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Diffstat (limited to 'arch/arm/mach-at91/pm.c')
-rw-r--r--arch/arm/mach-at91/pm.c36
1 files changed, 32 insertions, 4 deletions
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index df6d673e83d5..f4501dea98b0 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -541,10 +541,42 @@ extern u32 at91_pm_suspend_in_sram_sz;
static int at91_suspend_finish(unsigned long val)
{
+ unsigned char modified_gray_code[] = {
+ 0x00, 0x01, 0x02, 0x03, 0x06, 0x07, 0x04, 0x05, 0x0c, 0x0d,
+ 0x0e, 0x0f, 0x0a, 0x0b, 0x08, 0x09, 0x18, 0x19, 0x1a, 0x1b,
+ 0x1e, 0x1f, 0x1c, 0x1d, 0x14, 0x15, 0x16, 0x17, 0x12, 0x13,
+ 0x10, 0x11,
+ };
+ unsigned int tmp, index;
int i;
if (soc_pm.data.mode == AT91_PM_BACKUP && soc_pm.data.ramc_phy) {
/*
+ * Bootloader will perform DDR recalibration and will try to
+ * restore the ZQ0SR0 with the value saved here. But the
+ * calibration is buggy and restoring some values from ZQ0SR0
+ * is forbidden and risky thus we need to provide processed
+ * values for these (modified gray code values).
+ */
+ tmp = readl(soc_pm.data.ramc_phy + DDR3PHY_ZQ0SR0);
+
+ /* Store pull-down output impedance select. */
+ index = (tmp >> DDR3PHY_ZQ0SR0_PDO_OFF) & 0x1f;
+ soc_pm.bu->ddr_phy_calibration[0] = modified_gray_code[index];
+
+ /* Store pull-up output impedance select. */
+ index = (tmp >> DDR3PHY_ZQ0SR0_PUO_OFF) & 0x1f;
+ soc_pm.bu->ddr_phy_calibration[0] |= modified_gray_code[index];
+
+ /* Store pull-down on-die termination impedance select. */
+ index = (tmp >> DDR3PHY_ZQ0SR0_PDODT_OFF) & 0x1f;
+ soc_pm.bu->ddr_phy_calibration[0] |= modified_gray_code[index];
+
+ /* Store pull-up on-die termination impedance select. */
+ index = (tmp >> DDR3PHY_ZQ0SRO_PUODT_OFF) & 0x1f;
+ soc_pm.bu->ddr_phy_calibration[0] |= modified_gray_code[index];
+
+ /*
* The 1st 8 words of memory might get corrupted in the process
* of DDR PHY recalibration; it is saved here in securam and it
* will be restored later, after recalibration, by bootloader
@@ -1066,10 +1098,6 @@ static int __init at91_pm_backup_init(void)
of_scan_flat_dt(at91_pm_backup_scan_memcs, &located);
if (!located)
goto securam_fail;
-
- /* DDR3PHY_ZQ0SR0 */
- soc_pm.bu->ddr_phy_calibration[0] = readl(soc_pm.data.ramc_phy +
- 0x188);
}
return 0;