From 6c110561eb2d4d1496961c13a92f96f29eea7c72 Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Tue, 2 Apr 2019 11:57:42 -0500 Subject: memory: ti-emif-sram: Add ti_emif_run_hw_leveling for DDR3 hardware leveling In certain situations, such as when returning from low power modes, the EMIF must re-run hardware leveling to properly restore DDR3 access. This is accomplished by introducing a new ti-emif-sram-pm call, ti_emif_run_hw_leveling, to check if DDR3 is in use and if so, trigger the full write and read leveling processes. Suggested-by: Brad Griffis Signed-off-by: Dave Gerlach Acked-by: Santosh Shilimkar Signed-off-by: Tony Lindgren --- drivers/memory/emif.h | 4 ++++ drivers/memory/ti-emif-pm.c | 3 +++ drivers/memory/ti-emif-sram-pm.S | 41 ++++++++++++++++++++++++++++++++++++++++ include/linux/ti-emif-sram.h | 3 +++ 4 files changed, 51 insertions(+) diff --git a/drivers/memory/emif.h b/drivers/memory/emif.h index 9e9f8037955d..6b71fadb3cfa 100644 --- a/drivers/memory/emif.h +++ b/drivers/memory/emif.h @@ -537,6 +537,9 @@ #define MCONNID_SHIFT 0 #define MCONNID_MASK (0xff << 0) +/* READ_WRITE_LEVELING_CONTROL */ +#define RDWRLVLFULL_START 0x80000000 + /* DDR_PHY_CTRL_1 - EMIF4D */ #define DLL_SLAVE_DLY_CTRL_SHIFT_4D 4 #define DLL_SLAVE_DLY_CTRL_MASK_4D (0xFF << 4) @@ -598,6 +601,7 @@ extern struct emif_regs_amx3 ti_emif_regs_amx3; void ti_emif_save_context(void); void ti_emif_restore_context(void); +void ti_emif_run_hw_leveling(void); void ti_emif_enter_sr(void); void ti_emif_exit_sr(void); void ti_emif_abort_sr(void); diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c index 2250d03ea17f..ab07aa163138 100644 --- a/drivers/memory/ti-emif-pm.c +++ b/drivers/memory/ti-emif-pm.c @@ -138,6 +138,9 @@ static int ti_emif_alloc_sram(struct device *dev, emif_data->pm_functions.exit_sr = sram_resume_address(emif_data, (unsigned long)ti_emif_exit_sr); + emif_data->pm_functions.run_hw_leveling = + sram_resume_address(emif_data, + (unsigned long)ti_emif_run_hw_leveling); emif_data->pm_data.regs_virt = (struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt; diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S index a5369181e5c2..d75ae18efa7d 100644 --- a/drivers/memory/ti-emif-sram-pm.S +++ b/drivers/memory/ti-emif-sram-pm.S @@ -27,6 +27,7 @@ #define EMIF_POWER_MGMT_SELF_REFRESH_MODE_MASK 0x0700 #define EMIF_SDCFG_TYPE_DDR2 0x2 << SDRAM_TYPE_SHIFT +#define EMIF_SDCFG_TYPE_DDR3 0x3 << SDRAM_TYPE_SHIFT #define EMIF_STATUS_READY 0x4 #define AM43XX_EMIF_PHY_CTRL_REG_COUNT 0x120 @@ -244,6 +245,46 @@ emif_skip_restore_extra_regs: mov pc, lr ENDPROC(ti_emif_restore_context) +/* + * void ti_emif_run_hw_leveling(void) + * + * Used during resume to run hardware leveling again and restore the + * configuration of the EMIF PHY, only for DDR3. + */ +ENTRY(ti_emif_run_hw_leveling) + adr r4, ti_emif_pm_sram_data + ldr r0, [r4, #EMIF_PM_BASE_ADDR_PHYS_OFFSET] + + ldr r3, [r0, #EMIF_READ_WRITE_LEVELING_CONTROL] + orr r3, r3, #RDWRLVLFULL_START + ldr r2, [r0, #EMIF_SDRAM_CONFIG] + and r2, r2, #SDRAM_TYPE_MASK + cmp r2, #EMIF_SDCFG_TYPE_DDR3 + bne skip_hwlvl + + str r3, [r0, #EMIF_READ_WRITE_LEVELING_CONTROL] + + /* + * If EMIF registers are touched during initial stage of HW + * leveling sequence there will be an L3 NOC timeout error issued + * as the EMIF will not respond, which is not fatal, but it is + * avoidable. This small wait loop is enough time for this condition + * to clear, even at worst case of CPU running at max speed of 1Ghz. + */ + mov r2, #0x2000 +1: + subs r2, r2, #0x1 + bne 1b + + /* Bit clears when operation is complete */ +2: ldr r1, [r0, #EMIF_READ_WRITE_LEVELING_CONTROL] + tst r1, #RDWRLVLFULL_START + bne 2b + +skip_hwlvl: + mov pc, lr +ENDPROC(ti_emif_run_hw_leveling) + /* * void ti_emif_enter_sr(void) * diff --git a/include/linux/ti-emif-sram.h b/include/linux/ti-emif-sram.h index 53604b087f2c..2fc854155c27 100644 --- a/include/linux/ti-emif-sram.h +++ b/include/linux/ti-emif-sram.h @@ -55,6 +55,7 @@ struct ti_emif_pm_data { struct ti_emif_pm_functions { u32 save_context; u32 restore_context; + u32 run_hw_leveling; u32 enter_sr; u32 exit_sr; u32 abort_sr; @@ -126,6 +127,8 @@ static inline void ti_emif_asm_offsets(void) offsetof(struct ti_emif_pm_functions, save_context)); DEFINE(EMIF_PM_RESTORE_CONTEXT_OFFSET, offsetof(struct ti_emif_pm_functions, restore_context)); + DEFINE(EMIF_PM_RUN_HW_LEVELING, + offsetof(struct ti_emif_pm_functions, run_hw_leveling)); DEFINE(EMIF_PM_ENTER_SR_OFFSET, offsetof(struct ti_emif_pm_functions, enter_sr)); DEFINE(EMIF_PM_EXIT_SR_OFFSET, -- cgit From 11140cc40ddc3e7a2f2e3352e8a0587a93ba75df Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Tue, 2 Apr 2019 11:57:43 -0500 Subject: ARM: OMAP2+: sleep43xx: Run EMIF HW leveling on resume path When returning from DeepSleep mode on AM437x platforms the EMIF must run DDR hardware leveling, same as done during u-boot, to properly restore the EMIF PHY to it's operational state on platforms using DDR3. Call the ti-emif-sram-pm run_hw_leveling routine to perform this. This happens after all other EMIF values are restored so the exact same configuration used at boot is used at the end of EMIF resume as well. Signed-off-by: Dave Gerlach Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/sleep43xx.S | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mach-omap2/sleep43xx.S b/arch/arm/mach-omap2/sleep43xx.S index 5b9343b58fc7..0c1031442571 100644 --- a/arch/arm/mach-omap2/sleep43xx.S +++ b/arch/arm/mach-omap2/sleep43xx.S @@ -368,6 +368,9 @@ wait_emif_enable1: mov r1, #AM43XX_EMIF_POWEROFF_DISABLE str r1, [r2, #0x0] + ldr r1, [r9, #EMIF_PM_RUN_HW_LEVELING] + blx r1 + #ifdef CONFIG_CACHE_L2X0 ldr r2, l2_cache_base ldr r0, [r2, #L2X0_CTRL] -- cgit