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authorPeter De Schrijver <pdeschrijver@nvidia.com>2012-01-26 20:22:02 +0400
committerOlof Johansson <olof@lixom.net>2012-02-06 21:16:16 +0400
commitc76fcc8af16fafc4a349192f8f08a5f7e6d7e706 (patch)
treed4e761f8b529fd82fd29c4cddb46c3595dfa2471 /arch/arm/mach-tegra/sleep.S
parent364c7c3f99c7ab79f6134ff0c55251d7ef77db8f (diff)
downloadlinux-c76fcc8af16fafc4a349192f8f08a5f7e6d7e706.tar.xz
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.S91
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 000000000000..8f9fde161c34
--- /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)
+