[PATCH 06/20] board: ti: j721s2: Add resume detection

[Thomas Richard]

Hello Richard,

On 5/21/26 11:27 AM, Richard GENOUD wrote:
> Le 11/05/2026 à 12:48, 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>
>>> ---
>>>   board/ti/j721s2/evm.c | 37 +++++++++++++++++++++++++++++++++++++
>>>   1 file changed, 37 insertions(+)
>>>
>>> diff --git a/board/ti/j721s2/evm.c b/board/ti/j721s2/evm.c
>>> index 92d5c8498643..e18ba1a540c9 100644
>>> --- a/board/ti/j721s2/evm.c
>>> +++ b/board/ti/j721s2/evm.c
>>> @@ -22,9 +22,11 @@
>>>   #include <dm/uclass-internal.h>
>>>   #include <dm/root.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"
>>>     DECLARE_GLOBAL_DATA_PTR;
>>>   @@ -304,6 +306,41 @@ int board_late_init(void)
>>>       return 0;
>>>   }
>>>   +#if (IS_ENABLED(CONFIG_SPL_BUILD) &&
>>> IS_ENABLED(CONFIG_TARGET_J721S2_R5_EVM) &&
>>> IS_ENABLED(CONFIG_PMIC_TPS65941))
>>> +
>>> +/* in board_init_f(), there's no BSS, so we can't use global/static
>>> variables */
>>> +bool j7xx_board_is_resuming(void)
>>> +{
>>> +    struct udevice *pmic;
>>> +    int err;
>>> +
>>> +    if (gd_k3_resuming() != K3_RESUME_STATE_UNKNOWN)
>>> +        goto end;
>>> +
>>> +    err = uclass_get_device_by_name(UCLASS_PMIC,
>>> +                    "pmic at 48", &pmic);
>>> +    if (err) {
>>> +        printf("Getting PMIC init failed: %d\n", err);
>>> +        goto end;
>>> +    }
>>> +    debug("%s: PMIC is detected (%s)\n", __func__, pmic->name);
>>> +
>>> +    if (pmic_reg_read(pmic, K3_LPM_SCRATCH_PAD_REG) ==
>>> K3_LPM_MAGIC_SUSPEND) {
>>> +        debug("%s: board is resuming\n", __func__);
>>> +        gd_set_k3_resuming(K3_RESUME_STATE_RESUMING);
>>> +
>>> +        /* clean magic suspend */
>>> +        if (pmic_reg_write(pmic, K3_LPM_SCRATCH_PAD_REG, 0))
>>> +            printf("Failed to clean magic value for suspend
>>> detection in PMIC\n");
>>> +    } else {
>>> +        debug("%s: board is booting (no resume detected)\n", __func__);
>>> +        gd_set_k3_resuming(K3_RESUME_STATE_BOOTING);
>>> +    }
>>
>> Could all function be combined into common_j7xx_lpm.c for all supporting
>> SOCs.
> J722s function is a little bit different, but I'll find a way to
> factorize them.

Also PMIC NSLEEP triggers bits shall be set to prevent transition to S2R
state while clearing interrupts.
For example PMIC RTC Linux driver accesses to interrupt registers during
resume, in this case if NSLEEP triggers bits are not set it triggers a
S2R transition.

To set these bits, just write 0x03 in FSM_NSLEEP_TRIGGERS register of
the PMIC (0x86).

This shall be done for J7200/J784s4/J721s2.

For J722s, I don't know.

Best Regards,
Thomas