ramips: make the early_printk code detect which uart is used

only tested on mt7628

Signed-off-by: John Crispin <blogic@openwrt.org>
Backport of r46950

SVN-Revision: 47086

diff --git a/target/linux/ramips/patches-3.18/0015-MIPS-ralink-cleanup-early_printk.patch b/target/linux/ramips/patches-3.18/0015-MIPS-ralink-cleanup-early_printk.patch
index d139139322e85358bbcfb63d9ce3345607c8b461..3fffa804cfb330700327ff3f43eeb215fab10ea2 100644 (file)
--- a/target/linux/ramips/patches-3.18/0015-MIPS-ralink-cleanup-early_printk.patch
+++ b/target/linux/ramips/patches-3.18/0015-MIPS-ralink-cleanup-early_printk.patch
@@ -13,7 +13,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 
 --- a/arch/mips/ralink/early_printk.c
 +++ b/arch/mips/ralink/early_printk.c
-@@ -12,21 +12,24 @@
+@@ -12,21 +12,26 @@
  #include <asm/addrspace.h>
  
  #ifdef CONFIG_SOC_RT288X
@@ -40,15 +40,17 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +#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)
  {
-@@ -38,11 +41,23 @@ static inline u32 uart_r32(unsigned reg)
+@@ -38,11 +43,46 @@
        return __raw_readl(uart_membase + reg);
  }
  
@@ -57,6 +59,24 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +      return IS_ENABLED(CONFIG_SOC_MT7620) &&
 +              (__raw_readl(chipid_membase) == MT7628_CHIP_NAME1);
 +}
++
++static inline 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)
  {
@@ -65,6 +85,11 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 -      uart_w32(ch, UART_REG_TX);
 -      while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0)
 -              ;
++      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)