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path: root/drivers/memory/ti-emif-sram-pm.S
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-rw-r--r--drivers/memory/ti-emif-sram-pm.S367
1 files changed, 367 insertions, 0 deletions
diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S
new file mode 100644
index 000000000..9bcac35c3
--- /dev/null
+++ b/drivers/memory/ti-emif-sram-pm.S
@@ -0,0 +1,367 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Low level PM code for TI EMIF
+ *
+ * Copyright (C) 2016-2017 Texas Instruments Incorporated - http://www.ti.com/
+ * Dave Gerlach
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/memory.h>
+
+#include "emif.h"
+#include "ti-emif-asm-offsets.h"
+
+#define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES 0x00a0
+#define EMIF_POWER_MGMT_SR_TIMER_MASK 0x00f0
+#define EMIF_POWER_MGMT_SELF_REFRESH_MODE 0x0200
+#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
+
+#define EMIF_AM437X_REGISTERS 0x1
+
+ .arm
+ .align 3
+
+ENTRY(ti_emif_sram)
+
+/*
+ * void ti_emif_save_context(void)
+ *
+ * Used during suspend to save the context of all required EMIF registers
+ * to local memory if the EMIF is going to lose context during the sleep
+ * transition. Operates on the VIRTUAL address of the EMIF.
+ */
+ENTRY(ti_emif_save_context)
+ stmfd sp!, {r4 - r11, lr} @ save registers on stack
+
+ adr r4, ti_emif_pm_sram_data
+ ldr r0, [r4, #EMIF_PM_BASE_ADDR_VIRT_OFFSET]
+ ldr r2, [r4, #EMIF_PM_REGS_VIRT_OFFSET]
+
+ /* Save EMIF configuration */
+ ldr r1, [r0, #EMIF_SDRAM_CONFIG]
+ str r1, [r2, #EMIF_SDCFG_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_SDRAM_REFRESH_CONTROL]
+ str r1, [r2, #EMIF_REF_CTRL_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_SDRAM_TIMING_1]
+ str r1, [r2, #EMIF_TIMING1_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_SDRAM_TIMING_2]
+ str r1, [r2, #EMIF_TIMING2_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_SDRAM_TIMING_3]
+ str r1, [r2, #EMIF_TIMING3_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+ str r1, [r2, #EMIF_PMCR_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_POWER_MANAGEMENT_CTRL_SHDW]
+ str r1, [r2, #EMIF_PMCR_SHDW_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG]
+ str r1, [r2, #EMIF_ZQCFG_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_DDR_PHY_CTRL_1]
+ str r1, [r2, #EMIF_DDR_PHY_CTLR_1_OFFSET]
+
+ ldr r1, [r0, #EMIF_COS_CONFIG]
+ str r1, [r2, #EMIF_COS_CONFIG_OFFSET]
+
+ ldr r1, [r0, #EMIF_PRIORITY_TO_CLASS_OF_SERVICE_MAPPING]
+ str r1, [r2, #EMIF_PRIORITY_TO_COS_MAPPING_OFFSET]
+
+ ldr r1, [r0, #EMIF_CONNECTION_ID_TO_CLASS_OF_SERVICE_1_MAPPING]
+ str r1, [r2, #EMIF_CONNECT_ID_SERV_1_MAP_OFFSET]
+
+ ldr r1, [r0, #EMIF_CONNECTION_ID_TO_CLASS_OF_SERVICE_2_MAPPING]
+ str r1, [r2, #EMIF_CONNECT_ID_SERV_2_MAP_OFFSET]
+
+ ldr r1, [r0, #EMIF_OCP_CONFIG]
+ str r1, [r2, #EMIF_OCP_CONFIG_VAL_OFFSET]
+
+ ldr r5, [r4, #EMIF_PM_CONFIG_OFFSET]
+ cmp r5, #EMIF_SRAM_AM43_REG_LAYOUT
+ bne emif_skip_save_extra_regs
+
+ ldr r1, [r0, #EMIF_READ_WRITE_LEVELING_RAMP_CONTROL]
+ str r1, [r2, #EMIF_RD_WR_LEVEL_RAMP_CTRL_OFFSET]
+
+ ldr r1, [r0, #EMIF_READ_WRITE_EXECUTION_THRESHOLD]
+ str r1, [r2, #EMIF_RD_WR_EXEC_THRESH_OFFSET]
+
+ ldr r1, [r0, #EMIF_LPDDR2_NVM_TIMING]
+ str r1, [r2, #EMIF_LPDDR2_NVM_TIM_OFFSET]
+
+ ldr r1, [r0, #EMIF_LPDDR2_NVM_TIMING_SHDW]
+ str r1, [r2, #EMIF_LPDDR2_NVM_TIM_SHDW_OFFSET]
+
+ ldr r1, [r0, #EMIF_DLL_CALIB_CTRL]
+ str r1, [r2, #EMIF_DLL_CALIB_CTRL_VAL_OFFSET]
+
+ ldr r1, [r0, #EMIF_DLL_CALIB_CTRL_SHDW]
+ str r1, [r2, #EMIF_DLL_CALIB_CTRL_VAL_SHDW_OFFSET]
+
+ /* Loop and save entire block of emif phy regs */
+ mov r5, #0x0
+ add r4, r2, #EMIF_EXT_PHY_CTRL_VALS_OFFSET
+ add r3, r0, #EMIF_EXT_PHY_CTRL_1
+ddr_phy_ctrl_save:
+ ldr r1, [r3, r5]
+ str r1, [r4, r5]
+ add r5, r5, #0x4
+ cmp r5, #AM43XX_EMIF_PHY_CTRL_REG_COUNT
+ bne ddr_phy_ctrl_save
+
+emif_skip_save_extra_regs:
+ ldmfd sp!, {r4 - r11, pc} @ restore regs and return
+ENDPROC(ti_emif_save_context)
+
+/*
+ * void ti_emif_restore_context(void)
+ *
+ * Used during resume to restore the context of all required EMIF registers
+ * from local memory after the EMIF has lost context during a sleep transition.
+ * Operates on the PHYSICAL address of the EMIF.
+ */
+ENTRY(ti_emif_restore_context)
+ adr r4, ti_emif_pm_sram_data
+ ldr r0, [r4, #EMIF_PM_BASE_ADDR_PHYS_OFFSET]
+ ldr r2, [r4, #EMIF_PM_REGS_PHYS_OFFSET]
+
+ /* Config EMIF Timings */
+ ldr r1, [r2, #EMIF_DDR_PHY_CTLR_1_OFFSET]
+ str r1, [r0, #EMIF_DDR_PHY_CTRL_1]
+ str r1, [r0, #EMIF_DDR_PHY_CTRL_1_SHDW]
+
+ ldr r1, [r2, #EMIF_TIMING1_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_TIMING_1]
+ str r1, [r0, #EMIF_SDRAM_TIMING_1_SHDW]
+
+ ldr r1, [r2, #EMIF_TIMING2_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_TIMING_2]
+ str r1, [r0, #EMIF_SDRAM_TIMING_2_SHDW]
+
+ ldr r1, [r2, #EMIF_TIMING3_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_TIMING_3]
+ str r1, [r0, #EMIF_SDRAM_TIMING_3_SHDW]
+
+ ldr r1, [r2, #EMIF_REF_CTRL_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_REFRESH_CONTROL]
+ str r1, [r0, #EMIF_SDRAM_REFRESH_CTRL_SHDW]
+
+ ldr r1, [r2, #EMIF_PMCR_VAL_OFFSET]
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+
+ ldr r1, [r2, #EMIF_PMCR_SHDW_VAL_OFFSET]
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CTRL_SHDW]
+
+ ldr r1, [r2, #EMIF_COS_CONFIG_OFFSET]
+ str r1, [r0, #EMIF_COS_CONFIG]
+
+ ldr r1, [r2, #EMIF_PRIORITY_TO_COS_MAPPING_OFFSET]
+ str r1, [r0, #EMIF_PRIORITY_TO_CLASS_OF_SERVICE_MAPPING]
+
+ ldr r1, [r2, #EMIF_CONNECT_ID_SERV_1_MAP_OFFSET]
+ str r1, [r0, #EMIF_CONNECTION_ID_TO_CLASS_OF_SERVICE_1_MAPPING]
+
+ ldr r1, [r2, #EMIF_CONNECT_ID_SERV_2_MAP_OFFSET]
+ str r1, [r0, #EMIF_CONNECTION_ID_TO_CLASS_OF_SERVICE_2_MAPPING]
+
+ ldr r1, [r2, #EMIF_OCP_CONFIG_VAL_OFFSET]
+ str r1, [r0, #EMIF_OCP_CONFIG]
+
+ ldr r5, [r4, #EMIF_PM_CONFIG_OFFSET]
+ cmp r5, #EMIF_SRAM_AM43_REG_LAYOUT
+ bne emif_skip_restore_extra_regs
+
+ ldr r1, [r2, #EMIF_RD_WR_LEVEL_RAMP_CTRL_OFFSET]
+ str r1, [r0, #EMIF_READ_WRITE_LEVELING_RAMP_CONTROL]
+
+ ldr r1, [r2, #EMIF_RD_WR_EXEC_THRESH_OFFSET]
+ str r1, [r0, #EMIF_READ_WRITE_EXECUTION_THRESHOLD]
+
+ ldr r1, [r2, #EMIF_LPDDR2_NVM_TIM_OFFSET]
+ str r1, [r0, #EMIF_LPDDR2_NVM_TIMING]
+
+ ldr r1, [r2, #EMIF_LPDDR2_NVM_TIM_SHDW_OFFSET]
+ str r1, [r0, #EMIF_LPDDR2_NVM_TIMING_SHDW]
+
+ ldr r1, [r2, #EMIF_DLL_CALIB_CTRL_VAL_OFFSET]
+ str r1, [r0, #EMIF_DLL_CALIB_CTRL]
+
+ ldr r1, [r2, #EMIF_DLL_CALIB_CTRL_VAL_SHDW_OFFSET]
+ str r1, [r0, #EMIF_DLL_CALIB_CTRL_SHDW]
+
+ ldr r1, [r2, #EMIF_ZQCFG_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG]
+
+ /* Loop and restore entire block of emif phy regs */
+ mov r5, #0x0
+ /* Load ti_emif_regs_amx3 + EMIF_EXT_PHY_CTRL_VALS_OFFSET for address
+ * to phy register save space
+ */
+ add r3, r2, #EMIF_EXT_PHY_CTRL_VALS_OFFSET
+ add r4, r0, #EMIF_EXT_PHY_CTRL_1
+ddr_phy_ctrl_restore:
+ ldr r1, [r3, r5]
+ str r1, [r4, r5]
+ add r5, r5, #0x4
+ cmp r5, #AM43XX_EMIF_PHY_CTRL_REG_COUNT
+ bne ddr_phy_ctrl_restore
+
+emif_skip_restore_extra_regs:
+ /*
+ * Output impedence calib needed only for DDR3
+ * but since the initial state of this will be
+ * disabled for DDR2 no harm in restoring the
+ * old configuration
+ */
+ ldr r1, [r2, #EMIF_ZQCFG_VAL_OFFSET]
+ str r1, [r0, #EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG]
+
+ /* Write to sdcfg last for DDR2 only */
+ ldr r1, [r2, #EMIF_SDCFG_VAL_OFFSET]
+ and r2, r1, #SDRAM_TYPE_MASK
+ cmp r2, #EMIF_SDCFG_TYPE_DDR2
+ streq r1, [r0, #EMIF_SDRAM_CONFIG]
+
+ 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)
+ *
+ * Programs the EMIF to tell the SDRAM to enter into self-refresh
+ * mode during a sleep transition. Operates on the VIRTUAL address
+ * of the EMIF.
+ */
+ENTRY(ti_emif_enter_sr)
+ stmfd sp!, {r4 - r11, lr} @ save registers on stack
+
+ adr r4, ti_emif_pm_sram_data
+ ldr r0, [r4, #EMIF_PM_BASE_ADDR_VIRT_OFFSET]
+ ldr r2, [r4, #EMIF_PM_REGS_VIRT_OFFSET]
+
+ ldr r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+ bic r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE_MASK
+ orr r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+
+ ldmfd sp!, {r4 - r11, pc} @ restore regs and return
+ENDPROC(ti_emif_enter_sr)
+
+/*
+ * void ti_emif_exit_sr(void)
+ *
+ * Programs the EMIF to tell the SDRAM to exit self-refresh mode
+ * after a sleep transition. Operates on the PHYSICAL address of
+ * the EMIF.
+ */
+ENTRY(ti_emif_exit_sr)
+ adr r4, ti_emif_pm_sram_data
+ ldr r0, [r4, #EMIF_PM_BASE_ADDR_PHYS_OFFSET]
+ ldr r2, [r4, #EMIF_PM_REGS_PHYS_OFFSET]
+
+ /*
+ * Toggle EMIF to exit refresh mode:
+ * if EMIF lost context, PWR_MGT_CTRL is currently 0, writing disable
+ * (0x0), wont do diddly squat! so do a toggle from SR(0x2) to disable
+ * (0x0) here.
+ * *If* EMIF did not lose context, nothing broken as we write the same
+ * value(0x2) to reg before we write a disable (0x0).
+ */
+ ldr r1, [r2, #EMIF_PMCR_VAL_OFFSET]
+ bic r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE_MASK
+ orr r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+ bic r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE_MASK
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+
+ /* Wait for EMIF to become ready */
+1: ldr r1, [r0, #EMIF_STATUS]
+ tst r1, #EMIF_STATUS_READY
+ beq 1b
+
+ mov pc, lr
+ENDPROC(ti_emif_exit_sr)
+
+/*
+ * void ti_emif_abort_sr(void)
+ *
+ * Disables self-refresh after a failed transition to a low-power
+ * state so the kernel can jump back to DDR and follow abort path.
+ * Operates on the VIRTUAL address of the EMIF.
+ */
+ENTRY(ti_emif_abort_sr)
+ stmfd sp!, {r4 - r11, lr} @ save registers on stack
+
+ adr r4, ti_emif_pm_sram_data
+ ldr r0, [r4, #EMIF_PM_BASE_ADDR_VIRT_OFFSET]
+ ldr r2, [r4, #EMIF_PM_REGS_VIRT_OFFSET]
+
+ ldr r1, [r2, #EMIF_PMCR_VAL_OFFSET]
+ bic r1, r1, #EMIF_POWER_MGMT_SELF_REFRESH_MODE_MASK
+ str r1, [r0, #EMIF_POWER_MANAGEMENT_CONTROL]
+
+ /* Wait for EMIF to become ready */
+1: ldr r1, [r0, #EMIF_STATUS]
+ tst r1, #EMIF_STATUS_READY
+ beq 1b
+
+ ldmfd sp!, {r4 - r11, pc} @ restore regs and return
+ENDPROC(ti_emif_abort_sr)
+
+ .align 3
+ENTRY(ti_emif_pm_sram_data)
+ .space EMIF_PM_DATA_SIZE
+ENTRY(ti_emif_sram_sz)
+ .word . - ti_emif_save_context