projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| e8bf5bc7 LFT |
1 | /* |
| 2 | * Early printk for Nios2. | |
| 3 | * | |
| 4 | * Copyright (C) 2015, Altera Corporation | |
| 5 | * Copyright (C) 2010, Tobias Klauser <tklauser@distanz.ch> | |
| 6 | * Copyright (C) 2009, Wind River Systems Inc | |
| 7 | * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com | |
| 8 | * | |
| 9 | * This file is subject to the terms and conditions of the GNU General Public | |
| 10 | * License. See the file "COPYING" in the main directory of this archive | |
| 11 | * for more details. | |
| 12 | */ | |
| 13 | ||
| 14 | #include <linux/console.h> | |
| 15 | #include <linux/init.h> | |
| 16 | #include <linux/kernel.h> | |
| 17 | #include <linux/io.h> | |
| 18 | ||
| 19 | #include <asm/prom.h> | |
| 20 | ||
| 21 | static unsigned long base_addr; | |
| 22 | ||
| 23 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE) | |
| 24 | ||
| 25 | #define ALTERA_JTAGUART_DATA_REG 0 | |
| 26 | #define ALTERA_JTAGUART_CONTROL_REG 4 | |
| 27 | #define ALTERA_JTAGUART_CONTROL_WSPACE_MSK 0xFFFF0000 | |
| 28 | #define ALTERA_JTAGUART_CONTROL_AC_MSK 0x00000400 | |
| 29 | ||
| 30 | #define JUART_GET_CR() \ | |
| 31 | __builtin_ldwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG)) | |
| 32 | #define JUART_SET_CR(v) \ | |
| 33 | __builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG), v) | |
| 34 | #define JUART_SET_TX(v) \ | |
| 35 | __builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_DATA_REG), v) | |
| 36 | ||
| 37 | static void early_console_write(struct console *con, const char *s, unsigned n) | |
| 38 | { | |
| 39 | unsigned long status; | |
| 40 | ||
| 41 | while (n-- && *s) { | |
| 42 | while (((status = JUART_GET_CR()) | |
| 43 | & ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) { | |
| 44 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS) | |
| 45 | if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) | |
| 46 | return; /* no connection activity */ | |
| 47 | #endif | |
| 48 | } | |
| 49 | JUART_SET_TX(*s); | |
| 50 | s++; | |
| 51 | } | |
| 52 | } | |
| 53 | ||
| 54 | #elif defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE) | |
| 55 | ||
| 56 | #define ALTERA_UART_TXDATA_REG 4 | |
| 57 | #define ALTERA_UART_STATUS_REG 8 | |
| 58 | #define ALTERA_UART_STATUS_TRDY 0x0040 | |
| 59 | ||
| 60 | #define UART_GET_SR() \ | |
| 61 | __builtin_ldwio((void *)(base_addr + ALTERA_UART_STATUS_REG)) | |
| 62 | #define UART_SET_TX(v) \ | |
| 63 | __builtin_stwio((void *)(base_addr + ALTERA_UART_TXDATA_REG), v) | |
| 64 | ||
| 65 | static void early_console_putc(char c) | |
| 66 | { | |
| 67 | while (!(UART_GET_SR() & ALTERA_UART_STATUS_TRDY)) | |
| 68 | ; | |
| 69 | ||
| 70 | UART_SET_TX(c); | |
| 71 | } | |
| 72 | ||
| 73 | static void early_console_write(struct console *con, const char *s, unsigned n) | |
| 74 | { | |
| 75 | while (n-- && *s) { | |
| 76 | early_console_putc(*s); | |
| 77 | if (*s == '\n') | |
| 78 | early_console_putc('\r'); | |
| 79 | s++; | |
| 80 | } | |
| 81 | } | |
| 82 | ||
| 83 | #else | |
| 84 | # error Neither SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE \ | |
| 85 | selected | |
| 86 | #endif | |
| 87 | ||
| 88 | static struct console early_console_prom = { | |
| 89 | .name = "early", | |
| 90 | .write = early_console_write, | |
| 91 | .flags = CON_PRINTBUFFER | CON_BOOT, | |
| 92 | .index = -1 | |
| 93 | }; | |
| 94 | ||
| 95 | void __init setup_early_printk(void) | |
| 96 | { | |
| 97 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE) || \ | |
| 98 | defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE) | |
| 99 | base_addr = of_early_console(); | |
| 100 | #else | |
| 101 | base_addr = 0; | |
| 102 | #endif | |
| 103 | ||
| 104 | if (!base_addr) | |
| 105 | return; | |
| 106 | ||
| 107 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS) | |
| 108 | /* Clear activity bit so BYPASS doesn't stall if we've used JTAG for | |
| 109 | * downloading the kernel. This might cause early data to be lost even | |
| 110 | * if the JTAG terminal is running. | |
| 111 | */ | |
| 112 | JUART_SET_CR(JUART_GET_CR() | ALTERA_JTAGUART_CONTROL_AC_MSK); | |
| 113 | #endif | |
| 114 | ||
| 115 | early_console = &early_console_prom; | |
| 116 | register_console(early_console); | |
| 117 | pr_info("early_console initialized at 0x%08lx\n", base_addr); | |
| 118 | } |