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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>
This commit is contained in:
Vladimir Serbinenko 2015-02-17 23:39:45 +01:00
parent 891f71a541
commit d15bddab57
1 changed files with 45 additions and 36 deletions
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81
src/northbridge/intel/sandybridge/raminit_native.c
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@ -609,47 +609,56 @@ static void dram_timing(ramctr_timing * ctrl)
static void dram_freq(ramctr_timing * ctrl) static void dram_freq(ramctr_timing * ctrl)
{ {
u8 val2; if (ctrl->tCK > TCK_400MHZ) {
u32 reg1 = 0; printk (BIOS_ERR, "DRAM frequency is under lowest supported frequency (400 MHz). Increasing to 400 MHz as last resort");
/* 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 {
ctrl->tCK = TCK_400MHZ; ctrl->tCK = TCK_400MHZ;
} }
while (1) {
u8 val2;
u32 reg1 = 0;
/* Frequency mulitplier. */ /* Step 1 - Set target PCU frequency */
u32 FRQ = get_FRQ(ctrl->tCK);
/* Step 2 - Select frequency in the MCU */ if (ctrl->tCK <= TCK_1066MHZ) {
reg1 = FRQ; ctrl->tCK = TCK_1066MHZ;
reg1 |= 0x80000000; // set running bit } else if (ctrl->tCK <= TCK_933MHZ) {
MCHBAR32(0x5e00) = reg1; ctrl->tCK = TCK_933MHZ;
while (reg1 & 0x80000000) { } else if (ctrl->tCK <= TCK_800MHZ) {
printk(BIOS_DEBUG, " PLL busy..."); ctrl->tCK = TCK_800MHZ;
reg1 = MCHBAR32(0x5e00); } 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);
/* 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, "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);
}
printk(BIOS_DEBUG, "MCU frequency is set at : %d MHz\n",
(1000 << 8) / ctrl->tCK);
} }
static void dram_xover(ramctr_timing * ctrl) static void dram_xover(ramctr_timing * ctrl)