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cb14c4d641
kernel-ark/arch/ppc64/kernel/udbg.c
Milton Miller cb14c4d641 [PATCH] ppc64: Clean up CR handling 
Make the 16550 and real mode 16550 use tail recursion like the scc code
instead of repeating the routine except for the character sent.

Gcc recoginizes the tail recursion and handles it efficently without
stack allocations.  The maple real putc shrinks from 188 to 104 bytes
of instructions.  udbg_putc drops from 188 to 140 bytes.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-06 16:07:36 +10:00

353 lines
7.5 KiB
C
Raw Blame History

/*
* NS16550 Serial Port (uart) debugging stuff.
*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <stdarg.h>
#define WANT_PPCDBG_TAB /* Only defined here */
#include <linux/config.h>
#include <linux/types.h>
#include <asm/ppcdebug.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pmac_feature.h>
extern u8 real_readb(volatile u8 __iomem *addr);
extern void real_writeb(u8 data, volatile u8 __iomem *addr);
struct NS16550 {
/* this struct must be packed */
unsigned char rbr; /* 0 */
unsigned char ier; /* 1 */
unsigned char fcr; /* 2 */
unsigned char lcr; /* 3 */
unsigned char mcr; /* 4 */
unsigned char lsr; /* 5 */
unsigned char msr; /* 6 */
unsigned char scr; /* 7 */
};
#define thr rbr
#define iir fcr
#define dll rbr
#define dlm ier
#define dlab lcr
#define LSR_DR 0x01 /* Data ready */
#define LSR_OE 0x02 /* Overrun */
#define LSR_PE 0x04 /* Parity error */
#define LSR_FE 0x08 /* Framing error */
#define LSR_BI 0x10 /* Break */
#define LSR_THRE 0x20 /* Xmit holding register empty */
#define LSR_TEMT 0x40 /* Xmitter empty */
#define LSR_ERR 0x80 /* Error */
static volatile struct NS16550 __iomem *udbg_comport;
void udbg_init_uart(void __iomem *comport, unsigned int speed)
{
u16 dll = speed ? (115200 / speed) : 12;
if (comport) {
udbg_comport = (struct NS16550 __iomem *)comport;
out_8(&udbg_comport->lcr, 0x00);
out_8(&udbg_comport->ier, 0xff);
out_8(&udbg_comport->ier, 0x00);
out_8(&udbg_comport->lcr, 0x80); /* Access baud rate */
out_8(&udbg_comport->dll, dll & 0xff); /* 1 = 115200, 2 = 57600,
3 = 38400, 12 = 9600 baud */
out_8(&udbg_comport->dlm, dll >> 8); /* dll >> 8 which should be zero
for fast rates; */
out_8(&udbg_comport->lcr, 0x03); /* 8 data, 1 stop, no parity */
out_8(&udbg_comport->mcr, 0x03); /* RTS/DTR */
out_8(&udbg_comport->fcr ,0x07); /* Clear & enable FIFOs */
}
}
#ifdef CONFIG_PPC_PMAC
#define SCC_TXRDY 4
#define SCC_RXRDY 1
static volatile u8 __iomem *sccc;
static volatile u8 __iomem *sccd;
static unsigned char scc_inittab[] = {
13, 0, /* set baud rate divisor */
12, 0,
14, 1, /* baud rate gen enable, src=rtxc */
11, 0x50, /* clocks = br gen */
5, 0xea, /* tx 8 bits, assert DTR & RTS */
4, 0x46, /* x16 clock, 1 stop */
3, 0xc1, /* rx enable, 8 bits */
};
void udbg_init_scc(struct device_node *np)
{
u32 *reg;
unsigned long addr;
int i, x;
if (np == NULL)
np = of_find_node_by_name(NULL, "escc");
if (np == NULL || np->parent == NULL)
return;
udbg_printf("found SCC...\n");
/* Get address within mac-io ASIC */
reg = (u32 *)get_property(np, "reg", NULL);
if (reg == NULL)
return;
addr = reg[0];
udbg_printf("local addr: %lx\n", addr);
/* Get address of mac-io PCI itself */
reg = (u32 *)get_property(np->parent, "assigned-addresses", NULL);
if (reg == NULL)
return;
addr += reg[2];
udbg_printf("final addr: %lx\n", addr);
/* Setup for 57600 8N1 */
addr += 0x20;
sccc = (volatile u8 * __iomem) ioremap(addr & PAGE_MASK, PAGE_SIZE) ;
sccc += addr & ~PAGE_MASK;
sccd = sccc + 0x10;
udbg_printf("ioremap result sccc: %p\n", sccc);
mb();
for (i = 20000; i != 0; --i)
x = in_8(sccc);
out_8(sccc, 0x09); /* reset A or B side */
out_8(sccc, 0xc0);
for (i = 0; i < sizeof(scc_inittab); ++i)
out_8(sccc, scc_inittab[i]);
ppc_md.udbg_putc = udbg_putc;
ppc_md.udbg_getc = udbg_getc;
ppc_md.udbg_getc_poll = udbg_getc_poll;
udbg_puts("Hello World !\n");
}
#endif /* CONFIG_PPC_PMAC */
#ifdef CONFIG_PPC_PMAC
static void udbg_real_putc(unsigned char c)
{
while ((real_readb(sccc) & SCC_TXRDY) == 0)
;
real_writeb(c, sccd);
if (c == '\n')
udbg_real_putc('\r');
}
void udbg_init_pmac_realmode(void)
{
sccc = (volatile u8 __iomem *)0x80013020ul;
sccd = (volatile u8 __iomem *)0x80013030ul;
ppc_md.udbg_putc = udbg_real_putc;
ppc_md.udbg_getc = NULL;
ppc_md.udbg_getc_poll = NULL;
}
#endif /* CONFIG_PPC_PMAC */
#ifdef CONFIG_PPC_MAPLE
void udbg_maple_real_putc(unsigned char c)
{
if (udbg_comport) {
while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
/* wait for idle */;
real_writeb(c, &udbg_comport->thr); eieio();
if (c == '\n')
udbg_maple_real_putc('\r');
}
}
void udbg_init_maple_realmode(void)
{
udbg_comport = (volatile struct NS16550 __iomem *)0xf40003f8;
ppc_md.udbg_putc = udbg_maple_real_putc;
ppc_md.udbg_getc = NULL;
ppc_md.udbg_getc_poll = NULL;
}
#endif /* CONFIG_PPC_MAPLE */
void udbg_putc(unsigned char c)
{
if (udbg_comport) {
while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
/* wait for idle */;
out_8(&udbg_comport->thr, c);
if (c == '\n')
udbg_putc('\r');
}
#ifdef CONFIG_PPC_PMAC
else if (sccc) {
while ((in_8(sccc) & SCC_TXRDY) == 0)
;
out_8(sccd, c);
if (c == '\n')
udbg_putc('\r');
}
#endif /* CONFIG_PPC_PMAC */
}
int udbg_getc_poll(void)
{
if (udbg_comport) {
if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0)
return in_8(&udbg_comport->rbr);
else
return -1;
}
#ifdef CONFIG_PPC_PMAC
else if (sccc) {
if ((in_8(sccc) & SCC_RXRDY) != 0)
return in_8(sccd);
else
return -1;
}
#endif /* CONFIG_PPC_PMAC */
return -1;
}
unsigned char udbg_getc(void)
{
if (udbg_comport) {
while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0)
/* wait for char */;
return in_8(&udbg_comport->rbr);
}
#ifdef CONFIG_PPC_PMAC
else if (sccc) {
while ((in_8(sccc) & SCC_RXRDY) == 0)
;
return in_8(sccd);
}
#endif /* CONFIG_PPC_PMAC */
return 0;
}
void udbg_puts(const char *s)
{
if (ppc_md.udbg_putc) {
char c;
if (s && *s != '\0') {
while ((c = *s++) != '\0')
ppc_md.udbg_putc(c);
}
}
#if 0
else {
printk("%s", s);
}
#endif
}
int udbg_write(const char *s, int n)
{
int remain = n;
char c;
if (!ppc_md.udbg_putc)
return 0;
if (s && *s != '\0') {
while (((c = *s++) != '\0') && (remain-- > 0)) {
ppc_md.udbg_putc(c);
}
}
return n - remain;
}
int udbg_read(char *buf, int buflen)
{
char c, *p = buf;
int i;
if (!ppc_md.udbg_getc)
return 0;
for (i = 0; i < buflen; ++i) {
do {
c = ppc_md.udbg_getc();
} while (c == 0x11 || c == 0x13);
if (c == 0)
break;
*p++ = c;
}
return i;
}
void udbg_console_write(struct console *con, const char *s, unsigned int n)
{
udbg_write(s, n);
}
#define UDBG_BUFSIZE 256
void udbg_printf(const char *fmt, ...)
{
unsigned char buf[UDBG_BUFSIZE];
va_list args;
va_start(args, fmt);
vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
udbg_puts(buf);
va_end(args);
}
/* Special print used by PPCDBG() macro */
void udbg_ppcdbg(unsigned long debug_flags, const char *fmt, ...)
{
unsigned long active_debugs = debug_flags & ppc64_debug_switch;
if (active_debugs) {
va_list ap;
unsigned char buf[UDBG_BUFSIZE];
unsigned long i, len = 0;
for (i=0; i < PPCDBG_NUM_FLAGS; i++) {
if (((1U << i) & active_debugs) &&
trace_names[i]) {
len += strlen(trace_names[i]);
udbg_puts(trace_names[i]);
break;
}
}
snprintf(buf, UDBG_BUFSIZE, " [%s]: ", current->comm);
len += strlen(buf);
udbg_puts(buf);
while (len < 18) {
udbg_puts(" ");
len++;
}
va_start(ap, fmt);
vsnprintf(buf, UDBG_BUFSIZE, fmt, ap);
udbg_puts(buf);
va_end(ap);
}
}
unsigned long udbg_ifdebug(unsigned long flags)
{
return (flags & ppc64_debug_switch);
}
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