Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 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 | |
Michal Simek | 51f5fa5 | 2010-09-28 16:40:00 +1000 | [diff] [blame] | 27 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 28 | static void early_printk_uartlite_putc(char c) |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 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 */ |
Roel Kluin | 6e60c14 | 2009-04-16 22:49:17 +0200 | [diff] [blame] | 40 | while (--retries && (in_be32(base_addr + 8) & (1 << 3))) |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 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 | |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 49 | static void early_printk_uartlite_write(struct console *unused, |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 50 | const char *s, unsigned n) |
| 51 | { |
| 52 | while (*s && n-- > 0) { |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 53 | early_printk_uartlite_putc(*s); |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 54 | if (*s == '\n') |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 55 | early_printk_uartlite_putc('\r'); |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 56 | s++; |
| 57 | } |
| 58 | } |
| 59 | |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 60 | static struct console early_serial_uartlite_console = { |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 61 | .name = "earlyser", |
Michal Simek | 2af9ebe | 2010-09-28 16:33:53 +1000 | [diff] [blame] | 62 | .write = early_printk_uartlite_write, |
Michal Simek | e721a45 | 2011-04-04 15:45:06 +0200 | [diff] [blame^] | 63 | .flags = CON_PRINTBUFFER | CON_BOOT, |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 64 | .index = -1, |
| 65 | }; |
Michal Simek | 51f5fa5 | 2010-09-28 16:40:00 +1000 | [diff] [blame] | 66 | #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 67 | |
Michal Simek | 67f4aaa | 2010-09-28 16:17:03 +1000 | [diff] [blame] | 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, |
Michal Simek | e721a45 | 2011-04-04 15:45:06 +0200 | [diff] [blame^] | 107 | .flags = CON_PRINTBUFFER | CON_BOOT, |
Michal Simek | 67f4aaa | 2010-09-28 16:17:03 +1000 | [diff] [blame] | 108 | .index = -1, |
| 109 | }; |
| 110 | #endif /* CONFIG_SERIAL_8250_CONSOLE */ |
| 111 | |
Michal Simek | 9a7e8d8 | 2010-09-28 16:38:28 +1000 | [diff] [blame] | 112 | static struct console *early_console; |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 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 | { |
| 130 | if (early_console_initialized) |
| 131 | return 1; |
| 132 | |
Michal Simek | 51f5fa5 | 2010-09-28 16:40:00 +1000 | [diff] [blame] | 133 | #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 134 | base_addr = early_uartlite_console(); |
| 135 | if (base_addr) { |
| 136 | early_console_initialized = 1; |
Michal Simek | a43acfb | 2009-05-26 16:30:10 +0200 | [diff] [blame] | 137 | #ifdef CONFIG_MMU |
| 138 | early_console_reg_tlb_alloc(base_addr); |
| 139 | #endif |
Michal Simek | 9a7e8d8 | 2010-09-28 16:38:28 +1000 | [diff] [blame] | 140 | early_console = &early_serial_uartlite_console; |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 141 | early_printk("early_printk_console is enabled at 0x%08x\n", |
| 142 | base_addr); |
| 143 | |
Michal Simek | e721a45 | 2011-04-04 15:45:06 +0200 | [diff] [blame^] | 144 | register_console(early_console); |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 145 | |
| 146 | return 0; |
Michal Simek | 51f5fa5 | 2010-09-28 16:40:00 +1000 | [diff] [blame] | 147 | } |
| 148 | #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ |
| 149 | |
Michal Simek | 67f4aaa | 2010-09-28 16:17:03 +1000 | [diff] [blame] | 150 | #ifdef CONFIG_SERIAL_8250_CONSOLE |
| 151 | base_addr = early_uart16550_console(); |
| 152 | base_addr &= ~3; /* clear register offset */ |
| 153 | if (base_addr) { |
| 154 | early_console_initialized = 1; |
| 155 | #ifdef CONFIG_MMU |
| 156 | early_console_reg_tlb_alloc(base_addr); |
| 157 | #endif |
| 158 | early_console = &early_serial_uart16550_console; |
| 159 | |
| 160 | early_printk("early_printk_console is enabled at 0x%08x\n", |
| 161 | base_addr); |
| 162 | |
Michal Simek | e721a45 | 2011-04-04 15:45:06 +0200 | [diff] [blame^] | 163 | register_console(early_console); |
Michal Simek | 67f4aaa | 2010-09-28 16:17:03 +1000 | [diff] [blame] | 164 | |
| 165 | return 0; |
| 166 | } |
| 167 | #endif /* CONFIG_SERIAL_8250_CONSOLE */ |
| 168 | |
Michal Simek | 51f5fa5 | 2010-09-28 16:40:00 +1000 | [diff] [blame] | 169 | return 1; |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 170 | } |
| 171 | |
Michal Simek | e721a45 | 2011-04-04 15:45:06 +0200 | [diff] [blame^] | 172 | /* Remap early console to virtual address and do not allocate one TLB |
| 173 | * only for early console because of performance degression */ |
| 174 | void __init remap_early_printk(void) |
| 175 | { |
| 176 | if (!early_console_initialized || !early_console) |
| 177 | return; |
| 178 | printk(KERN_INFO "early_printk_console remaping from 0x%x to ", |
| 179 | base_addr); |
| 180 | base_addr = (u32) ioremap(base_addr, PAGE_SIZE); |
| 181 | printk(KERN_CONT "0x%x\n", base_addr); |
| 182 | } |
| 183 | |
Michal Simek | 89272a5 | 2009-03-27 14:25:22 +0100 | [diff] [blame] | 184 | void __init disable_early_printk(void) |
| 185 | { |
| 186 | if (!early_console_initialized || !early_console) |
| 187 | return; |
| 188 | printk(KERN_WARNING "disabling early console\n"); |
| 189 | unregister_console(early_console); |
| 190 | early_console_initialized = 0; |
| 191 | } |