Re: [PATCH 18/20] board: ti: evm: Store wakeup reason on scratchpad memory

Fri, 22 May 2026 08:57:56 -0700 

Le 30/04/2026 à 19:32, Andrew Davis a écrit :

On 4/30/26 3:44 AM, Richard Genoud (TI) wrote:

From: Abhash Kumar Jha <[email protected]>

While resuming from suspend, the wakeup reason need to be stored
and this will be used by the Linux kernel once its up.

Use the 32 bytes of MCU_PSRAM0_RAM area (addr = 0x40280000) to
store the wakeup reason.

Read the value as soon as it starts and store it internally.

Signed-off-by: Abhash Kumar Jha <[email protected]>
---
  arch/arm/mach-k3/include/mach/j721e_hardware.h  | 1 +
  arch/arm/mach-k3/include/mach/j784s4_hardware.h | 1 +
  board/ti/common/k3-lpm.h                        | 5 +++++
  board/ti/j721e/evm.c                            | 9 +++++++++
  board/ti/j784s4/evm.c                           | 9 +++++++++
  5 files changed, 25 insertions(+)
diff --git a/arch/arm/mach-k3/include/mach/j721e_hardware.h b/arch/ arm/mach-k3/include/mach/j721e_hardware.h 
index 587dd10eb1ea..d58e2b3e1bb2 100644
--- a/arch/arm/mach-k3/include/mach/j721e_hardware.h
+++ b/arch/arm/mach-k3/include/mach/j721e_hardware.h
@@ -47,6 +47,7 @@
  /* MCU SCRATCHPAD usage */
  #define TI_SRAM_SCRATCH_BOARD_EEPROM_START CONFIG_SYS_K3_MCU_SCRATCHPAD_BASE 
+#define TI_SRAM_SCRATCH_LPM_START        0x40280000


Should this be a Kconfig option?

Andrew


Yes, definitely.

Thanks!



  #if defined(CONFIG_SYS_K3_SPL_ATF) && !defined(__ASSEMBLY__)
diff --git a/arch/arm/mach-k3/include/mach/j784s4_hardware.h b/arch/ arm/mach-k3/include/mach/j784s4_hardware.h 
index dd51473419dd..2fc81902f879 100644
--- a/arch/arm/mach-k3/include/mach/j784s4_hardware.h
+++ b/arch/arm/mach-k3/include/mach/j784s4_hardware.h
@@ -46,6 +46,7 @@
  /* MCU SCRATCHPAD usage */
  #define TI_SRAM_SCRATCH_BOARD_EEPROM_START CONFIG_SYS_K3_MCU_SCRATCHPAD_BASE 
+#define TI_SRAM_SCRATCH_LPM_START        0x40280000
  #if defined(CONFIG_SYS_K3_SPL_ATF) && !defined(__ASSEMBLY__)
diff --git a/board/ti/common/k3-lpm.h b/board/ti/common/k3-lpm.h
index a2141a0c25a8..dfd8f8486f08 100644
--- a/board/ti/common/k3-lpm.h
+++ b/board/ti/common/k3-lpm.h
@@ -13,5 +13,10 @@
  /* PMIC register where the magic value resides */
  #define K3_LPM_SCRATCH_PAD_REG 0xcb
+struct lpm_scratch_space {
+    u16 wake_src;
+    u16 reserved;
+} __packed;
+
  #endif /* __K3_LPM_H */
diff --git a/board/ti/j721e/evm.c b/board/ti/j721e/evm.c
index 41eea1bdea95..a9f469fea1f7 100644
--- a/board/ti/j721e/evm.c
+++ b/board/ti/j721e/evm.c
@@ -474,6 +474,9 @@ err_free_gpio:
  #if (IS_ENABLED(CONFIG_SPL_BUILD) && IS_ENABLED(CONFIG_TARGET_J7200_R5_EVM)) 
+#define LPM_WAKE_SOURCE_PMIC_GPIO 0x91
+#define LPM_WAKE_SOURCE_MAIN_IO   0x80
+
  static void clear_isolation(void)
  {
      int ret;
@@ -498,12 +501,15 @@ bool j7xx_board_is_resuming(void)
  {
      struct udevice *pmica;
      u32 pmctrl_val = readl(PMCTRL_IO_1);
+    struct lpm_scratch_space *lpm_scratch;
      int ret;
      if (gd_k3_resuming() != K3_RESUME_STATE_UNKNOWN)
          goto end;
+    lpm_scratch = (struct lpm_scratch_space *)TI_SRAM_SCRATCH_LPM_START;
      if ((pmctrl_val & IO_ISO_STATUS) == IO_ISO_STATUS) {
+        lpm_scratch->wake_src = LPM_WAKE_SOURCE_MAIN_IO;
          clear_isolation();
          gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
          debug("Resuming from IO_DDR mode\n");
@@ -520,6 +526,7 @@ bool j7xx_board_is_resuming(void)
      if (pmic_reg_read(pmica, K3_LPM_SCRATCH_PAD_REG) == K3_LPM_MAGIC_SUSPEND) { 
          debug("%s: board is resuming\n", __func__);
+        lpm_scratch->wake_src = LPM_WAKE_SOURCE_PMIC_GPIO;
          gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
          /* clean magic suspend */
@@ -527,6 +534,8 @@ bool j7xx_board_is_resuming(void)
              printf("Failed to clean magic value for suspend detection in PMICA\n"); 
      } else {
          debug("%s: board is booting (no resume detected)\n", __func__);
+        lpm_scratch->wake_src = 0;
+        lpm_scratch->reserved = 0;
          gd_set_k3_resuming(K3_RESUME_STATE_BOOTING);
      }
  end:
diff --git a/board/ti/j784s4/evm.c b/board/ti/j784s4/evm.c
index eef56556a33c..b94ec7f3653b 100644
--- a/board/ti/j784s4/evm.c
+++ b/board/ti/j784s4/evm.c
@@ -68,6 +68,9 @@ int board_late_init(void)
  #if (IS_ENABLED(CONFIG_SPL_BUILD) && (IS_ENABLED(CONFIG_TARGET_J784S4_R5_EVM) || \ 
                        IS_ENABLED(CONFIG_TARGET_J742S2_R5_EVM)))
+#define LPM_WAKE_SOURCE_PMIC_GPIO 0x91
+#define LPM_WAKE_SOURCE_MCU_IO    0x81
+
  static void clear_isolation(void)
  {
      int ret;
@@ -93,12 +96,15 @@ bool j7xx_board_is_resuming(void)
  {
      struct udevice *pmic;
      u32 pmctrl_val = readl(WKUP_CTRL_MMR0_BASE + PMCTRL_IO_0);
+    struct lpm_scratch_space *lpm_scratch;
      int err;
      if (gd_k3_resuming() != K3_RESUME_STATE_UNKNOWN)
          goto end;
+    lpm_scratch = (struct lpm_scratch_space *)TI_SRAM_SCRATCH_LPM_START;
      if ((pmctrl_val & IO_ISO_STATUS) == IO_ISO_STATUS) {
+        lpm_scratch->wake_src = LPM_WAKE_SOURCE_MCU_IO;
          clear_isolation();
          gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
          debug("board is resuming from IO_DDR mode\n");
@@ -115,6 +121,7 @@ bool j7xx_board_is_resuming(void)
      if (pmic_reg_read(pmic, K3_LPM_SCRATCH_PAD_REG) == K3_LPM_MAGIC_SUSPEND) { 
          debug("%s: board is resuming\n", __func__);
+        lpm_scratch->wake_src = LPM_WAKE_SOURCE_PMIC_GPIO;
          gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
          /* clean magic suspend */
@@ -122,6 +129,8 @@ bool j7xx_board_is_resuming(void)
              printf("Failed to clean magic value for suspend detection in PMIC\n"); 
      } else {
          debug("%s: board is booting (no resume detected)\n", __func__);
+        lpm_scratch->wake_src = 0;
+        lpm_scratch->reserved = 0;
          gd_set_k3_resuming(K3_RESUME_STATE_BOOTING);
      }
  end:

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