Fix initialization problem on TQM5200 without SM501

Patch by Martin Krause, 8 Apr. 2005

diff --git a/CHANGELOG b/CHANGELOG
index a65666658764aefb5756a6505bf72e5b5cfe8a38..dc50004c8e6a1994fc23885831b698a43b41170c 100644 (file)
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,9 @@
 Changes for U-Boot 1.1.4:
 ======================================================================
 
+* Fix initialization problem on TQM5200 without SM501
+  Patch by Martin Krause, 8 Apr. 2005
+
 * Add RTC support for STK52XX.200
   Patch by Martin Krause, 7 Apr. 2005
 

diff --git a/board/tqm5200/tqm5200.c b/board/tqm5200/tqm5200.c
index 90275ecd8e5639eed77e235be640fec099740854..dbd78d5e3a20f3fa8ac42f584aa829c14d92761f 100644 (file)
--- a/board/tqm5200/tqm5200.c
+++ b/board/tqm5200/tqm5200.c
@@ -425,7 +425,7 @@ int last_stage_init (void)
         * Check for SRAM and SRAM size
         */
 
-       /* save origianl SRAM content  */
+       /* save original SRAM content  */
        save = *(volatile u16 *)CFG_CS2_START;
        restore = 1;
 
@@ -447,8 +447,7 @@ int last_stage_init (void)
                *(vu_long *)MPC5XXX_CS2_STOP = 0x0000FFFF;
                restore = 0;
                __asm__ volatile ("sync");
-       }
-       else if (*(volatile u16 *)(CFG_CS2_START + (1<<19)) == 0xA5A5) {
+       } else if (*(volatile u16 *)(CFG_CS2_START + (1<<19)) == 0xA5A5) {
                /* make sure that we access a mirrored address */
                *(volatile u16 *)CFG_CS2_START = 0x1111;
                __asm__ volatile ("sync");
@@ -461,8 +460,7 @@ int last_stage_init (void)
                }
                else
                        puts ("!! possible error in SRAM detection\n");
-       }
-       else {
+       } else {
                puts ("SRAM:  1 MB\n");
        }
        /* restore origianl SRAM content  */
@@ -497,8 +495,7 @@ int last_stage_init (void)
                *(vu_long *)MPC5XXX_CS1_STOP = 0x0000FFFF;
                restore = 0;
                __asm__ volatile ("sync");
-       }
-       else {
+       } else {
                puts ("VGA:   SMI501 (Voyager) with 8 MB\n");
        }
        /* restore origianl FB content  */
@@ -598,11 +595,46 @@ void video_get_info_str (int line_number, char *info)
 #endif
 
 /*
- * Returns SM501 register base address. First thing called in the driver.
+ * Returns SM501 register base address. First thing called in the
+ * driver. Checks if SM501 is physically present.
  */
 unsigned int board_video_init (void)
 {
-       return SM501_MMIO_BASE;
+       u16 save, tmp;
+       int restore, ret;
+
+       /*
+        * Check for Grafic Controller
+        */
+
+       /* save origianl FB content  */
+       save = *(volatile u16 *)CFG_CS1_START;
+       restore = 1;
+
+       /* write test pattern to FB memory */
+       *(volatile u16 *)CFG_CS1_START = 0xA5A5;
+       __asm__ volatile ("sync");
+       /*
+        * Put a different pattern on the data lines: otherwise they may float
+        * long enough to read back what we wrote.
+        */
+       tmp = *(volatile u16 *)CFG_FLASH_BASE;
+       if (tmp == 0xA5A5)
+               puts ("!! possible error in grafic controller detection\n");
+
+       if (*(volatile u16 *)CFG_CS1_START != 0xA5A5) {
+               /* no grafic controller found */
+               restore = 0;
+               ret = 0;
+       } else {
+               ret = SM501_MMIO_BASE;
+       }
+
+       if (restore) {
+               *(volatile u16 *)CFG_CS1_START = save;
+               __asm__ volatile ("sync");
+       }
+       return ret;
 }
 
 /*