MIPS: Loongson: Cleanups of serial port support

This patchs uses a loongson_uart_base variable instead of the
uart_base[] array and adds a new kernel option to avoid to compile
uart_base.c all the time, which will save a little bit of memory for us.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
http://patchwork.linux-mips.org/patch/727/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 25 insertions, 16 deletions

diff --git a/arch/mips/loongson/common/uart_base.c b/arch/mips/loongson/common/uart_base.c
index 1d636f4f7505..78ff66ae749e 100644
--- a/arch/mips/loongson/common/uart_base.c
+++ b/arch/mips/loongson/common/uart_base.c
@@ -13,24 +13,33 @@
 
 #include <loongson.h>
 
-unsigned long __maybe_unused _loongson_uart_base;
+/* ioremapped */
+unsigned long _loongson_uart_base;
 EXPORT_SYMBOL(_loongson_uart_base);
+/* raw */
+unsigned long loongson_uart_base;
+EXPORT_SYMBOL(loongson_uart_base);
 
-unsigned long __maybe_unused uart8250_base[] = {
-        [MACH_LOONGSON_UNKNOWN] 0,
-        [MACH_LEMOTE_FL2E]      (LOONGSON_PCIIO_BASE + 0x3f8),
-        [MACH_LEMOTE_FL2F]      (LOONGSON_PCIIO_BASE + 0x2f8),
-        [MACH_LEMOTE_ML2F7]     (LOONGSON_LIO1_BASE + 0x3f8),
-        [MACH_LEMOTE_YL2F89]    (LOONGSON_LIO1_BASE + 0x3f8),
-        [MACH_DEXXON_GDIUM2F10] (LOONGSON_LIO1_BASE + 0x3f8),
-        [MACH_LEMOTE_NAS]       (LOONGSON_LIO1_BASE + 0x3f8),
-        [MACH_LEMOTE_LL2F]      (LOONGSON_PCIIO_BASE + 0x2f8),
-        [MACH_LOONGSON_END]     0,
-};
-EXPORT_SYMBOL(uart8250_base);
-
-void __maybe_unused prom_init_uart_base(void)
+void prom_init_loongson_uart_base(void)
 {
+        switch (mips_machtype) {
+        case MACH_LEMOTE_FL2E:
+                loongson_uart_base = LOONGSON_PCIIO_BASE + 0x3f8;
+                break;
+        case MACH_LEMOTE_FL2F:
+        case MACH_LEMOTE_LL2F:
+                loongson_uart_base = LOONGSON_PCIIO_BASE + 0x2f8;
+                break;
+        case MACH_LEMOTE_ML2F7:
+        case MACH_LEMOTE_YL2F89:
+        case MACH_DEXXON_GDIUM2F10:
+        case MACH_LEMOTE_NAS:
+        default:
+                /* The CPU provided serial port */
+                loongson_uart_base = LOONGSON_LIO1_BASE + 0x3f8;
+                break;
+        }
+
         _loongson_uart_base =
-                (unsigned long)ioremap_nocache(uart8250_base[mips_machtype], 8);
+                (unsigned long)ioremap_nocache(loongson_uart_base, 8);
 }