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| author | Vladimir Serbinenko <phcoder@gmail.com> | 2015-02-17 23:39:45 +0100 |
|---|---|---|
| committer | Vladimir Serbinenko <phcoder@gmail.com> | 2015-02-19 00:21:31 +0100 |
| commit | d15bddab57caedf283659c4d644e4696fb0e570e (patch) | |
| tree | b9e617e97cc502e1128c714799d51c9d359f2b47 /src/northbridge | |
| parent | 891f71a541fc036bd7de892d2eabd7df23bcecbb (diff) | |
| download | coreboot-d15bddab57caedf283659c4d644e4696fb0e570e.tar.xz | |
sandybridge: Try lower frequency if PLL didn't lock.
Change-Id: I2c2d586fc572b78b5019f8ef2714959799a8d2a9
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/8480
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Diffstat (limited to 'src/northbridge')
| -rw-r--r-- | src/northbridge/intel/sandybridge/raminit_native.c | 81 |
1 files changed, 45 insertions, 36 deletions
diff --git a/src/northbridge/intel/sandybridge/raminit_native.c b/src/northbridge/intel/sandybridge/raminit_native.c index 764ec38b37..7c7c5b2be6 100644 --- a/src/northbridge/intel/sandybridge/raminit_native.c +++ b/src/northbridge/intel/sandybridge/raminit_native.c @@ -609,47 +609,56 @@ static void dram_timing(ramctr_timing * ctrl) static void dram_freq(ramctr_timing * ctrl) { - u8 val2; - u32 reg1 = 0; - - /* Step 1 - Set target PCU frequency */ - - if (ctrl->tCK <= TCK_1066MHZ) { - ctrl->tCK = TCK_1066MHZ; - } else if (ctrl->tCK <= TCK_933MHZ) { - ctrl->tCK = TCK_933MHZ; - } else if (ctrl->tCK <= TCK_800MHZ) { - ctrl->tCK = TCK_800MHZ; - } else if (ctrl->tCK <= TCK_666MHZ) { - ctrl->tCK = TCK_666MHZ; - } else if (ctrl->tCK <= TCK_533MHZ) { - ctrl->tCK = TCK_533MHZ; - } else { + if (ctrl->tCK > TCK_400MHZ) { + printk (BIOS_ERR, "DRAM frequency is under lowest supported frequency (400 MHz). Increasing to 400 MHz as last resort"); ctrl->tCK = TCK_400MHZ; } + while (1) { + u8 val2; + u32 reg1 = 0; + + /* Step 1 - Set target PCU frequency */ + + if (ctrl->tCK <= TCK_1066MHZ) { + ctrl->tCK = TCK_1066MHZ; + } else if (ctrl->tCK <= TCK_933MHZ) { + ctrl->tCK = TCK_933MHZ; + } else if (ctrl->tCK <= TCK_800MHZ) { + ctrl->tCK = TCK_800MHZ; + } else if (ctrl->tCK <= TCK_666MHZ) { + ctrl->tCK = TCK_666MHZ; + } else if (ctrl->tCK <= TCK_533MHZ) { + ctrl->tCK = TCK_533MHZ; + } else if (ctrl->tCK <= TCK_400MHZ) { + ctrl->tCK = TCK_400MHZ; + } else { + die ("No lock frequency found"); + } - /* Frequency mulitplier. */ - u32 FRQ = get_FRQ(ctrl->tCK); + /* Frequency mulitplier. */ + u32 FRQ = get_FRQ(ctrl->tCK); - /* Step 2 - Select frequency in the MCU */ - reg1 = FRQ; - reg1 |= 0x80000000; // set running bit - MCHBAR32(0x5e00) = reg1; - while (reg1 & 0x80000000) { - printk(BIOS_DEBUG, " PLL busy..."); - reg1 = MCHBAR32(0x5e00); - } - printk(BIOS_DEBUG, "done\n"); - - /* Step 3 - Verify lock frequency */ - reg1 = MCHBAR32(0x5e04); - val2 = (u8) reg1; - if (val2 < FRQ) { - printk(BIOS_DEBUG, "Lock frequency is lower, recalculating\n"); - ctrl->tCK = 256000 / (val2 * BASEFREQ); + /* Step 2 - Select frequency in the MCU */ + reg1 = FRQ; + reg1 |= 0x80000000; // set running bit + MCHBAR32(0x5e00) = reg1; + while (reg1 & 0x80000000) { + printk(BIOS_DEBUG, " PLL busy..."); + reg1 = MCHBAR32(0x5e00); + } + printk(BIOS_DEBUG, "done\n"); + + /* Step 3 - Verify lock frequency */ + reg1 = MCHBAR32(0x5e04); + val2 = (u8) reg1; + if (val2 >= FRQ) { + printk(BIOS_DEBUG, "MCU frequency is set at : %d MHz\n", + (1000 << 8) / ctrl->tCK); + return; + } + printk(BIOS_DEBUG, "PLL didn't lock. Retrying at lower frequency\n"); + ctrl->tCK++; } - printk(BIOS_DEBUG, "MCU frequency is set at : %d MHz\n", - (1000 << 8) / ctrl->tCK); } static void dram_xover(ramctr_timing * ctrl) |