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Diffstat (limited to 'kernel/arch/mips/ralink/early_printk.c')
-rw-r--r--kernel/arch/mips/ralink/early_printk.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/arch/mips/ralink/early_printk.c b/kernel/arch/mips/ralink/early_printk.c
index 255d695ec..3c59ffe5f 100644
--- a/kernel/arch/mips/ralink/early_printk.c
+++ b/kernel/arch/mips/ralink/early_printk.c
@@ -25,11 +25,13 @@
#define MT7628_CHIP_NAME1 0x20203832
#define UART_REG_TX 0x04
+#define UART_REG_LCR 0x0c
#define UART_REG_LSR 0x14
#define UART_REG_LSR_RT2880 0x1c
static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE);
static __iomem void *chipid_membase = (__iomem void *) KSEG1ADDR(CHIPID_BASE);
+static int init_complete;
static inline void uart_w32(u32 val, unsigned reg)
{
@@ -47,8 +49,32 @@ static inline int soc_is_mt7628(void)
(__raw_readl(chipid_membase) == MT7628_CHIP_NAME1);
}
+static void find_uart_base(void)
+{
+ int i;
+
+ if (!soc_is_mt7628())
+ return;
+
+ for (i = 0; i < 3; i++) {
+ u32 reg = uart_r32(UART_REG_LCR + (0x100 * i));
+
+ if (!reg)
+ continue;
+
+ uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE +
+ (0x100 * i));
+ break;
+ }
+}
+
void prom_putchar(unsigned char ch)
{
+ if (!init_complete) {
+ find_uart_base();
+ init_complete = 1;
+ }
+
if (IS_ENABLED(CONFIG_SOC_MT7621) || soc_is_mt7628()) {
uart_w32(ch, UART_TX);
while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0)