Commit | Line | Data |
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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 | ||
89272a51 MS |
24 | static u32 base_addr; |
25 | ||
51f5fa50 | 26 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE |
2af9ebe9 | 27 | static void early_printk_uartlite_putc(char c) |
89272a51 MS |
28 | { |
29 | /* | |
30 | * Limit how many times we'll spin waiting for TX FIFO status. | |
31 | * This will prevent lockups if the base address is incorrectly | |
32 | * set, or any other issue on the UARTLITE. | |
33 | * This limit is pretty arbitrary, unless we are at about 10 baud | |
34 | * we'll never timeout on a working UART. | |
35 | */ | |
36 | ||
ca12adc8 | 37 | unsigned retries = 1000000; |
89272a51 | 38 | /* read status bit - 0x8 offset */ |
6e60c148 | 39 | while (--retries && (in_be32(base_addr + 8) & (1 << 3))) |
89272a51 MS |
40 | ; |
41 | ||
42 | /* Only attempt the iowrite if we didn't timeout */ | |
43 | /* write to TX_FIFO - 0x4 offset */ | |
44 | if (retries) | |
45 | out_be32(base_addr + 4, c & 0xff); | |
46 | } | |
47 | ||
2af9ebe9 | 48 | static void early_printk_uartlite_write(struct console *unused, |
89272a51 MS |
49 | const char *s, unsigned n) |
50 | { | |
51 | while (*s && n-- > 0) { | |
89272a51 | 52 | if (*s == '\n') |
2af9ebe9 | 53 | early_printk_uartlite_putc('\r'); |
a8c2e555 | 54 | early_printk_uartlite_putc(*s); |
89272a51 MS |
55 | s++; |
56 | } | |
57 | } | |
58 | ||
2af9ebe9 | 59 | static struct console early_serial_uartlite_console = { |
89272a51 | 60 | .name = "earlyser", |
2af9ebe9 | 61 | .write = early_printk_uartlite_write, |
e721a45f | 62 | .flags = CON_PRINTBUFFER | CON_BOOT, |
89272a51 MS |
63 | .index = -1, |
64 | }; | |
51f5fa50 | 65 | #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ |
89272a51 | 66 | |
67f4aaa2 MS |
67 | #ifdef CONFIG_SERIAL_8250_CONSOLE |
68 | static void early_printk_uart16550_putc(char c) | |
69 | { | |
70 | /* | |
71 | * Limit how many times we'll spin waiting for TX FIFO status. | |
72 | * This will prevent lockups if the base address is incorrectly | |
73 | * set, or any other issue on the UARTLITE. | |
74 | * This limit is pretty arbitrary, unless we are at about 10 baud | |
75 | * we'll never timeout on a working UART. | |
76 | */ | |
77 | ||
78 | #define UART_LSR_TEMT 0x40 /* Transmitter empty */ | |
79 | #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ | |
80 | #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) | |
81 | ||
82 | unsigned retries = 10000; | |
83 | ||
84 | while (--retries && | |
85 | !((in_be32(base_addr + 0x14) & BOTH_EMPTY) == BOTH_EMPTY)) | |
86 | ; | |
87 | ||
88 | if (retries) | |
89 | out_be32(base_addr, c & 0xff); | |
90 | } | |
91 | ||
92 | static void early_printk_uart16550_write(struct console *unused, | |
93 | const char *s, unsigned n) | |
94 | { | |
95 | while (*s && n-- > 0) { | |
67f4aaa2 MS |
96 | if (*s == '\n') |
97 | early_printk_uart16550_putc('\r'); | |
a8c2e555 | 98 | early_printk_uart16550_putc(*s); |
67f4aaa2 MS |
99 | s++; |
100 | } | |
101 | } | |
102 | ||
103 | static struct console early_serial_uart16550_console = { | |
104 | .name = "earlyser", | |
105 | .write = early_printk_uart16550_write, | |
e721a45f | 106 | .flags = CON_PRINTBUFFER | CON_BOOT, |
67f4aaa2 MS |
107 | .index = -1, |
108 | }; | |
109 | #endif /* CONFIG_SERIAL_8250_CONSOLE */ | |
110 | ||
89272a51 MS |
111 | int __init setup_early_printk(char *opt) |
112 | { | |
2aa8e375 MS |
113 | int version = 0; |
114 | ||
d0380e6c | 115 | if (early_console) |
89272a51 MS |
116 | return 1; |
117 | ||
2aa8e375 | 118 | base_addr = of_early_console(&version); |
89272a51 | 119 | if (base_addr) { |
a43acfbb MS |
120 | #ifdef CONFIG_MMU |
121 | early_console_reg_tlb_alloc(base_addr); | |
122 | #endif | |
2aa8e375 MS |
123 | switch (version) { |
124 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE | |
125 | case UARTLITE: | |
6bd55f0b MS |
126 | pr_info("Early console on uartlite at 0x%08x\n", |
127 | base_addr); | |
2aa8e375 MS |
128 | early_console = &early_serial_uartlite_console; |
129 | break; | |
130 | #endif | |
67f4aaa2 | 131 | #ifdef CONFIG_SERIAL_8250_CONSOLE |
2aa8e375 | 132 | case UART16550: |
6bd55f0b MS |
133 | pr_info("Early console on uart16650 at 0x%08x\n", |
134 | base_addr); | |
2aa8e375 MS |
135 | early_console = &early_serial_uart16550_console; |
136 | break; | |
67f4aaa2 | 137 | #endif |
2aa8e375 | 138 | default: |
6bd55f0b | 139 | pr_info("Unsupported early console %d\n", |
2aa8e375 MS |
140 | version); |
141 | return 1; | |
142 | } | |
67f4aaa2 | 143 | |
e721a45f | 144 | register_console(early_console); |
67f4aaa2 MS |
145 | return 0; |
146 | } | |
51f5fa50 | 147 | return 1; |
89272a51 MS |
148 | } |
149 | ||
e721a45f MS |
150 | /* Remap early console to virtual address and do not allocate one TLB |
151 | * only for early console because of performance degression */ | |
152 | void __init remap_early_printk(void) | |
153 | { | |
d0380e6c | 154 | if (!early_console) |
e721a45f | 155 | return; |
6bd55f0b | 156 | pr_info("early_printk_console remapping from 0x%x to ", base_addr); |
e721a45f | 157 | base_addr = (u32) ioremap(base_addr, PAGE_SIZE); |
6bd55f0b | 158 | pr_cont("0x%x\n", base_addr); |
e02db0aa | 159 | |
0fc7374b | 160 | #ifdef CONFIG_MMU |
e02db0aa MS |
161 | /* |
162 | * Early console is on the top of skipped TLB entries | |
163 | * decrease tlb_skip size ensure that hardcoded TLB entry will be | |
164 | * used by generic algorithm | |
165 | * FIXME check if early console mapping is on the top by rereading | |
166 | * TLB entry and compare baseaddr | |
167 | * mts rtlbx, (tlb_skip - 1) | |
168 | * nop | |
169 | * mfs rX, rtlblo | |
170 | * nop | |
171 | * cmp rX, orig_base_addr | |
172 | */ | |
173 | tlb_skip -= 1; | |
0fc7374b | 174 | #endif |
e721a45f MS |
175 | } |
176 | ||
89272a51 MS |
177 | void __init disable_early_printk(void) |
178 | { | |
d0380e6c | 179 | if (!early_console) |
89272a51 | 180 | return; |
6bd55f0b | 181 | pr_warn("disabling early console\n"); |
89272a51 | 182 | unregister_console(early_console); |
d0380e6c | 183 | early_console = NULL; |
89272a51 | 184 | } |