From 330e76d3169721a55658c3b4fed872df6b0d6239 Mon Sep 17 00:00:00 2001 From: Matt Coster Date: Thu, 10 Apr 2025 10:55:04 +0100 Subject: [PATCH] drm/imagination: Add power domain control The first supported GPU only used a single power domain so this was automatically handled by the device runtime. In order to support multiple power domains, they must be enumerated from devicetree and linked to both the GPU device and each other to ensure correct power sequencing at start time. For all Imagination Rogue GPUs, power domains are named "a", "b", etc. and the sequence A->B->... is always valid for startup with the reverse true for shutdown. Note this is not always the *only* valid sequence, but it's simple and does not require special-casing for different GPU power topologies. Reviewed-by: Frank Binns Link: https://lore.kernel.org/r/20250410-sets-bxs-4-64-patch-v1-v6-5-eda620c5865f@imgtec.com Signed-off-by: Matt Coster --- drivers/gpu/drm/imagination/pvr_device.h | 8 ++ drivers/gpu/drm/imagination/pvr_drv.c | 7 ++ drivers/gpu/drm/imagination/pvr_power.c | 114 +++++++++++++++++++++++ drivers/gpu/drm/imagination/pvr_power.h | 3 + 4 files changed, 132 insertions(+) diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h index 6d0dfacb677b..2dd8a8885fe0 100644 --- a/drivers/gpu/drm/imagination/pvr_device.h +++ b/drivers/gpu/drm/imagination/pvr_device.h @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -131,6 +132,13 @@ struct pvr_device { */ struct clk *mem_clk; + struct pvr_device_power { + struct device **domain_devs; + struct device_link **domain_links; + + u32 domain_count; + } power; + /** @irq: IRQ number. */ int irq; diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c index 3130193f8fff..ac4f5855c569 100644 --- a/drivers/gpu/drm/imagination/pvr_drv.c +++ b/drivers/gpu/drm/imagination/pvr_drv.c @@ -1411,6 +1411,10 @@ pvr_probe(struct platform_device *plat_dev) platform_set_drvdata(plat_dev, drm_dev); + err = pvr_power_domains_init(pvr_dev); + if (err) + return err; + init_rwsem(&pvr_dev->reset_sem); pvr_context_device_init(pvr_dev); @@ -1450,6 +1454,8 @@ err_watchdog_fini: err_context_fini: pvr_context_device_fini(pvr_dev); + pvr_power_domains_fini(pvr_dev); + return err; } @@ -1470,6 +1476,7 @@ static void pvr_remove(struct platform_device *plat_dev) pvr_watchdog_fini(pvr_dev); pvr_queue_device_fini(pvr_dev); pvr_context_device_fini(pvr_dev); + pvr_power_domains_fini(pvr_dev); } static const struct of_device_id dt_match[] = { diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c index ba7816fd28ec..19b079b357df 100644 --- a/drivers/gpu/drm/imagination/pvr_power.c +++ b/drivers/gpu/drm/imagination/pvr_power.c @@ -10,10 +10,13 @@ #include #include +#include #include #include #include +#include #include +#include #include #include #include @@ -431,3 +434,114 @@ pvr_watchdog_fini(struct pvr_device *pvr_dev) { cancel_delayed_work_sync(&pvr_dev->watchdog.work); } + +int pvr_power_domains_init(struct pvr_device *pvr_dev) +{ + struct device *dev = from_pvr_device(pvr_dev)->dev; + + struct device_link **domain_links __free(kfree) = NULL; + struct device **domain_devs __free(kfree) = NULL; + int domain_count; + int link_count; + + char dev_name[2] = "a"; + int err; + int i; + + domain_count = of_count_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells"); + if (domain_count < 0) + return domain_count; + + if (domain_count <= 1) + return 0; + + link_count = domain_count + (domain_count - 1); + + domain_devs = kcalloc(domain_count, sizeof(*domain_devs), GFP_KERNEL); + if (!domain_devs) + return -ENOMEM; + + domain_links = kcalloc(link_count, sizeof(*domain_links), GFP_KERNEL); + if (!domain_links) + return -ENOMEM; + + for (i = 0; i < domain_count; i++) { + struct device *domain_dev; + + dev_name[0] = 'a' + i; + domain_dev = dev_pm_domain_attach_by_name(dev, dev_name); + if (IS_ERR_OR_NULL(domain_dev)) { + err = domain_dev ? PTR_ERR(domain_dev) : -ENODEV; + goto err_detach; + } + + domain_devs[i] = domain_dev; + } + + for (i = 0; i < domain_count; i++) { + struct device_link *link; + + link = device_link_add(dev, domain_devs[i], DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME); + if (!link) { + err = -ENODEV; + goto err_unlink; + } + + domain_links[i] = link; + } + + for (i = domain_count; i < link_count; i++) { + struct device_link *link; + + link = device_link_add(domain_devs[i - domain_count + 1], + domain_devs[i - domain_count], + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME); + if (!link) { + err = -ENODEV; + goto err_unlink; + } + + domain_links[i] = link; + } + + pvr_dev->power = (struct pvr_device_power){ + .domain_devs = no_free_ptr(domain_devs), + .domain_links = no_free_ptr(domain_links), + .domain_count = domain_count, + }; + + return 0; + +err_unlink: + while (--i >= 0) + device_link_del(domain_links[i]); + + i = domain_count; + +err_detach: + while (--i >= 0) + dev_pm_domain_detach(domain_devs[i], true); + + return err; +} + +void pvr_power_domains_fini(struct pvr_device *pvr_dev) +{ + const int domain_count = pvr_dev->power.domain_count; + + int i = domain_count + (domain_count - 1); + + while (--i >= 0) + device_link_del(pvr_dev->power.domain_links[i]); + + i = domain_count; + + while (--i >= 0) + dev_pm_domain_detach(pvr_dev->power.domain_devs[i], true); + + kfree(pvr_dev->power.domain_links); + kfree(pvr_dev->power.domain_devs); + + pvr_dev->power = (struct pvr_device_power){ 0 }; +} diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h index 9a9312dcb2da..ada85674a7ca 100644 --- a/drivers/gpu/drm/imagination/pvr_power.h +++ b/drivers/gpu/drm/imagination/pvr_power.h @@ -38,4 +38,7 @@ pvr_power_put(struct pvr_device *pvr_dev) return pm_runtime_put(drm_dev->dev); } +int pvr_power_domains_init(struct pvr_device *pvr_dev); +void pvr_power_domains_fini(struct pvr_device *pvr_dev); + #endif /* PVR_POWER_H */