On 14/01/2020 07:16, Nicolas Boichat wrote: > When there is a single power domain per device, the core will > ensure the power domain is switched on (so it is technically > equivalent to having not power domain specified at all). > > However, when there are multiple domains, as in MT8183 Bifrost > GPU, we need to handle them in driver code. > > Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > > --- > > The downstream driver we use on chromeos-4.19 currently uses 2 > additional devices in device tree to accomodate for this [1], but > I believe this solution is cleaner. > > [1] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/refs/heads/chromeos-4.19/drivers/gpu/arm/midgard/platform/mediatek/mali_kbase_runtime_pm.c#31 > > v3: > - Use the compatible matching data to specify the number of power > domains. Note that setting 0 or 1 in num_pm_domains is equivalent > as the core will handle these 2 cases in the exact same way > (automatically, without driver intervention), and there should > be no adverse consequence in this case (the concern is about > switching on only some power domains and not others). > > drivers/gpu/drm/panfrost/panfrost_device.c | 95 ++++++++++++++++++++-- > drivers/gpu/drm/panfrost/panfrost_device.h | 9 ++ > drivers/gpu/drm/panfrost/panfrost_drv.c | 1 + > 3 files changed, 97 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c > index c30e0a3772a4f57..7c9766f76cc7689 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_device.c > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c > @@ -5,6 +5,7 @@ > #include <linux/clk.h> > #include <linux/reset.h> > #include <linux/platform_device.h> > +#include <linux/pm_domain.h> > #include <linux/regulator/consumer.h> > > #include "panfrost_device.h" > @@ -119,6 +120,75 @@ static void panfrost_regulator_fini(struct panfrost_device *pfdev) > pfdev->regulators); > } > > +static void panfrost_pm_domain_fini(struct panfrost_device *pfdev) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(pfdev->pm_domain_devs); i++) { > + if (!pfdev->pm_domain_devs[i]) > + break; > + > + if (pfdev->pm_domain_links[i]) > + device_link_del(pfdev->pm_domain_links[i]); > + > + dev_pm_domain_detach(pfdev->pm_domain_devs[i], true); > + } > +} > + > +static int panfrost_pm_domain_init(struct panfrost_device *pfdev) > +{ > + int err; > + int i, num_domains; > + > + num_domains = of_count_phandle_with_args(pfdev->dev->of_node, > + "power-domains", > + "#power-domain-cells"); > + > + /* > + * Single domain is handled by the core, and, if only a single power > + * the power domain is requested, the property is optional. > + */ > + if (num_domains < 2 && pfdev->comp->num_pm_domains < 2) > + return 0; > + > + if (num_domains != pfdev->comp->num_pm_domains) { > + dev_err(pfdev->dev, > + "Incorrect number of power domains: %d provided, %d needed\n", > + num_domains, pfdev->comp->num_pm_domains); > + return -EINVAL; > + } > + > + BUG_ON(num_domains > ARRAY_SIZE(pfdev->pm_domain_devs)); > + > + for (i = 0; i < num_domains; i++) { > + pfdev->pm_domain_devs[i] = > + dev_pm_domain_attach_by_id(pfdev->dev, i); > + if (IS_ERR(pfdev->pm_domain_devs[i])) { > + err = PTR_ERR(pfdev->pm_domain_devs[i]); > + pfdev->pm_domain_devs[i] = NULL; > + dev_err(pfdev->dev, > + "failed to get pm-domain %d: %d\n", i, err); > + goto err; > + } > + > + pfdev->pm_domain_links[i] = device_link_add(pfdev->dev, > + pfdev->pm_domain_devs[i], DL_FLAG_PM_RUNTIME | > + DL_FLAG_STATELESS | DL_FLAG_RPM_ACTIVE); > + if (!pfdev->pm_domain_links[i]) { > + dev_err(pfdev->pm_domain_devs[i], > + "adding device link failed!\n"); > + err = -ENODEV; > + goto err; > + } > + } > + > + return 0; > + > +err: > + panfrost_pm_domain_fini(pfdev); > + return err; > +} > + > int panfrost_device_init(struct panfrost_device *pfdev) > { > int err; > @@ -149,37 +219,45 @@ int panfrost_device_init(struct panfrost_device *pfdev) > goto err_out1; > } > > + err = panfrost_pm_domain_init(pfdev); > + if (err) { > + dev_err(pfdev->dev, "pm_domain init failed %d\n", err); No need for this print - panfrost_pm_domain_init() will output a (more appropriate) error message on failure. > + goto err_out2; > + } > + > res = platform_get_resource(pfdev->pdev, IORESOURCE_MEM, 0); > pfdev->iomem = devm_ioremap_resource(pfdev->dev, res); > if (IS_ERR(pfdev->iomem)) { > dev_err(pfdev->dev, "failed to ioremap iomem\n"); > err = PTR_ERR(pfdev->iomem); > - goto err_out2; > + goto err_out3; > } > > err = panfrost_gpu_init(pfdev); > if (err) > - goto err_out2; > + goto err_out3; > > err = panfrost_mmu_init(pfdev); > if (err) > - goto err_out3; > + goto err_out4; > > err = panfrost_job_init(pfdev); > if (err) > - goto err_out4; > + goto err_out5; > > err = panfrost_perfcnt_init(pfdev); > if (err) > - goto err_out5; > + goto err_out6; > > return 0; > -err_out5: > +err_out6: > panfrost_job_fini(pfdev); > -err_out4: > +err_out5: > panfrost_mmu_fini(pfdev); > -err_out3: > +err_out4: > panfrost_gpu_fini(pfdev); > +err_out3: > + panfrost_pm_domain_fini(pfdev); > err_out2: > panfrost_reset_fini(pfdev); > err_out1: > @@ -196,6 +274,7 @@ void panfrost_device_fini(struct panfrost_device *pfdev) > panfrost_mmu_fini(pfdev); > panfrost_gpu_fini(pfdev); > panfrost_reset_fini(pfdev); > + panfrost_pm_domain_fini(pfdev); NIT: The reverse of the construction order would be to do this before panfrost_reset_fini(). Otherwise this LGTM. Thanks, Steve > panfrost_regulator_fini(pfdev); > panfrost_clk_fini(pfdev); > } > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h > index 021f063ffb3747f..143eab57180a2e1 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_device.h > +++ b/drivers/gpu/drm/panfrost/panfrost_device.h > @@ -21,6 +21,7 @@ struct panfrost_perfcnt; > > #define NUM_JOB_SLOTS 3 > #define MAX_REGULATORS 2 > +#define MAX_PM_DOMAINS 3 > > struct panfrost_features { > u16 id; > @@ -61,6 +62,11 @@ struct panfrost_compatible { > /* Supplies count and names. */ > int num_supplies; > const char * const *supply_names; > + /* > + * Number of power domains required, note that values 0 and 1 are > + * handled identically, as only values > 1 need special handling. > + */ > + int num_pm_domains; > }; > > struct panfrost_device { > @@ -73,6 +79,9 @@ struct panfrost_device { > struct clk *bus_clock; > struct regulator_bulk_data regulators[MAX_REGULATORS]; > struct reset_control *rstc; > + /* pm_domains for devices with more than one. */ > + struct device *pm_domain_devs[MAX_PM_DOMAINS]; > + struct device_link *pm_domain_links[MAX_PM_DOMAINS]; > > struct panfrost_features features; > const struct panfrost_compatible* comp; > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c > index db3563b80150c9d..42b87e29e605149 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > @@ -589,6 +589,7 @@ const char * const default_supplies[] = { "mali" }; > static const struct panfrost_compatible default_data = { > .num_supplies = ARRAY_SIZE(default_supplies), > .supply_names = default_supplies, > + .num_pm_domains = 1, /* optional */ > }; > > static const struct of_device_id dt_match[] = { >
