On 5/18/23 14:48, Dmitry Osipenko wrote: > On 5/9/23 22:03, Benjamin Bara wrote: >> From: Benjamin Bara <benjamin.bara@xxxxxxxxxxx> >> >> There are a couple of boards which use a tps6586x as >> "ti,system-power-controller", e.g. the tegra20-tamonten.dtsi. >> For these, the only registered restart handler is the warm reboot via >> tegra's PMC. As the bootloader of the tegra20 requires the VDE, it must >> be ensured that VDE is enabled (which is the case after a cold reboot). >> For the "normal reboot", this is basically the case since 8f0c714ad9be. >> However, this workaround is not executed in case of an emergency restart. >> In case of an emergency restart, the system now simply hangs in the >> bootloader, as VDE is not enabled (because it is not used). >> >> The TPS658629-Q1 provides a SOFT RST bit in the SUPPLYENE reg to request >> a (cold) reboot, which takes at least 20ms (as the data sheet states). >> This avoids the hang-up. >> >> Tested on a TPS658640. >> >> Signed-off-by: Benjamin Bara <benjamin.bara@xxxxxxxxxxx> >> --- >> drivers/mfd/tps6586x.c | 26 ++++++++++++++++++++++++++ >> 1 file changed, 26 insertions(+) >> >> diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c >> index b12c9e18970a..3b8faa058e59 100644 >> --- a/drivers/mfd/tps6586x.c >> +++ b/drivers/mfd/tps6586x.c >> @@ -30,6 +30,7 @@ >> #include <linux/mfd/tps6586x.h> >> >> #define TPS6586X_SUPPLYENE 0x14 >> +#define SOFT_RST_BIT BIT(0) >> #define EXITSLREQ_BIT BIT(1) >> #define SLEEP_MODE_BIT BIT(3) >> >> @@ -475,6 +476,24 @@ static int tps6586x_power_off_handler(struct sys_off_data *data) >> return notifier_from_errno(-ETIME); >> } >> >> +static int tps6586x_restart_handler(struct sys_off_data *data) >> +{ >> + int ret; >> + >> + /* TPS6586X only provides a hard/cold reboot, skip others. */ >> + if (data->mode != REBOOT_UNDEFINED && data->mode != REBOOT_COLD && >> + data->mode != REBOOT_HARD) >> + return NOTIFY_DONE; > > Not sure whether it's worthwhile to care about the reboot mode. If we > would really care, then the supported modes should be a part of sys-off > handler definition. Maybe Rafael could comment on it. > > Otherwise looks good. > > Reviewed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> Benjamin, could you please add acks and review tags to the commits and send v7? I'd also suggest to drop the "data->mode" checks unless there is a good practical reason to keep them. There are no other drivers in kernel that do such checks. -- Best regards, Dmitry