diff options
Diffstat (limited to 'board')
| -rw-r--r-- | board/edb93xx/sdram_cfg.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/board/edb93xx/sdram_cfg.c b/board/edb93xx/sdram_cfg.c index 25b214be4b..3d4fe08e19 100644 --- a/board/edb93xx/sdram_cfg.c +++ b/board/edb93xx/sdram_cfg.c @@ -31,9 +31,9 @@ (SDRAM_BASE_ADDR | SDRAM_BANK_SEL_##bank | SDRAM_MODE_REG_VAL)) #define PRECHARGE_BANK(bank) (*(volatile uint32_t *) \ - (SDRAM_BASE_ADDR | SDRAM_BANK_SEL_##bank)) + (SDRAM_BASE_ADDR | SDRAM_BANK_SEL_##bank)) = 0 -static void force_precharge(void); +static void precharge_all_banks(void); static void setup_refresh_timer(void); static void program_mode_registers(void); @@ -48,7 +48,7 @@ void sdram_cfg(void) early_udelay(200); - force_precharge(); + precharge_all_banks(); setup_refresh_timer(); @@ -58,13 +58,22 @@ void sdram_cfg(void) writel(GLCONFIG_CKE, &sdram->glconfig); } -static void force_precharge(void) +static void precharge_all_banks(void) { + struct sdram_regs *sdram = (struct sdram_regs *)SDRAM_BASE; + + /* Issue PRECHARGE ALL commands */ + writel(GLCONFIG_INIT | GLCONFIG_CKE, &sdram->glconfig); + /* - * Errata most EP93xx revisions say that PRECHARGE ALL isn't always + * Errata of most EP93xx revisions say that PRECHARGE ALL isn't always * issued. * - * Do a read from each bank to make sure they're precharged + * Cirrus proposes a workaround which consists in performing a read from + * each bank to force the precharge. This causes some boards to hang. + * Writing to the SDRAM banks instead of reading has the same + * side-effect (the SDRAM controller issues the necessary precharges), + * but is known to work on all supported boards */ PRECHARGE_BANK(0); |