diff options
author | Joseph Lo <josephl@nvidia.com> | 2013-08-12 09:40:05 (GMT) |
---|---|---|
committer | Stephen Warren <swarren@nvidia.com> | 2013-08-12 19:30:11 (GMT) |
commit | 731a9274382f8e6f4961df79fe12ebcc5431a5df (patch) | |
tree | e46be9d206edf67c0bb3ec211489b98266aff827 /arch/arm/mach-tegra/sleep-tegra20.S | |
parent | e7a932b1961c3936c7ae5b8d1628f39dc50a746d (diff) | |
download | linux-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/sleep-tegra20.S')
-rw-r--r-- | arch/arm/mach-tegra/sleep-tegra20.S | 296 |
1 files changed, 296 insertions, 0 deletions
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 |