diff options
| -rw-r--r-- | arch/microblaze/Kconfig.debug | 2 | ||||
| -rw-r--r-- | arch/microblaze/include/asm/prom.h | 1 | ||||
| -rw-r--r-- | arch/microblaze/kernel/early_printk.c | 63 | ||||
| -rw-r--r-- | arch/microblaze/kernel/prom.c | 34 |
4 files changed, 99 insertions, 1 deletions
diff --git a/arch/microblaze/Kconfig.debug b/arch/microblaze/Kconfig.debug index e6e5e0da28c3..e66e25c4b0b2 100644 --- a/arch/microblaze/Kconfig.debug +++ b/arch/microblaze/Kconfig.debug @@ -10,7 +10,7 @@ source "lib/Kconfig.debug" config EARLY_PRINTK bool "Early printk function for kernel" - depends on SERIAL_UARTLITE_CONSOLE + depends on SERIAL_UARTLITE_CONSOLE || SERIAL_8250_CONSOLE default n help This option turns on/off early printk messages to console. diff --git a/arch/microblaze/include/asm/prom.h b/arch/microblaze/include/asm/prom.h index 101fa098f62a..bdc38312ae4a 100644 --- a/arch/microblaze/include/asm/prom.h +++ b/arch/microblaze/include/asm/prom.h @@ -27,6 +27,7 @@ /* Other Prototypes */ extern int early_uartlite_console(void); +extern int early_uart16550_console(void); #ifdef CONFIG_PCI /* diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c index 685a64e93ede..c3616a080ebf 100644 --- a/arch/microblaze/kernel/early_printk.c +++ b/arch/microblaze/kernel/early_printk.c @@ -65,6 +65,50 @@ static struct console early_serial_uartlite_console = { }; #endif /* CONFIG_SERIAL_UARTLITE_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, ...) @@ -103,6 +147,25 @@ int __init setup_early_printk(char *opt) } #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; } diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c index 427b13b4740f..608e5cf2e10a 100644 --- a/arch/microblaze/kernel/prom.c +++ b/arch/microblaze/kernel/prom.c @@ -89,6 +89,40 @@ int __init early_uartlite_console(void) { return of_scan_flat_dt(early_init_dt_scan_serial, NULL); } + +/* MS this is Microblaze specifig function */ +static int __init early_init_dt_scan_serial_full(unsigned long node, + const char *uname, int depth, void *data) +{ + unsigned long l; + char *p; + unsigned int addr; + + pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); + +/* find all serial nodes */ + if (strncmp(uname, "serial", 6) != 0) + return 0; + + early_init_dt_check_for_initrd(node); + +/* find compatible node with uartlite */ + p = of_get_flat_dt_prop(node, "compatible", &l); + + if ((strncmp(p, "xlnx,xps-uart16550", 18) != 0) && + (strncmp(p, "xlnx,axi-uart16550", 18) != 0)) + return 0; + + addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l); + addr += *(u32 *)of_get_flat_dt_prop(node, "reg-offset", &l); + return addr; /* return address */ +} + +/* this function is looking for early uartlite console - Microblaze specific */ +int __init early_uart16550_console(void) +{ + return of_scan_flat_dt(early_init_dt_scan_serial_full, NULL); +} #endif void __init early_init_devtree(void *params) |