diff options
Diffstat (limited to 'arch/powerpc/platforms/powermac/udbg_scc.c')
| -rw-r--r-- | arch/powerpc/platforms/powermac/udbg_scc.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powermac/udbg_scc.c b/arch/powerpc/platforms/powermac/udbg_scc.c new file mode 100644 index 000000000000..e87d53acfb61 --- /dev/null +++ b/arch/powerpc/platforms/powermac/udbg_scc.c @@ -0,0 +1,165 @@ +/* + * udbg for for zilog scc ports as found on Apple PowerMacs + * + * Copyright (C) 2001-2005 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 <linux/config.h> +#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) +{ + u32 *reg; + unsigned long addr; + struct device_node *stdout = NULL, *escc = NULL, *macio = NULL; + struct device_node *ch, *ch_def = NULL, *ch_a = NULL; + char *path; + int i, x; + + escc = of_find_node_by_name(NULL, "escc"); + if (escc == NULL) + goto bail; + macio = of_get_parent(escc); + if (macio == NULL) + goto bail; + path = (char *)get_property(of_chosen, "linux,stdout-path", NULL); + if (path != NULL) + stdout = of_find_node_by_path(path); + for (ch = NULL; (ch = of_get_next_child(escc, ch)) != NULL;) { + if (ch == stdout) + ch_def = of_node_get(ch); + if (strcmp(ch->name, "ch-a") == 0) + 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 = (u32 *)get_property(escc, "reg", NULL); + if (reg == NULL) + goto bail; + addr = reg[0]; + + /* Get address of mac-io PCI itself */ + reg = (u32 *)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); + + + /* Setup for 57600 8N1 */ + if (ch == ch_a) + addr += 0x20; + sccc = (volatile u8 * __iomem) ioremap(addr & PAGE_MASK, PAGE_SIZE) ; + sccc += addr & ~PAGE_MASK; + sccd = sccc + 0x10; + + 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]); + + 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 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 */ |