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authorJoseph Lo <josephl@nvidia.com>2013-08-12 09:40:04 (GMT)
committerStephen Warren <swarren@nvidia.com>2013-08-12 19:30:11 (GMT)
commite7a932b1961c3936c7ae5b8d1628f39dc50a746d (patch)
tree757f5862da9fad0e10185382f9a9bbaca4723579 /arch/arm/mach-tegra/sleep.h
parent95872f427eca73b19ac9466c25afd9bb876dc1aa (diff)
downloadlinux-e7a932b1961c3936c7ae5b8d1628f39dc50a746d.tar.xz
ARM: tegra: add LP1 suspend support for Tegra30
The LP1 suspend mode will power off the CPU, clock gated the PLLs and put SDRAM to self-refresh mode. Any interrupt can wake up device from LP1. The sequence when LP1 suspending: * tunning off L1 data cache and the MMU * storing some EMC registers, DPD (deep power down) status, clk source of mselect and SCLK burst policy * putting SDRAM into self-refresh * switching CPU to CLK_M (12MHz OSC) * tunning off PLLM, PLLP, PLLA, PLLC and PLLX * switching SCLK to CLK_S (32KHz OSC) * shutting off the CPU rail The sequence of LP1 resuming: * re-enabling PLLM, PLLP, PLLA, PLLC and PLLX * restoring the clk source of mselect and SCLK burst policy * setting up CCLK burst policy to PLLX * restoring DPD status and some EMC registers * resuming SDRAM to normal mode * jumping to the "tegra_resume" from PMC_SCRATCH41 Due to the SDRAM will be put into self-refresh mode, the low level procedures of LP1 suspending and resuming should be copied to TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K) when suspending. Before restoring the CPU context when resuming, the SDRAM needs to be switched back to normal mode. And the PLLs need to be re-enabled, SCLK burst policy be restored, CCLK burst policy be set in PLLX. Then jumping to "tegra_resume" that was expected to be stored in PMC_SCRATCH41 to restore CPU context and back to kernel. Based on the work by: Scott Williams <scwilliams@nvidia.com> Signed-off-by: Joseph Lo <josephl@nvidia.com> Signed-off-by: Stephen Warren <swarren@nvidia.com>
Diffstat (limited to 'arch/arm/mach-tegra/sleep.h')
-rw-r--r--arch/arm/mach-tegra/sleep.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h
index e907e40..a4edbb3 100644
--- a/arch/arm/mach-tegra/sleep.h
+++ b/arch/arm/mach-tegra/sleep.h
@@ -46,6 +46,14 @@
#define TEGRA_FLUSH_CACHE_ALL 1
#ifdef __ASSEMBLY__
+/* waits until the microsecond counter (base) is > rn */
+.macro wait_until, rn, base, tmp
+ add \rn, \rn, #1
+1001: ldr \tmp, [\base]
+ cmp \tmp, \rn
+ bmi 1001b
+.endm
+
/* returns the offset of the flow controller halt register for a cpu */
.macro cpu_to_halt_reg rd, rcpu
cmp \rcpu, #0