diff options
| author | Peter De Schrijver <pdeschrijver@nvidia.com> | 2012-01-26 18:22:02 +0200 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2012-02-06 09:16:16 -0800 |
| commit | c76fcc8af16fafc4a349192f8f08a5f7e6d7e706 (patch) | |
| tree | d4e761f8b529fd82fd29c4cddb46c3595dfa2471 /arch/arm/mach-tegra/sleep.S | |
| parent | 364c7c3f99c7ab79f6134ff0c55251d7ef77db8f (diff) | |
ARM: tegra: assembler code for LP3
Configure the flow controller for clockgating and enter WFI
Based on work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'arch/arm/mach-tegra/sleep.S')
| -rw-r--r-- | arch/arm/mach-tegra/sleep.S | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S new file mode 100644 index 00000000000..8f9fde161c3 --- /dev/null +++ b/arch/arm/mach-tegra/sleep.S @@ -0,0 +1,91 @@ +/* + * arch/arm/mach-tegra/sleep.S + * + * Copyright (c) 2010-2011, NVIDIA Corporation. + * Copyright (c) 2011, Google, Inc. + * + * Author: Colin Cross <ccross@android.com> + * Gary King <gking@nvidia.com> + * + * 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. + */ + +#include <linux/linkage.h> +#include <mach/io.h> +#include <mach/iomap.h> + +#include "flowctrl.h" + +#define TEGRA_FLOW_CTRL_VIRT (TEGRA_FLOW_CTRL_BASE - IO_PPSB_PHYS \ + + IO_PPSB_VIRT) + +/* returns the offset of the flow controller halt register for a cpu */ +.macro cpu_to_halt_reg rd, rcpu + cmp \rcpu, #0 + subne \rd, \rcpu, #1 + movne \rd, \rd, lsl #3 + addne \rd, \rd, #0x14 + moveq \rd, #0 +.endm + +/* returns the offset of the flow controller csr register for a cpu */ +.macro cpu_to_csr_reg rd, rcpu + cmp \rcpu, #0 + subne \rd, \rcpu, #1 + movne \rd, \rd, lsl #3 + addne \rd, \rd, #0x18 + moveq \rd, #8 +.endm + +/* returns the ID of the current processor */ +.macro cpu_id, rd + mrc p15, 0, \rd, c0, c0, 5 + and \rd, \rd, #0xF +.endm + +/* loads a 32-bit value into a register without a data access */ +.macro mov32, reg, val + movw \reg, #:lower16:\val + movt \reg, #:upper16:\val +.endm + +/* + * tegra_cpu_wfi + * + * puts current CPU in clock-gated wfi using the flow controller + * + * corrupts r0-r3 + * must be called with MMU on + */ + +ENTRY(tegra_cpu_wfi) + cpu_id r0 + cpu_to_halt_reg r1, r0 + cpu_to_csr_reg r2, r0 + mov32 r0, TEGRA_FLOW_CTRL_VIRT + mov r3, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG + str r3, [r0, r2] @ clear event & interrupt status + mov r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT | FLOW_CTRL_JTAG_RESUME + str r3, [r0, r1] @ put flow controller in wait irq mode + dsb + wfi + mov r3, #0 + str r3, [r0, r1] @ clear flow controller halt status + mov r3, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG + str r3, [r0, r2] @ clear event & interrupt status + dsb + mov pc, lr +ENDPROC(tegra_cpu_wfi) + |