[PATCH V3 6/8] ARM: tegra: add LP1 suspend support for Tegra20
Joseph Lo
josephl at nvidia.com
Mon Aug 12 05:40:05 EDT 2013
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 at android.com>
Gary King <gking at nvidia.com>
Signed-off-by: Joseph Lo <josephl at nvidia.com>
---
V3:
* switch SCLK burst policy reg to CLK_S after disabling PLLs to align
with Tegra30/114
V2:
* using IS_ENABLE for SoC specific code
* calculating "tegra20_sdram_pad_save" by assembly symbol
---
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/pm-tegra20.c | 34 +++++
arch/arm/mach-tegra/pm.c | 8 +
arch/arm/mach-tegra/pm.h | 2 +
arch/arm/mach-tegra/sleep-tegra20.S | 296 ++++++++++++++++++++++++++++++++++++
5 files changed, 341 insertions(+)
create mode 100644 arch/arm/mach-tegra/pm-tegra20.c
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index d341980..a3fe22d 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra20_speedo.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_emc.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += sleep-tegra20.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += pm-tegra20.o
ifeq ($(CONFIG_CPU_IDLE),y)
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += cpuidle-tegra20.o
endif
diff --git a/arch/arm/mach-tegra/pm-tegra20.c b/arch/arm/mach-tegra/pm-tegra20.c
new file mode 100644
index 0000000..d65e1d7
--- /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
diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index d557159..d2f736a 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -211,6 +211,10 @@ static int tegra_sleep_core(unsigned long v2p)
static bool tegra_lp1_iram_hook(void)
{
switch (tegra_chip_id) {
+ case TEGRA20:
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
+ tegra20_lp1_iram_hook();
+ break;
case TEGRA30:
if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
tegra30_lp1_iram_hook();
@@ -233,6 +237,10 @@ static bool tegra_lp1_iram_hook(void)
static bool tegra_sleep_core_init(void)
{
switch (tegra_chip_id) {
+ case TEGRA20:
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
+ tegra20_sleep_core_init();
+ break;
case TEGRA30:
if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
tegra30_sleep_core_init();
diff --git a/arch/arm/mach-tegra/pm.h b/arch/arm/mach-tegra/pm.h
index 803bd53..fe204e5 100644
--- a/arch/arm/mach-tegra/pm.h
+++ b/arch/arm/mach-tegra/pm.h
@@ -30,6 +30,8 @@ struct tegra_lp1_iram {
extern struct tegra_lp1_iram tegra_lp1_iram;
extern void (*tegra_sleep_core_finish)(unsigned long v2p);
+void tegra20_lp1_iram_hook(void);
+void tegra20_sleep_core_init(void);
void tegra30_lp1_iram_hook(void);
void tegra30_sleep_core_init(void);
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index f87721d..5c3bd11 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -23,10 +23,49 @@
#include <asm/assembler.h>
#include <asm/proc-fns.h>
#include <asm/cp15.h>
+#include <asm/cache.h>
#include "sleep.h"
#include "flowctrl.h"
+#define EMC_CFG 0xc
+#define EMC_ADR_CFG 0x10
+#define EMC_REFRESH 0x70
+#define EMC_NOP 0xdc
+#define EMC_SELF_REF 0xe0
+#define EMC_REQ_CTRL 0x2b0
+#define EMC_EMC_STATUS 0x2b4
+
+#define CLK_RESET_CCLK_BURST 0x20
+#define CLK_RESET_CCLK_DIVIDER 0x24
+#define CLK_RESET_SCLK_BURST 0x28
+#define CLK_RESET_SCLK_DIVIDER 0x2c
+#define CLK_RESET_PLLC_BASE 0x80
+#define CLK_RESET_PLLM_BASE 0x90
+#define CLK_RESET_PLLP_BASE 0xa0
+
+#define APB_MISC_XM2CFGCPADCTRL 0x8c8
+#define APB_MISC_XM2CFGDPADCTRL 0x8cc
+#define APB_MISC_XM2CLKCFGPADCTRL 0x8d0
+#define APB_MISC_XM2COMPPADCTRL 0x8d4
+#define APB_MISC_XM2VTTGENPADCTRL 0x8d8
+#define APB_MISC_XM2CFGCPADCTRL2 0x8e4
+#define APB_MISC_XM2CFGDPADCTRL2 0x8e8
+
+.macro pll_enable, rd, r_car_base, pll_base
+ ldr \rd, [\r_car_base, #\pll_base]
+ tst \rd, #(1 << 30)
+ orreq \rd, \rd, #(1 << 30)
+ streq \rd, [\r_car_base, #\pll_base]
+.endm
+
+.macro emc_device_mask, rd, base
+ ldr \rd, [\base, #EMC_ADR_CFG]
+ tst \rd, #(0x3 << 24)
+ moveq \rd, #(0x1 << 8) @ just 1 device
+ movne \rd, #(0x3 << 8) @ 2 devices
+.endm
+
#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
/*
* tegra20_hotplug_shutdown(void)
@@ -181,6 +220,28 @@ ENTRY(tegra20_cpu_is_resettable_soon)
ENDPROC(tegra20_cpu_is_resettable_soon)
/*
+ * tegra20_sleep_core_finish(unsigned long v2p)
+ *
+ * Enters suspend in LP0 or LP1 by turning off the mmu and jumping to
+ * tegra20_tear_down_core in IRAM
+ */
+ENTRY(tegra20_sleep_core_finish)
+ /* Flush, disable the L1 data cache and exit SMP */
+ bl tegra_disable_clean_inv_dcache
+
+ mov32 r3, tegra_shut_off_mmu
+ add r3, r3, r0
+
+ mov32 r0, tegra20_tear_down_core
+ mov32 r1, tegra20_iram_start
+ sub r0, r0, r1
+ mov32 r1, TEGRA_IRAM_CODE_AREA
+ add r0, r0, r1
+
+ mov pc, r3
+ENDPROC(tegra20_sleep_core_finish)
+
+/*
* tegra20_sleep_cpu_secondary_finish(unsigned long v2p)
*
* Enters WFI on secondary CPU by exiting coherency.
@@ -251,6 +312,150 @@ ENTRY(tegra20_tear_down_cpu)
b tegra20_enter_sleep
ENDPROC(tegra20_tear_down_cpu)
+/* START OF ROUTINES COPIED TO IRAM */
+ .align L1_CACHE_SHIFT
+ .globl tegra20_iram_start
+tegra20_iram_start:
+
+/*
+ * tegra20_lp1_reset
+ *
+ * reset vector for LP1 restore; copied into IRAM during suspend.
+ * Brings the system back up to a safe staring point (SDRAM out of
+ * self-refresh, PLLC, PLLM and PLLP reenabled, CPU running on PLLP,
+ * system clock running on the same PLL that it suspended at), and
+ * jumps to tegra_resume to restore virtual addressing and PLLX.
+ * The physical address of tegra_resume expected to be stored in
+ * PMC_SCRATCH41.
+ *
+ * NOTE: THIS *MUST* BE RELOCATED TO TEGRA_IRAM_CODE_AREA.
+ */
+ENTRY(tegra20_lp1_reset)
+ /*
+ * The CPU and system bus are running at 32KHz and executing from
+ * IRAM when this code is executed; immediately switch to CLKM and
+ * enable PLLM, PLLP, PLLC.
+ */
+ mov32 r0, TEGRA_CLK_RESET_BASE
+
+ mov r1, #(1 << 28)
+ str r1, [r0, #CLK_RESET_SCLK_BURST]
+ str r1, [r0, #CLK_RESET_CCLK_BURST]
+ mov r1, #0
+ str r1, [r0, #CLK_RESET_CCLK_DIVIDER]
+ str r1, [r0, #CLK_RESET_SCLK_DIVIDER]
+
+ pll_enable r1, r0, CLK_RESET_PLLM_BASE
+ pll_enable r1, r0, CLK_RESET_PLLP_BASE
+ pll_enable r1, r0, CLK_RESET_PLLC_BASE
+
+ adr r2, tegra20_sdram_pad_address
+ adr r4, tegra20_sdram_pad_save
+ mov r5, #0
+
+ ldr r6, tegra20_sdram_pad_size
+padload:
+ ldr r7, [r2, r5] @ r7 is the addr in the pad_address
+
+ ldr r1, [r4, r5]
+ str r1, [r7] @ restore the value in pad_save
+
+ add r5, r5, #4
+ cmp r6, r5
+ bne padload
+
+padload_done:
+ /* 255uS delay for PLL stabilization */
+ mov32 r7, TEGRA_TMRUS_BASE
+ ldr r1, [r7]
+ add r1, r1, #0xff
+ wait_until r1, r7, r9
+
+ adr r4, tegra20_sclk_save
+ ldr r4, [r4]
+ str r4, [r0, #CLK_RESET_SCLK_BURST]
+ mov32 r4, ((1 << 28) | (4)) @ burst policy is PLLP
+ str r4, [r0, #CLK_RESET_CCLK_BURST]
+
+ mov32 r0, TEGRA_EMC_BASE
+ ldr r1, [r0, #EMC_CFG]
+ bic r1, r1, #(1 << 31) @ disable DRAM_CLK_STOP
+ str r1, [r0, #EMC_CFG]
+
+ mov r1, #0
+ str r1, [r0, #EMC_SELF_REF] @ take DRAM out of self refresh
+ mov r1, #1
+ str r1, [r0, #EMC_NOP]
+ str r1, [r0, #EMC_NOP]
+ str r1, [r0, #EMC_REFRESH]
+
+ emc_device_mask r1, r0
+
+exit_selfrefresh_loop:
+ ldr r2, [r0, #EMC_EMC_STATUS]
+ ands r2, r2, r1
+ bne exit_selfrefresh_loop
+
+ mov r1, #0 @ unstall all transactions
+ str r1, [r0, #EMC_REQ_CTRL]
+
+ mov32 r0, TEGRA_PMC_BASE
+ ldr r0, [r0, #PMC_SCRATCH41]
+ mov pc, r0 @ jump to tegra_resume
+ENDPROC(tegra20_lp1_reset)
+
+/*
+ * tegra20_tear_down_core
+ *
+ * copied into and executed from IRAM
+ * puts memory in self-refresh for LP0 and LP1
+ */
+tegra20_tear_down_core:
+ bl tegra20_sdram_self_refresh
+ bl tegra20_switch_cpu_to_clk32k
+ b tegra20_enter_sleep
+
+/*
+ * tegra20_switch_cpu_to_clk32k
+ *
+ * In LP0 and LP1 all PLLs will be turned off. Switch the CPU and system clock
+ * to the 32KHz clock.
+ */
+tegra20_switch_cpu_to_clk32k:
+ /*
+ * start by switching to CLKM to safely disable PLLs, then switch to
+ * CLKS.
+ */
+ mov r0, #(1 << 28)
+ str r0, [r5, #CLK_RESET_SCLK_BURST]
+ str r0, [r5, #CLK_RESET_CCLK_BURST]
+ mov r0, #0
+ str r0, [r5, #CLK_RESET_CCLK_DIVIDER]
+ str r0, [r5, #CLK_RESET_SCLK_DIVIDER]
+
+ /* 2uS delay delay between changing SCLK and disabling PLLs */
+ mov32 r7, TEGRA_TMRUS_BASE
+ ldr r1, [r7]
+ add r1, r1, #2
+ wait_until r1, r7, r9
+
+ /* disable PLLM, PLLP and PLLC */
+ ldr r0, [r5, #CLK_RESET_PLLM_BASE]
+ bic r0, r0, #(1 << 30)
+ str r0, [r5, #CLK_RESET_PLLM_BASE]
+ ldr r0, [r5, #CLK_RESET_PLLP_BASE]
+ bic r0, r0, #(1 << 30)
+ str r0, [r5, #CLK_RESET_PLLP_BASE]
+ ldr r0, [r5, #CLK_RESET_PLLC_BASE]
+ bic r0, r0, #(1 << 30)
+ str r0, [r5, #CLK_RESET_PLLC_BASE]
+
+ /* switch to CLKS */
+ mov r0, #0 /* brust policy = 32KHz */
+ str r0, [r5, #CLK_RESET_SCLK_BURST]
+
+ mov pc, lr
+
/*
* tegra20_enter_sleep
*
@@ -275,4 +480,95 @@ halted:
isb
b halted
+/*
+ * tegra20_sdram_self_refresh
+ *
+ * called with MMU off and caches disabled
+ * puts sdram in self refresh
+ * must be executed from IRAM
+ */
+tegra20_sdram_self_refresh:
+ mov32 r1, TEGRA_EMC_BASE @ r1 reserved for emc base addr
+
+ mov r2, #3
+ str r2, [r1, #EMC_REQ_CTRL] @ stall incoming DRAM requests
+
+emcidle:
+ ldr r2, [r1, #EMC_EMC_STATUS]
+ tst r2, #4
+ beq emcidle
+
+ mov r2, #1
+ str r2, [r1, #EMC_SELF_REF]
+
+ emc_device_mask r2, r1
+
+emcself:
+ ldr r3, [r1, #EMC_EMC_STATUS]
+ and r3, r3, r2
+ cmp r3, r2
+ bne emcself @ loop until DDR in self-refresh
+
+ adr r2, tegra20_sdram_pad_address
+ adr r3, tegra20_sdram_pad_safe
+ adr r4, tegra20_sdram_pad_save
+ mov r5, #0
+
+ ldr r6, tegra20_sdram_pad_size
+padsave:
+ ldr r0, [r2, r5] @ r0 is the addr in the pad_address
+
+ ldr r1, [r0]
+ str r1, [r4, r5] @ save the content of the addr
+
+ ldr r1, [r3, r5]
+ str r1, [r0] @ set the save val to the addr
+
+ add r5, r5, #4
+ cmp r6, r5
+ bne padsave
+padsave_done:
+
+ mov32 r5, TEGRA_CLK_RESET_BASE
+ ldr r0, [r5, #CLK_RESET_SCLK_BURST]
+ adr r2, tegra20_sclk_save
+ str r0, [r2]
+ dsb
+ mov pc, lr
+
+tegra20_sdram_pad_address:
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2CLKCFGPADCTRL
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2COMPPADCTRL
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2VTTGENPADCTRL
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL2
+ .word TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL2
+
+tegra20_sdram_pad_size:
+ .word tegra20_sdram_pad_size - tegra20_sdram_pad_address
+
+tegra20_sdram_pad_safe:
+ .word 0x8
+ .word 0x8
+ .word 0x0
+ .word 0x8
+ .word 0x5500
+ .word 0x08080040
+ .word 0x0
+
+tegra20_sclk_save:
+ .word 0x0
+
+tegra20_sdram_pad_save:
+ .rept (tegra20_sdram_pad_size - tegra20_sdram_pad_address) / 4
+ .long 0
+ .endr
+
+ .ltorg
+/* dummy symbol for end of IRAM */
+ .align L1_CACHE_SHIFT
+ .globl tegra20_iram_end
+tegra20_iram_end:
+ b .
#endif
--
1.8.3.4
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