In preparation for suspend-resume support for AM33XX, add the assembly file with the code which is copied to internal memory (OCMC RAM) during bootup and runs from there. As part of the low power entry (DeepSleep0 mode in AM33XX TRM), the code running from OCMC RAM does the following 1. Stores the EMIF configuration 2. Puts external memory in self-refresh 3. Disables EMIF clock 4. Puts the PLLs in bypass 5. Executes WFI after writing to MPU_CLKCTRL register. If no interrupts have come, WFI execution on MPU gets registered as an interrupt with the WKUP-M3. WKUP-M3 takes care of disabling some clocks which MPU should not (L3, L4, OCMC RAM etc) and takes care of clockdomain and powerdomain transitions as part of the DeepSleep0 mode entry. In case a late interrupt comes in, WFI ends up as a NOP and MPU continues execution from internal memory. The 'abort path' code undoes whatever was done as part of the low power entry and indicates a suspend failure by passing a non-zero value to the cpu_resume routine. The 'resume path' code is similar to the 'abort path' with the key difference of MMU being enabled in the 'abort path' but being disabled in the 'resume path' due to MPU getting powered off. In addition to the top level steps outlined above, there are some additional register writes related to external memory controller which help in lowering the overall power consumption in the suspended state. These include changing the state of the IOs to LVCMOS mode and enabling pull downs on the IOs to reduce leakage in low power state. Signed-off-by: Vaibhav Bedia <vaibhav.bedia@xxxxxx> Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx> Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> --- v1->v2: This is a new patch in the series to keep the assembly code additionl separate as mentioned by Kevin Hilman arch/arm/mach-omap2/sleep33xx.S | 584 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 584 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-omap2/sleep33xx.S diff --git a/arch/arm/mach-omap2/sleep33xx.S b/arch/arm/mach-omap2/sleep33xx.S new file mode 100644 index 0000000..98fa76c --- /dev/null +++ b/arch/arm/mach-omap2/sleep33xx.S @@ -0,0 +1,584 @@ +/* + * Low level suspend code for AM33XX SoCs + * + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ + * Vaibhav Bedia <vaibhav.bedia@xxxxxx> + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/linkage.h> +#include <linux/ti_emif.h> +#include <asm/memory.h> +#include <asm/assembler.h> + +#include "cm33xx.h" +#include "pm33xx.h" +#include "prm33xx.h" +#include "control.h" + + .text + .align 3 + + .macro pll_bypass, name, clk_mode_addr, idlest_addr, pll_mode +pll_bypass_\name: + ldr r0, \clk_mode_addr + ldr r1, [r0] + str r1, clk_mode_\pll_mode + bic r1, r1, #(7 << 0) + orr r1, r1, #0x5 + str r1, [r0] + ldr r0, \idlest_addr +wait_pll_bypass_\name: + ldr r1, [r0] + tst r1, #0x0 + bne wait_pll_bypass_\name + .endm + + .macro pll_lock, name, clk_mode_addr, idlest_addr, pll_mode +pll_lock_\name: + ldr r0, \clk_mode_addr + ldr r1, clk_mode_\pll_mode + str r1, [r0] + and r1, r1, #0x7 + cmp r1, #0x7 + bne pll_mode_restored_\name + ldr r0, \idlest_addr +wait_pll_lock_\name: + ldr r1, [r0] + ands r1, #0x1 + beq wait_pll_lock_\name +pll_mode_restored_\name: + nop + .endm + + .macro ddr_self_refresh, num +ddr_self_refresh_\num: + add r1, r0, #EMIF_POWER_MANAGEMENT_CONTROL + ldr r2, [r1] + orr r2, r2, #0xa0 @ a reasonable delay for entering SR + str r2, [r1, #0] + str r2, [r1, #4] @ write to shadow register also + + ldr r2, ddr_start @ do a dummy access to DDR + ldr r3, [r2, #0] + ldr r3, [r1, #0] @ now set the LP MODE to Self-Refresh + orr r3, r3, #0x200 + str r3, [r1, #0] + + mov r1, #0x1000 @ Give some time for system to enter SR +wait_sr_\num: + subs r1, r1, #1 + bne wait_sr_\num + .endm + + .macro wait_sdram_config, num +wait_sdram_config_\num: + mov r0, #0x100 +wait_sc_\num: + subs r0, r0 ,#1 + bne wait_sc_\num + .endm + +ENTRY(am33xx_do_wfi) + stmfd sp!, {r4 - r11, lr} @ save registers on stack + /* Get the EMIF virtual address */ + ldr r0, emif_addr_func + blx r0 + /* Save it for later use */ + str r0, emif_addr_virt + + /* This ensures isb */ + ldr r0, dcache_flush + blx r0 + + /* Same as v7_flush_icache_all - saving a branch */ + mov r0, #0 + mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate + + ldr r0, emif_addr_virt + /* Save EMIF configuration */ + ldr r1, [r0, #EMIF_SDRAM_CONFIG] + str r1, emif_sdcfg_val + ldr r1, [r0, #EMIF_SDRAM_REFRESH_CONTROL] + str r1, emif_ref_ctrl_val + ldr r1, [r0, #EMIF_SDRAM_TIMING_1] + str r1, emif_timing1_val + ldr r1, [r0, #EMIF_SDRAM_TIMING_2] + str r1, emif_timing2_val + ldr r1, [r0, #EMIF_SDRAM_TIMING_3] + str r1, emif_timing3_val + ldr r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL] + str r1, emif_pmcr_val + ldr r1, [r0, #EMIF_POWER_MANAGEMENT_CTRL_SHDW] + str r1, emif_pmcr_shdw_val + ldr r1, [r0, #EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG] + str r1, emif_zqcfg_val + ldr r1, [r0, #EMIF_DDR_PHY_CTRL_1] + str r1, emif_rd_lat_val + + /* Ensure that all the writes to DDR leave the A8 */ + dsb + dmb + isb + + ddr_self_refresh 1 + + /* Disable EMIF at this point */ + ldr r1, virt_emif_clkctrl + ldr r2, [r1] + bic r2, r2, #(3 << 0) + str r2, [r1] + + ldr r1, virt_emif_clkctrl +wait_emif_disable: + ldr r2, [r1] + ldr r3, module_disabled_val + cmp r2, r3 + bne wait_emif_disable + + /* + * For the MPU WFI to be registered as an interrupt + * to WKUP_M3, MPU_CLKCTRL.MODULEMODE needs to be set + * to DISABLED + */ + ldr r1, virt_mpu_clkctrl + ldr r2, [r1] + bic r2, r2, #(3 << 0) + str r2, [r1] + + /* DDR3 reset override and mDDR mode selection */ + ldr r0, virt_ddr_io_ctrl + mov r1, #(0x9 << 28) + str r1, [r0] + + /* Weak pull down for DQ, DM */ + ldr r1, virt_ddr_data0_ioctrl + ldr r2, susp_io_pull_data + str r2, [r1] + + ldr r1, virt_ddr_data1_ioctrl + ldr r2, susp_io_pull_data + str r2, [r1] + + /* Disable VTP */ + ldr r1, virt_ddr_vtp_ctrl + ldr r2, susp_vtp_ctrl_val + str r2, [r1] + + /* Enable SRAM LDO ret mode */ + ldr r0, virt_sram_ldo_addr + ldr r1, [r0] + orr r1, #1 + str r1, [r0] + +put_pll_bypass: + /* Put the PLLs in bypass mode */ + pll_bypass core, virt_core_clk_mode, virt_core_idlest, core_val + pll_bypass ddr, virt_ddr_clk_mode, virt_ddr_idlest, ddr_val + pll_bypass disp, virt_disp_clk_mode, virt_disp_idlest, disp_val + pll_bypass per, virt_per_clk_mode, virt_per_idlest, per_val + pll_bypass mpu, virt_mpu_clk_mode, virt_mpu_idlest, mpu_val + + dsb + dmb + isb + + wfi + + /* NOPs to ensure the A8 pipeline is clean */ + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + + /* We come here in case of an abort due to a late interrupt */ + + /* Set MPU_CLKCTRL.MODULEMODE back to ENABLE */ + ldr r1, virt_mpu_clkctrl + mov r2, #0x2 + str r2, [r1] + + /* Relock the PLLs */ + pll_lock mpu_abt, virt_mpu_clk_mode, virt_mpu_idlest, mpu_val + pll_lock per_abt, virt_per_clk_mode, virt_per_idlest, per_val + pll_lock disp_abt, virt_disp_clk_mode, virt_disp_idlest, disp_val + pll_lock ddr_abt, virt_ddr_clk_mode, virt_ddr_idlest, ddr_val + pll_lock core_abt, virt_core_clk_mode, virt_core_idlest, core_val + + /* Disable SRAM LDO ret mode */ + ldr r0, virt_sram_ldo_addr + ldr r1, [r0] + bic r1, #1 + str r1, [r0] + + /* Restore the pull for DQ, DM */ + ldr r1, virt_ddr_data0_ioctrl + ldr r2, resume_io_pull_data + str r2, [r1] + + ldr r1, virt_ddr_data1_ioctrl + ldr r2, resume_io_pull_data + str r2, [r1] + + /* Enable EMIF */ + ldr r1, virt_emif_clkctrl + mov r2, #0x2 + str r2, [r1] +wait_emif_enable: + ldr r3, [r1] + cmp r2, r3 + bne wait_emif_enable + + /* Enable VTP */ +config_vtp_abt: + ldr r0, virt_ddr_vtp_ctrl + ldr r1, [r0] + mov r2, #0x0 @ clear the register + str r2, [r0] + mov r2, #0x6 @ write the filter value + str r2, [r0] + + ldr r1, [r0] + ldr r2, vtp_enable @ set the enable bit + orr r2, r2, r1 + str r2, [r0] + + ldr r1, [r0] @ toggle the CLRZ bit + bic r1, #1 + str r1, [r0] + + ldr r1, [r0] + orr r1, #1 + str r1, [r0] + +poll_vtp_ready_abt: + ldr r1, [r0] @ poll for VTP ready + tst r1, #(AM33XX_VTP_CTRL_READY) + beq poll_vtp_ready_abt + + /* DDR3 reset override and mDDR mode clear */ + ldr r0, virt_ddr_io_ctrl + mov r1, #0 + str r1, [r0] + +emif_self_refresh_dis: + /* Disable EMIF self-refresh */ + ldr r0, emif_addr_virt + add r0, r0, #EMIF_POWER_MANAGEMENT_CONTROL + ldr r1, [r0] + bic r1, r1, #LP_MODE_MASK + str r1, [r0] + str r1, [r0, #4] + + /* + * A write to SDRAM CONFIG register triggers + * an init sequence and hence it must be done + * at the end + */ + ldr r0, emif_addr_virt + add r0, r0, #EMIF_SDRAM_CONFIG + ldr r4, emif_sdcfg_val + str r4, [r0] + + mov r0, #0x1000 +wait_abt: + subs r0, r0, #1 + bne wait_abt + + /* Let the suspend code know about the abort */ + mov r0, #1 + ldmfd sp!, {r4 - r11, pc} @ restore regs and return +ENDPROC(am33xx_do_wfi) + + .align +ENTRY(am33xx_resume_offset) + .word . - am33xx_do_wfi + +ENTRY(am33xx_resume_from_deep_sleep) + /* Take the PLLs out of LP_BYPASS */ + pll_lock mpu, phys_mpu_clk_mode, phys_mpu_idlest, mpu_val + pll_lock per, phys_per_clk_mode, phys_per_idlest, per_val + pll_lock disp, phys_disp_clk_mode, phys_disp_idlest, disp_val + pll_lock ddr, phys_ddr_clk_mode, phys_ddr_idlest, ddr_val + pll_lock core, phys_core_clk_mode, phys_core_idlest, core_val + + /* Disable SRAM LDO ret mode */ + ldr r0, phys_sram_ldo_addr + ldr r1, [r0] + bic r1, #1 + str r1, [r0] + + /* Restore the pull for DQ, DM */ + ldr r1, phys_ddr_data0_ioctrl + ldr r2, resume_io_pull_data + str r2, [r1] + + ldr r1, phys_ddr_data1_ioctrl + ldr r2, resume_io_pull_data + str r2, [r1] + +config_vtp: + ldr r0, phys_ddr_vtp_ctrl + ldr r1, [r0] + mov r2, #0x0 @ clear the register + str r2, [r0] + mov r2, #0x6 @ write the filter value + str r2, [r0] + + ldr r1, [r0] + ldr r2, vtp_enable @ set the enable bit + orr r2, r2, r1 + str r2, [r0] + + ldr r1, [r0] @ toggle the CLRZ bit + bic r1, #1 + str r1, [r0] + + ldr r1, [r0] + orr r1, #1 + str r1, [r0] + +poll_vtp_ready: + ldr r1, [r0] @ poll for VTP ready + tst r1, #AM33XX_VTP_CTRL_READY + beq poll_vtp_ready + + /* DDR3 reset override and mDDR mode clear */ + ldr r0, phys_ddr_io_ctrl + mov r1, #0 + str r1, [r0] + + /* Enable EMIF */ + ldr r1, phys_emif_clkctrl + mov r2, #0x2 + str r2, [r1] +wait_emif_enable1: + ldr r3, [r1] + cmp r2, r3 + bne wait_emif_enable1 + +config_emif_timings: + ldr r3, emif_phys_addr + ldr r4, emif_rd_lat_val + str r4, [r3, #EMIF_DDR_PHY_CTRL_1] + str r4, [r3, #EMIF_DDR_PHY_CTRL_1_SHDW] + ldr r4, emif_timing1_val + str r4, [r3, #EMIF_SDRAM_TIMING_1] + str r4, [r3, #EMIF_SDRAM_TIMING_1_SHDW] + ldr r4, emif_timing2_val + str r4, [r3, #EMIF_SDRAM_TIMING_2] + str r4, [r3, #EMIF_SDRAM_TIMING_2_SHDW] + ldr r4, emif_timing3_val + str r4, [r3, #EMIF_SDRAM_TIMING_3] + str r4, [r3, #EMIF_SDRAM_TIMING_3_SHDW] + ldr r4, emif_ref_ctrl_val + str r4, [r3, #EMIF_SDRAM_REFRESH_CONTROL] + str r4, [r3, #EMIF_SDRAM_REFRESH_CTRL_SHDW] + ldr r4, emif_pmcr_val + str r4, [r3, #EMIF_POWER_MANAGEMENT_CONTROL] + ldr r4, emif_pmcr_shdw_val + str r4, [r3, #EMIF_POWER_MANAGEMENT_CTRL_SHDW] + + /* + * A write to SDRAM CONFIG register triggers + * an init sequence and hence it must be done + * at the end + */ + ldr r4, emif_sdcfg_val + str r4, [r3, #EMIF_SDRAM_CONFIG] + + /* Back from la-la-land. Kill some time for sanity to settle in */ + mov r0, #0x1000 +wait_resume: + subs r0, r0, #1 + bne wait_resume + + /* We are back. Branch to the common CPU resume routine */ + mov r0, #0 + ldr pc, resume_addr +ENDPROC(am33xx_resume_from_deep_sleep) + + +/* + * Local variables + */ + .align +resume_addr: + .word cpu_resume - PAGE_OFFSET + 0x80000000 +dcache_flush: + .word v7_flush_dcache_all +emif_addr_func: + .word am33xx_get_emif_base +ddr_start: + .word PAGE_OFFSET +emif_phys_addr: + .word AM33XX_EMIF_BASE +virt_mpu_idlest: + .word AM33XX_CM_IDLEST_DPLL_MPU +virt_mpu_clk_mode: + .word AM33XX_CM_CLKMODE_DPLL_MPU +phys_mpu_clk_mode: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_CLKMODE_DPLL_MPU_OFFSET) +phys_mpu_idlest: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_IDLEST_DPLL_MPU_OFFSET) +virt_core_idlest: + .word AM33XX_CM_IDLEST_DPLL_CORE +virt_core_clk_mode: + .word AM33XX_CM_CLKMODE_DPLL_CORE +phys_core_clk_mode: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_CLKMODE_DPLL_CORE_OFFSET) +phys_core_idlest: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_IDLEST_DPLL_CORE_OFFSET) +virt_per_idlest: + .word AM33XX_CM_IDLEST_DPLL_PER +virt_per_clk_mode: + .word AM33XX_CM_CLKMODE_DPLL_PER +phys_per_clk_mode: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_CLKMODE_DPLL_PER_OFFSET) +phys_per_idlest: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_IDLEST_DPLL_PER_OFFSET) +virt_disp_idlest: + .word AM33XX_CM_IDLEST_DPLL_DISP +virt_disp_clk_mode: + .word AM33XX_CM_CLKMODE_DPLL_DISP +phys_disp_clk_mode: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_CLKMODE_DPLL_DISP_OFFSET) +phys_disp_idlest: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_IDLEST_DPLL_DISP_OFFSET) +virt_ddr_idlest: + .word AM33XX_CM_IDLEST_DPLL_DDR +virt_ddr_clk_mode: + .word AM33XX_CM_CLKMODE_DPLL_DDR +phys_ddr_clk_mode: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_CLKMODE_DPLL_DDR_OFFSET) +phys_ddr_idlest: + .word (AM33XX_CM_BASE + AM33XX_CM_WKUP_MOD + \ + AM33XX_CM_IDLEST_DPLL_DDR_OFFSET) +virt_sram_ldo_addr: + .word AM33XX_PRM_LDO_SRAM_MPU_CTRL +phys_sram_ldo_addr: + .word (AM33XX_PRM_BASE + AM33XX_PRM_DEVICE_MOD + \ + AM33XX_PRM_LDO_SRAM_MPU_CTRL_OFFSET) +virt_mpu_clkctrl: + .word AM33XX_CM_MPU_MPU_CLKCTRL +virt_emif_clkctrl: + .word AM33XX_CM_PER_EMIF_CLKCTRL +phys_emif_clkctrl: + .word (AM33XX_CM_BASE + AM33XX_CM_PER_MOD + \ + AM33XX_CM_PER_EMIF_CLKCTRL_OFFSET) +module_disabled_val: + .word 0x30000 + +/* DDR related defines */ +virt_ddr_io_ctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_IO_CTRL) +phys_ddr_io_ctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_IO_CTRL +virt_ddr_vtp_ctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_VTP0_CTRL_REG) +phys_ddr_vtp_ctrl: + .word AM33XX_CTRL_BASE + AM33XX_VTP0_CTRL_REG +virt_ddr_cmd0_ioctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_CMD0_IOCTRL) +phys_ddr_cmd0_ioctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_CMD0_IOCTRL +virt_ddr_cmd1_ioctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_CMD1_IOCTRL) +phys_ddr_cmd1_ioctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_CMD1_IOCTRL +virt_ddr_cmd2_ioctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_CMD2_IOCTRL) +phys_ddr_cmd2_ioctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_CMD2_IOCTRL +virt_ddr_data0_ioctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_DATA0_IOCTRL) +phys_ddr_data0_ioctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_DATA0_IOCTRL +virt_ddr_data1_ioctrl: + .word AM33XX_CTRL_REGADDR(AM33XX_DDR_DATA1_IOCTRL) +phys_ddr_data1_ioctrl: + .word AM33XX_CTRL_BASE + AM33XX_DDR_DATA1_IOCTRL +vtp_enable: + .word AM33XX_VTP_CTRL_ENABLE + +/* + * Values recommended by the HW team. These change the pulls + * on certain IOs of DATA and CMD macros + */ +susp_io_pull_data: + .word 0x3FF00003 +susp_io_pull_cmd1: + .word 0xFFE0018B +susp_io_pull_cmd2: + .word 0xFFA0098B +resume_io_pull_data: + .word 0x18B +resume_io_pull_cmd: + .word 0x18B +susp_vtp_ctrl_val: + .word 0x10117 + +/* Placeholder for storing EMIF configuration */ +emif_addr_virt: + .word 0xDEADBEEF +emif_rd_lat_val: + .word 0xDEADBEEF +emif_timing1_val: + .word 0xDEADBEEF +emif_timing2_val: + .word 0xDEADBEEF +emif_timing3_val: + .word 0xDEADBEEF +emif_sdcfg_val: + .word 0xDEADBEEF +emif_ref_ctrl_val: + .word 0xDEADBEEF +emif_zqcfg_val: + .word 0xDEADBEEF +emif_pmcr_val: + .word 0xDEADBEEF +emif_pmcr_shdw_val: + .word 0xDEADBEEF + +/* Placeholder for storing PLL mode */ +clk_mode_mpu_val: + .word 0xDEADBEEF +clk_mode_per_val: + .word 0xDEADBEEF +clk_mode_disp_val: + .word 0xDEADBEEF +clk_mode_ddr_val: + .word 0xDEADBEEF +clk_mode_core_val: + .word 0xDEADBEEF + + .align 3 +ENTRY(am33xx_do_wfi_sz) + .word . - am33xx_do_wfi + -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
