diff options
Diffstat (limited to 'cpu/ppc4xx')
| -rw-r--r-- | cpu/ppc4xx/cpu_init.c | 100 |
1 files changed, 99 insertions, 1 deletions
diff --git a/cpu/ppc4xx/cpu_init.c b/cpu/ppc4xx/cpu_init.c index 5d15e2f..b35f1f0 100644 --- a/cpu/ppc4xx/cpu_init.c +++ b/cpu/ppc4xx/cpu_init.c @@ -99,10 +99,107 @@ DECLARE_GLOBAL_DATA_PTR; # endif #endif /* CFG_INIT_DCACHE_CS */ +#ifndef CFG_PLL_RECONFIG +#define CFG_PLL_RECONFIG 0 +#endif + +void reconfigure_pll(u32 new_cpu_freq) +{ +#if defined(CONFIG_440EPX) + int reset_needed = 0; + u32 reg, temp; + u32 prbdv0, target_prbdv0, /* CLK_PRIMBD */ + fwdva, target_fwdva, fwdvb, target_fwdvb, /* CLK_PLLD */ + fbdv, target_fbdv, lfbdv, target_lfbdv, + perdv0, target_perdv0, /* CLK_PERD */ + spcid0, target_spcid0; /* CLK_SPCID */ + + /* Reconfigure clocks if necessary. + * See PPC440EPx User's Manual, sections 8.2 and 14 */ + if (new_cpu_freq == 667) { + target_prbdv0 = 2; + target_fwdva = 2; + target_fwdvb = 4; + target_fbdv = 20; + target_lfbdv = 1; + target_perdv0 = 4; + target_spcid0 = 4; + + mfcpr(clk_primbd, reg); + temp = (reg & PRBDV_MASK) >> 24; + prbdv0 = temp ? temp : 8; + if (prbdv0 != target_prbdv0) { + reg &= ~PRBDV_MASK; + reg |= ((target_prbdv0 == 8 ? 0 : target_prbdv0) << 24); + mtcpr(clk_primbd, reg); + reset_needed = 1; + } + + mfcpr(clk_plld, reg); + + temp = (reg & PLLD_FWDVA_MASK) >> 16; + fwdva = temp ? temp : 16; + + temp = (reg & PLLD_FWDVB_MASK) >> 8; + fwdvb = temp ? temp : 8; + + temp = (reg & PLLD_FBDV_MASK) >> 24; + fbdv = temp ? temp : 32; + + temp = (reg & PLLD_LFBDV_MASK); + lfbdv = temp ? temp : 64; + + if (fwdva != target_fwdva || fbdv != target_fbdv || lfbdv != target_lfbdv) { + reg &= ~(PLLD_FWDVA_MASK | PLLD_FWDVB_MASK | + PLLD_FBDV_MASK | PLLD_LFBDV_MASK); + reg |= ((target_fwdva == 16 ? 0 : target_fwdva) << 16) | + ((target_fwdvb == 8 ? 0 : target_fwdvb) << 8) | + ((target_fbdv == 32 ? 0 : target_fbdv) << 24) | + (target_lfbdv == 64 ? 0 : target_lfbdv); + mtcpr(clk_plld, reg); + reset_needed = 1; + } + + mfcpr(clk_perd, reg); + perdv0 = (reg & CPR0_PERD_PERDV0_MASK) >> 24; + if (perdv0 != target_perdv0) { + reg &= ~CPR0_PERD_PERDV0_MASK; + reg |= (target_perdv0 << 24); + mtcpr(clk_perd, reg); + reset_needed = 1; + } + + mfcpr(clk_spcid, reg); + temp = (reg & CPR0_SPCID_SPCIDV0_MASK) >> 24; + spcid0 = temp ? temp : 4; + if (spcid0 != target_spcid0) { + reg &= ~CPR0_SPCID_SPCIDV0_MASK; + reg |= ((target_spcid0 == 4 ? 0 : target_spcid0) << 24); + mtcpr(clk_spcid, reg); + reset_needed = 1; + } + + /* Set reload inhibit so configuration will persist across + * processor resets */ + mfcpr(clk_icfg, reg); + reg &= ~CPR0_ICFG_RLI_MASK; + reg |= 1 << 31; + mtcpr(clk_icfg, reg); + } + + /* Reset processor if configuration changed */ + if (reset_needed) { + __asm__ __volatile__ ("sync; isync"); + mtspr(dbcr0, 0x20000000); + } +#endif +} + /* * Breath some life into the CPU... * - * Set up the memory map, + * Reconfigure PLL if necessary, + * set up the memory map, * initialize a bunch of registers */ void @@ -111,6 +208,7 @@ cpu_init_f (void) #if defined(CONFIG_WATCHDOG) unsigned long val; #endif + reconfigure_pll(CFG_PLL_RECONFIG); #if (defined(CONFIG_405EP) || defined (CONFIG_405EX)) && !defined(CFG_4xx_GPIO_TABLE) /* |