diff options
| -rw-r--r-- | cpu/ppc4xx/cpu_init.c | 69 | ||||
| -rw-r--r-- | include/ppc440.h | 7 | ||||
| -rw-r--r-- | include/ppc4xx.h | 2 |
3 files changed, 77 insertions, 1 deletions
diff --git a/cpu/ppc4xx/cpu_init.c b/cpu/ppc4xx/cpu_init.c index a00da408c..ccd999367 100644 --- a/cpu/ppc4xx/cpu_init.c +++ b/cpu/ppc4xx/cpu_init.c @@ -330,3 +330,72 @@ int cpu_init_r (void) return 0; } + +#if defined(CONFIG_PCI) && \ + (defined(CONFIG_440EP) || defined(CONFIG_440EPX) || \ + defined(CONFIG_440GR) || defined(CONFIG_440GRX)) +/* + * 440EP(x)/GR(x) PCI async/sync clocking restriction: + * + * In asynchronous PCI mode, the synchronous PCI clock must meet + * certain requirements. The following equation describes the + * relationship that must be maintained between the asynchronous PCI + * clock and synchronous PCI clock. Select an appropriate PCI:PLB + * ratio to maintain the relationship: + * + * AsyncPCIClk - 1MHz <= SyncPCIclock <= (2 * AsyncPCIClk) - 1MHz + */ +static int ppc4xx_pci_sync_clock_ok(u32 sync, u32 async) +{ + if (((async - 1000000) > sync) || (sync > ((2 * async) - 1000000))) + return 0; + else + return 1; +} + +int ppc4xx_pci_sync_clock_config(u32 async) +{ + sys_info_t sys_info; + u32 sync; + int div; + u32 reg; + u32 spcid_val[] = { + CPR0_SPCID_SPCIDV0_DIV1, CPR0_SPCID_SPCIDV0_DIV2, + CPR0_SPCID_SPCIDV0_DIV3, CPR0_SPCID_SPCIDV0_DIV4 }; + + get_sys_info(&sys_info); + sync = sys_info.freqPCI; + + /* + * First check if the equation above is met + */ + if (!ppc4xx_pci_sync_clock_ok(sync, async)) { + /* + * Reconfigure PCI sync clock to meet the equation. + * Start with highest possible PCI sync frequency + * (divider 1). + */ + for (div = 1; div <= 4; div++) { + sync = sys_info.freqPLB / div; + if (ppc4xx_pci_sync_clock_ok(sync, async)) + break; + } + + if (div <= 4) { + mtcpr(CPR0_SPCID, spcid_val[div]); + + mfcpr(CPR0_ICFG, reg); + reg |= CPR0_ICFG_RLI_MASK; + mtcpr(CPR0_ICFG, reg); + + /* do chip reset */ + mtspr(SPRN_DBCR0, 0x20000000); + } else { + /* Impossible to configure the PCI sync clock */ + return -1; + } + } + + return 0; +} +#endif diff --git a/include/ppc440.h b/include/ppc440.h index fe0db93b5..e54a977dc 100644 --- a/include/ppc440.h +++ b/include/ppc440.h @@ -1701,9 +1701,14 @@ #define PLLSYS1_NTO1_MASK 0x00000001 /* CPU:PLB N-to-1 ratio */ #endif /* CONFIG_440GX */ -#if defined (CONFIG_440EPX) || defined (CONFIG_440GRX) +#if defined(CONFIG_440EP) || defined(CONFIG_440GR) || \ + defined(CONFIG_440EPX) || defined(CONFIG_440GRX) #define CPR0_ICFG_RLI_MASK 0x80000000 #define CPR0_SPCID_SPCIDV0_MASK 0x03000000 +#define CPR0_SPCID_SPCIDV0_DIV1 0x01000000 +#define CPR0_SPCID_SPCIDV0_DIV2 0x02000000 +#define CPR0_SPCID_SPCIDV0_DIV3 0x03000000 +#define CPR0_SPCID_SPCIDV0_DIV4 0x00000000 #define CPR0_PERD_PERDV0_MASK 0x07000000 #endif diff --git a/include/ppc4xx.h b/include/ppc4xx.h index 3bff00a55..5024db447 100644 --- a/include/ppc4xx.h +++ b/include/ppc4xx.h @@ -221,6 +221,8 @@ static inline void set_mcsr(u32 val) asm volatile("mtspr 0x23c, %0" : "=r" (val) :); } +int ppc4xx_pci_sync_clock_config(u32 async); + #endif /* __ASSEMBLY__ */ /* for multi-cpu support */ |