diff options
| author |   Joseph Lo <josephl@nvidia.com> | 2013-08-12 17:40:04 +0800 |
|---|---|---|
| committer |   Stephen Warren <swarren@nvidia.com> | 2013-08-12 13:30:11 -0600 |
| commit | e7a932b1961c3936c7ae5b8d1628f39dc50a746d (patch) | |
| tree | 757f5862da9fad0e10185382f9a9bbaca4723579 /arch/arm/mach-tegra/sleep.S | |
| parent | ARM: tegra: add common LP1 suspend support (diff) | |
| download | linux-dev-e7a932b1961c3936c7ae5b8d1628f39dc50a746d.tar.xz linux-dev-e7a932b1961c3936c7ae5b8d1628f39dc50a746d.zip | |
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.S')
| -rw-r--r-- | arch/arm/mach-tegra/sleep.S | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S index 8388113419fd..8d06213fbc47 100644 --- a/arch/arm/mach-tegra/sleep.S +++ b/arch/arm/mach-tegra/sleep.S @@ -134,10 +134,10 @@ ENTRY(tegra_shut_off_mmu) #ifdef CONFIG_CACHE_L2X0 /* Disable L2 cache */ check_cpu_part_num 0xc09, r9, r10 - movweq r4, #:lower16:(TEGRA_ARM_PERIF_BASE + 0x3000) - movteq r4, #:upper16:(TEGRA_ARM_PERIF_BASE + 0x3000) - moveq r5, #0 - streq r5, [r4, #L2X0_CTRL] + movweq r2, #:lower16:(TEGRA_ARM_PERIF_BASE + 0x3000) + movteq r2, #:upper16:(TEGRA_ARM_PERIF_BASE + 0x3000) + moveq r3, #0 + streq r3, [r2, #L2X0_CTRL] #endif mov pc, r0 ENDPROC(tegra_shut_off_mmu) |