diff options
Diffstat (limited to 'arch/microblaze/kernel/early_printk.c')
| -rw-r--r-- | arch/microblaze/kernel/early_printk.c | 87 |
1 files changed, 78 insertions, 9 deletions
diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c index 7de84923ba07..c3616a080ebf 100644 --- a/arch/microblaze/kernel/early_printk.c +++ b/arch/microblaze/kernel/early_printk.c @@ -24,7 +24,8 @@ static u32 early_console_initialized; static u32 base_addr; -static void early_printk_putc(char c) +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE +static void early_printk_uartlite_putc(char c) { /* * Limit how many times we'll spin waiting for TX FIFO status. @@ -45,25 +46,70 @@ static void early_printk_putc(char c) out_be32(base_addr + 4, c & 0xff); } -static void early_printk_write(struct console *unused, +static void early_printk_uartlite_write(struct console *unused, const char *s, unsigned n) { while (*s && n-- > 0) { - early_printk_putc(*s); + early_printk_uartlite_putc(*s); if (*s == '\n') - early_printk_putc('\r'); + early_printk_uartlite_putc('\r'); s++; } } -static struct console early_serial_console = { +static struct console early_serial_uartlite_console = { .name = "earlyser", - .write = early_printk_write, + .write = early_printk_uartlite_write, .flags = CON_PRINTBUFFER, .index = -1, }; +#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ -static struct console *early_console = &early_serial_console; +#ifdef CONFIG_SERIAL_8250_CONSOLE +static void early_printk_uart16550_putc(char c) +{ + /* + * Limit how many times we'll spin waiting for TX FIFO status. + * This will prevent lockups if the base address is incorrectly + * set, or any other issue on the UARTLITE. + * This limit is pretty arbitrary, unless we are at about 10 baud + * we'll never timeout on a working UART. + */ + + #define UART_LSR_TEMT 0x40 /* Transmitter empty */ + #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ + #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + + unsigned retries = 10000; + + while (--retries && + !((in_be32(base_addr + 0x14) & BOTH_EMPTY) == BOTH_EMPTY)) + ; + + if (retries) + out_be32(base_addr, c & 0xff); +} + +static void early_printk_uart16550_write(struct console *unused, + const char *s, unsigned n) +{ + while (*s && n-- > 0) { + early_printk_uart16550_putc(*s); + if (*s == '\n') + early_printk_uart16550_putc('\r'); + s++; + } +} + +static struct console early_serial_uart16550_console = { + .name = "earlyser", + .write = early_printk_uart16550_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; +#endif /* CONFIG_SERIAL_8250_CONSOLE */ + +static struct console *early_console; void early_printk(const char *fmt, ...) { @@ -84,20 +130,43 @@ int __init setup_early_printk(char *opt) if (early_console_initialized) return 1; +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE base_addr = early_uartlite_console(); if (base_addr) { early_console_initialized = 1; #ifdef CONFIG_MMU early_console_reg_tlb_alloc(base_addr); #endif + early_console = &early_serial_uartlite_console; early_printk("early_printk_console is enabled at 0x%08x\n", base_addr); /* register_console(early_console); */ return 0; - } else - return 1; + } +#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ + +#ifdef CONFIG_SERIAL_8250_CONSOLE + base_addr = early_uart16550_console(); + base_addr &= ~3; /* clear register offset */ + if (base_addr) { + early_console_initialized = 1; +#ifdef CONFIG_MMU + early_console_reg_tlb_alloc(base_addr); +#endif + early_console = &early_serial_uart16550_console; + + early_printk("early_printk_console is enabled at 0x%08x\n", + base_addr); + + /* register_console(early_console); */ + + return 0; + } +#endif /* CONFIG_SERIAL_8250_CONSOLE */ + + return 1; } void __init disable_early_printk(void) |