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authorThierry Reding <treding@nvidia.com>2015-09-08 09:38:04 (GMT)
committerTom Warren <twarren@nvidia.com>2015-09-16 23:11:31 (GMT)
commit8e1601d994e2fa8b8c7826470c3d923a684492a4 (patch)
treebe4bc580ea0ce2f4005efbf1f54a5f346e5c8c21
parentaba11d4476b56eb7712184597eb303ae544f0c69 (diff)
downloadu-boot-8e1601d994e2fa8b8c7826470c3d923a684492a4.tar.xz
ARM: tegra114: Clear IDDQ when enabling PLLC
Enabling a PLL while IDDQ is high. The Linux kernel checks for this condition and warns about it verbosely, so while this seems to work fine, fix it up according to the programming guidelines provided in the Tegra K1 TRM (v02p), Section 5.3.8.1 ("PLLC and PLLC4 Startup Sequence"). The Tegra114 TRM doesn't contain this information, but the programming of PLLC is the same on Tegra114 and Tegra124. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Tom Warren <twarren@nvidia.com>
-rw-r--r--arch/arm/include/asm/arch-tegra114/clock.h3
-rw-r--r--arch/arm/mach-tegra/tegra114/clock.c5
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/include/asm/arch-tegra114/clock.h b/arch/arm/include/asm/arch-tegra114/clock.h
index abbefcd..9bee397 100644
--- a/arch/arm/include/asm/arch-tegra114/clock.h
+++ b/arch/arm/include/asm/arch-tegra114/clock.h
@@ -25,4 +25,7 @@
#define OSC_FREQ_SHIFT 28
#define OSC_FREQ_MASK (0xF << OSC_FREQ_SHIFT)
+/* CLK_RST_CONTROLLER_PLLC_MISC_0 */
+#define PLLC_IDDQ (1 << 26)
+
#endif /* _TEGRA114_CLOCK_H_ */
diff --git a/arch/arm/mach-tegra/tegra114/clock.c b/arch/arm/mach-tegra/tegra114/clock.c
index cec843b..e6ef873 100644
--- a/arch/arm/mach-tegra/tegra114/clock.c
+++ b/arch/arm/mach-tegra/tegra114/clock.c
@@ -629,6 +629,11 @@ void clock_early_init(void)
tegra30_set_up_pllp();
+ /* clear IDDQ before accessing any other PLLC registers */
+ pllinfo = &tegra_pll_info_table[CLOCK_ID_CGENERAL];
+ clrbits_le32(&clkrst->crc_pll[CLOCK_ID_CGENERAL].pll_misc, PLLC_IDDQ);
+ udelay(2);
+
/*
* PLLC output frequency set to 600Mhz
* PLLD output frequency set to 925Mhz