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>
--
Best regards,
Dmitry
