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linux/drivers/char/vme_scc.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

1043 lines
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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/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);
static irqreturn_t scc_rx_int(int irq, void *data);
static irqreturn_t scc_stat_int(int irq, void *data);
static irqreturn_t scc_spcond_int(int irq, void *data);
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 const 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->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_mutex = 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, IRQF_DISABLED,
"SCC-A TX", port);
request_irq(MVME147_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-A status", port);
request_irq(MVME147_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
"SCC-A RX", port);
request_irq(MVME147_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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, IRQF_DISABLED,
"SCC-B TX", port);
request_irq(MVME147_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-B status", port);
request_irq(MVME147_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
"SCC-B RX", port);
request_irq(MVME147_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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, IRQF_DISABLED,
"SCC-A TX", port);
request_irq(MVME162_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-A status", port);
request_irq(MVME162_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
"SCC-A RX", port);
request_irq(MVME162_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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, IRQF_DISABLED,
"SCC-B TX", port);
request_irq(MVME162_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-B status", port);
request_irq(MVME162_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
"SCC-B RX", port);
request_irq(MVME162_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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, IRQF_DISABLED,
"SCC-A TX", port);
request_irq(BVME_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-A status", port);
request_irq(BVME_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
"SCC-A RX", port);
request_irq(BVME_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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, IRQF_DISABLED,
"SCC-B TX", port);
request_irq(BVME_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
"SCC-B status", port);
request_irq(BVME_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
"SCC-B RX", port);
request_irq(BVME_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
"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)
{
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);
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 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 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 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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