Commit | Line | Data |
---|---|---|
d58577d8 JL |
1 | /* |
2 | * The platform specific code for virtex devices since a boot loader is not | |
3 | * always used. | |
4 | * | |
5 | * (C) Copyright 2008 Xilinx, Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published | |
9 | * by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include "ops.h" | |
13 | #include "io.h" | |
14 | #include "stdio.h" | |
15 | ||
16 | #define UART_DLL 0 /* Out: Divisor Latch Low */ | |
17 | #define UART_DLM 1 /* Out: Divisor Latch High */ | |
18 | #define UART_FCR 2 /* Out: FIFO Control Register */ | |
19 | #define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */ | |
20 | #define UART_FCR_CLEAR_XMIT 0x04 /* Clear the XMIT FIFO */ | |
21 | #define UART_LCR 3 /* Out: Line Control Register */ | |
22 | #define UART_MCR 4 /* Out: Modem Control Register */ | |
23 | #define UART_MCR_RTS 0x02 /* RTS complement */ | |
24 | #define UART_MCR_DTR 0x01 /* DTR complement */ | |
25 | #define UART_LCR_DLAB 0x80 /* Divisor latch access bit */ | |
26 | #define UART_LCR_WLEN8 0x03 /* Wordlength: 8 bits */ | |
27 | ||
28 | static int virtex_ns16550_console_init(void *devp) | |
29 | { | |
30 | unsigned char *reg_base; | |
31 | u32 reg_shift, reg_offset, clk, spd; | |
32 | u16 divisor; | |
33 | int n; | |
34 | ||
35 | if (dt_get_virtual_reg(devp, (void **)®_base, 1) < 1) | |
36 | return -1; | |
37 | ||
38 | n = getprop(devp, "reg-offset", ®_offset, sizeof(reg_offset)); | |
39 | if (n == sizeof(reg_offset)) | |
40 | reg_base += reg_offset; | |
41 | ||
42 | n = getprop(devp, "reg-shift", ®_shift, sizeof(reg_shift)); | |
43 | if (n != sizeof(reg_shift)) | |
44 | reg_shift = 0; | |
45 | ||
46 | n = getprop(devp, "current-speed", (void *)&spd, sizeof(spd)); | |
47 | if (n != sizeof(spd)) | |
48 | spd = 9600; | |
49 | ||
50 | /* should there be a default clock rate?*/ | |
51 | n = getprop(devp, "clock-frequency", (void *)&clk, sizeof(clk)); | |
52 | if (n != sizeof(clk)) | |
53 | return -1; | |
54 | ||
55 | divisor = clk / (16 * spd); | |
56 | ||
57 | /* Access baud rate */ | |
58 | out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_DLAB); | |
59 | ||
60 | /* Baud rate based on input clock */ | |
61 | out_8(reg_base + (UART_DLL << reg_shift), divisor & 0xFF); | |
62 | out_8(reg_base + (UART_DLM << reg_shift), divisor >> 8); | |
63 | ||
64 | /* 8 data, 1 stop, no parity */ | |
65 | out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_WLEN8); | |
66 | ||
67 | /* RTS/DTR */ | |
68 | out_8(reg_base + (UART_MCR << reg_shift), UART_MCR_RTS | UART_MCR_DTR); | |
69 | ||
70 | /* Clear transmitter and receiver */ | |
71 | out_8(reg_base + (UART_FCR << reg_shift), | |
72 | UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); | |
73 | return 0; | |
74 | } | |
75 | ||
76 | /* For virtex, the kernel may be loaded without using a bootloader and if so | |
77 | some UARTs need more setup than is provided in the normal console init | |
78 | */ | |
79 | int platform_specific_init(void) | |
80 | { | |
81 | void *devp; | |
82 | char devtype[MAX_PROP_LEN]; | |
83 | char path[MAX_PATH_LEN]; | |
84 | ||
85 | devp = finddevice("/chosen"); | |
86 | if (devp == NULL) | |
87 | return -1; | |
88 | ||
89 | if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) { | |
90 | devp = finddevice(path); | |
91 | if (devp == NULL) | |
92 | return -1; | |
93 | ||
94 | if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0) | |
95 | && !strcmp(devtype, "serial") | |
96 | && (dt_is_compatible(devp, "ns16550"))) | |
97 | virtex_ns16550_console_init(devp); | |
98 | } | |
99 | return 0; | |
100 | } |