2 * 16550 serial console support.
4 * Original copied from <file:arch/ppc/boot/common/ns16550.c>
5 * (which had no copyright)
6 * Modifications: 2006 (c) MontaVista Software, Inc.
8 * Modified by: Mark A. Greer <mgreer@mvista.com>
18 #define UART_DLL 0 /* Out: Divisor Latch Low */
19 #define UART_DLM 1 /* Out: Divisor Latch High */
20 #define UART_FCR 2 /* Out: FIFO Control Register */
21 #define UART_LCR 3 /* Out: Line Control Register */
22 #define UART_MCR 4 /* Out: Modem Control Register */
23 #define UART_LSR 5 /* In: Line Status Register */
24 #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
25 #define UART_LSR_DR 0x01 /* Receiver data ready */
26 #define UART_MSR 6 /* In: Modem Status Register */
27 #define UART_SCR 7 /* I/O: Scratch Register */
29 static unsigned char *reg_base
;
32 static int ns16550_open(void)
34 out_8(reg_base
+ (UART_FCR
<< reg_shift
), 0x06);
38 static void ns16550_putc(unsigned char c
)
40 while ((in_8(reg_base
+ (UART_LSR
<< reg_shift
)) & UART_LSR_THRE
) == 0);
44 static unsigned char ns16550_getc(void)
46 while ((in_8(reg_base
+ (UART_LSR
<< reg_shift
)) & UART_LSR_DR
) == 0);
47 return in_8(reg_base
);
50 static u8
ns16550_tstc(void)
52 return ((in_8(reg_base
+ (UART_LSR
<< reg_shift
)) & UART_LSR_DR
) != 0);
55 int ns16550_console_init(void *devp
, struct serial_console_data
*scdp
)
59 n
= getprop(devp
, "virtual-reg", ®_base
, sizeof(reg_base
));
60 if (n
!= sizeof(reg_base
))
63 n
= getprop(devp
, "reg-shift", ®_shift
, sizeof(reg_shift
));
64 if (n
!= sizeof(reg_shift
))
67 scdp
->open
= ns16550_open
;
68 scdp
->putc
= ns16550_putc
;
69 scdp
->getc
= ns16550_getc
;
70 scdp
->tstc
= ns16550_tstc
;