diff options
Diffstat (limited to 'cpu')
| -rw-r--r-- | cpu/mpc85xx/speed.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/cpu/mpc85xx/speed.c b/cpu/mpc85xx/speed.c index d90d397..699441b4 100644 --- a/cpu/mpc85xx/speed.c +++ b/cpu/mpc85xx/speed.c @@ -65,6 +65,9 @@ void get_sys_info (sys_info_t * sysInfo) int get_clocks (void) { sys_info_t sys_info; +#ifdef CONFIG_MPC8544 + volatile ccsr_gur_t *gur = (void *) CFG_MPC85xx_GUTS_ADDR; +#endif #if defined(CONFIG_CPM2) volatile ccsr_cpm_t *cpm = (ccsr_cpm_t *)CFG_MPC85xx_CPM_ADDR; uint sccr, dfbrg; @@ -78,8 +81,34 @@ int get_clocks (void) gd->cpu_clk = sys_info.freqProcessor; gd->bus_clk = sys_info.freqSystemBus; gd->mem_clk = sys_info.freqDDRBus; + + /* + * 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. + */ +#if defined(CONFIG_MPC8540) || defined(CONFIG_MPC8541) || \ + defined(CONFIG_MPC8560) || defined(CONFIG_MPC8555) gd->i2c1_clk = sys_info.freqSystemBus; - gd->i2c2_clk = sys_info.freqSystemBus; +#elif defined(CONFIG_MPC8544) + /* + * On the 8544, the I2C clock is the same as the SEC clock. This can be + * either CCB/2 or CCB/3, depending on the value of cfg_sec_freq. See + * 4.4.3.3 of the 8544 RM. Note that this might actually work for all + * 85xx, but only the 8544 has cfg_sec_freq, so it's unknown if the + * PORDEVSR2_SEC_CFG bit is 0 on all 85xx boards that are not an 8544. + */ + if (gur->pordevsr2 & MPC85xx_PORDEVSR2_SEC_CFG) + gd->i2c1_clk = sys_info.freqSystemBus / 3; + else + gd->i2c1_clk = sys_info.freqSystemBus / 2; +#else + /* Most 85xx SOCs use CCB/2, so this is the default behavior. */ + gd->i2c1_clk = sys_info.freqSystemBus / 2; +#endif + gd->i2c2_clk = gd->i2c1_clk; #if defined(CONFIG_CPM2) gd->vco_out = 2*sys_info.freqSystemBus; |