[PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[Dave Gerlach]

Hi,

This is a minor update to previous series sent here [1] to switch to
SPDX license headers. Because update is so minor I have included original
cover letter below unmodified with the exception of updated links.

This series contains the remaining code to enable suspend to mem and standby
on am335x and am437x platforms. All dependencies have been merged and this
is just a rebase on v4.16-rc1. For this to work on am437x-gp-evm this
bug fix patch [2] is required but suspend works fine on am335x platforms
without it. V3 of this series can be found here [3].

This code also depends on firmware for the wkup_m3 that is available here [4]
that can either be placed in /lib/firmware or built in to the kernel.

For testing the drivers required are:

CONFIG_MAILBOX
CONFIG_OMAP2PLUS_MBOX
CONFIG_WKUP_M3_RPROC
CONFIG_SOC_TI
CONFIG_WKUP_M3_IPC
CONFIG_TI_EMIF_SRAM
CONFIG_AMX3_PM

There is a device tree patch series to follow immediately after this that will
completely enable suspend, all patches pushed here [5] for convenience
including the aforementioned [2] regulator bug fix if anyone is testing.

Regards,
Dave

[1] https://www.spinics.net/lists/linux-omap/msg141652.html
[2] https://www.spinics.net/lists/linux-omap/msg141626.html
[3] https://www.spinics.net/lists/arm-kernel/msg595931.html
[4] https://git.ti.com/processor-firmware/ti-amx3-cm3-pm-firmware/blobs/7eb9c0856a9e8b3b42bf64f761da135852b8eea7/bin/am335x-pm-firmware.elf
[5] https://github.com/dgerlach/linux-pm/tree/upstream/v4.16/amx3-suspend-v5

Dave Gerlach (4):
  ARM: OMAP2+: Introduce low-level suspend code for AM33XX
  ARM: OMAP2+: Introduce low-level suspend code for AM43XX
  ARM: OMAP2+: pm33xx-core: Add platform code needed for PM
  soc: ti: Add pm33xx driver for basic suspend support

 Documentation/devicetree/bindings/arm/omap/mpu.txt |  16 +
 arch/arm/mach-omap2/Kconfig                        |   1 +
 arch/arm/mach-omap2/Makefile                       |  16 +
 arch/arm/mach-omap2/common.h                       |   7 +
 arch/arm/mach-omap2/io.c                           |   2 +
 arch/arm/mach-omap2/pm-asm-offsets.c               |  31 ++
 arch/arm/mach-omap2/pm.h                           |   3 +
 arch/arm/mach-omap2/pm33xx-core.c                  | 189 ++++++++++
 arch/arm/mach-omap2/sleep33xx.S                    | 214 ++++++++++++
 arch/arm/mach-omap2/sleep43xx.S                    | 387 +++++++++++++++++++++
 drivers/soc/ti/Kconfig                             |   9 +
 drivers/soc/ti/Makefile                            |   1 +
 drivers/soc/ti/pm33xx.c                            | 349 +++++++++++++++++++
 include/linux/platform_data/pm33xx.h               |  42 +++
 14 files changed, 1267 insertions(+)
 create mode 100644 arch/arm/mach-omap2/pm-asm-offsets.c
 create mode 100644 arch/arm/mach-omap2/pm33xx-core.c
 create mode 100644 arch/arm/mach-omap2/sleep33xx.S
 create mode 100644 arch/arm/mach-omap2/sleep43xx.S
 create mode 100644 drivers/soc/ti/pm33xx.c
 create mode 100644 include/linux/platform_data/pm33xx.h

-- 
2.16.1

[PATCH v5 1/4] ARM: OMAP2+: Introduce low-level suspend code for AM33XX

[Dave Gerlach]

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. Calls routine to store the EMIF configuration
2. Calls routine to place external memory in self-refresh
3. Disables EMIF clock
4. 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.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/sleep33xx.S | 212 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 212 insertions(+)
 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 000000000000..04015f98b6e3
--- /dev/null
+++ b/arch/arm/mach-omap2/sleep33xx.S
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Low level suspend code for AM33XX SoCs
+ *
+ * Copyright (C) 2012-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Dave Gerlach, Vaibhav Bedia
+ */
+
+#include <linux/linkage.h>
+#include <linux/ti-emif-sram.h>
+#include <asm/assembler.h>
+#include <asm/memory.h>
+
+#include "iomap.h"
+#include "cm33xx.h"
+
+#define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED			0x00030000
+#define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE			0x0003
+#define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE			0x0002
+
+	.arm
+	.align 3
+
+ENTRY(am33xx_do_wfi)
+	stmfd	sp!, {r4 - r11, lr}	@ save registers on stack
+
+	/*
+	 * Flush all data from the L1 and L2 data cache before disabling
+	 * SCTLR.C bit.
+	 */
+	ldr	r1, kernel_flush
+	blx	r1
+
+	/*
+	 * Clear the SCTLR.C bit to prevent further data cache
+	 * allocation. Clearing SCTLR.C would make all the data accesses
+	 * strongly ordered and would not hit the cache.
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r0, r0, #(1 << 2)	@ Disable the C bit
+	mcr	p15, 0, r0, c1, c0, 0
+	isb
+
+	/*
+	 * Invalidate L1 and L2 data cache.
+	 */
+	ldr	r1, kernel_flush
+	blx	r1
+
+	adr	r9, am33xx_emif_sram_table
+
+	ldr	r3, [r9, #EMIF_PM_ENTER_SR_OFFSET]
+	blx	r3
+
+	ldr	r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET]
+	blx	r3
+
+	/* Disable EMIF */
+	ldr     r1, virt_emif_clkctrl
+	ldr     r2, [r1]
+	bic     r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
+	str     r2, [r1]
+
+	ldr	r1, virt_emif_clkctrl
+wait_emif_disable:
+	ldr	r2, [r1]
+	mov	r3, #AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED
+	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, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
+	str	r2, [r1]
+
+	/*
+	 * Execute an ISB instruction to ensure that all of the
+	 * CP15 register changes have been committed.
+	 */
+	isb
+
+	/*
+	 * Execute a barrier instruction to ensure that all cache,
+	 * TLB and branch predictor maintenance operations issued
+	 * have completed.
+	 */
+	dsb
+	dmb
+
+	/*
+	 * Execute a WFI instruction and wait until the
+	 * STANDBYWFI output is asserted to indicate that the
+	 * CPU is in idle and low power state. CPU can specualatively
+	 * prefetch the instructions so add NOPs after WFI. Thirteen
+	 * NOPs as per Cortex-A8 pipeline.
+	 */
+	wfi
+
+	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, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r2, [r1]
+
+	/* Re-enable EMIF */
+	ldr	r1, virt_emif_clkctrl
+	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r2, [r1]
+wait_emif_enable:
+	ldr	r3, [r1]
+	cmp	r2, r3
+	bne	wait_emif_enable
+
+
+	ldr	r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
+	blx	r1
+
+	/*
+	 * Set SCTLR.C bit to allow data cache allocation
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	orr	r0, r0, #(1 << 2)	@ Enable the C bit
+	mcr	p15, 0, r0, c1, c0, 0
+	isb
+
+	/* 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)
+	/* Re-enable EMIF */
+	ldr	r0, phys_emif_clkctrl
+	mov	r1, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r1, [r0]
+wait_emif_enable1:
+	ldr	r2, [r0]
+	cmp	r1, r2
+	bne	wait_emif_enable1
+
+	adr	r9, am33xx_emif_sram_table
+
+	ldr	r1, [r9, #EMIF_PM_RESTORE_CONTEXT_OFFSET]
+	blx	r1
+
+	ldr	r1, [r9, #EMIF_PM_EXIT_SR_OFFSET]
+	blx	r1
+
+resume_to_ddr:
+	/* 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
+kernel_flush:
+	.word   v7_flush_dcache_all
+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)
+
+.align 3
+/* DDR related defines */
+am33xx_emif_sram_table:
+	.space EMIF_PM_FUNCTIONS_SIZE
+
+ENTRY(am33xx_pm_sram)
+	.word am33xx_do_wfi
+	.word am33xx_do_wfi_sz
+	.word am33xx_resume_offset
+	.word am33xx_emif_sram_table
+	.word am33xx_pm_ro_sram_data
+
+.align 3
+ENTRY(am33xx_pm_ro_sram_data)
+	.space AMX3_PM_RO_SRAM_DATA_SIZE
+
+ENTRY(am33xx_do_wfi_sz)
+	.word	. - am33xx_do_wfi
-- 
2.16.1

[PATCH v5 2/4] ARM: OMAP2+: Introduce low-level suspend code for AM43XX

[Dave Gerlach]

Although similar to AM33XX, introduce a new low-level asm file for
suspend containing new context save and restore paths for EMIF and l2
cache disabling and enabling.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/sleep43xx.S | 385 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 385 insertions(+)
 create mode 100644 arch/arm/mach-omap2/sleep43xx.S

diff --git a/arch/arm/mach-omap2/sleep43xx.S b/arch/arm/mach-omap2/sleep43xx.S
new file mode 100644
index 000000000000..0defc735e319
--- /dev/null
+++ b/arch/arm/mach-omap2/sleep43xx.S
@@ -0,0 +1,385 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Low level suspend code for AM43XX SoCs
+ *
+ * Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Dave Gerlach, Vaibhav Bedia
+ */
+
+#include <linux/linkage.h>
+#include <linux/ti-emif-sram.h>
+
+#include <asm/assembler.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <asm/memory.h>
+
+#include "cm33xx.h"
+#include "common.h"
+#include "iomap.h"
+#include "omap-secure.h"
+#include "omap44xx.h"
+#include "prm33xx.h"
+#include "prcm43xx.h"
+
+#define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED		0x00030000
+#define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE		0x0003
+#define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE		0x0002
+
+#define AM43XX_EMIF_POWEROFF_ENABLE			0x1
+#define AM43XX_EMIF_POWEROFF_DISABLE			0x0
+
+#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP		0x1
+#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO		0x3
+
+#define AM43XX_CM_BASE					0x44DF0000
+
+#define AM43XX_CM_REGADDR(inst, reg)                           \
+       AM33XX_L4_WK_IO_ADDRESS(AM43XX_CM_BASE + (inst) + (reg))
+
+#define AM43XX_CM_MPU_CLKSTCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
+					AM43XX_CM_MPU_MPU_CDOFFS)
+#define AM43XX_CM_MPU_MPU_CLKCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
+					AM43XX_CM_MPU_MPU_CLKCTRL_OFFSET)
+#define AM43XX_CM_PER_EMIF_CLKCTRL  AM43XX_CM_REGADDR(AM43XX_CM_PER_INST, \
+					AM43XX_CM_PER_EMIF_CLKCTRL_OFFSET)
+#define AM43XX_PRM_EMIF_CTRL_OFFSET			0x0030
+
+	.arm
+	.align 3
+
+ENTRY(am43xx_do_wfi)
+	stmfd	sp!, {r4 - r11, lr}	@ save registers on stack
+
+	/* Retrieve l2 cache virt address BEFORE we shut off EMIF */
+	ldr	r1, get_l2cache_base
+	blx	r1
+	mov	r8, r0
+
+	/*
+	 * Flush all data from the L1 and L2 data cache before disabling
+	 * SCTLR.C bit.
+	 */
+	ldr	r1, kernel_flush
+	blx	r1
+
+	/*
+	 * Clear the SCTLR.C bit to prevent further data cache
+	 * allocation. Clearing SCTLR.C would make all the data accesses
+	 * strongly ordered and would not hit the cache.
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r0, r0, #(1 << 2)	@ Disable the C bit
+	mcr	p15, 0, r0, c1, c0, 0
+	isb
+	dsb
+
+	/*
+	 * Invalidate L1 and L2 data cache.
+	 */
+	ldr	r1, kernel_flush
+	blx	r1
+
+#ifdef CONFIG_CACHE_L2X0
+	/*
+	 * Clean and invalidate the L2 cache.
+	 */
+#ifdef CONFIG_PL310_ERRATA_727915
+	mov	r0, #0x03
+	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+	dsb
+	smc	#0
+	dsb
+#endif
+	mov	r0, r8
+	adr	r4, am43xx_pm_ro_sram_data
+	ldr	r3, [r4, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
+
+	mov	r2, r0
+	ldr	r0, [r2, #L2X0_AUX_CTRL]
+	str	r0, [r3, #AMX3_PM_L2_AUX_CTRL_VAL_OFFSET]
+	ldr	r0, [r2, #L310_PREFETCH_CTRL]
+	str	r0, [r3, #AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET]
+
+	ldr	r0, l2_val
+	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
+wait:
+	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
+	ldr	r1, l2_val
+	ands	r0, r0, r1
+	bne	wait
+#ifdef CONFIG_PL310_ERRATA_727915
+	mov	r0, #0x00
+	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+	dsb
+	smc	#0
+	dsb
+#endif
+l2x_sync:
+	mov	r0, r8
+	mov	r2, r0
+	mov	r0, #0x0
+	str	r0, [r2, #L2X0_CACHE_SYNC]
+sync:
+	ldr	r0, [r2, #L2X0_CACHE_SYNC]
+	ands	r0, r0, #0x1
+	bne	sync
+#endif
+
+	adr     r9, am43xx_emif_sram_table
+
+	ldr     r3, [r9, #EMIF_PM_ENTER_SR_OFFSET]
+	blx     r3
+
+	ldr     r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET]
+	blx     r3
+
+	/* Disable EMIF */
+	ldr	r1, am43xx_virt_emif_clkctrl
+	ldr	r2, [r1]
+	bic	r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
+	str	r2, [r1]
+
+wait_emif_disable:
+	ldr	r2, [r1]
+	mov	r3, #AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED
+	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, am43xx_virt_mpu_clkctrl
+	ldr	r2, [r1]
+	bic	r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
+	str	r2, [r1]
+
+	/*
+	 * Put MPU CLKDM to SW_SLEEP
+	 */
+	ldr	r1, am43xx_virt_mpu_clkstctrl
+	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP
+	str	r2, [r1]
+
+	/*
+	 * Execute a barrier instruction to ensure that all cache,
+	 * TLB and branch predictor maintenance operations issued
+	 * have completed.
+	 */
+	dsb
+	dmb
+
+	/*
+	 * Execute a WFI instruction and wait until the
+	 * STANDBYWFI output is asserted to indicate that the
+	 * CPU is in idle and low power state. CPU can specualatively
+	 * prefetch the instructions so add NOPs after WFI. Sixteen
+	 * NOPs as per Cortex-A9 pipeline.
+	 */
+	wfi
+
+	nop
+	nop
+	nop
+	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 */
+	ldr	r1, am43xx_virt_mpu_clkstctrl
+	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
+	str	r2, [r1]
+
+	/* Set MPU_CLKCTRL.MODULEMODE back to ENABLE */
+	ldr	r1, am43xx_virt_mpu_clkctrl
+	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r2, [r1]
+
+	/* Re-enable EMIF */
+	ldr	r1, am43xx_virt_emif_clkctrl
+	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r2, [r1]
+wait_emif_enable:
+	ldr	r3, [r1]
+	cmp	r2, r3
+	bne	wait_emif_enable
+
+	/*
+	 * Set SCTLR.C bit to allow data cache allocation
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	orr	r0, r0, #(1 << 2)	@ Enable the C bit
+	mcr	p15, 0, r0, c1, c0, 0
+	isb
+
+	ldr     r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
+	blx     r1
+
+	/* Let the suspend code know about the abort */
+	mov	r0, #1
+	ldmfd	sp!, {r4 - r11, pc}	@ restore regs and return
+ENDPROC(am43xx_do_wfi)
+
+	.align
+ENTRY(am43xx_resume_offset)
+	.word . - am43xx_do_wfi
+
+ENTRY(am43xx_resume_from_deep_sleep)
+	/* Set MPU CLKSTCTRL to HW AUTO so that CPUidle works properly */
+	ldr	r1, am43xx_virt_mpu_clkstctrl
+	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
+	str	r2, [r1]
+
+	/* For AM43xx, use EMIF power down until context is restored */
+	ldr	r2, am43xx_phys_emif_poweroff
+	mov	r1, #AM43XX_EMIF_POWEROFF_ENABLE
+	str	r1, [r2, #0x0]
+
+	/* Re-enable EMIF */
+	ldr	r1, am43xx_phys_emif_clkctrl
+	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
+	str	r2, [r1]
+wait_emif_enable1:
+	ldr	r3, [r1]
+	cmp	r2, r3
+	bne	wait_emif_enable1
+
+	adr     r9, am43xx_emif_sram_table
+
+	ldr     r1, [r9, #EMIF_PM_RESTORE_CONTEXT_OFFSET]
+	blx     r1
+
+	ldr     r1, [r9, #EMIF_PM_EXIT_SR_OFFSET]
+	blx     r1
+
+	ldr     r2, am43xx_phys_emif_poweroff
+	mov     r1, #AM43XX_EMIF_POWEROFF_DISABLE
+	str     r1, [r2, #0x0]
+
+#ifdef CONFIG_CACHE_L2X0
+	ldr	r2, l2_cache_base
+	ldr	r0, [r2, #L2X0_CTRL]
+	and	r0, #0x0f
+	cmp	r0, #1
+	beq	skip_l2en			@ Skip if already enabled
+
+	adr	r4, am43xx_pm_ro_sram_data
+	ldr	r3, [r4, #AMX3_PM_RO_SRAM_DATA_PHYS_OFFSET]
+	ldr     r0, [r3, #AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET]
+
+	ldr	r12, l2_smc1
+	dsb
+	smc	#0
+	dsb
+set_aux_ctrl:
+	ldr     r0, [r3, #AMX3_PM_L2_AUX_CTRL_VAL_OFFSET]
+	ldr	r12, l2_smc2
+	dsb
+	smc	#0
+	dsb
+
+	/* L2 invalidate on resume */
+	ldr	r0, l2_val
+	ldr	r2, l2_cache_base
+	str	r0, [r2, #L2X0_INV_WAY]
+wait2:
+	ldr	r0, [r2, #L2X0_INV_WAY]
+	ldr	r1, l2_val
+	ands	r0, r0, r1
+	bne	wait2
+#ifdef CONFIG_PL310_ERRATA_727915
+	mov	r0, #0x00
+	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+	dsb
+	smc	#0
+	dsb
+#endif
+l2x_sync2:
+	ldr	r2, l2_cache_base
+	mov	r0, #0x0
+	str	r0, [r2, #L2X0_CACHE_SYNC]
+sync2:
+	ldr	r0, [r2, #L2X0_CACHE_SYNC]
+	ands	r0, r0, #0x1
+	bne	sync2
+
+	mov	r0, #0x1
+	ldr	r12, l2_smc3
+	dsb
+	smc	#0
+	dsb
+#endif
+skip_l2en:
+	/* We are back. Branch to the common CPU resume routine */
+	mov	r0, #0
+	ldr	pc, resume_addr
+ENDPROC(am43xx_resume_from_deep_sleep)
+
+/*
+ * Local variables
+ */
+	.align
+resume_addr:
+	.word	cpu_resume - PAGE_OFFSET + 0x80000000
+get_l2cache_base:
+	.word	omap4_get_l2cache_base
+kernel_flush:
+	.word   v7_flush_dcache_all
+ddr_start:
+	.word	PAGE_OFFSET
+
+am43xx_phys_emif_poweroff:
+	.word   (AM43XX_CM_BASE + AM43XX_PRM_DEVICE_INST + \
+		 AM43XX_PRM_EMIF_CTRL_OFFSET)
+am43xx_virt_mpu_clkstctrl:
+	.word	(AM43XX_CM_MPU_CLKSTCTRL)
+am43xx_virt_mpu_clkctrl:
+	.word	(AM43XX_CM_MPU_MPU_CLKCTRL)
+am43xx_virt_emif_clkctrl:
+	.word	(AM43XX_CM_PER_EMIF_CLKCTRL)
+am43xx_phys_emif_clkctrl:
+	.word	(AM43XX_CM_BASE + AM43XX_CM_PER_INST + \
+		 AM43XX_CM_PER_EMIF_CLKCTRL_OFFSET)
+
+/* L2 cache related defines for AM437x */
+l2_cache_base:
+	.word	OMAP44XX_L2CACHE_BASE
+l2_smc1:
+	.word	OMAP4_MON_L2X0_PREFETCH_INDEX
+l2_smc2:
+	.word	OMAP4_MON_L2X0_AUXCTRL_INDEX
+l2_smc3:
+	.word	OMAP4_MON_L2X0_CTRL_INDEX
+l2_val:
+	.word	0xffff
+
+.align 3
+/* DDR related defines */
+ENTRY(am43xx_emif_sram_table)
+	.space EMIF_PM_FUNCTIONS_SIZE
+
+ENTRY(am43xx_pm_sram)
+	.word am43xx_do_wfi
+	.word am43xx_do_wfi_sz
+	.word am43xx_resume_offset
+	.word am43xx_emif_sram_table
+	.word am43xx_pm_ro_sram_data
+
+.align 3
+
+ENTRY(am43xx_pm_ro_sram_data)
+	.space AMX3_PM_RO_SRAM_DATA_SIZE
+
+ENTRY(am43xx_do_wfi_sz)
+	.word	. - am43xx_do_wfi
-- 
2.16.1

[PATCH v5 3/4] ARM: OMAP2+: pm33xx-core: Add platform code needed for PM

[Dave Gerlach]

Most of the PM code needed for am335x and am437x can be moved into a
module under drivers but some core code must remain in mach-omap2 at the
moment. This includes some internal clockdomain APIs and low-level ARM
APIs which are also not exported for use by modules.

Implement a few functions that handle these low-level platform
operations can be passed to the pm33xx module through the use of
platform data.

In addition to this, to be able to share data structures between C and
the sleep33xx and sleep43xx assembly code, we can automatically generate
all of the C struct member offsets and sizes as macros by processing
pm-asm-offsets.c into assembly code and then extracting the relevant
data as is done for the generated platform asm-offsets.h files.

Finally, add amx3_common_pm_init to create a dummy platform_device for
pm33xx so that our soon to be introduced pm33xx module can probe on
am335x and am437x platforms to enable basic suspend to mem and standby
support.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/Kconfig          |   1 +
 arch/arm/mach-omap2/Makefile         |  16 +++
 arch/arm/mach-omap2/common.h         |   7 ++
 arch/arm/mach-omap2/io.c             |   2 +
 arch/arm/mach-omap2/pm-asm-offsets.c |  31 ++++++
 arch/arm/mach-omap2/pm.h             |   3 +
 arch/arm/mach-omap2/pm33xx-core.c    | 189 +++++++++++++++++++++++++++++++++++
 arch/arm/mach-omap2/sleep33xx.S      |   2 +
 arch/arm/mach-omap2/sleep43xx.S      |   2 +
 include/linux/platform_data/pm33xx.h |  42 ++++++++
 10 files changed, 295 insertions(+)
 create mode 100644 arch/arm/mach-omap2/pm-asm-offsets.c
 create mode 100644 arch/arm/mach-omap2/pm33xx-core.c
 create mode 100644 include/linux/platform_data/pm33xx.h

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 00b1f17f8d44..9f27b486a536 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -72,6 +72,7 @@ config SOC_AM43XX
 	select ARM_ERRATA_754322
 	select ARM_ERRATA_775420
 	select OMAP_INTERCONNECT
+	select ARM_CPU_SUSPEND if PM
 
 config SOC_DRA7XX
 	bool "TI DRA7XX"
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index c15bbcad5f67..4603c30fef73 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -88,6 +88,8 @@ omap-4-5-pm-common			+= pm44xx.o
 obj-$(CONFIG_ARCH_OMAP4)		+= $(omap-4-5-pm-common)
 obj-$(CONFIG_SOC_OMAP5)			+= $(omap-4-5-pm-common)
 obj-$(CONFIG_SOC_DRA7XX)		+= $(omap-4-5-pm-common)
+obj-$(CONFIG_SOC_AM33XX)		+= pm33xx-core.o sleep33xx.o
+obj-$(CONFIG_SOC_AM43XX)		+= pm33xx-core.o sleep43xx.o
 obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
 
 obj-$(CONFIG_POWER_AVS_OMAP)		+= sr_device.o
@@ -95,6 +97,8 @@ obj-$(CONFIG_POWER_AVS_OMAP_CLASS3)    += smartreflex-class3.o
 
 AFLAGS_sleep24xx.o			:=-Wa,-march=armv6
 AFLAGS_sleep34xx.o			:=-Wa,-march=armv7-a$(plus_sec)
+AFLAGS_sleep33xx.o			:=-Wa,-march=armv7-a$(plus_sec)
+AFLAGS_sleep43xx.o			:=-Wa,-march=armv7-a$(plus_sec)
 
 endif
 
@@ -232,3 +236,15 @@ obj-y					+= $(omap-hsmmc-m) $(omap-hsmmc-y)
 obj-y					+= omap_phy_internal.o
 
 obj-$(CONFIG_MACH_OMAP2_TUSB6010)	+= usb-tusb6010.o
+
+arch/arm/mach-omap2/pm-asm-offsets.s: arch/arm/mach-omap2/pm-asm-offsets.c
+	$(call if_changed_dep,cc_s_c)
+
+include/generated/ti-pm-asm-offsets.h: arch/arm/mach-omap2/pm-asm-offsets.s FORCE
+	$(call filechk,offsets,__TI_PM_ASM_OFFSETS_H__)
+
+# For rule to generate ti-emif-asm-offsets.h dependency
+include drivers/memory/Makefile.asm-offsets
+
+arch/arm/mach-omap2/sleep33xx.o: include/generated/ti-pm-asm-offsets.h include/generated/ti-emif-asm-offsets.h
+arch/arm/mach-omap2/sleep43xx.o: include/generated/ti-pm-asm-offsets.h include/generated/ti-emif-asm-offsets.h
diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index bc202835371b..fbe0b78bf489 100644
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -77,6 +77,13 @@ static inline int omap4_pm_init_early(void)
 }
 #endif
 
+#if defined(CONFIG_PM) && (defined(CONFIG_SOC_AM33XX) || \
+	defined(CONFIG_SOC_AM43XX))
+void amx3_common_pm_init(void);
+#else
+static inline void amx3_common_pm_init(void) { }
+#endif
+
 extern void omap2_init_common_infrastructure(void);
 
 extern void omap_init_time(void);
diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index cb5d7314cf99..cf546dfe3b32 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -622,6 +622,7 @@ void __init am33xx_init_early(void)
 void __init am33xx_init_late(void)
 {
 	omap_common_late_init();
+	amx3_common_pm_init();
 }
 #endif
 
@@ -646,6 +647,7 @@ void __init am43xx_init_late(void)
 {
 	omap_common_late_init();
 	omap2_clk_enable_autoidle_all();
+	amx3_common_pm_init();
 }
 #endif
 
diff --git a/arch/arm/mach-omap2/pm-asm-offsets.c b/arch/arm/mach-omap2/pm-asm-offsets.c
new file mode 100644
index 000000000000..6d4392da7c11
--- /dev/null
+++ b/arch/arm/mach-omap2/pm-asm-offsets.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI AM33XX and AM43XX PM Assembly Offsets
+ *
+ * Copyright (C) 2017-2018 Texas Instruments Inc.
+ */
+
+#include <linux/kbuild.h>
+#include <linux/platform_data/pm33xx.h>
+
+int main(void)
+{
+	DEFINE(AMX3_PM_WFI_FLAGS_OFFSET,
+	       offsetof(struct am33xx_pm_sram_data, wfi_flags));
+	DEFINE(AMX3_PM_L2_AUX_CTRL_VAL_OFFSET,
+	       offsetof(struct am33xx_pm_sram_data, l2_aux_ctrl_val));
+	DEFINE(AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET,
+	       offsetof(struct am33xx_pm_sram_data, l2_prefetch_ctrl_val));
+	DEFINE(AMX3_PM_SRAM_DATA_SIZE, sizeof(struct am33xx_pm_sram_data));
+
+	BLANK();
+
+	DEFINE(AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET,
+	       offsetof(struct am33xx_pm_ro_sram_data, amx3_pm_sram_data_virt));
+	DEFINE(AMX3_PM_RO_SRAM_DATA_PHYS_OFFSET,
+	       offsetof(struct am33xx_pm_ro_sram_data, amx3_pm_sram_data_phys));
+	DEFINE(AMX3_PM_RO_SRAM_DATA_SIZE,
+	       sizeof(struct am33xx_pm_ro_sram_data));
+
+	return 0;
+}
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 8e30772cfe32..c73776b82348 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -81,6 +81,9 @@ extern unsigned int omap3_do_wfi_sz;
 /* ... and its pointer from SRAM after copy */
 extern void (*omap3_do_wfi_sram)(void);
 
+extern struct am33xx_pm_sram_addr am33xx_pm_sram;
+extern struct am33xx_pm_sram_addr am43xx_pm_sram;
+
 extern void omap3_save_scratchpad_contents(void);
 
 #define PM_RTA_ERRATUM_i608		(1 << 0)
diff --git a/arch/arm/mach-omap2/pm33xx-core.c b/arch/arm/mach-omap2/pm33xx-core.c
new file mode 100644
index 000000000000..93c0b5ba9f09
--- /dev/null
+++ b/arch/arm/mach-omap2/pm33xx-core.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AM33XX Arch Power Management Routines
+ *
+ * Copyright (C) 2016-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Dave Gerlach
+ */
+
+#include <asm/smp_scu.h>
+#include <asm/suspend.h>
+#include <linux/errno.h>
+#include <linux/platform_data/pm33xx.h>
+
+#include "cm33xx.h"
+#include "common.h"
+#include "control.h"
+#include "clockdomain.h"
+#include "iomap.h"
+#include "omap_hwmod.h"
+#include "pm.h"
+#include "powerdomain.h"
+#include "prm33xx.h"
+#include "soc.h"
+#include "sram.h"
+
+static struct powerdomain *cefuse_pwrdm, *gfx_pwrdm, *per_pwrdm, *mpu_pwrdm;
+static struct clockdomain *gfx_l4ls_clkdm;
+static void __iomem *scu_base;
+
+static int __init am43xx_map_scu(void)
+{
+	scu_base = ioremap(scu_a9_get_base(), SZ_256);
+
+	if (!scu_base)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int amx3_common_init(void)
+{
+	gfx_pwrdm = pwrdm_lookup("gfx_pwrdm");
+	per_pwrdm = pwrdm_lookup("per_pwrdm");
+	mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
+
+	if ((!gfx_pwrdm) || (!per_pwrdm) || (!mpu_pwrdm))
+		return -ENODEV;
+
+	(void)clkdm_for_each(omap_pm_clkdms_setup, NULL);
+
+	/* CEFUSE domain can be turned off post bootup */
+	cefuse_pwrdm = pwrdm_lookup("cefuse_pwrdm");
+	if (cefuse_pwrdm)
+		omap_set_pwrdm_state(cefuse_pwrdm, PWRDM_POWER_OFF);
+	else
+		pr_err("PM: Failed to get cefuse_pwrdm\n");
+
+	return 0;
+}
+
+static int am33xx_suspend_init(void)
+{
+	int ret;
+
+	gfx_l4ls_clkdm = clkdm_lookup("gfx_l4ls_gfx_clkdm");
+
+	if (!gfx_l4ls_clkdm) {
+		pr_err("PM: Cannot lookup gfx_l4ls_clkdm clockdomains\n");
+		return -ENODEV;
+	}
+
+	ret = amx3_common_init();
+
+	return ret;
+}
+
+static int am43xx_suspend_init(void)
+{
+	int ret = 0;
+
+	ret = am43xx_map_scu();
+	if (ret) {
+		pr_err("PM: Could not ioremap SCU\n");
+		return ret;
+	}
+
+	ret = amx3_common_init();
+
+	return ret;
+}
+
+static void amx3_pre_suspend_common(void)
+{
+	omap_set_pwrdm_state(gfx_pwrdm, PWRDM_POWER_OFF);
+}
+
+static void amx3_post_suspend_common(void)
+{
+	int status;
+	/*
+	 * Because gfx_pwrdm is the only one under MPU control,
+	 * comment on transition status
+	 */
+	status = pwrdm_read_pwrst(gfx_pwrdm);
+	if (status != PWRDM_POWER_OFF)
+		pr_err("PM: GFX domain did not transition: %x\n", status);
+}
+
+static int am33xx_suspend(unsigned int state, int (*fn)(unsigned long))
+{
+	int ret = 0;
+
+	amx3_pre_suspend_common();
+	ret = cpu_suspend(0, fn);
+	amx3_post_suspend_common();
+
+	/*
+	 * BUG: GFX_L4LS clock domain needs to be woken up to
+	 * ensure thet L4LS clock domain does not get stuck in
+	 * transition. If that happens L3 module does not get
+	 * disabled, thereby leading to PER power domain
+	 * transition failing
+	 */
+
+	clkdm_wakeup(gfx_l4ls_clkdm);
+	clkdm_sleep(gfx_l4ls_clkdm);
+
+	return ret;
+}
+
+static int am43xx_suspend(unsigned int state, int (*fn)(unsigned long))
+{
+	int ret = 0;
+
+	amx3_pre_suspend_common();
+	scu_power_mode(scu_base, SCU_PM_POWEROFF);
+	ret = cpu_suspend(0, fn);
+	scu_power_mode(scu_base, SCU_PM_NORMAL);
+	amx3_post_suspend_common();
+
+	return ret;
+}
+
+static struct am33xx_pm_sram_addr *amx3_get_sram_addrs(void)
+{
+	if (soc_is_am33xx())
+		return &am33xx_pm_sram;
+	else if (soc_is_am437x())
+		return &am43xx_pm_sram;
+	else
+		return NULL;
+}
+
+static struct am33xx_pm_platform_data am33xx_ops = {
+	.init = am33xx_suspend_init,
+	.soc_suspend = am33xx_suspend,
+	.get_sram_addrs = amx3_get_sram_addrs,
+};
+
+static struct am33xx_pm_platform_data am43xx_ops = {
+	.init = am43xx_suspend_init,
+	.soc_suspend = am43xx_suspend,
+	.get_sram_addrs = amx3_get_sram_addrs,
+};
+
+static struct am33xx_pm_platform_data *am33xx_pm_get_pdata(void)
+{
+	if (soc_is_am33xx())
+		return &am33xx_ops;
+	else if (soc_is_am437x())
+		return &am43xx_ops;
+	else
+		return NULL;
+}
+
+void __init amx3_common_pm_init(void)
+{
+	struct am33xx_pm_platform_data *pdata;
+	struct platform_device_info devinfo;
+
+	pdata = am33xx_pm_get_pdata();
+
+	memset(&devinfo, 0, sizeof(devinfo));
+	devinfo.name = "pm33xx";
+	devinfo.data = pdata;
+	devinfo.size_data = sizeof(*pdata);
+	devinfo.id = -1;
+	platform_device_register_full(&devinfo);
+}
diff --git a/arch/arm/mach-omap2/sleep33xx.S b/arch/arm/mach-omap2/sleep33xx.S
index 04015f98b6e3..218d79930b04 100644
--- a/arch/arm/mach-omap2/sleep33xx.S
+++ b/arch/arm/mach-omap2/sleep33xx.S
@@ -6,6 +6,8 @@
  *	Dave Gerlach, Vaibhav Bedia
  */
 
+#include <generated/ti-emif-asm-offsets.h>
+#include <generated/ti-pm-asm-offsets.h>
 #include <linux/linkage.h>
 #include <linux/ti-emif-sram.h>
 #include <asm/assembler.h>
diff --git a/arch/arm/mach-omap2/sleep43xx.S b/arch/arm/mach-omap2/sleep43xx.S
index 0defc735e319..59770a69396b 100644
--- a/arch/arm/mach-omap2/sleep43xx.S
+++ b/arch/arm/mach-omap2/sleep43xx.S
@@ -6,6 +6,8 @@
  *	Dave Gerlach, Vaibhav Bedia
  */
 
+#include <generated/ti-emif-asm-offsets.h>
+#include <generated/ti-pm-asm-offsets.h>
 #include <linux/linkage.h>
 #include <linux/ti-emif-sram.h>
 
diff --git a/include/linux/platform_data/pm33xx.h b/include/linux/platform_data/pm33xx.h
new file mode 100644
index 000000000000..f9bed2a0af9d
--- /dev/null
+++ b/include/linux/platform_data/pm33xx.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * TI pm33xx platform data
+ *
+ * Copyright (C) 2016-2018 Texas Instruments, Inc.
+ *	Dave Gerlach <d-gerlach@ti.com>
+ */
+
+#ifndef _LINUX_PLATFORM_DATA_PM33XX_H
+#define _LINUX_PLATFORM_DATA_PM33XX_H
+
+#include <linux/kbuild.h>
+#include <linux/types.h>
+
+#ifndef __ASSEMBLER__
+struct am33xx_pm_sram_addr {
+	void (*do_wfi)(void);
+	unsigned long *do_wfi_sz;
+	unsigned long *resume_offset;
+	unsigned long *emif_sram_table;
+	unsigned long *ro_sram_data;
+};
+
+struct am33xx_pm_platform_data {
+	int	(*init)(void);
+	int	(*soc_suspend)(unsigned int state, int (*fn)(unsigned long));
+	struct  am33xx_pm_sram_addr *(*get_sram_addrs)(void);
+};
+
+struct am33xx_pm_sram_data {
+	u32 wfi_flags;
+	u32 l2_aux_ctrl_val;
+	u32 l2_prefetch_ctrl_val;
+} __packed __aligned(8);
+
+struct am33xx_pm_ro_sram_data {
+	u32 amx3_pm_sram_data_virt;
+	u32 amx3_pm_sram_data_phys;
+} __packed __aligned(8);
+
+#endif /* __ASSEMBLER__ */
+#endif /* _LINUX_PLATFORM_DATA_PM33XX_H */
-- 
2.16.1

[PATCH v5 4/4] soc: ti: Add pm33xx driver for basic suspend support

[Dave Gerlach]

AM335x and AM437x support various low power modes as documented
in section 8.1.4.3 of the AM335x Technical Reference Manual and
section 6.4.3 of the AM437x Technical Reference Manual.

DeepSleep0 mode offers the lowest power mode with limited
wakeup sources without a system reboot and is mapped as
the suspend state in the kernel. In this state, MPU and
PER domains are turned off with the internal RAM held in
retention to facilitate the resume process. As part of
the boot process, the assembly code is copied over to OCMCRAM
so it can be executed to turn of the EMIF and put DDR into self
refresh.

Both platforms have a Cortex-M3 (WKUP_M3) which assists the MPU
in DeepSleep0 entry and exit. WKUP_M3 takes care
of the clockdomain and powerdomain transitions based on the
intended low power state. MPU needs to load the appropriate
WKUP_M3 binary onto the WKUP_M3 memory space before it can
leverage any of the PM features like DeepSleep. This loading
is handled by the remoteproc driver wkup_m3_rproc.

Communication with the WKUP_M3 is handled by a wkup_m3_ipc
driver that exposes the specific PM functionality to be used
the PM code.

In the current implementation when the suspend process
is initiated, MPU interrupts the WKUP_M3 to let it know about
the intent of entering DeepSleep0 and waits for an ACK. When
the ACK is received MPU continues with its suspend process
to suspend all the drivers and then jumps to assembly in
OCMC RAM. The assembly code puts the external RAM in self-refresh
mode, gates the MPU clock, and then finally executes the WFI
instruction. Execution of the WFI instruction with MPU clock gated
triggers another interrupt to the WKUP_M3 which then continues
with the power down sequence wherein the clockdomain and
powerdomain transition takes place. As part of the sleep sequence,
WKUP_M3 unmasks the interrupt lines for the wakeup sources. WFI
execution on WKUP_M3 causes the hardware to disable the main
oscillator of the SoC and from here system remains in sleep state
until a wake source brings the system into resume path.

When a wakeup event occurs, WKUP_M3 starts the power-up
sequence by switching on the power domains and finally
enabling the clock to MPU. Since the MPU gets powered down
as part of the sleep sequence in the resume path ROM code
starts executing. The ROM code detects a wakeup from sleep
and then jumps to the resume location in OCMC which was
populated in one of the IPC registers as part of the suspend
sequence.

Code is based on work by Vaibhav Bedia.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 Documentation/devicetree/bindings/arm/omap/mpu.txt |  16 +
 drivers/soc/ti/Kconfig                             |   9 +
 drivers/soc/ti/Makefile                            |   1 +
 drivers/soc/ti/pm33xx.c                            | 349 +++++++++++++++++++++
 4 files changed, 375 insertions(+)
 create mode 100644 drivers/soc/ti/pm33xx.c

diff --git a/Documentation/devicetree/bindings/arm/omap/mpu.txt b/Documentation/devicetree/bindings/arm/omap/mpu.txt
index 763695db2bd9..f301e636fd52 100644
--- a/Documentation/devicetree/bindings/arm/omap/mpu.txt
+++ b/Documentation/devicetree/bindings/arm/omap/mpu.txt
@@ -13,6 +13,13 @@ Required properties:
 Optional properties:
 - sram:	Phandle to the ocmcram node
 
+am335x and am437x only:
+- pm-sram: Phandles to ocmcram nodes to be used for power management.
+	   First should be type 'protect-exec' for the driver to use to copy
+	   and run PM functions, second should be regular pool to be used for
+	   data region for code. See Documentation/devicetree/bindings/sram/sram.txt
+	   for more details.
+
 Examples:
 
 - For an OMAP5 SMP system:
@@ -36,3 +43,12 @@ mpu {
     compatible = "ti,omap3-mpu";
     ti,hwmods = "mpu";
 };
+
+- For an AM335x system:
+
+mpu {
+	compatible = "ti,omap3-mpu";
+	ti,hwmods = "mpu";
+	pm-sram = <&pm_sram_code
+		   &pm_sram_data>;
+};
diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
index 39e152abe6b9..92770d84a288 100644
--- a/drivers/soc/ti/Kconfig
+++ b/drivers/soc/ti/Kconfig
@@ -28,6 +28,15 @@ config KEYSTONE_NAVIGATOR_DMA
 
 	  If unsure, say N.
 
+config AMX3_PM
+	tristate "AMx3 Power Management"
+	depends on SOC_AM33XX || SOC_AM43XX
+	depends on WKUP_M3_IPC && TI_EMIF_SRAM && SRAM
+	help
+	  Enable power management on AM335x and AM437x. Required for suspend to mem
+	  and standby states on both AM335x and AM437x platforms and for deeper cpuidle
+	  c-states on AM335x.
+
 config WKUP_M3_IPC
 	tristate "TI AMx3 Wkup-M3 IPC Driver"
 	depends on WKUP_M3_RPROC
diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile
index 8e205287f120..a22edc0b258a 100644
--- a/drivers/soc/ti/Makefile
+++ b/drivers/soc/ti/Makefile
@@ -5,5 +5,6 @@
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS)	+= knav_qmss.o
 knav_qmss-y := knav_qmss_queue.o knav_qmss_acc.o
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA)	+= knav_dma.o
+obj-$(CONFIG_AMX3_PM)			+= pm33xx.o
 obj-$(CONFIG_WKUP_M3_IPC)		+= wkup_m3_ipc.o
 obj-$(CONFIG_TI_SCI_PM_DOMAINS)		+= ti_sci_pm_domains.o
diff --git a/drivers/soc/ti/pm33xx.c b/drivers/soc/ti/pm33xx.c
new file mode 100644
index 000000000000..652739c7f718
--- /dev/null
+++ b/drivers/soc/ti/pm33xx.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AM33XX Power Management Routines
+ *
+ * Copyright (C) 2012-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Vaibhav Bedia, Dave Gerlach
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/genalloc.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/pm33xx.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/sram.h>
+#include <linux/suspend.h>
+#include <linux/ti-emif-sram.h>
+#include <linux/wkup_m3_ipc.h>
+
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/system_misc.h>
+
+#define AMX3_PM_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
+					 (unsigned long)pm_sram->do_wfi)
+
+static int (*am33xx_do_wfi_sram)(unsigned long unused);
+static phys_addr_t am33xx_do_wfi_sram_phys;
+
+static struct gen_pool *sram_pool, *sram_pool_data;
+static unsigned long ocmcram_location, ocmcram_location_data;
+
+static struct am33xx_pm_platform_data *pm_ops;
+static struct am33xx_pm_sram_addr *pm_sram;
+
+static struct device *pm33xx_dev;
+static struct wkup_m3_ipc *m3_ipc;
+
+static u32 sram_suspend_address(unsigned long addr)
+{
+	return ((unsigned long)am33xx_do_wfi_sram +
+		AMX3_PM_SRAM_SYMBOL_OFFSET(addr));
+}
+
+#ifdef CONFIG_SUSPEND
+static int am33xx_pm_suspend(suspend_state_t suspend_state)
+{
+	int i, ret = 0;
+
+	ret = pm_ops->soc_suspend((unsigned long)suspend_state,
+				  am33xx_do_wfi_sram);
+
+	if (ret) {
+		dev_err(pm33xx_dev, "PM: Kernel suspend failure\n");
+	} else {
+		i = m3_ipc->ops->request_pm_status(m3_ipc);
+
+		switch (i) {
+		case 0:
+			dev_info(pm33xx_dev,
+				 "PM: Successfully put all powerdomains to target state\n");
+			break;
+		case 1:
+			dev_err(pm33xx_dev,
+				"PM: Could not transition all powerdomains to target state\n");
+			ret = -1;
+			break;
+		default:
+			dev_err(pm33xx_dev,
+				"PM: CM3 returned unknown result = %d\n", i);
+			ret = -1;
+		}
+	}
+
+	return ret;
+}
+
+static int am33xx_pm_enter(suspend_state_t suspend_state)
+{
+	int ret = 0;
+
+	switch (suspend_state) {
+	case PM_SUSPEND_MEM:
+	case PM_SUSPEND_STANDBY:
+		ret = am33xx_pm_suspend(suspend_state);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int am33xx_pm_begin(suspend_state_t state)
+{
+	int ret = -EINVAL;
+
+	switch (state) {
+	case PM_SUSPEND_MEM:
+		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_DEEPSLEEP);
+		break;
+	case PM_SUSPEND_STANDBY:
+		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_STANDBY);
+		break;
+	}
+
+	return ret;
+}
+
+static void am33xx_pm_end(void)
+{
+	m3_ipc->ops->finish_low_power(m3_ipc);
+}
+
+static int am33xx_pm_valid(suspend_state_t state)
+{
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+	case PM_SUSPEND_MEM:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static const struct platform_suspend_ops am33xx_pm_ops = {
+	.begin		= am33xx_pm_begin,
+	.end		= am33xx_pm_end,
+	.enter		= am33xx_pm_enter,
+	.valid		= am33xx_pm_valid,
+};
+#endif /* CONFIG_SUSPEND */
+
+static void am33xx_pm_set_ipc_ops(void)
+{
+	u32 resume_address;
+	int temp;
+
+	temp = ti_emif_get_mem_type();
+	if (temp < 0) {
+		dev_err(pm33xx_dev, "PM: Cannot determine memory type, no PM available\n");
+		return;
+	}
+	m3_ipc->ops->set_mem_type(m3_ipc, temp);
+
+	/* Physical resume address to be used by ROM code */
+	resume_address = am33xx_do_wfi_sram_phys +
+			 *pm_sram->resume_offset + 0x4;
+
+	m3_ipc->ops->set_resume_address(m3_ipc, (void *)resume_address);
+}
+
+static void am33xx_pm_free_sram(void)
+{
+	gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
+	gen_pool_free(sram_pool_data, ocmcram_location_data,
+		      sizeof(struct am33xx_pm_ro_sram_data));
+}
+
+/*
+ * Push the minimal suspend-resume code to SRAM
+ */
+static int am33xx_pm_alloc_sram(void)
+{
+	struct device_node *np;
+	int ret = 0;
+
+	np = of_find_compatible_node(NULL, NULL, "ti,omap3-mpu");
+	if (!np) {
+		np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
+		if (!np) {
+			dev_err(pm33xx_dev, "PM: %s: Unable to find device node for mpu\n",
+				__func__);
+			return -ENODEV;
+		}
+	}
+
+	sram_pool = of_gen_pool_get(np, "pm-sram", 0);
+	if (!sram_pool) {
+		dev_err(pm33xx_dev, "PM: %s: Unable to get sram pool for ocmcram\n",
+			__func__);
+		ret = -ENODEV;
+		goto mpu_put_node;
+	}
+
+	sram_pool_data = of_gen_pool_get(np, "pm-sram", 1);
+	if (!sram_pool_data) {
+		dev_err(pm33xx_dev, "PM: %s: Unable to get sram data pool for ocmcram\n",
+			__func__);
+		ret = -ENODEV;
+		goto mpu_put_node;
+	}
+
+	ocmcram_location = gen_pool_alloc(sram_pool, *pm_sram->do_wfi_sz);
+	if (!ocmcram_location) {
+		dev_err(pm33xx_dev, "PM: %s: Unable to allocate memory from ocmcram\n",
+			__func__);
+		ret = -ENOMEM;
+		goto mpu_put_node;
+	}
+
+	ocmcram_location_data = gen_pool_alloc(sram_pool_data,
+					       sizeof(struct emif_regs_amx3));
+	if (!ocmcram_location_data) {
+		dev_err(pm33xx_dev, "PM: Unable to allocate memory from ocmcram\n");
+		gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
+		ret = -ENOMEM;
+	}
+
+mpu_put_node:
+	of_node_put(np);
+	return ret;
+}
+
+static int am33xx_push_sram_idle(void)
+{
+	struct am33xx_pm_ro_sram_data ro_sram_data;
+	int ret;
+	u32 table_addr, ro_data_addr;
+	void *copy_addr;
+
+	ro_sram_data.amx3_pm_sram_data_virt = ocmcram_location_data;
+	ro_sram_data.amx3_pm_sram_data_phys =
+		gen_pool_virt_to_phys(sram_pool_data, ocmcram_location_data);
+
+	/* Save physical address to calculate resume offset during pm init */
+	am33xx_do_wfi_sram_phys = gen_pool_virt_to_phys(sram_pool,
+							ocmcram_location);
+
+	am33xx_do_wfi_sram = sram_exec_copy(sram_pool, (void *)ocmcram_location,
+					    pm_sram->do_wfi,
+					    *pm_sram->do_wfi_sz);
+	if (!am33xx_do_wfi_sram) {
+		dev_err(pm33xx_dev,
+			"PM: %s: am33xx_do_wfi copy to sram failed\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	table_addr =
+		sram_suspend_address((unsigned long)pm_sram->emif_sram_table);
+	ret = ti_emif_copy_pm_function_table(sram_pool, (void *)table_addr);
+	if (ret) {
+		dev_dbg(pm33xx_dev,
+			"PM: %s: EMIF function copy failed\n", __func__);
+		return -EPROBE_DEFER;
+	}
+
+	ro_data_addr =
+		sram_suspend_address((unsigned long)pm_sram->ro_sram_data);
+	copy_addr = sram_exec_copy(sram_pool, (void *)ro_data_addr,
+				   &ro_sram_data,
+				   sizeof(ro_sram_data));
+	if (!copy_addr) {
+		dev_err(pm33xx_dev,
+			"PM: %s: ro_sram_data copy to sram failed\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int am33xx_pm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (!of_machine_is_compatible("ti,am33xx") &&
+	    !of_machine_is_compatible("ti,am43"))
+		return -ENODEV;
+
+	pm_ops = dev->platform_data;
+	if (!pm_ops) {
+		dev_err(dev, "PM: Cannot get core PM ops!\n");
+		return -ENODEV;
+	}
+
+	pm_sram = pm_ops->get_sram_addrs();
+	if (!pm_sram) {
+		dev_err(dev, "PM: Cannot get PM asm function addresses!!\n");
+		return -ENODEV;
+	}
+
+	pm33xx_dev = dev;
+
+	ret = am33xx_pm_alloc_sram();
+	if (ret)
+		return ret;
+
+	ret = am33xx_push_sram_idle();
+	if (ret)
+		goto err_free_sram;
+
+	m3_ipc = wkup_m3_ipc_get();
+	if (!m3_ipc) {
+		dev_dbg(dev, "PM: Cannot get wkup_m3_ipc handle\n");
+		ret = -EPROBE_DEFER;
+		goto err_free_sram;
+	}
+
+	am33xx_pm_set_ipc_ops();
+
+#ifdef CONFIG_SUSPEND
+	suspend_set_ops(&am33xx_pm_ops);
+#endif /* CONFIG_SUSPEND */
+
+	ret = pm_ops->init();
+	if (ret) {
+		dev_err(dev, "Unable to call core pm init!\n");
+		ret = -ENODEV;
+		goto err_put_wkup_m3_ipc;
+	}
+
+	return 0;
+
+err_put_wkup_m3_ipc:
+	wkup_m3_ipc_put(m3_ipc);
+err_free_sram:
+	am33xx_pm_free_sram();
+	pm33xx_dev = NULL;
+	return ret;
+}
+
+static int am33xx_pm_remove(struct platform_device *pdev)
+{
+	suspend_set_ops(NULL);
+	wkup_m3_ipc_put(m3_ipc);
+	am33xx_pm_free_sram();
+	return 0;
+}
+
+static struct platform_driver am33xx_pm_driver = {
+	.driver = {
+		.name   = "pm33xx",
+	},
+	.probe = am33xx_pm_probe,
+	.remove = am33xx_pm_remove,
+};
+module_platform_driver(am33xx_pm_driver);
+
+MODULE_ALIAS("platform:pm33xx");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("am33xx power management driver");
-- 
2.16.1

Re: [PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[Santosh Shilimkar]

Hi Tony,

On 2/23/2018 7:43 AM, Dave Gerlach wrote:
> Hi,
> 
> This is a minor update to previous series sent here [1] to switch to
> SPDX license headers. Because update is so minor I have included original
> cover letter below unmodified with the exception of updated links.
> 
> This series contains the remaining code to enable suspend to mem and standby
> on am335x and am437x platforms. All dependencies have been merged and this
> is just a rebase on v4.16-rc1. For this to work on am437x-gp-evm this
> bug fix patch [2] is required but suspend works fine on am335x platforms
> without it. V3 of this series can be found here [3].
> 
> This code also depends on firmware for the wkup_m3 that is available here [4]
> that can either be placed in /lib/firmware or built in to the kernel.
> 
> For testing the drivers required are:
> 
> CONFIG_MAILBOX
> CONFIG_OMAP2PLUS_MBOX
> CONFIG_WKUP_M3_RPROC
> CONFIG_SOC_TI
> CONFIG_WKUP_M3_IPC
> CONFIG_TI_EMIF_SRAM
> CONFIG_AMX3_PM
> 
> There is a device tree patch series to follow immediately after this that will
> completely enable suspend, all patches pushed here [5] for convenience
> including the aforementioned [2] regulator bug fix if anyone is testing.
> 
> Regards,
> Dave
> 
> [1] https://www.spinics.net/lists/linux-omap/msg141652.html
> [2] https://www.spinics.net/lists/linux-omap/msg141626.html
> [3] https://www.spinics.net/lists/arm-kernel/msg595931.html
> [4] https://git.ti.com/processor-firmware/ti-amx3-cm3-pm-firmware/blobs/7eb9c0856a9e8b3b42bf64f761da135852b8eea7/bin/am335x-pm-firmware.elf
> [5] https://github.com/dgerlach/linux-pm/tree/upstream/v4.16/amx3-suspend-v5
> 
> Dave Gerlach (4):
>    ARM: OMAP2+: Introduce low-level suspend code for AM33XX
>    ARM: OMAP2+: Introduce low-level suspend code for AM43XX
>    ARM: OMAP2+: pm33xx-core: Add platform code needed for PM
>    soc: ti: Add pm33xx driver for basic suspend support
> 
Are you going to pickup this series ?

Regards,
Santosh

Re: [PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[Tony Lindgren]

* Santosh Shilimkar <santosh.shilimkar@oracle.com> [180225 23:36]:
> > Dave Gerlach (4):
> >    ARM: OMAP2+: Introduce low-level suspend code for AM33XX
> >    ARM: OMAP2+: Introduce low-level suspend code for AM43XX
> >    ARM: OMAP2+: pm33xx-core: Add platform code needed for PM
> >    soc: ti: Add pm33xx driver for basic suspend support
> > 
> Are you going to pickup this series ?

Yes planning to apply it today or tomorrow.

Regards,

Tony

Re: [PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[santosh.shilimkar]

On 2/26/18 1:26 PM, Tony Lindgren wrote:
> * Santosh Shilimkar <santosh.shilimkar@oracle.com> [180225 23:36]:
>>> Dave Gerlach (4):
>>>     ARM: OMAP2+: Introduce low-level suspend code for AM33XX
>>>     ARM: OMAP2+: Introduce low-level suspend code for AM43XX
>>>     ARM: OMAP2+: pm33xx-core: Add platform code needed for PM
>>>     soc: ti: Add pm33xx driver for basic suspend support
>>>
>> Are you going to pickup this series ?
> 
> Yes planning to apply it today or tomorrow.
> 
Sounds good.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>

Re: [PATCH v5 0/4] ARM: OMAP2+: AM33XX/AM43XX: Add suspend-resume support

[Tony Lindgren]

* santosh.shilimkar@oracle.com <santosh.shilimkar@oracle.com> [180227 00:19]:
> On 2/26/18 1:26 PM, Tony Lindgren wrote:
> > * Santosh Shilimkar <santosh.shilimkar@oracle.com> [180225 23:36]:
> > > > Dave Gerlach (4):
> > > >     ARM: OMAP2+: Introduce low-level suspend code for AM33XX
> > > >     ARM: OMAP2+: Introduce low-level suspend code for AM43XX
> > > >     ARM: OMAP2+: pm33xx-core: Add platform code needed for PM
> > > >     soc: ti: Add pm33xx driver for basic suspend support
> > > > 
> > > Are you going to pickup this series ?
> > 
> > Yes planning to apply it today or tomorrow.
> > 
> Sounds good.
> 
> Acked-by: Santosh Shilimkar <ssantosh@kernel.org>

Applied and pushed out into omap-for-v4.17/ampm.

Thanks,

Tony