Commit | Line | Data |
---|---|---|
89272a51 MS |
1 | /* |
2 | * Early printk support for Microblaze. | |
3 | * | |
4 | * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu> | |
5 | * Copyright (C) 2007-2009 PetaLogix | |
6 | * Copyright (C) 2003-2006 Yasushi SHOJI <yashi@atmark-techno.com> | |
7 | * | |
8 | * This file is subject to the terms and conditions of the GNU General Public | |
9 | * License. See the file "COPYING" in the main directory of this archive | |
10 | * for more details. | |
11 | */ | |
12 | ||
13 | #include <linux/console.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/tty.h> | |
18 | #include <linux/io.h> | |
19 | #include <asm/processor.h> | |
20 | #include <linux/fcntl.h> | |
21 | #include <asm/setup.h> | |
22 | #include <asm/prom.h> | |
23 | ||
24 | static u32 early_console_initialized; | |
25 | static u32 base_addr; | |
26 | ||
51f5fa50 | 27 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE |
2af9ebe9 | 28 | static void early_printk_uartlite_putc(char c) |
89272a51 MS |
29 | { |
30 | /* | |
31 | * Limit how many times we'll spin waiting for TX FIFO status. | |
32 | * This will prevent lockups if the base address is incorrectly | |
33 | * set, or any other issue on the UARTLITE. | |
34 | * This limit is pretty arbitrary, unless we are at about 10 baud | |
35 | * we'll never timeout on a working UART. | |
36 | */ | |
37 | ||
38 | unsigned retries = 10000; | |
39 | /* read status bit - 0x8 offset */ | |
6e60c148 | 40 | while (--retries && (in_be32(base_addr + 8) & (1 << 3))) |
89272a51 MS |
41 | ; |
42 | ||
43 | /* Only attempt the iowrite if we didn't timeout */ | |
44 | /* write to TX_FIFO - 0x4 offset */ | |
45 | if (retries) | |
46 | out_be32(base_addr + 4, c & 0xff); | |
47 | } | |
48 | ||
2af9ebe9 | 49 | static void early_printk_uartlite_write(struct console *unused, |
89272a51 MS |
50 | const char *s, unsigned n) |
51 | { | |
52 | while (*s && n-- > 0) { | |
2af9ebe9 | 53 | early_printk_uartlite_putc(*s); |
89272a51 | 54 | if (*s == '\n') |
2af9ebe9 | 55 | early_printk_uartlite_putc('\r'); |
89272a51 MS |
56 | s++; |
57 | } | |
58 | } | |
59 | ||
2af9ebe9 | 60 | static struct console early_serial_uartlite_console = { |
89272a51 | 61 | .name = "earlyser", |
2af9ebe9 | 62 | .write = early_printk_uartlite_write, |
e721a45f | 63 | .flags = CON_PRINTBUFFER | CON_BOOT, |
89272a51 MS |
64 | .index = -1, |
65 | }; | |
51f5fa50 | 66 | #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ |
89272a51 | 67 | |
67f4aaa2 MS |
68 | #ifdef CONFIG_SERIAL_8250_CONSOLE |
69 | static void early_printk_uart16550_putc(char c) | |
70 | { | |
71 | /* | |
72 | * Limit how many times we'll spin waiting for TX FIFO status. | |
73 | * This will prevent lockups if the base address is incorrectly | |
74 | * set, or any other issue on the UARTLITE. | |
75 | * This limit is pretty arbitrary, unless we are at about 10 baud | |
76 | * we'll never timeout on a working UART. | |
77 | */ | |
78 | ||
79 | #define UART_LSR_TEMT 0x40 /* Transmitter empty */ | |
80 | #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ | |
81 | #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) | |
82 | ||
83 | unsigned retries = 10000; | |
84 | ||
85 | while (--retries && | |
86 | !((in_be32(base_addr + 0x14) & BOTH_EMPTY) == BOTH_EMPTY)) | |
87 | ; | |
88 | ||
89 | if (retries) | |
90 | out_be32(base_addr, c & 0xff); | |
91 | } | |
92 | ||
93 | static void early_printk_uart16550_write(struct console *unused, | |
94 | const char *s, unsigned n) | |
95 | { | |
96 | while (*s && n-- > 0) { | |
97 | early_printk_uart16550_putc(*s); | |
98 | if (*s == '\n') | |
99 | early_printk_uart16550_putc('\r'); | |
100 | s++; | |
101 | } | |
102 | } | |
103 | ||
104 | static struct console early_serial_uart16550_console = { | |
105 | .name = "earlyser", | |
106 | .write = early_printk_uart16550_write, | |
e721a45f | 107 | .flags = CON_PRINTBUFFER | CON_BOOT, |
67f4aaa2 MS |
108 | .index = -1, |
109 | }; | |
110 | #endif /* CONFIG_SERIAL_8250_CONSOLE */ | |
111 | ||
9a7e8d80 | 112 | static struct console *early_console; |
89272a51 MS |
113 | |
114 | void early_printk(const char *fmt, ...) | |
115 | { | |
116 | char buf[512]; | |
117 | int n; | |
118 | va_list ap; | |
119 | ||
120 | if (early_console_initialized) { | |
121 | va_start(ap, fmt); | |
122 | n = vscnprintf(buf, 512, fmt, ap); | |
123 | early_console->write(early_console, buf, n); | |
124 | va_end(ap); | |
125 | } | |
126 | } | |
127 | ||
128 | int __init setup_early_printk(char *opt) | |
129 | { | |
2aa8e375 MS |
130 | int version = 0; |
131 | ||
89272a51 MS |
132 | if (early_console_initialized) |
133 | return 1; | |
134 | ||
2aa8e375 | 135 | base_addr = of_early_console(&version); |
89272a51 | 136 | if (base_addr) { |
a43acfbb MS |
137 | #ifdef CONFIG_MMU |
138 | early_console_reg_tlb_alloc(base_addr); | |
139 | #endif | |
2aa8e375 MS |
140 | switch (version) { |
141 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE | |
142 | case UARTLITE: | |
143 | printk(KERN_INFO "Early console on uartlite " | |
144 | "at 0x%08x\n", base_addr); | |
145 | early_console = &early_serial_uartlite_console; | |
146 | break; | |
147 | #endif | |
67f4aaa2 | 148 | #ifdef CONFIG_SERIAL_8250_CONSOLE |
2aa8e375 MS |
149 | case UART16550: |
150 | printk(KERN_INFO "Early console on uart16650 " | |
151 | "at 0x%08x\n", base_addr); | |
152 | early_console = &early_serial_uart16550_console; | |
153 | break; | |
67f4aaa2 | 154 | #endif |
2aa8e375 MS |
155 | default: |
156 | printk(KERN_INFO "Unsupported early console %d\n", | |
157 | version); | |
158 | return 1; | |
159 | } | |
67f4aaa2 | 160 | |
e721a45f | 161 | register_console(early_console); |
2aa8e375 | 162 | early_console_initialized = 1; |
67f4aaa2 MS |
163 | return 0; |
164 | } | |
51f5fa50 | 165 | return 1; |
89272a51 MS |
166 | } |
167 | ||
e721a45f MS |
168 | /* Remap early console to virtual address and do not allocate one TLB |
169 | * only for early console because of performance degression */ | |
170 | void __init remap_early_printk(void) | |
171 | { | |
172 | if (!early_console_initialized || !early_console) | |
173 | return; | |
174 | printk(KERN_INFO "early_printk_console remaping from 0x%x to ", | |
175 | base_addr); | |
176 | base_addr = (u32) ioremap(base_addr, PAGE_SIZE); | |
177 | printk(KERN_CONT "0x%x\n", base_addr); | |
178 | } | |
179 | ||
89272a51 MS |
180 | void __init disable_early_printk(void) |
181 | { | |
182 | if (!early_console_initialized || !early_console) | |
183 | return; | |
184 | printk(KERN_WARNING "disabling early console\n"); | |
185 | unregister_console(early_console); | |
186 | early_console_initialized = 0; | |
187 | } |