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authorJoseph Lo <josephl@nvidia.com>2013-08-12 13:40:05 +0400
committerStephen Warren <swarren@nvidia.com>2013-08-12 23:30:11 +0400
commit731a9274382f8e6f4961df79fe12ebcc5431a5df (patch)
treee46be9d206edf67c0bb3ec211489b98266aff827 /arch/arm/mach-tegra/pm-tegra20.c
parente7a932b1961c3936c7ae5b8d1628f39dc50a746d (diff)
downloadlinux-731a9274382f8e6f4961df79fe12ebcc5431a5df.tar.xz
ARM: tegra: add LP1 suspend support for Tegra20
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 * putting SDRAM into self-refresh * storing some EMC registers and SCLK burst policy * switching CPU to CLK_M (12MHz OSC) * switching SCLK to CLK_S (32KHz OSC) * tunning off PLLM, PLLP and PLLC * shutting off the CPU rail The sequence of LP1 resuming: * re-enabling PLLM, PLLP, and PLLC * restoring some EMC registers and SCLK burst policy * setting up CCLK burst policy to PLLP * 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 PLLP. 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: Colin Cross <ccross@android.com> Gary King <gking@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/pm-tegra20.c')
-rw-r--r--arch/arm/mach-tegra/pm-tegra20.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/pm-tegra20.c b/arch/arm/mach-tegra/pm-tegra20.c
new file mode 100644
index 000000000000..d65e1d786400
--- /dev/null
+++ b/arch/arm/mach-tegra/pm-tegra20.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+
+#include "pm.h"
+
+#ifdef CONFIG_PM_SLEEP
+extern u32 tegra20_iram_start, tegra20_iram_end;
+extern void tegra20_sleep_core_finish(unsigned long);
+
+void tegra20_lp1_iram_hook(void)
+{
+ tegra_lp1_iram.start_addr = &tegra20_iram_start;
+ tegra_lp1_iram.end_addr = &tegra20_iram_end;
+}
+
+void tegra20_sleep_core_init(void)
+{
+ tegra_sleep_core_finish = tegra20_sleep_core_finish;
+}
+#endif