On Fri 11 Sep 08:09 CDT 2020, Dmitry Baryshkov wrote:
> Some GDSCs (SM8250's MDSS_GDSC for example) need switchable power domain
> to be on to be able to access hardware registers. Use dev_pm/opp to
^
What you describe here ----+ sounds like the GDSC controller is part of
the power-domain specified and hence needs to be enabled in order to
control the GDSC.
But in contrast what the patch implements is a mechanism where the
GDSC power-domain is a child of some other power-domain. So the commit
message needs to better reflect what's implemented.
Then looking at the DT representation I think it says that the
controller sits in the specified power-domain, rather than the exposed
power-domain...
> enable corresponding power domain.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> drivers/clk/qcom/gdsc.c | 56 ++++++++++++++++++++++++++++++++++++++---
> drivers/clk/qcom/gdsc.h | 5 ++++
> 2 files changed, 57 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
> index bfc4ac02f9ea..a522e062a79a 100644
> --- a/drivers/clk/qcom/gdsc.c
> +++ b/drivers/clk/qcom/gdsc.c
> @@ -11,6 +11,7 @@
> #include <linux/kernel.h>
> #include <linux/ktime.h>
> #include <linux/pm_domain.h>
> +#include <linux/pm_opp.h>
> #include <linux/regmap.h>
> #include <linux/regulator/consumer.h>
> #include <linux/reset-controller.h>
> @@ -110,13 +111,31 @@ static int gdsc_poll_status(struct gdsc *sc, enum gdsc_status status)
> return -ETIMEDOUT;
> }
>
> +int gdsc_toggle_on(struct gdsc *sc)
This should be "static" and I think you should include "supply" in the
name to denote that it doesn't turn on the gdsc, but rather its supply.
> +{
> + if (sc->rsupply)
> + return regulator_enable(sc->rsupply);
> + if (sc->pd_dev)
> + return dev_pm_genpd_set_performance_state(sc->pd_dev, sc->pd_opp);
> + return 0;
> +}
> +
> +int gdsc_toggle_off(struct gdsc *sc)
> +{
> + if (sc->pd_dev)
> + return dev_pm_genpd_set_performance_state(sc->pd_dev, 0);
> + if (sc->rsupply)
> + return regulator_disable(sc->rsupply);
> + return 0;
> +}
> +
> static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
> {
> int ret;
> u32 val = (status == GDSC_ON) ? 0 : SW_COLLAPSE_MASK;
>
> - if (status == GDSC_ON && sc->rsupply) {
> - ret = regulator_enable(sc->rsupply);
> + if (status == GDSC_ON) {
> + ret = gdsc_toggle_on(sc);
> if (ret < 0)
> return ret;
> }
> @@ -153,8 +172,8 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
> ret = gdsc_poll_status(sc, status);
> WARN(ret, "%s status stuck at 'o%s'", sc->pd.name, status ? "ff" : "n");
>
> - if (!ret && status == GDSC_OFF && sc->rsupply) {
> - ret = regulator_disable(sc->rsupply);
> + if (!ret && status == GDSC_OFF) {
> + ret = gdsc_toggle_off(sc);
> if (ret < 0)
> return ret;
> }
> @@ -407,6 +426,27 @@ int gdsc_register(struct gdsc_desc *desc,
> return PTR_ERR(scs[i]->rsupply);
> }
>
> + for (i = 0; i < num; i++) {
> + if (!scs[i] || !scs[i]->domain)
> + continue;
> +
> + scs[i]->pd_opp = of_get_required_opp_performance_state(dev->of_node, scs[i]->perf_idx);
> + if (scs[i]->pd_opp < 0)
> + return scs[i]->pd_opp;
> +
> + scs[i]->pd_dev = dev_pm_domain_attach_by_name(dev, scs[i]->domain);
> + if (IS_ERR(scs[i]->pd_dev)) {
> + ret = PTR_ERR(scs[i]->pd_dev);
> + /* Single domain has been already attached, so reuse dev */
> + if (ret == -EEXIST) {
> + scs[i]->pd_dev = dev;
> + } else {
> + scs[i]->pd_dev = NULL;
> + goto pm_detach;
> + }
> + }
> + }
> +
> data->num_domains = num;
> for (i = 0; i < num; i++) {
> if (!scs[i])
> @@ -428,6 +468,12 @@ int gdsc_register(struct gdsc_desc *desc,
> }
>
> return of_genpd_add_provider_onecell(dev->of_node, data);
> +
> +pm_detach:
> + for (i = 0; i < num; i++)
> + if (scs[i]->pd_dev)
> + dev_pm_domain_detach(scs[i]->pd_dev, false);
I think that if dev_pm_domain_attach_by_name() returned -EEXIST you
will attempt to detach the main device's domain here.
> + return ret;
> }
>
> void gdsc_unregister(struct gdsc_desc *desc)
> @@ -443,6 +489,8 @@ void gdsc_unregister(struct gdsc_desc *desc)
> continue;
> if (scs[i]->parent)
> pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd);
> + if (scs[i]->pd_dev && scs[i]->pd_dev != dev)
> + dev_pm_domain_detach(scs[i]->pd_dev, true);
Ditto
Regards,
Bjorn
> }
> of_genpd_del_provider(dev->of_node);
> }
> diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
> index bd537438c793..d58575f8f25f 100644
> --- a/drivers/clk/qcom/gdsc.h
> +++ b/drivers/clk/qcom/gdsc.h
> @@ -57,6 +57,11 @@ struct gdsc {
>
> const char *supply;
> struct regulator *rsupply;
> +
> + const char *domain;
> + unsigned int perf_idx;
> + struct device *pd_dev;
> + int pd_opp;
> };
>
> struct gdsc_desc {
> --
> 2.28.0
>
