RE: [PATCH 4/5] remoteproc: stm32: Allow hold boot management by the SCMI reset controller

[Peng Fan]

> Subject: Re: [PATCH 4/5] remoteproc: stm32: Allow hold boot management
> by the SCMI reset controller
> 
> 
> 
> On 4/4/23 06:55, Peng Fan wrote:
> >> Subject: [PATCH 4/5] remoteproc: stm32: Allow hold boot management
> by
> >> the SCMI reset controller
> >>
> >> The hold boot can be managed by the SCMI controller as a reset.
> >> If the "hold_boot" reset is defined in the device tree, use it.
> >> Else use the syscon controller directly to access to the register.
> >>
> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> >> ---
> >>  drivers/remoteproc/stm32_rproc.c | 34
> >> ++++++++++++++++++++++++++-----
> >> -
> >>  1 file changed, 28 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/stm32_rproc.c
> >> b/drivers/remoteproc/stm32_rproc.c
> >> index 4be651e734ee..6b0d8f30a5c7 100644
> >> --- a/drivers/remoteproc/stm32_rproc.c
> >> +++ b/drivers/remoteproc/stm32_rproc.c
> >> @@ -78,6 +78,7 @@ struct stm32_mbox {
> >>
> >>  struct stm32_rproc {
> >>  	struct reset_control *rst;
> >> +	struct reset_control *hold_boot_rst;
> >>  	struct stm32_syscon hold_boot;
> >>  	struct stm32_syscon pdds;
> >>  	struct stm32_syscon m4_state;
> >> @@ -398,6 +399,14 @@ static int stm32_rproc_set_hold_boot(struct
> >> rproc *rproc, bool hold)
> >>  	struct stm32_syscon hold_boot = ddata->hold_boot;
> >>  	int val, err;
> >>
> >> +	if (ddata->hold_boot_rst) {
> >> +		/* Use the SCMI reset controller */
> >> +		if (!hold)
> >> +			return reset_control_deassert(ddata-
> >>> hold_boot_rst);
> >> +		else
> >> +			return reset_control_assert(ddata->hold_boot_rst);
> >> +	}
> >> +
> >>  	val = hold ? HOLD_BOOT : RELEASE_BOOT;
> >>
> >>  	err = regmap_update_bits(hold_boot.map, hold_boot.reg, @@ -
> >> 693,16 +702,29 @@ static int stm32_rproc_parse_dt(struct
> >> platform_device *pdev,
> >>  		dev_info(dev, "wdg irq registered\n");
> >>  	}
> >>
> >> -	ddata->rst = devm_reset_control_get_by_index(dev, 0);
> >> +	ddata->rst = devm_reset_control_get(dev, "mcu_rst");
> > [Peng Fan]
> > This may break legacy device tree.
> 
> That partially true by the fact that I impose the "reset-names" property (but
> also suppress the "st,syscfg-tz" property)
> 
> But this should not be the case as the arch/arm/boot/dts/stm32mp151.dtsi
> is updated in patch 2/5. The DTS files associated to this chip include it.

DT  maintainers may comment, from my understanding is updating driver
should not break legacy dts, saying 5.15, 5.10 dts.

Regards,
Peng.

> 
> Thanks,
> Arnaud
> 
> 
> >
> > Regards,
> > Peng.
> >
> >>  	if (IS_ERR(ddata->rst))
> >>  		return dev_err_probe(dev, PTR_ERR(ddata->rst),
> >>  				     "failed to get mcu_reset\n");
> >>
> >> -	err = stm32_rproc_get_syscon(np, "st,syscfg-holdboot",
> >> -				     &ddata->hold_boot);
> >> -	if (err) {
> >> -		dev_err(dev, "failed to get hold boot\n");
> >> -		return err;
> >> +	ddata->hold_boot_rst = devm_reset_control_get(dev, "hold_boot");
> >> +	if (IS_ERR(ddata->hold_boot_rst)) {
> >> +		if (PTR_ERR(ddata->hold_boot_rst) == -EPROBE_DEFER)
> >> +			return PTR_ERR(ddata->hold_boot_rst);
> >> +		ddata->hold_boot_rst = NULL;
> >> +	}
> >> +
> >> +	if (!ddata->hold_boot_rst) {
> >> +		/*
> >> +		 * If the hold boot is not managed by the SCMI reset
> >> controller,
> >> +		 * manage it through the syscon controller
> >> +		 */
> >> +		err = stm32_rproc_get_syscon(np, "st,syscfg-holdboot",
> >> +					     &ddata->hold_boot);
> >> +		if (err) {
> >> +			dev_err(dev, "failed to get hold boot\n");
> >> +			return err;
> >> +		}
> >>  	}
> >>
> >>  	err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
> >> --
> >> 2.25.1
> >