diff options
Diffstat (limited to 'arch/powerpc/kernel/udbg_16550.c')
| -rw-r--r-- | arch/powerpc/kernel/udbg_16550.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c new file mode 100644 index 00000000000..9313574ab93 --- /dev/null +++ b/arch/powerpc/kernel/udbg_16550.c @@ -0,0 +1,123 @@ +/* + * udbg for for NS16550 compatable serial ports + * + * 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/io.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; + +static void udbg_550_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_550_putc('\r'); + } +} + +static int udbg_550_getc_poll(void) +{ + if (udbg_comport) { + if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0) + return in_8(&udbg_comport->rbr); + else + return -1; + } + return -1; +} + +static unsigned char udbg_550_getc(void) +{ + if (udbg_comport) { + while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0) + /* wait for char */; + return in_8(&udbg_comport->rbr); + } + return 0; +} + +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 */ + udbg_putc = udbg_550_putc; + udbg_getc = udbg_550_getc; + udbg_getc_poll = udbg_550_getc_poll; + } +} + +#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; + + udbg_putc = udbg_maple_real_putc; + udbg_getc = NULL; + udbg_getc_poll = NULL; +} +#endif /* CONFIG_PPC_MAPLE */ |