On Wed 30 Jun 08:31 CDT 2021, Dmitry Baryshkov wrote: > On sm8250 dispcc and videocc registers are powered up by the MMCX power > domain. Currently we used a regulator to enable this domain on demand, > however this has some consequences, as genpd code is not reentrant. > > Teach Qualcomm clock controller code about setting up power domains and > using them for gdsc control. > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> There's a proposal to add a generic binding for statically assigning a performance states here: https://lore.kernel.org/linux-arm-msm/1622095949-2014-1-git-send-email-rnayak@xxxxxxxxxxxxxx/ But that said, do you really need this? The requirement for driving MMCX to LOW_SVS on SM8250 (and NOM on SM8150/SC8180x) seems to only come from the fact that you push MDP_CLK to 460MHz in &mdss. But then in &mdss_mdp you do the same using an opp-table based on the actual MDP_CLK, which per its power-domains will scale MMCX accordingly. So wouldn't it be sufficient to ensure that MDSS_GDSC is parented by MMCX and then use opp-tables associated with the devices that scales the clock and thereby actually carries the "required-opps". I presume your testing indicates that it doesn't matter on sm8250, but as stated above, 460MHz on sm8150/sc8180x requires nominal, so per your suggestion we'd have to vote nominal in &mdss, which means that if the DPU decides to go to 200MHz the &mdss will still keep the voltage at NOM, even though the DPU's opp-table says that LOW_SVS is sufficient. Regards, Bjorn > --- > drivers/clk/qcom/common.c | 55 ++++++++++++++++++++++++++++++++++----- > drivers/clk/qcom/gdsc.c | 6 +++++ > 2 files changed, 55 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c > index 60d2a78d1395..eeb5b8c93032 100644 > --- a/drivers/clk/qcom/common.c > +++ b/drivers/clk/qcom/common.c > @@ -10,6 +10,8 @@ > #include <linux/clk-provider.h> > #include <linux/reset-controller.h> > #include <linux/of.h> > +#include <linux/pm_opp.h> > +#include <linux/pm_runtime.h> > > #include "common.h" > #include "clk-rcg.h" > @@ -76,6 +78,16 @@ qcom_cc_map(struct platform_device *pdev, const struct qcom_cc_desc *desc) > struct resource *res; > struct device *dev = &pdev->dev; > > + if (of_find_property(dev->of_node, "required-opps", NULL)) { > + int pd_opp; > + > + pd_opp = of_get_required_opp_performance_state(dev->of_node, 0); > + if (pd_opp < 0) > + return ERR_PTR(pd_opp); > + > + dev_pm_genpd_set_performance_state(dev, pd_opp); > + } > + > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > base = devm_ioremap_resource(dev, res); > if (IS_ERR(base)) > @@ -224,6 +236,11 @@ static struct clk_hw *qcom_cc_clk_hw_get(struct of_phandle_args *clkspec, > return cc->rclks[idx] ? &cc->rclks[idx]->hw : NULL; > } > > +static void qcom_cc_pm_runtime_disable(void *data) > +{ > + pm_runtime_disable(data); > +} > + > int qcom_cc_really_probe(struct platform_device *pdev, > const struct qcom_cc_desc *desc, struct regmap *regmap) > { > @@ -236,11 +253,28 @@ int qcom_cc_really_probe(struct platform_device *pdev, > struct clk_regmap **rclks = desc->clks; > size_t num_clk_hws = desc->num_clk_hws; > struct clk_hw **clk_hws = desc->clk_hws; > + bool use_pm = false; > > cc = devm_kzalloc(dev, sizeof(*cc), GFP_KERNEL); > if (!cc) > return -ENOMEM; > > + if (of_find_property(dev->of_node, "required-opps", NULL)) { > + use_pm = true; > + > + pm_runtime_enable(dev); > + ret = pm_runtime_get_sync(dev); > + if (ret < 0) { > + pm_runtime_put(dev); > + pm_runtime_disable(dev); > + return ret; > + } > + > + ret = devm_add_action_or_reset(dev, qcom_cc_pm_runtime_disable, dev); > + if (ret) > + return ret; > + } > + > reset = &cc->reset; > reset->rcdev.of_node = dev->of_node; > reset->rcdev.ops = &qcom_reset_ops; > @@ -251,7 +285,7 @@ int qcom_cc_really_probe(struct platform_device *pdev, > > ret = devm_reset_controller_register(dev, &reset->rcdev); > if (ret) > - return ret; > + goto err; > > if (desc->gdscs && desc->num_gdscs) { > scd = devm_kzalloc(dev, sizeof(*scd), GFP_KERNEL); > @@ -262,11 +296,11 @@ int qcom_cc_really_probe(struct platform_device *pdev, > scd->num = desc->num_gdscs; > ret = gdsc_register(scd, &reset->rcdev, regmap); > if (ret) > - return ret; > + goto err; > ret = devm_add_action_or_reset(dev, qcom_cc_gdsc_unregister, > scd); > if (ret) > - return ret; > + goto err; > } > > cc->rclks = rclks; > @@ -277,7 +311,7 @@ int qcom_cc_really_probe(struct platform_device *pdev, > for (i = 0; i < num_clk_hws; i++) { > ret = devm_clk_hw_register(dev, clk_hws[i]); > if (ret) > - return ret; > + goto err; > } > > for (i = 0; i < num_clks; i++) { > @@ -286,14 +320,23 @@ int qcom_cc_really_probe(struct platform_device *pdev, > > ret = devm_clk_register_regmap(dev, rclks[i]); > if (ret) > - return ret; > + goto err; > } > > ret = devm_of_clk_add_hw_provider(dev, qcom_cc_clk_hw_get, cc); > if (ret) > - return ret; > + goto err; > + > + if (use_pm) > + pm_runtime_put(dev); > > return 0; > + > +err: > + if (use_pm) > + pm_runtime_put(dev); > + > + return ret; > } > EXPORT_SYMBOL_GPL(qcom_cc_really_probe); > > diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c > index 51ed640e527b..40c384bda4fc 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_runtime.h> > #include <linux/regmap.h> > #include <linux/regulator/consumer.h> > #include <linux/reset-controller.h> > @@ -237,6 +238,8 @@ static int gdsc_enable(struct generic_pm_domain *domain) > struct gdsc *sc = domain_to_gdsc(domain); > int ret; > > + pm_runtime_get_sync(domain->dev.parent); > + > if (sc->pwrsts == PWRSTS_ON) > return gdsc_deassert_reset(sc); > > @@ -326,6 +329,8 @@ static int gdsc_disable(struct generic_pm_domain *domain) > if (sc->flags & CLAMP_IO) > gdsc_assert_clamp_io(sc); > > + pm_runtime_put(domain->dev.parent); > + > return 0; > } > > @@ -427,6 +432,7 @@ int gdsc_register(struct gdsc_desc *desc, > continue; > scs[i]->regmap = regmap; > scs[i]->rcdev = rcdev; > + scs[i]->pd.dev.parent = desc->dev; > ret = gdsc_init(scs[i]); > if (ret) > return ret; > -- > 2.30.2 >
