irq, void *data, struct pt_regs *fp);
static irqreturn_t scc_rx_int(int irq, void *data, struct pt_regs *fp);
static irqreturn_t scc_stat_int(int irq, void *data, struct pt_regs *fp);
static irqreturn_t scc_spcond_int(int irq, void *data, struct pt_regs *fp);
static void scc_setsignals(struct scc_port *port, int dtr, int rts);
static void scc_break_ctl(struct tty_struct *tty, int break_state);
static struct tty_driver *scc_driver;
struct scc_port scc_ports[2];
int scc_initialized = 0;
/*---------------------------------------------------------------------------
* Interface from generic_serial.c back here
*--------------------------------------------------------------------------*/
static struct real_driver scc_real_driver = {
scc_disable_tx_interrupts,
scc_enable_tx_interrupts,
scc_disable_rx_interrupts,
scc_enable_rx_interrupts,
scc_get_CD,
scc_shutdown_port,
scc_set_real_termios,
scc_chars_in_buffer,
scc_close,
scc_hungup,
NULL
};
static struct tty_operations scc_ops = {
.open = scc_open,
.close = gs_close,
.write = gs_write,
.put_char = gs_put_char,
.flush_chars = gs_flush_chars,
.write_room = gs_write_room,
.chars_in_buffer = gs_chars_in_buffer,
.flush_buffer = gs_flush_buffer,
.ioctl = scc_ioctl,
.throttle = scc_throttle,
.unthrottle = scc_unthrottle,
.set_termios = gs_set_termios,
.stop = gs_stop,
.start = gs_start,
.hangup = gs_hangup,
.break_ctl = scc_break_ctl,
};
/*----------------------------------------------------------------------------
* vme_scc_init() and support functions
*---------------------------------------------------------------------------*/
static int scc_init_drivers(void)
{
int error;
scc_driver = alloc_tty_driver(2);
if (!scc_driver)
return -ENOMEM;
scc_driver->owner = THIS_MODULE;
scc_driver->driver_name = "scc";
scc_driver->name = "ttyS";
scc_driver->devfs_name = "tts/";
scc_driver->major = TTY_MAJOR;
scc_driver->minor_start = SCC_MINOR_BASE;
scc_driver->type = TTY_DRIVER_TYPE_SERIAL;
scc_driver->subtype = SERIAL_TYPE_NORMAL;
scc_driver->init_termios = tty_std_termios;
scc_driver->init_termios.c_cflag =
B9600 | CS8 | CREAD | HUPCL | CLOCAL;
scc_driver->flags = TTY_DRIVER_REAL_RAW;
tty_set_operations(scc_driver, &scc_ops);
if ((error = tty_register_driver(scc_driver))) {
printk(KERN_ERR "scc: Couldn't register scc driver, error = %d\n",
error);
put_tty_driver(scc_driver);
return 1;
}
return 0;
}
/* ports[] array is indexed by line no (i.e. [0] for ttyS0, [1] for ttyS1).
*/
static void scc_init_portstructs(void)
{
struct scc_port *port;
int i;
for (i = 0; i < 2; i++) {
port = scc_ports + i;
port->gs.magic = SCC_MAGIC;
port->gs.close_delay = HZ/2;
port->gs.closing_wait = 30 * HZ;
port->gs.rd = &scc_real_driver;
#ifdef NEW_WRITE_LOCKING
port->gs.port_write_sem = MUTEX;
#endif
init_waitqueue_head(&port->gs.open_wait);
init_waitqueue_head(&port->gs.close_wait);
}
}
#ifdef CONFIG_MVME147_SCC
static int mvme147_scc_init(void)
{
struct scc_port *port;
printk(KERN_INFO "SCC: MVME147 Serial Driver\n");
/* Init channel A */
port = &scc_ports[0];
port->channel = CHANNEL_A;
port->ctrlp = (volatile unsigned char *)M147_SCC_A_ADDR;
port->datap = port->ctrlp + 1;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(MVME147_IRQ_SCCA_TX, scc_tx_int, SA_INTERRUPT,
"SCC-A TX", port);
request_irq(MVME147_IRQ_SCCA_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-A status", port);
request_irq(MVME147_IRQ_SCCA_RX, scc_rx_int, SA_INTERRUPT,
"SCC-A RX", port);
request_irq(MVME147_IRQ_SCCA_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-A special cond", port);
{
SCC_ACCESS_INIT(port);
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
/* Set the interrupt vector */
SCCwrite(INT_VECTOR_REG, MVME147_IRQ_SCC_BASE);
/* Interrupt parameters: vector includes status, status low */
SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
}
/* Init channel B */
port = &scc_ports[1];
port->channel = CHANNEL_B;
port->ctrlp = (volatile unsigned char *)M147_SCC_B_ADDR;
port->datap = port->ctrlp + 1;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(MVME147_IRQ_SCCB_TX, scc_tx_int, SA_INTERRUPT,
"SCC-B TX", port);
request_irq(MVME147_IRQ_SCCB_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-B status", port);
request_irq(MVME147_IRQ_SCCB_RX, scc_rx_int, SA_INTERRUPT,
"SCC-B RX", port);
request_irq(MVME147_IRQ_SCCB_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-B special cond", port);
{
SCC_ACCESS_INIT(port);
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
}
/* Ensure interrupts are enabled in the PCC chip */
m147_pcc->serial_cntrl=PCC_LEVEL_SERIAL|PCC_INT_ENAB;
/* Initialise the tty driver structures and register */
scc_init_portstructs();
scc_init_drivers();
return 0;
}
#endif
#ifdef CONFIG_MVME162_SCC
static int mvme162_scc_init(void)
{
struct scc_port *port;
if (!(mvme16x_config & MVME16x_CONFIG_GOT_SCCA))
return (-ENODEV);
printk(KERN_INFO "SCC: MVME162 Serial Driver\n");
/* Init channel A */
port = &scc_ports[0];
port->channel = CHANNEL_A;
port->ctrlp = (volatile unsigned char *)MVME_SCC_A_ADDR;
port->datap = port->ctrlp + 2;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(MVME162_IRQ_SCCA_TX, scc_tx_int, SA_INTERRUPT,
"SCC-A TX", port);
request_irq(MVME162_IRQ_SCCA_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-A status", port);
request_irq(MVME162_IRQ_SCCA_RX, scc_rx_int, SA_INTERRUPT,
"SCC-A RX", port);
request_irq(MVME162_IRQ_SCCA_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-A special cond", port);
{
SCC_ACCESS_INIT(port);
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
/* Set the interrupt vector */
SCCwrite(INT_VECTOR_REG, MVME162_IRQ_SCC_BASE);
/* Interrupt parameters: vector includes status, status low */
SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
}
/* Init channel B */
port = &scc_ports[1];
port->channel = CHANNEL_B;
port->ctrlp = (volatile unsigned char *)MVME_SCC_B_ADDR;
port->datap = port->ctrlp + 2;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(MVME162_IRQ_SCCB_TX, scc_tx_int, SA_INTERRUPT,
"SCC-B TX", port);
request_irq(MVME162_IRQ_SCCB_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-B status", port);
request_irq(MVME162_IRQ_SCCB_RX, scc_rx_int, SA_INTERRUPT,
"SCC-B RX", port);
request_irq(MVME162_IRQ_SCCB_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-B special cond", port);
{
SCC_ACCESS_INIT(port); /* Either channel will do */
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
}
/* Ensure interrupts are enabled in the MC2 chip */
*(volatile char *)0xfff4201d = 0x14;
/* Initialise the tty driver structures and register */
scc_init_portstructs();
scc_init_drivers();
return 0;
}
#endif
#ifdef CONFIG_BVME6000_SCC
static int bvme6000_scc_init(void)
{
struct scc_port *port;
printk(KERN_INFO "SCC: BVME6000 Serial Driver\n");
/* Init channel A */
port = &scc_ports[0];
port->channel = CHANNEL_A;
port->ctrlp = (volatile unsigned char *)BVME_SCC_A_ADDR;
port->datap = port->ctrlp + 4;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(BVME_IRQ_SCCA_TX, scc_tx_int, SA_INTERRUPT,
"SCC-A TX", port);
request_irq(BVME_IRQ_SCCA_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-A status", port);
request_irq(BVME_IRQ_SCCA_RX, scc_rx_int, SA_INTERRUPT,
"SCC-A RX", port);
request_irq(BVME_IRQ_SCCA_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-A special cond", port);
{
SCC_ACCESS_INIT(port);
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
/* Set the interrupt vector */
SCCwrite(INT_VECTOR_REG, BVME_IRQ_SCC_BASE);
/* Interrupt parameters: vector includes status, status low */
SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
}
/* Init channel B */
port = &scc_ports[1];
port->channel = CHANNEL_B;
port->ctrlp = (volatile unsigned char *)BVME_SCC_B_ADDR;
port->datap = port->ctrlp + 4;
port->port_a = &scc_ports[0];
port->port_b = &scc_ports[1];
request_irq(BVME_IRQ_SCCB_TX, scc_tx_int, SA_INTERRUPT,
"SCC-B TX", port);
request_irq(BVME_IRQ_SCCB_STAT, scc_stat_int, SA_INTERRUPT,
"SCC-B status", port);
request_irq(BVME_IRQ_SCCB_RX, scc_rx_int, SA_INTERRUPT,
"SCC-B RX", port);
request_irq(BVME_IRQ_SCCB_SPCOND, scc_spcond_int, SA_INTERRUPT,
"SCC-B special cond", port);
{
SCC_ACCESS_INIT(port); /* Either channel will do */
/* disable interrupts for this channel */
SCCwrite(INT_AND_DMA_REG, 0);
}
/* Initialise the tty driver structures and register */
scc_init_portstructs();
scc_init_drivers();
return 0;
}
#endif
static int vme_scc_init(void)
{
int res = -ENODEV;
#ifdef CONFIG_MVME147_SCC
if (MACH_IS_MVME147)
res = mvme147_scc_init();
#endif
#ifdef CONFIG_MVME162_SCC
if (MACH_IS_MVME16x)
res = mvme162_scc_init();
#endif
#ifdef CONFIG_BVME6000_SCC
if (MACH_IS_BVME6000)
res = bvme6000_scc_init();
#endif
return res;
}
module_init(vme_scc_init);
/*---------------------------------------------------------------------------
* Interrupt handlers
*--------------------------------------------------------------------------*/
static irqreturn_t scc_rx_int(int irq, void *data, struct pt_regs *fp)
{
unsigned char ch;
struct scc_port *port = data;
struct tty_struct *tty = port->gs.tty;
SCC_ACCESS_INIT(port);
ch = SCCread_NB(RX_DATA_REG);
if (!tty) {
printk(KERN_WARNING "scc_rx_int with NULL tty!\n");
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
return IRQ_HANDLED;
}
tty_insert_flip_char(tty, ch, 0);
/* Check if another character is already ready; in that case, the
* spcond_int() function must be used, because this character may have an
* error condition that isn't signalled by the interrupt vector used!
*/
if (SCCread(INT_PENDING_REG) &
(port->channel == CHANNEL_A ? IPR_A_RX : IPR_B_RX)) {
scc_spcond_int (irq, data, fp);
return IRQ_HANDLED;
}
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
static irqreturn_t scc_spcond_int(int irq, void *data, struct pt_regs *fp)
{
struct scc_port *port = data;
struct tty_struct *tty = port->gs.tty;
unsigned char stat, ch, err;
int int_pending_mask = port->channel == CHANNEL_A ?
IPR_A_RX : IPR_B_RX;
SCC_ACCESS_INIT(port);
if (!tty) {
printk(KERN_WARNING "scc_spcond_int with NULL tty!\n");
SCCwrite(COMMAND_REG, CR_ERROR_RESET);
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
return IRQ_HANDLED;
}
do {
stat = SCCread(SPCOND_STATUS_REG);
ch = SCCread_NB(RX_DATA_REG);
if (stat & SCSR_RX_OVERRUN)
err = TTY_OVERRUN;
else if (stat & SCSR_PARITY_ERR)
err = TTY_PARITY;
else if (stat & SCSR_CRC_FRAME_ERR)
err = TTY_FRAME;
else
err = 0;
tty_insert_flip_char(tty, ch, err);
/* ++TeSche: *All* errors have to be cleared manually,
* else the condition persists for the next chars
*/
if (err)
SCCwrite(COMMAND_REG, CR_ERROR_RESET);
} while(SCCread(INT_PENDING_REG) & int_pending_mask);
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
static irqreturn_t scc_tx_int(int irq, void *data, struct pt_regs *fp)
{
struct scc_port *port = data;
SCC_ACCESS_INIT(port);
if (!port->gs.tty) {
printk(KERN_WARNING "scc_tx_int with NULL tty!\n");
SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET);
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
return IRQ_HANDLED;
}
while ((SCCread_NB(STATUS_REG) & SR_TX_BUF_EMPTY)) {
if (port->x_char) {
SCCwrite(TX_DATA_REG, port->x_char);
port->x_char = 0;
}
else if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
port->gs.tty->hw_stopped)
break;
else {
SCCwrite(TX_DATA_REG, port->gs.xmit_buf[port->gs.xmit_tail++]);
port->gs.xmit_tail = port->gs.xmit_tail & (SERIAL_XMIT_SIZE-1);
if (--port->gs.xmit_cnt <= 0)
break;
}
}
if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
port->gs.tty->hw_stopped) {
/* disable tx interrupts */
SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET); /* disable tx_int on next tx underrun? */
port->gs.flags &= ~GS_TX_INTEN;
}
if (port->gs.tty && port->gs.xmit_cnt <= port->gs.wakeup_chars)
tty_wakeup(port->gs.tty);
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
return IRQ_HANDLED;
}
static irqreturn_t scc_stat_int(int irq, void *data, struct pt_regs *fp)
{
struct scc_port *port = data;
unsigned channel = port->channel;
unsigned char last_sr, sr, changed;
SCC_ACCESS_INIT(port);
last_sr = scc_last_status_reg[channel];
sr = scc_last_status_reg[channel] = SCCread_NB(STATUS_REG);
changed = last_sr ^ sr;
if (changed & SR_DCD) {
port->c_dcd = !!(sr & SR_DCD);
if (!(port->gs.flags & ASYNC_CHECK_CD))
; /* Don't report DCD changes */
else if (port->c_dcd) {
wake_up_interruptible(&port->gs.open_wait);
}
else {
if (port->gs.tty)
tty_hangup (port->gs.tty);
}
}
SCCwrite(COMMAND_REG, CR_EXTSTAT_RESET);
SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
return IRQ_HANDLED;
}
/*---------------------------------------------------------------------------
* generic_serial.c callback funtions
*--------------------------------------------------------------------------*/
static void scc_disable_tx_interrupts(void *ptr)
{
struct scc_port *port = ptr;
unsigned long flags;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
SCCmod(INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
port->gs.flags &= ~GS_TX_INTEN;
local_irq_restore(flags);
}
static void scc_enable_tx_interrupts(void *ptr)
{
struct scc_port *port = ptr;
unsigned long flags;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
SCCmod(INT_AND_DMA_REG, 0xff, IDR_TX_INT_ENAB);
/* restart the transmitter */
scc_tx_int (0, port, 0);
local_irq_restore(flags);
}
static void scc_disable_rx_interrupts(void *ptr)
{
struct scc_port *port = ptr;
unsigned long flags;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
SCCmod(INT_AND_DMA_REG,
~(IDR_RX_INT_MASK|IDR_PARERR_AS_SPCOND|IDR_EXTSTAT_INT_ENAB), 0);
local_irq_restore(flags);
}
static void scc_enable_rx_interrupts(void *ptr)
{
struct scc_port *port = ptr;
unsigned long flags;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
SCCmod(INT_AND_DMA_REG, 0xff,
IDR_EXTSTAT_INT_ENAB|IDR_PARERR_AS_SPCOND|IDR_RX_INT_ALL);
local_irq_restore(flags);
}
static int scc_get_CD(void *ptr)
{
struct scc_port *port = ptr;
unsigned channel = port->channel;
return !!(scc_last_status_reg[channel] & SR_DCD);
}
static void scc_shutdown_port(void *ptr)
{
struct scc_port *port = ptr;
port->gs.flags &= ~ GS_ACTIVE;
if (port->gs.tty && port->gs.tty->termios->c_cflag & HUPCL) {
scc_setsignals (port, 0, 0);
}
}
static int scc_set_real_termios (void *ptr)
{
/* the SCC has char sizes 5,7,6,8 in that order! */
static int chsize_map[4] = { 0, 2, 1, 3 };
unsigned cflag, baud, chsize, channel, brgval = 0;
unsigned long flags;
struct scc_port *port = ptr;
SCC_ACCESS_INIT(port);
if (!port->gs.tty || !port->gs.tty->termios) return 0;
channel = port->channel;
if (channel == CHANNEL_A)
return 0; /* Settings controlled by boot PROM */
cflag = port->gs.tty->termios->c_cflag;
baud = port->gs.baud;
chsize = (cflag & CSIZE) >> 4;
if (baud == 0) {
/* speed == 0 -> drop DTR */
local_irq_save(flags);
SCCmod(TX_CTRL_REG, ~TCR_DTR, 0);
local_irq_restore(flags);
return 0;
}
else if ((MACH_IS_MVME16x && (baud < 50 || baud > 38400)) ||
(MACH_IS_MVME147 && (baud < 50 || baud > 19200)) ||
(MACH_IS_BVME6000 &&(baud < 50 || baud > 76800))) {
printk(KERN_NOTICE "SCC: Bad speed requested, %d\n", baud);
return 0;
}
if (cflag & CLOCAL)
port->gs.flags &= ~ASYNC_CHECK_CD;
else
port->gs.flags |= ASYNC_CHECK_CD;
#ifdef CONFIG_MVME147_SCC
if (MACH_IS_MVME147)
brgval = (M147_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
#endif
#ifdef CONFIG_MVME162_SCC
if (MACH_IS_MVME16x)
brgval = (MVME_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
#endif
#ifdef CONFIG_BVME6000_SCC
if (MACH_IS_BVME6000)
brgval = (BVME_SCC_RTxC + baud/2) / (16 * 2 * baud) - 2;
#endif
/* Now we have all parameters and can go to set them: */
local_irq_save(flags);
/* receiver's character size and auto-enables */
SCCmod(RX_CTRL_REG, ~(RCR_CHSIZE_MASK|RCR_AUTO_ENAB_MODE),
(chsize_map[chsize] << 6) |
((cflag & CRTSCTS) ? RCR_AUTO_ENAB_MODE : 0));
/* parity and stop bits (both, Tx and Rx), clock mode never changes */
SCCmod (AUX1_CTRL_REG,
~(A1CR_PARITY_MASK | A1CR_MODE_MASK),
((cflag & PARENB
? (cflag & PARODD ? A1CR_PARITY_ODD : A1CR_PARITY_EVEN)
: A1CR_PARITY_NONE)
| (cflag & CSTOPB ? A1CR_MODE_ASYNC_2 : A1CR_MODE_ASYNC_1)));
/* sender's character size, set DTR for valid baud rate */
SCCmod(TX_CTRL_REG, ~TCR_CHSIZE_MASK, chsize_map[chsize] << 5 | TCR_DTR);
/* clock sources never change */
/* disable BRG before changing the value */
SCCmod(DPLL_CTRL_REG, ~DCR_BRG_ENAB, 0);
/* BRG value */
SCCwrite(TIMER_LOW_REG, brgval & 0xff);
SCCwrite(TIMER_HIGH_REG, (brgval >> 8) & 0xff);
/* BRG enable, and clock source never changes */
SCCmod(DPLL_CTRL_REG, 0xff, DCR_BRG_ENAB);
local_irq_restore(flags);
return 0;
}
static int scc_chars_in_buffer (void *ptr)
{
struct scc_port *port = ptr;
SCC_ACCESS_INIT(port);
return (SCCread (SPCOND_STATUS_REG) & SCSR_ALL_SENT) ? 0 : 1;
}
/* Comment taken from sx.c (2.4.0):
I haven't the foggiest why the decrement use count has to happen
here. The whole linux serial drivers stuff needs to be redesigned.
My guess is that this is a hack to minimize the impact of a bug
elsewhere. Thinking about it some more. (try it sometime) Try
running minicom on a serial port that is driven by a modularized
driver. Have the modem hangup. Then remove the driver module. Then
exit minicom. I expect an "oops". -- REW */
static void scc_hungup(void *ptr)
{
scc_disable_tx_interrupts(ptr);
scc_disable_rx_interrupts(ptr);
}
static void scc_close(void *ptr)
{
scc_disable_tx_interrupts(ptr);
scc_disable_rx_interrupts(ptr);
}
/*---------------------------------------------------------------------------
* Internal support functions
*--------------------------------------------------------------------------*/
static void scc_setsignals(struct scc_port *port, int dtr, int rts)
{
unsigned long flags;
unsigned char t;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
t = SCCread(TX_CTRL_REG);
if (dtr >= 0) t = dtr? (t | TCR_DTR): (t & ~TCR_DTR);
if (rts >= 0) t = rts? (t | TCR_RTS): (t & ~TCR_RTS);
SCCwrite(TX_CTRL_REG, t);
local_irq_restore(flags);
}
static void scc_send_xchar(struct tty_struct *tty, char ch)
{
struct scc_port *port = (struct scc_port *)tty->driver_data;
port->x_char = ch;
if (ch)
scc_enable_tx_interrupts(port);
}
/*---------------------------------------------------------------------------
* Driver entrypoints referenced from above
*--------------------------------------------------------------------------*/
static int scc_open (struct tty_struct * tty, struct file * filp)
{
int line = tty->index;
int retval;
struct scc_port *port = &scc_ports[line];
int i, channel = port->channel;
unsigned long flags;
SCC_ACCESS_INIT(port);
#if defined(CONFIG_MVME162_SCC) || defined(CONFIG_MVME147_SCC)
static const struct {
unsigned reg, val;
} mvme_init_tab[] = {
/* Values for MVME162 and MVME147 */
/* no parity, 1 stop bit, async, 1:16 */
{ AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
/* parity error is special cond, ints disabled, no DMA */
{ INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
/* Rx 8 bits/char, no auto enable, Rx off */
{ RX_CTRL_REG, RCR_CHSIZE_8 },
/* DTR off, Tx 8 bits/char, RTS off, Tx off */
{ TX_CTRL_REG, TCR_CHSIZE_8 },
/* special features off */
{ AUX2_CTRL_REG, 0 },
{ CLK_CTRL_REG, CCR_RXCLK_BRG | CCR_TXCLK_BRG },
{ DPLL_CTRL_REG, DCR_BRG_ENAB | DCR_BRG_USE_PCLK },
/* Start Rx */
{ RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
/* Start Tx */
{ TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
/* Ext/Stat ints: DCD only */
{ INT_CTRL_REG, ICR_ENAB_DCD_INT },
/* Reset Ext/Stat ints */
{ COMMAND_REG, CR_EXTSTAT_RESET },
/* ...again */
{ COMMAND_REG, CR_EXTSTAT_RESET },
};
#endif
#if defined(CONFIG_BVME6000_SCC)
static const struct {
unsigned reg, val;
} bvme_init_tab[] = {
/* Values for BVME6000 */
/* no parity, 1 stop bit, async, 1:16 */
{ AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
/* parity error is special cond, ints disabled, no DMA */
{ INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
/* Rx 8 bits/char, no auto enable, Rx off */
{ RX_CTRL_REG, RCR_CHSIZE_8 },
/* DTR off, Tx 8 bits/char, RTS off, Tx off */
{ TX_CTRL_REG, TCR_CHSIZE_8 },
/* special features off */
{ AUX2_CTRL_REG, 0 },
{ CLK_CTRL_REG, CCR_RTxC_XTAL | CCR_RXCLK_BRG | CCR_TXCLK_BRG },
{ DPLL_CTRL_REG, DCR_BRG_ENAB },
/* Start Rx */
{ RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
/* Start Tx */
{ TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
/* Ext/Stat ints: DCD only */
{ INT_CTRL_REG, ICR_ENAB_DCD_INT },
/* Reset Ext/Stat ints */
{ COMMAND_REG, CR_EXTSTAT_RESET },
/* ...again */
{ COMMAND_REG, CR_EXTSTAT_RESET },
};
#endif
if (!(port->gs.flags & ASYNC_INITIALIZED)) {
local_irq_save(flags);
#if defined(CONFIG_MVME147_SCC) || defined(CONFIG_MVME162_SCC)
if (MACH_IS_MVME147 || MACH_IS_MVME16x) {
for (i = 0; i < ARRAY_SIZE(mvme_init_tab); ++i)
SCCwrite(mvme_init_tab[i].reg, mvme_init_tab[i].val);
}
#endif
#if defined(CONFIG_BVME6000_SCC)
if (MACH_IS_BVME6000) {
for (i = 0; i < ARRAY_SIZE(bvme_init_tab); ++i)
SCCwrite(bvme_init_tab[i].reg, bvme_init_tab[i].val);
}
#endif
/* remember status register for detection of DCD and CTS changes */
scc_last_status_reg[channel] = SCCread(STATUS_REG);
port->c_dcd = 0; /* Prevent initial 1->0 interrupt */
scc_setsignals (port, 1,1);
local_irq_restore(flags);
}
tty->driver_data = port;
port->gs.tty = tty;
port->gs.count++;
retval = gs_init_port(&port->gs);
if (retval) {
port->gs.count--;
return retval;
}
port->gs.flags |= GS_ACTIVE;
retval = gs_block_til_ready(port, filp);
if (retval) {
port->gs.count--;
return retval;
}
port->c_dcd = scc_get_CD (port);
scc_enable_rx_interrupts(port);
return 0;
}
static void scc_throttle (struct tty_struct * tty)
{
struct scc_port *port = (struct scc_port *)tty->driver_data;
unsigned long flags;
SCC_ACCESS_INIT(port);
if (tty->termios->c_cflag & CRTSCTS) {
local_irq_save(flags);
SCCmod(TX_CTRL_REG, ~TCR_RTS, 0);
local_irq_restore(flags);
}
if (I_IXOFF(tty))
scc_send_xchar(tty, STOP_CHAR(tty));
}
static void scc_unthrottle (struct tty_struct * tty)
{
struct scc_port *port = (struct scc_port *)tty->driver_data;
unsigned long flags;
SCC_ACCESS_INIT(port);
if (tty->termios->c_cflag & CRTSCTS) {
local_irq_save(flags);
SCCmod(TX_CTRL_REG, 0xff, TCR_RTS);
local_irq_restore(flags);
}
if (I_IXOFF(tty))
scc_send_xchar(tty, START_CHAR(tty));
}
static int scc_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
return -ENOIOCTLCMD;
}
static void scc_break_ctl(struct tty_struct *tty, int break_state)
{
struct scc_port *port = (struct scc_port *)tty->driver_data;
unsigned long flags;
SCC_ACCESS_INIT(port);
local_irq_save(flags);
SCCmod(TX_CTRL_REG, ~TCR_SEND_BREAK,
break_state ? TCR_SEND_BREAK : 0);
local_irq_restore(flags);
}
/*---------------------------------------------------------------------------
* Serial console stuff...
*--------------------------------------------------------------------------*/
#define scc_delay() do { __asm__ __volatile__ (" nop; nop"); } while (0)
static void scc_ch_write (char ch)
{
volatile char *p = NULL;
#ifdef CONFIG_MVME147_SCC
if (MACH_IS_MVME147)
p = (volatile char *)M147_SCC_A_ADDR;
#endif
#ifdef CONFIG_MVME162_SCC
if (MACH_IS_MVME16x)
p = (volatile char *)MVME_SCC_A_ADDR;
#endif
#ifdef CONFIG_BVME6000_SCC
if (MACH_IS_BVME6000)
p = (volatile char *)BVME_SCC_A_ADDR;
#endif
do {
scc_delay();
}
while (!(*p & 4));
scc_delay();
*p = 8;
scc_delay();
*p = ch;
}
/* The console must be locked when we get here. */
static void scc_console_write (struct console *co, const char *str, unsigned count)
{
unsigned long flags;
local_irq_save(flags);
while (count--)
{
if (*str == '\n')
scc_ch_write ('\r');
scc_ch_write (*str++);
}
local_irq_restore(flags);
}
static struct tty_driver *scc_console_device(struct console *c, int *index)
{
*index = c->index;
return scc_driver;
}
static int __init scc_console_setup(struct console *co, char *options)
{
return 0;
}
static struct console sercons = {
.name = "ttyS",
.write = scc_console_write,
.device = scc_console_device,
.setup = scc_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static int __init vme_scc_console_init(void)
{
if (vme_brdtype == VME_TYPE_MVME147 ||
vme_brdtype == VME_TYPE_MVME162 ||
vme_brdtype == VME_TYPE_MVME172 ||
vme_brdtype == VME_TYPE_BVME4000 ||
vme_brdtype == VME_TYPE_BVME6000)
register_console(&sercons);
return 0;
}
console_initcall(vme_scc_console_init);
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