Re: [PATCH v3 2/7] soc: rockchip: io-domain: add rk3568 support

[Heiko Stübner]

Hi Robin,

Am Donnerstag, 5. August 2021, 18:27:36 CEST schrieb Robin Murphy:
> On 2021-08-05 13:01, Michael Riesch wrote:
> > From: Jianqun Xu <jay.xu@xxxxxxxxxxxxxx>
> > 
> > The io-domain registers on RK3568 SoCs have three separated bits to
> > enable/disable the 1.8v/2.5v/3.3v power.
> > 
> > This patch make the write to be a operation, allow rk3568 uses a private
> > register set function.
> > 
> > Since the 2.5v is not used on RK3568, so the driver only set
> 
> FWIW, this seems at odds with what the first paragraph says - can anyone 
> clarify what exactly "not used" means here? Is it that the I/O domain 
> controller has been redesigned to support more than two logic levels on 
> the new generation of SoCs, but RK3568's I/O pads still only physically 
> support 1.8v and 3.3v; or is it that it *can* support 2.5v as well but 
> no currently-known RK3568-based designs use that?
> 
> In the former case it's just a wording issue in the commit message, but 
> in the latter it's arguably worth implementing support now for the sake 
> of future compatibility.

I hadn't looked that deeply into the rk356x io-domain config, but at least
on a register level in the TRM it seems there are separate bits for
"3.3V control", "2.5V control", "1.8V control" [0] for each io-domain.

Of course the documentation is otherwise somewhat sparse.

Maybe Jay or Kever [added] can explain a bit more about the 3 voltage
levels.


In general though, I tend to find the approach good enough for now.

Especially as the io-domain stuff is always said to "can cause damage
to the soc if used incorrectly" and it looks like nobody (including
Rockchip) seems to have actual hardware using these 2.5V levels right now.

So having code in there that no-one ever tested doesn't feel too good ;-)

Adding this later when needed should be somewhat easy, as it really only
needs adding of handling that 3rd control bit per domain.


Heiko



[0] what happens if none of the 3 is active? ;-)


> 
> Robin.
> 
> > 1.8v [enable] + 3.3v [disable] for 1.8v mode
> > 1.8v [disable] + 3.3v [enable] for 3.3v mode
> > 
> > There is not register order requirement which has been cleared by our IC
> > team.
> > 
> > Signed-off-by: Jianqun Xu <jay.xu@xxxxxxxxxxxxxx>
> > ---
> >   drivers/soc/rockchip/io-domain.c | 88 +++++++++++++++++++++++++++++---
> >   1 file changed, 80 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/soc/rockchip/io-domain.c b/drivers/soc/rockchip/io-domain.c
> > index cf8182fc3642..13c446fd33a9 100644
> > --- a/drivers/soc/rockchip/io-domain.c
> > +++ b/drivers/soc/rockchip/io-domain.c
> > @@ -51,13 +51,11 @@
> >   #define RK3399_PMUGRF_CON0_VSEL		BIT(8)
> >   #define RK3399_PMUGRF_VSEL_SUPPLY_NUM	9
> >   
> > -struct rockchip_iodomain;
> > +#define RK3568_PMU_GRF_IO_VSEL0		(0x0140)
> > +#define RK3568_PMU_GRF_IO_VSEL1		(0x0144)
> > +#define RK3568_PMU_GRF_IO_VSEL2		(0x0148)
> >   
> > -struct rockchip_iodomain_soc_data {
> > -	int grf_offset;
> > -	const char *supply_names[MAX_SUPPLIES];
> > -	void (*init)(struct rockchip_iodomain *iod);
> > -};
> > +struct rockchip_iodomain;
> >   
> >   struct rockchip_iodomain_supply {
> >   	struct rockchip_iodomain *iod;
> > @@ -66,13 +64,62 @@ struct rockchip_iodomain_supply {
> >   	int idx;
> >   };
> >   
> > +struct rockchip_iodomain_soc_data {
> > +	int grf_offset;
> > +	const char *supply_names[MAX_SUPPLIES];
> > +	void (*init)(struct rockchip_iodomain *iod);
> > +	int (*write)(struct rockchip_iodomain_supply *supply, int uV);
> > +};
> > +
> >   struct rockchip_iodomain {
> >   	struct device *dev;
> >   	struct regmap *grf;
> >   	const struct rockchip_iodomain_soc_data *soc_data;
> >   	struct rockchip_iodomain_supply supplies[MAX_SUPPLIES];
> > +	int (*write)(struct rockchip_iodomain_supply *supply, int uV);
> >   };
> >   
> > +static int rk3568_iodomain_write(struct rockchip_iodomain_supply *supply, int uV)
> > +{
> > +	struct rockchip_iodomain *iod = supply->iod;
> > +	u32 is_3v3 = uV > MAX_VOLTAGE_1_8;
> > +	u32 val0, val1;
> > +	int b;
> > +
> > +	switch (supply->idx) {
> > +	case 0: /* pmuio1 */
> > +		break;
> > +	case 1: /* pmuio2 */
> > +		b = supply->idx;
> > +		val0 = BIT(16 + b) | (is_3v3 ? 0 : BIT(b));
> > +		b = supply->idx + 4;
> > +		val1 = BIT(16 + b) | (is_3v3 ? BIT(b) : 0);
> > +
> > +		regmap_write(iod->grf, RK3568_PMU_GRF_IO_VSEL2, val0);
> > +		regmap_write(iod->grf, RK3568_PMU_GRF_IO_VSEL2, val1);
> > +		break;
> > +	case 3: /* vccio2 */
> > +		break;
> > +	case 2: /* vccio1 */
> > +	case 4: /* vccio3 */
> > +	case 5: /* vccio4 */
> > +	case 6: /* vccio5 */
> > +	case 7: /* vccio6 */
> > +	case 8: /* vccio7 */
> > +		b = supply->idx - 1;
> > +		val0 = BIT(16 + b) | (is_3v3 ? 0 : BIT(b));
> > +		val1 = BIT(16 + b) | (is_3v3 ? BIT(b) : 0);
> > +
> > +		regmap_write(iod->grf, RK3568_PMU_GRF_IO_VSEL0, val0);
> > +		regmap_write(iod->grf, RK3568_PMU_GRF_IO_VSEL1, val1);
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	};
> > +
> > +	return 0;
> > +}
> > +
> >   static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply,
> >   				   int uV)
> >   {
> > @@ -136,7 +183,7 @@ static int rockchip_iodomain_notify(struct notifier_block *nb,
> >   			return NOTIFY_BAD;
> >   	}
> >   
> > -	ret = rockchip_iodomain_write(supply, uV);
> > +	ret = supply->iod->write(supply, uV);
> >   	if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
> >   		return NOTIFY_BAD;
> >   
> > @@ -398,6 +445,22 @@ static const struct rockchip_iodomain_soc_data soc_data_rk3399_pmu = {
> >   	.init = rk3399_pmu_iodomain_init,
> >   };
> >   
> > +static const struct rockchip_iodomain_soc_data soc_data_rk3568_pmu = {
> > +	.grf_offset = 0x140,
> > +	.supply_names = {
> > +		"pmuio1",
> > +		"pmuio2",
> > +		"vccio1",
> > +		"vccio2",
> > +		"vccio3",
> > +		"vccio4",
> > +		"vccio5",
> > +		"vccio6",
> > +		"vccio7",
> > +	},
> > +	.write = rk3568_iodomain_write,
> > +};
> > +
> >   static const struct rockchip_iodomain_soc_data soc_data_rv1108 = {
> >   	.grf_offset = 0x404,
> >   	.supply_names = {
> > @@ -469,6 +532,10 @@ static const struct of_device_id rockchip_iodomain_match[] = {
> >   		.compatible = "rockchip,rk3399-pmu-io-voltage-domain",
> >   		.data = &soc_data_rk3399_pmu
> >   	},
> > +	{
> > +		.compatible = "rockchip,rk3568-pmu-io-voltage-domain",
> > +		.data = &soc_data_rk3568_pmu
> > +	},
> >   	{
> >   		.compatible = "rockchip,rv1108-io-voltage-domain",
> >   		.data = &soc_data_rv1108
> > @@ -502,6 +569,11 @@ static int rockchip_iodomain_probe(struct platform_device *pdev)
> >   	match = of_match_node(rockchip_iodomain_match, np);
> >   	iod->soc_data = match->data;
> >   
> > +	if (iod->soc_data->write)
> > +		iod->write = iod->soc_data->write;
> > +	else
> > +		iod->write = rockchip_iodomain_write;
> > +
> >   	parent = pdev->dev.parent;
> >   	if (parent && parent->of_node) {
> >   		iod->grf = syscon_node_to_regmap(parent->of_node);
> > @@ -562,7 +634,7 @@ static int rockchip_iodomain_probe(struct platform_device *pdev)
> >   		supply->reg = reg;
> >   		supply->nb.notifier_call = rockchip_iodomain_notify;
> >   
> > -		ret = rockchip_iodomain_write(supply, uV);
> > +		ret = iod->write(supply, uV);
> >   		if (ret) {
> >   			supply->reg = NULL;
> >   			goto unreg_notify;
> > 
>