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path: root/arch/microblaze/kernel/early_printk.c
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Diffstat (limited to 'arch/microblaze/kernel/early_printk.c')
-rw-r--r--arch/microblaze/kernel/early_printk.c87
1 files changed, 78 insertions, 9 deletions
diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c
index 7de84923ba0..c3616a080eb 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)