MIPS: Loongson1B: Improve early printk
- Determine serial port for early printk according to kernel command line.
- Move to 8250/16550 serial early printk driver.
Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8023/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/loongson1/Kconfig b/arch/mips/loongson1/Kconfig
index e23c25d..4ed9744 100644
--- a/arch/mips/loongson1/Kconfig
+++ b/arch/mips/loongson1/Kconfig
@@ -16,6 +16,7 @@
select SYS_SUPPORTS_HIGHMEM
select SYS_SUPPORTS_MIPS16
select SYS_HAS_EARLY_PRINTK
+ select USE_GENERIC_EARLY_PRINTK_8250
select COMMON_CLK
endchoice
diff --git a/arch/mips/loongson1/common/prom.c b/arch/mips/loongson1/common/prom.c
index 2a47af5..6860098 100644
--- a/arch/mips/loongson1/common/prom.c
+++ b/arch/mips/loongson1/common/prom.c
@@ -27,7 +27,7 @@
i = strlen(envname);
while (*env) {
- if (strncmp(envname, *env, i) == 0 && *(*env+i) == '=')
+ if (strncmp(envname, *env, i) == 0 && *(*env + i) == '=')
return *env + i + 1;
env++;
}
@@ -49,7 +49,7 @@
for (i = 1; i < prom_argc; i++) {
strcpy(c, prom_argv[i]);
c += strlen(prom_argv[i]);
- if (i < prom_argc-1)
+ if (i < prom_argc - 1)
*c++ = ' ';
}
*c = 0;
@@ -57,6 +57,7 @@
void __init prom_init(void)
{
+ void __iomem *uart_base;
prom_argc = fw_arg0;
prom_argv = (char **)fw_arg1;
prom_envp = (char **)fw_arg2;
@@ -65,23 +66,18 @@
memsize = env_or_default("memsize", DEFAULT_MEMSIZE);
highmemsize = env_or_default("highmemsize", 0x0);
+
+ if (strstr(arcs_cmdline, "console=ttyS3"))
+ uart_base = ioremap_nocache(LS1X_UART3_BASE, 0x0f);
+ else if (strstr(arcs_cmdline, "console=ttyS2"))
+ uart_base = ioremap_nocache(LS1X_UART2_BASE, 0x0f);
+ else if (strstr(arcs_cmdline, "console=ttyS1"))
+ uart_base = ioremap_nocache(LS1X_UART1_BASE, 0x0f);
+ else
+ uart_base = ioremap_nocache(LS1X_UART0_BASE, 0x0f);
+ setup_8250_early_printk_port((unsigned long)uart_base, 0, 0);
}
void __init prom_free_prom_memory(void)
{
}
-
-#define PORT(offset) (u8 *)(KSEG1ADDR(LS1X_UART0_BASE + offset))
-
-void prom_putchar(char c)
-{
- int timeout;
-
- timeout = 1024;
-
- while (((readb(PORT(UART_LSR)) & UART_LSR_THRE) == 0)
- && (timeout-- > 0))
- ;
-
- writeb(c, PORT(UART_TX));
-}