Fix calculation of I2C clock for some 86xx chips

[u-boot] / cpu / mpc86xx / speed.c

diff --git a/cpu/mpc86xx/speed.c b/cpu/mpc86xx/speed.c
index 312ca128277350241c30dfa61229892283ef0aaf..da5b58b73f29441761d0abd430f8d1f19a879103 100644 (file)
--- a/cpu/mpc86xx/speed.c
+++ b/cpu/mpc86xx/speed.c
@@ -29,6 +29,10 @@
 #include <mpc86xx.h>
 #include <asm/processor.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
+/* used in some defintiions of CONFIG_SYS_CLK_FREQ */
+extern unsigned long get_board_sys_clk(unsigned long dummy);
 
 void get_sys_info(sys_info_t *sysInfo)
 {
@@ -96,13 +100,26 @@ void get_sys_info(sys_info_t *sysInfo)
 
 int get_clocks(void)
 {
-       DECLARE_GLOBAL_DATA_PTR;
        sys_info_t sys_info;
 
        get_sys_info(&sys_info);
        gd->cpu_clk = sys_info.freqProcessor;
        gd->bus_clk = sys_info.freqSystemBus;
 
+       /*
+        * The base clock for I2C depends on the actual SOC.  Unfortunately,
+        * there is no pattern that can be used to determine the frequency, so
+        * the only choice is to look up the actual SOC number and use the value
+        * for that SOC. This information is taken from application note
+        * AN2919.
+        */
+#ifdef CONFIG_MPC8610
+       gd->i2c1_clk = sys_info.freqSystemBus;
+#else
+       gd->i2c1_clk = sys_info.freqSystemBus / 2;
+#endif
+       gd->i2c2_clk = gd->i2c1_clk;
+
        if (gd->cpu_clk != 0)
                return 0;
        else