diff options
| author | Gary King <gking@nvidia.com> | 2010-04-14 20:11:24 -0700 |
|---|---|---|
| committer | Gary King <gking@nvidia.com> | 2010-04-15 20:09:05 -0700 |
| commit | 69171ba958a221624ccabf08a9cde5ff03b51cf1 (patch) | |
| tree | 7280a0980cc1496eeddab24ca0ba711114025198 /arch/arm/mach-tegra/power-macros.S | |
| parent | 42705eb0a3d53b5c23f9ea439e97099b66320703 (diff) | |
[ARM] tegra: add LP2 idle-mode support
LP2 idle mode power-gates the main CPU complex, requiring a
full processor state save and restore from a reset vector
processor context area is allocated during platform initialization
from the kernel, and mapped into the hotplug page tables (which also
serve as the initial page tables for the LP2 main processor reset)
restoring the processor from LP2 requires calculation of a system-
and APB-clock-dependent CPU power good timer value. on Harmony,
2ms is a good baseline value for this, and the APB clock is running at
13.5MHz. these values need to be un-hardcoded for other platforms.
Change-Id: I70a18a1d995e1d34da64d60fbdcd4568ef442f0c
Diffstat (limited to 'arch/arm/mach-tegra/power-macros.S')
| -rw-r--r-- | arch/arm/mach-tegra/power-macros.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/power-macros.S b/arch/arm/mach-tegra/power-macros.S new file mode 100644 index 000000000000..492416439760 --- /dev/null +++ b/arch/arm/mach-tegra/power-macros.S @@ -0,0 +1,45 @@ +/* + * arch/arm/mach-tegra/power-macros.S + * + * Assembly macros useful for power state save / restore routines + * + * Copyright (c) 2010, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +/* returns the ID of the current processor */ +.macro cpu_id, rd + mrc p15, 0, \rd, c0, c0, 5 + and \rd, \rd, #0xF +.endm + +/* waits until the microsecond counter (base) ticks, for exact timing loops */ +.macro wait_for_us, rd, base, tmp + ldr \rd, [\base] +1001: ldr \tmp, [\base] + cmp \rd, \tmp + beq 1001b + mov \tmp, \rd +.endm + +/* waits until the microsecond counter (base) is >= rn */ +.macro wait_until, rn, base, tmp +1002: ldr \tmp, [\base] + sub \tmp, \tmp, \rn + ands \tmp, \tmp, #0x80000000 + dmb + bne 1002b +.endm |