[PATCH 03/20] board: ti: j721e: Add resume detection for J721e/J7200

[Richard GENOUD]

Le 21/05/2026 à 10:42, Richard GENOUD a écrit :
> Le 11/05/2026 à 11:53, Kumar, Udit a écrit :
>>
>>
>> On 4/30/2026 2:13 PM, Richard Genoud (TI) wrote:
>>> From: "Thomas Richard (TI)" <thomas.richard at bootlin.com>
>>>
>>> Add the capability to detect a resume. This overrides the weak
>>> function j7xx_board_is_resuming(void).
>>> To detect the resume, SPL searches a magic value (0xBA) in a register
>>> of PMICA.
>>> This value is set by DM-Firmware during the suspend sequence.
>>>
>>> Signed-off-by: Thomas Richard (TI) <thomas.richard at bootlin.com>
>>> Co-developed-by: Gregory CLEMENT (TI) <gregory.clement at bootlin.com>
>>> Signed-off-by: Gregory CLEMENT (TI) <gregory.clement at bootlin.com>
>>> Co-developed-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
>>> Signed-off-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
>>> ---
>>>   board/ti/common/k3-lpm.h | 17 +++++++++++++++++
>>>   board/ti/j721e/evm.c     | 37 +++++++++++++++++++++++++++++++++++++
>>>   2 files changed, 54 insertions(+)
>>>   create mode 100644 board/ti/common/k3-lpm.h
>>>
>>> diff --git a/board/ti/common/k3-lpm.h b/board/ti/common/k3-lpm.h
>>> new file mode 100644
>>> index 000000000000..a2141a0c25a8
>>> --- /dev/null
>>> +++ b/board/ti/common/k3-lpm.h
>>> @@ -0,0 +1,17 @@
>>> +/* SPDX-License-Identifier: GPL-2.0+ */
>>> +/*
>>> + * Copyright (C) 2026, Texas Instruments Incorporated - https:// 
>>> www.ti.com/
>>> + * Copyright (C) 2026, Bootlin
>>> + */
>>> +
>>> +#ifndef __K3_LPM_H
>>> +#define __K3_LPM_H
>>> +
>>> +/* Magic value in PMIC register to indicate the suspend state 
>>> (SOC_OFF) */
>>> +#define K3_LPM_MAGIC_SUSPEND 0xba
>>> +
>>> +/* PMIC register where the magic value resides */
>>> +#define K3_LPM_SCRATCH_PAD_REG 0xcb
>>> +
>>> +#endif /* __K3_LPM_H */
>>> +
>>> diff --git a/board/ti/j721e/evm.c b/board/ti/j721e/evm.c
>>> index 881392bd963a..67ff13828514 100644
>>> --- a/board/ti/j721e/evm.c
>>> +++ b/board/ti/j721e/evm.c
>>> @@ -17,9 +17,11 @@
>>>   #include <spl.h>
>>>   #include <dm.h>
>>>   #include <asm/arch/k3-ddr.h>
>>> +#include <power/pmic.h>
>>>   #include "../common/board_detect.h"
>>>   #include "../common/fdt_ops.h"
>>> +#include "../common/k3-lpm.h"
>>>   #define board_is_j721e_som()    (board_ti_k3_is("J721EX-PM1-SOM") || \
>>>                    board_ti_k3_is("J721EX-PM2-SOM"))
>>> @@ -469,6 +471,41 @@ err_free_gpio:
>>>       }
>>>   }
>>> +#if (IS_ENABLED(CONFIG_SPL_BUILD) && 
>>> IS_ENABLED(CONFIG_TARGET_J7200_R5_EVM))
>>> +
>>> +bool j7xx_board_is_resuming(void)
>>> +{
>>> +    struct udevice *pmica;
>>> +    int ret;
>>> +
>>> +    if (gd_k3_resuming() != K3_RESUME_STATE_UNKNOWN)
>>> +        goto end;
>>> +
>>> +    ret = uclass_get_device_by_name(UCLASS_PMIC,
>>> +                    "pmic at 48", &pmica);
>>> +    if (ret) {
>>> +        printf("Getting PMICA init failed: %d\n", ret);
>>> +        goto end;
>>> +    }
>>> +    debug("%s: PMICA is detected (%s)\n", __func__, pmica->name);
>>> +
>>> +    if (pmic_reg_read(pmica, K3_LPM_SCRATCH_PAD_REG) == 
>>> K3_LPM_MAGIC_SUSPEND) {
>>> +        debug("%s: board is resuming\n", __func__);
>>> +        gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
>>
>> If you failed to clear magic word then, we are not in correct state.
>> So doing all work with PMIC, set state to resuming
> That's right, I'll check the error.
Sorry, I answered too quickly.
I mean, yes, if we fail to clean the magic value from PMIC, the next 
boot may be incorrectly detected as resuming.

>>
>>> +
>>> +        /* clean magic suspend */
>>> +        if (pmic_reg_write(pmica, K3_LPM_SCRATCH_PAD_REG, 0))
>>> +            printf("Failed to clean magic value for suspend 
>>> detection in PMICA\n");
But what could we do in this case?
We could hang() the board, reboot...
Or gd_set_k3_resuming back to K3_RESUME_STATE_UNKNOWN and hope that the 
next call to j7xx_board_is_resuming() will successfully clean the magic 
value.

Otherwise, we can reset this magic value in the DM startup?

>>> +    } else {
>>> +        debug("%s: board is booting (no resume detected)\n", __func__);
>>> +        gd_set_k3_resuming(K3_RESUME_STATE_BOOTING);
>>> +    }
>>> +end:
>>> +    return gd_k3_resuming() == K3_RESUME_STATE_RESUMING;
>>> +}
>>> +
>>> +#endif /* CONFIG_SPL_BUILD && CONFIG_TARGET_J7200_R5_EVM */
>>> +
>>>   void spl_board_init(void)
>>>   {
>>>       struct udevice *dev;
>>
> 
> Thanks!
> 
> Regards,
> Richard

Regards,
Richard