mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
180 lines
3.8 KiB
180 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* udbg for zilog scc ports as found on Apple PowerMacs |
|
* |
|
* Copyright (C) 2001-2005 PPC 64 Team, IBM Corp |
|
*/ |
|
#include <linux/types.h> |
|
#include <asm/udbg.h> |
|
#include <asm/processor.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); |
|
|
|
#define SCC_TXRDY 4 |
|
#define SCC_RXRDY 1 |
|
|
|
static volatile u8 __iomem *sccc; |
|
static volatile u8 __iomem *sccd; |
|
|
|
static void udbg_scc_putc(char c) |
|
{ |
|
if (sccc) { |
|
while ((in_8(sccc) & SCC_TXRDY) == 0) |
|
; |
|
out_8(sccd, c); |
|
if (c == '\n') |
|
udbg_scc_putc('\r'); |
|
} |
|
} |
|
|
|
static int udbg_scc_getc_poll(void) |
|
{ |
|
if (sccc) { |
|
if ((in_8(sccc) & SCC_RXRDY) != 0) |
|
return in_8(sccd); |
|
else |
|
return -1; |
|
} |
|
return -1; |
|
} |
|
|
|
static int udbg_scc_getc(void) |
|
{ |
|
if (sccc) { |
|
while ((in_8(sccc) & SCC_RXRDY) == 0) |
|
; |
|
return in_8(sccd); |
|
} |
|
return -1; |
|
} |
|
|
|
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_scc_init(int force_scc) |
|
{ |
|
const u32 *reg; |
|
unsigned long addr; |
|
struct device_node *stdout = NULL, *escc = NULL, *macio = NULL; |
|
struct device_node *ch, *ch_def = NULL, *ch_a = NULL; |
|
const char *path; |
|
int i; |
|
|
|
escc = of_find_node_by_name(NULL, "escc"); |
|
if (escc == NULL) |
|
goto bail; |
|
macio = of_get_parent(escc); |
|
if (macio == NULL) |
|
goto bail; |
|
path = of_get_property(of_chosen, "linux,stdout-path", NULL); |
|
if (path != NULL) |
|
stdout = of_find_node_by_path(path); |
|
for_each_child_of_node(escc, ch) { |
|
if (ch == stdout) |
|
ch_def = of_node_get(ch); |
|
if (of_node_name_eq(ch, "ch-a")) |
|
ch_a = of_node_get(ch); |
|
} |
|
if (ch_def == NULL && !force_scc) |
|
goto bail; |
|
|
|
ch = ch_def ? ch_def : ch_a; |
|
|
|
/* Get address within mac-io ASIC */ |
|
reg = of_get_property(escc, "reg", NULL); |
|
if (reg == NULL) |
|
goto bail; |
|
addr = reg[0]; |
|
|
|
/* Get address of mac-io PCI itself */ |
|
reg = of_get_property(macio, "assigned-addresses", NULL); |
|
if (reg == NULL) |
|
goto bail; |
|
addr += reg[2]; |
|
|
|
/* Lock the serial port */ |
|
pmac_call_feature(PMAC_FTR_SCC_ENABLE, ch, |
|
PMAC_SCC_ASYNC | PMAC_SCC_FLAG_XMON, 1); |
|
|
|
if (ch == ch_a) |
|
addr += 0x20; |
|
sccc = ioremap(addr & PAGE_MASK, PAGE_SIZE) ; |
|
sccc += addr & ~PAGE_MASK; |
|
sccd = sccc + 0x10; |
|
|
|
mb(); |
|
|
|
for (i = 20000; i != 0; --i) |
|
in_8(sccc); |
|
out_8(sccc, 0x09); /* reset A or B side */ |
|
out_8(sccc, 0xc0); |
|
|
|
/* If SCC was the OF output port, read the BRG value, else |
|
* Setup for 38400 or 57600 8N1 depending on the machine |
|
*/ |
|
if (ch_def != NULL) { |
|
out_8(sccc, 13); |
|
scc_inittab[1] = in_8(sccc); |
|
out_8(sccc, 12); |
|
scc_inittab[3] = in_8(sccc); |
|
} else if (of_machine_is_compatible("RackMac1,1") |
|
|| of_machine_is_compatible("RackMac1,2") |
|
|| of_machine_is_compatible("MacRISC4")) { |
|
/* Xserves and G5s default to 57600 */ |
|
scc_inittab[1] = 0; |
|
scc_inittab[3] = 0; |
|
} else { |
|
/* Others default to 38400 */ |
|
scc_inittab[1] = 0; |
|
scc_inittab[3] = 1; |
|
} |
|
|
|
for (i = 0; i < sizeof(scc_inittab); ++i) |
|
out_8(sccc, scc_inittab[i]); |
|
|
|
|
|
udbg_putc = udbg_scc_putc; |
|
udbg_getc = udbg_scc_getc; |
|
udbg_getc_poll = udbg_scc_getc_poll; |
|
|
|
udbg_puts("Hello World !\n"); |
|
|
|
bail: |
|
of_node_put(macio); |
|
of_node_put(escc); |
|
of_node_put(stdout); |
|
of_node_put(ch_def); |
|
of_node_put(ch_a); |
|
} |
|
|
|
#ifdef CONFIG_PPC64 |
|
static void udbg_real_scc_putc(char c) |
|
{ |
|
while ((real_readb(sccc) & SCC_TXRDY) == 0) |
|
; |
|
real_writeb(c, sccd); |
|
if (c == '\n') |
|
udbg_real_scc_putc('\r'); |
|
} |
|
|
|
void __init udbg_init_pmac_realmode(void) |
|
{ |
|
sccc = (volatile u8 __iomem *)0x80013020ul; |
|
sccd = (volatile u8 __iomem *)0x80013030ul; |
|
|
|
udbg_putc = udbg_real_scc_putc; |
|
udbg_getc = NULL; |
|
udbg_getc_poll = NULL; |
|
} |
|
#endif /* CONFIG_PPC64 */
|
|
|