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75996c92f4
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 <bartosz.golaszewski@linaro.org> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-5-827473c8fbf4@linaro.org [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2024 Linaro Ltd.
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* Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
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*/
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#include <linux/device.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/pci-pwrctrl.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/slab.h>
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struct pci_pwrctrl_slot_data {
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struct pci_pwrctrl ctx;
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struct regulator_bulk_data *supplies;
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int num_supplies;
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};
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static void devm_pci_pwrctrl_slot_power_off(void *data)
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{
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struct pci_pwrctrl_slot_data *slot = data;
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regulator_bulk_disable(slot->num_supplies, slot->supplies);
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regulator_bulk_free(slot->num_supplies, slot->supplies);
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}
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static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
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{
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struct pci_pwrctrl_slot_data *slot;
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struct device *dev = &pdev->dev;
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int ret;
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slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
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if (!slot)
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return -ENOMEM;
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ret = of_regulator_bulk_get_all(dev, dev_of_node(dev),
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&slot->supplies);
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if (ret < 0) {
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dev_err_probe(dev, ret, "Failed to get slot regulators\n");
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return ret;
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}
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slot->num_supplies = ret;
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ret = regulator_bulk_enable(slot->num_supplies, slot->supplies);
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if (ret < 0) {
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dev_err_probe(dev, ret, "Failed to enable slot regulators\n");
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goto err_regulator_free;
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}
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ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off,
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slot);
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if (ret)
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goto err_regulator_disable;
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pci_pwrctrl_init(&slot->ctx, dev);
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ret = devm_pci_pwrctrl_device_set_ready(dev, &slot->ctx);
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if (ret)
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return dev_err_probe(dev, ret, "Failed to register pwrctrl driver\n");
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return 0;
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err_regulator_disable:
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regulator_bulk_disable(slot->num_supplies, slot->supplies);
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err_regulator_free:
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regulator_bulk_free(slot->num_supplies, slot->supplies);
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return ret;
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}
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static const struct of_device_id pci_pwrctrl_slot_of_match[] = {
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{
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.compatible = "pciclass,0604",
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, pci_pwrctrl_slot_of_match);
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static struct platform_driver pci_pwrctrl_slot_driver = {
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.driver = {
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.name = "pci-pwrctrl-slot",
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.of_match_table = pci_pwrctrl_slot_of_match,
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},
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.probe = pci_pwrctrl_slot_probe,
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};
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module_platform_driver(pci_pwrctrl_slot_driver);
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MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
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MODULE_DESCRIPTION("Generic PCI Power Control driver for PCI Slots");
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MODULE_LICENSE("GPL");
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