slot.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2024 Linaro Ltd.
 4 * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 5 */
 6
 7#include <linux/clk.h>
 8#include <linux/device.h>
 9#include <linux/mod_devicetable.h>
10#include <linux/module.h>
11#include <linux/pci-pwrctrl.h>
12#include <linux/platform_device.h>
13#include <linux/regulator/consumer.h>
14#include <linux/slab.h>
15
16struct pci_pwrctrl_slot_data {
17	struct pci_pwrctrl ctx;
18	struct regulator_bulk_data *supplies;
19	int num_supplies;
20};
21
22static void devm_pci_pwrctrl_slot_power_off(void *data)
23{
24	struct pci_pwrctrl_slot_data *slot = data;
25
26	regulator_bulk_disable(slot->num_supplies, slot->supplies);
27	regulator_bulk_free(slot->num_supplies, slot->supplies);
28}
29
30static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
31{
32	struct pci_pwrctrl_slot_data *slot;
33	struct device *dev = &pdev->dev;
34	struct clk *clk;
35	int ret;
36
37	slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
38	if (!slot)
39		return -ENOMEM;
40
41	ret = of_regulator_bulk_get_all(dev, dev_of_node(dev),
42					&slot->supplies);
43	if (ret < 0) {
44		dev_err_probe(dev, ret, "Failed to get slot regulators\n");
45		return ret;
46	}
47
48	slot->num_supplies = ret;
49	ret = regulator_bulk_enable(slot->num_supplies, slot->supplies);
50	if (ret < 0) {
51		dev_err_probe(dev, ret, "Failed to enable slot regulators\n");
52		regulator_bulk_free(slot->num_supplies, slot->supplies);
53		return ret;
54	}
55
56	ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off,
57				       slot);
58	if (ret)
59		return ret;
60
61	clk = devm_clk_get_optional_enabled(dev, NULL);
62	if (IS_ERR(clk)) {
63		return dev_err_probe(dev, PTR_ERR(clk),
64				     "Failed to enable slot clock\n");
65	}
66
67	pci_pwrctrl_init(&slot->ctx, dev);
68
69	ret = devm_pci_pwrctrl_device_set_ready(dev, &slot->ctx);
70	if (ret)
71		return dev_err_probe(dev, ret, "Failed to register pwrctrl driver\n");
72
73	return 0;
74}
75
76static const struct of_device_id pci_pwrctrl_slot_of_match[] = {
77	{
78		.compatible = "pciclass,0604",
79	},
80	{ }
81};
82MODULE_DEVICE_TABLE(of, pci_pwrctrl_slot_of_match);
83
84static struct platform_driver pci_pwrctrl_slot_driver = {
85	.driver = {
86		.name = "pci-pwrctrl-slot",
87		.of_match_table = pci_pwrctrl_slot_of_match,
88	},
89	.probe = pci_pwrctrl_slot_probe,
90};
91module_platform_driver(pci_pwrctrl_slot_driver);
92
93MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
94MODULE_DESCRIPTION("Generic PCI Power Control driver for PCI Slots");
95MODULE_LICENSE("GPL");