From 957f40d039a98d630146f74f94b3f60a40a449e4 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Thu, 16 Jan 2025 19:39:11 +0530 Subject: [PATCH 1/5] PCI/pwrctrl: Move creation of pwrctrl devices to pci_scan_device() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Current way of creating pwrctrl devices requires iterating through the child devicetree nodes of the PCI bridge in pci_pwrctrl_create_devices(). Even though it works, it creates confusion as there is no symmetry between this and pci_pwrctrl_unregister() function that removes the pwrctrl devices. So to make these two functions symmetric, move the creation of pwrctrl devices to pci_scan_device(). During the scan of each device in a slot, the devicetree node (if exists) for the PCI device will be checked. If it has the supplies populated, then the pwrctrl device will be created. Since the PCI device scan happens so early, there would be no "struct pci_dev" available for the device. So the host bridge is used as the parent of all pwrctrl devices. One nice side effect of this move is that, it is now possible to have pwrctrl devices for PCI bridges as well (to control the supplies of PCI slots). Suggested-by: Lukas Wunner Tested-by: Bartosz Golaszewski Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-1-827473c8fbf4@linaro.org [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński --- drivers/pci/bus.c | 43 -------------------------------------- drivers/pci/probe.c | 34 ++++++++++++++++++++++++++++++ drivers/pci/pwrctrl/core.c | 2 +- 3 files changed, 35 insertions(+), 44 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 98910bc0fcc4..b6851101ac36 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -331,47 +331,6 @@ void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } void __weak pcibios_bus_add_device(struct pci_dev *pdev) { } -/* - * Create pwrctrl devices (if required) for the PCI devices to handle the power - * state. - */ -static void pci_pwrctrl_create_devices(struct pci_dev *dev) -{ - struct device_node *np = dev_of_node(&dev->dev); - struct device *parent = &dev->dev; - struct platform_device *pdev; - - /* - * First ensure that we are starting from a PCI bridge and it has a - * corresponding devicetree node. - */ - if (np && pci_is_bridge(dev)) { - /* - * Now look for the child PCI device nodes and create pwrctrl - * devices for them. The pwrctrl device drivers will manage the - * power state of the devices. - */ - for_each_available_child_of_node_scoped(np, child) { - /* - * First check whether the pwrctrl device really - * needs to be created or not. This is decided - * based on at least one of the power supplies - * being defined in the devicetree node of the - * device. - */ - if (!of_pci_supply_present(child)) { - pci_dbg(dev, "skipping OF node: %s\n", child->name); - return; - } - - /* Now create the pwrctrl device */ - pdev = of_platform_device_create(child, NULL, parent); - if (!pdev) - pci_err(dev, "failed to create OF node: %s\n", child->name); - } - } -} - /** * pci_bus_add_device - start driver for a single device * @dev: device to add @@ -396,8 +355,6 @@ void pci_bus_add_device(struct pci_dev *dev) pci_proc_attach_device(dev); pci_bridge_d3_update(dev); - pci_pwrctrl_create_devices(dev); - /* * If the PCI device is associated with a pwrctrl device with a * power supply, create a device link between the PCI device and diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b6536ed599c3..95a91778bb5d 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -9,6 +9,8 @@ #include #include #include +#include +#include #include #include #include @@ -2493,6 +2495,36 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, } EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); +/* + * Create pwrctrl device (if required) for the PCI device to handle the power + * state. + */ +static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn) +{ + struct pci_host_bridge *host = pci_find_host_bridge(bus); + struct platform_device *pdev; + struct device_node *np; + + np = of_pci_find_child_device(dev_of_node(&bus->dev), devfn); + if (!np || of_find_device_by_node(np)) + return; + + /* + * First check whether the pwrctrl device really needs to be created or + * not. This is decided based on at least one of the power supplies + * being defined in the devicetree node of the device. + */ + if (!of_pci_supply_present(np)) { + pr_debug("PCI/pwrctrl: Skipping OF node: %s\n", np->name); + return; + } + + /* Now create the pwrctrl device */ + pdev = of_platform_device_create(np, NULL, &host->dev); + if (!pdev) + pr_err("PCI/pwrctrl: Failed to create pwrctrl device for OF node: %s\n", np->name); +} + /* * Read the config data for a PCI device, sanity-check it, * and fill in the dev structure. @@ -2502,6 +2534,8 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) struct pci_dev *dev; u32 l; + pci_pwrctrl_create_device(bus, devfn); + if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) return NULL; diff --git a/drivers/pci/pwrctrl/core.c b/drivers/pci/pwrctrl/core.c index 2fb174db91e5..9cc7e2b7f2b5 100644 --- a/drivers/pci/pwrctrl/core.c +++ b/drivers/pci/pwrctrl/core.c @@ -44,7 +44,7 @@ static void rescan_work_func(struct work_struct *work) struct pci_pwrctrl, work); pci_lock_rescan_remove(); - pci_rescan_bus(to_pci_dev(pwrctrl->dev->parent)->bus); + pci_rescan_bus(to_pci_host_bridge(pwrctrl->dev->parent)->bus); pci_unlock_rescan_remove(); } From 2d923930f2e3fe1ecf060169f57980da819a191f Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Thu, 16 Jan 2025 19:39:12 +0530 Subject: [PATCH 2/5] PCI/pwrctrl: Move pci_pwrctrl_unregister() to pci_destroy_dev() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The PCI core will try to access the devices even after pci_stop_dev() for things like Data Object Exchange (DOE), ASPM, etc. So, move pci_pwrctrl_unregister() to the near end of pci_destroy_dev() to make sure that the devices are powered down only after the PCI core is done with them. Suggested-by: Lukas Wunner Reviewed-by: Lukas Wunner Tested-by: Bartosz Golaszewski Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-2-827473c8fbf4@linaro.org [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński --- drivers/pci/remove.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index efc37fcb73e2..58859f9d92f7 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -41,7 +41,6 @@ static void pci_stop_dev(struct pci_dev *dev) if (!pci_dev_test_and_clear_added(dev)) return; - pci_pwrctrl_unregister(&dev->dev); device_release_driver(&dev->dev); pci_proc_detach_device(dev); pci_remove_sysfs_dev_files(dev); @@ -64,6 +63,7 @@ static void pci_destroy_dev(struct pci_dev *dev) pci_doe_destroy(dev); pcie_aspm_exit_link_state(dev); pci_bridge_d3_update(dev); + pci_pwrctrl_unregister(&dev->dev); pci_free_resources(dev); put_device(&dev->dev); } From 2489eeb777aff943cb93b287385f2e8c68978db0 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Thu, 16 Jan 2025 19:39:13 +0530 Subject: [PATCH 3/5] PCI/pwrctrl: Skip scanning for the device further if pwrctrl device is created MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The pwrctrl core will rescan the bus once the device is powered on. So there is no need to continue scanning for the device further. Reviewed-by: Bartosz Golaszewski Tested-by: Bartosz Golaszewski Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-3-827473c8fbf4@linaro.org Signed-off-by: Krzysztof Wilczyński --- drivers/pci/probe.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 95a91778bb5d..1191b02ae9f8 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2495,11 +2495,7 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, } EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); -/* - * Create pwrctrl device (if required) for the PCI device to handle the power - * state. - */ -static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn) +static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, int devfn) { struct pci_host_bridge *host = pci_find_host_bridge(bus); struct platform_device *pdev; @@ -2507,7 +2503,7 @@ static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn) np = of_pci_find_child_device(dev_of_node(&bus->dev), devfn); if (!np || of_find_device_by_node(np)) - return; + return NULL; /* * First check whether the pwrctrl device really needs to be created or @@ -2516,13 +2512,17 @@ static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn) */ if (!of_pci_supply_present(np)) { pr_debug("PCI/pwrctrl: Skipping OF node: %s\n", np->name); - return; + return NULL; } /* Now create the pwrctrl device */ pdev = of_platform_device_create(np, NULL, &host->dev); - if (!pdev) - pr_err("PCI/pwrctrl: Failed to create pwrctrl device for OF node: %s\n", np->name); + if (!pdev) { + pr_err("PCI/pwrctrl: Failed to create pwrctrl device for node: %s\n", np->name); + return NULL; + } + + return pdev; } /* @@ -2534,7 +2534,14 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) struct pci_dev *dev; u32 l; - pci_pwrctrl_create_device(bus, devfn); + /* + * Create pwrctrl device (if required) for the PCI device to handle the + * power state. If the pwrctrl device is created, then skip scanning + * further as the pwrctrl core will rescan the bus after powering on + * the device. + */ + if (pci_pwrctrl_create_device(bus, devfn)) + return NULL; if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) return NULL; From 2a95c1f3468bbeb4222e90f27a8f1c94d87e1df6 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Thu, 16 Jan 2025 19:39:14 +0530 Subject: [PATCH 4/5] dt-bindings: vendor-prefixes: Document the 'pciclass' prefix MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The "pciclass" is an existing prefix used to identify the PCI bridge devices, but it is not a vendor prefix. So document it in the non-vendor prefix list. Tested-by: Bartosz Golaszewski Acked-by: Rob Herring (Arm) Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-4-827473c8fbf4@linaro.org [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński --- Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml index 5079ca6ce1d1..8e8bc6a7f0bd 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml @@ -18,7 +18,7 @@ patternProperties: # DO NOT ADD NEW PROPERTIES TO THIS LIST "^(at25|bm|devbus|dmacap|dsa|exynos|fsi[ab]|gpio-fan|gpio-key|gpio|gpmc|hdmi|i2c-gpio),.*": true "^(keypad|m25p|max8952|max8997|max8998|mpmc),.*": true - "^(pinctrl-single|#pinctrl-single|PowerPC),.*": true + "^(pciclass|pinctrl-single|#pinctrl-single|PowerPC),.*": true "^(pl022|pxa-mmc|rcar_sound|rotary-encoder|s5m8767|sdhci),.*": true "^(simple-audio-card|st-plgpio|st-spics|ts),.*": true From 75996c92f4de309f855471927e6489f5a354cfd4 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Thu, 16 Jan 2025 19:39:15 +0530 Subject: [PATCH 5/5] PCI/pwrctrl: Add pwrctrl driver for PCI slots MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This driver is used to control the power state of the devices attached to the PCI slots. Currently, it controls the voltage rails of the PCI slots defined in the devicetree node of the root port. The voltage rails for PCI slots are documented in the DT-schema: https://github.com/devicetree-org/dt-schema/blob/v2024.11/dtschema/schemas/pci/pci-bus-common.yaml#L153 Since this driver has to work with different kind of slots (PCIe x1/x4/x8/x16, Mini PCIe, PCI, etc.), the driver is thus using the of_regulator_bulk_get_all() API to obtain the voltage regulators defined in the DT node, instead of hardcoding them. As such, the DT node of the root port should define the relevant supply properties corresponding to the voltage rails of the PCI slot. Tested-by: Bartosz Golaszewski Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-5-827473c8fbf4@linaro.org [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński --- drivers/pci/pwrctrl/Kconfig | 11 +++++ drivers/pci/pwrctrl/Makefile | 3 ++ drivers/pci/pwrctrl/slot.c | 93 ++++++++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+) create mode 100644 drivers/pci/pwrctrl/slot.c diff --git a/drivers/pci/pwrctrl/Kconfig b/drivers/pci/pwrctrl/Kconfig index 54589bb2403b..990cab67d413 100644 --- a/drivers/pci/pwrctrl/Kconfig +++ b/drivers/pci/pwrctrl/Kconfig @@ -10,3 +10,14 @@ config PCI_PWRCTL_PWRSEQ tristate select POWER_SEQUENCING select PCI_PWRCTL + +config PCI_PWRCTL_SLOT + tristate "PCI Power Control driver for PCI slots" + select PCI_PWRCTL + help + Say Y here to enable the PCI Power Control driver to control the power + state of PCI slots. + + This is a generic driver that controls the power state of different + PCI slots. The voltage regulators powering the rails of the PCI slots + are expected to be defined in the devicetree node of the PCI bridge. diff --git a/drivers/pci/pwrctrl/Makefile b/drivers/pci/pwrctrl/Makefile index 75c7ce531c7e..ddfb12c5aadf 100644 --- a/drivers/pci/pwrctrl/Makefile +++ b/drivers/pci/pwrctrl/Makefile @@ -4,3 +4,6 @@ obj-$(CONFIG_PCI_PWRCTL) += pci-pwrctrl-core.o pci-pwrctrl-core-y := core.o obj-$(CONFIG_PCI_PWRCTL_PWRSEQ) += pci-pwrctrl-pwrseq.o + +obj-$(CONFIG_PCI_PWRCTL_SLOT) += pci-pwrctl-slot.o +pci-pwrctl-slot-y := slot.o diff --git a/drivers/pci/pwrctrl/slot.c b/drivers/pci/pwrctrl/slot.c new file mode 100644 index 000000000000..18becc144913 --- /dev/null +++ b/drivers/pci/pwrctrl/slot.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Linaro Ltd. + * Author: Manivannan Sadhasivam + */ + +#include +#include +#include +#include +#include +#include +#include + +struct pci_pwrctrl_slot_data { + struct pci_pwrctrl ctx; + struct regulator_bulk_data *supplies; + int num_supplies; +}; + +static void devm_pci_pwrctrl_slot_power_off(void *data) +{ + struct pci_pwrctrl_slot_data *slot = data; + + regulator_bulk_disable(slot->num_supplies, slot->supplies); + regulator_bulk_free(slot->num_supplies, slot->supplies); +} + +static int pci_pwrctrl_slot_probe(struct platform_device *pdev) +{ + struct pci_pwrctrl_slot_data *slot; + struct device *dev = &pdev->dev; + int ret; + + slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL); + if (!slot) + return -ENOMEM; + + ret = of_regulator_bulk_get_all(dev, dev_of_node(dev), + &slot->supplies); + if (ret < 0) { + dev_err_probe(dev, ret, "Failed to get slot regulators\n"); + return ret; + } + + slot->num_supplies = ret; + ret = regulator_bulk_enable(slot->num_supplies, slot->supplies); + if (ret < 0) { + dev_err_probe(dev, ret, "Failed to enable slot regulators\n"); + goto err_regulator_free; + } + + ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off, + slot); + if (ret) + goto err_regulator_disable; + + pci_pwrctrl_init(&slot->ctx, dev); + + ret = devm_pci_pwrctrl_device_set_ready(dev, &slot->ctx); + if (ret) + return dev_err_probe(dev, ret, "Failed to register pwrctrl driver\n"); + + return 0; + +err_regulator_disable: + regulator_bulk_disable(slot->num_supplies, slot->supplies); +err_regulator_free: + regulator_bulk_free(slot->num_supplies, slot->supplies); + + return ret; +} + +static const struct of_device_id pci_pwrctrl_slot_of_match[] = { + { + .compatible = "pciclass,0604", + }, + { } +}; +MODULE_DEVICE_TABLE(of, pci_pwrctrl_slot_of_match); + +static struct platform_driver pci_pwrctrl_slot_driver = { + .driver = { + .name = "pci-pwrctrl-slot", + .of_match_table = pci_pwrctrl_slot_of_match, + }, + .probe = pci_pwrctrl_slot_probe, +}; +module_platform_driver(pci_pwrctrl_slot_driver); + +MODULE_AUTHOR("Manivannan Sadhasivam "); +MODULE_DESCRIPTION("Generic PCI Power Control driver for PCI Slots"); +MODULE_LICENSE("GPL");