xref: /linux/drivers/pci/pwrctrl/generic.c (revision ff124bbbca1d3a07fa1392ffdbbdeece71f68ece)
1*ff124bbbSNeil Armstrong // SPDX-License-Identifier: GPL-2.0-only
2*ff124bbbSNeil Armstrong /*
3*ff124bbbSNeil Armstrong  * Copyright (C) 2024 Linaro Ltd.
4*ff124bbbSNeil Armstrong  * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
5*ff124bbbSNeil Armstrong  */
6*ff124bbbSNeil Armstrong 
7*ff124bbbSNeil Armstrong #include <linux/clk.h>
8*ff124bbbSNeil Armstrong #include <linux/device.h>
9*ff124bbbSNeil Armstrong #include <linux/mod_devicetable.h>
10*ff124bbbSNeil Armstrong #include <linux/module.h>
11*ff124bbbSNeil Armstrong #include <linux/of_graph.h>
12*ff124bbbSNeil Armstrong #include <linux/pci-pwrctrl.h>
13*ff124bbbSNeil Armstrong #include <linux/platform_device.h>
14*ff124bbbSNeil Armstrong #include <linux/pwrseq/consumer.h>
15*ff124bbbSNeil Armstrong #include <linux/regulator/consumer.h>
16*ff124bbbSNeil Armstrong #include <linux/slab.h>
17*ff124bbbSNeil Armstrong 
18*ff124bbbSNeil Armstrong struct slot_pwrctrl {
19*ff124bbbSNeil Armstrong 	struct pci_pwrctrl pwrctrl;
20*ff124bbbSNeil Armstrong 	struct regulator_bulk_data *supplies;
21*ff124bbbSNeil Armstrong 	int num_supplies;
22*ff124bbbSNeil Armstrong 	struct clk *clk;
23*ff124bbbSNeil Armstrong 	struct pwrseq_desc *pwrseq;
24*ff124bbbSNeil Armstrong };
25*ff124bbbSNeil Armstrong 
26*ff124bbbSNeil Armstrong static int slot_pwrctrl_power_on(struct pci_pwrctrl *pwrctrl)
27*ff124bbbSNeil Armstrong {
28*ff124bbbSNeil Armstrong 	struct slot_pwrctrl *slot = container_of(pwrctrl,
29*ff124bbbSNeil Armstrong 						struct slot_pwrctrl, pwrctrl);
30*ff124bbbSNeil Armstrong 	int ret;
31*ff124bbbSNeil Armstrong 
32*ff124bbbSNeil Armstrong 	if (slot->pwrseq) {
33*ff124bbbSNeil Armstrong 		pwrseq_power_on(slot->pwrseq);
34*ff124bbbSNeil Armstrong 		return 0;
35*ff124bbbSNeil Armstrong 	}
36*ff124bbbSNeil Armstrong 
37*ff124bbbSNeil Armstrong 	ret = regulator_bulk_enable(slot->num_supplies, slot->supplies);
38*ff124bbbSNeil Armstrong 	if (ret < 0) {
39*ff124bbbSNeil Armstrong 		dev_err(slot->pwrctrl.dev, "Failed to enable slot regulators\n");
40*ff124bbbSNeil Armstrong 		return ret;
41*ff124bbbSNeil Armstrong 	}
42*ff124bbbSNeil Armstrong 
43*ff124bbbSNeil Armstrong 	return clk_prepare_enable(slot->clk);
44*ff124bbbSNeil Armstrong }
45*ff124bbbSNeil Armstrong 
46*ff124bbbSNeil Armstrong static int slot_pwrctrl_power_off(struct pci_pwrctrl *pwrctrl)
47*ff124bbbSNeil Armstrong {
48*ff124bbbSNeil Armstrong 	struct slot_pwrctrl *slot = container_of(pwrctrl,
49*ff124bbbSNeil Armstrong 						struct slot_pwrctrl, pwrctrl);
50*ff124bbbSNeil Armstrong 
51*ff124bbbSNeil Armstrong 	if (slot->pwrseq) {
52*ff124bbbSNeil Armstrong 		pwrseq_power_off(slot->pwrseq);
53*ff124bbbSNeil Armstrong 		return 0;
54*ff124bbbSNeil Armstrong 	}
55*ff124bbbSNeil Armstrong 
56*ff124bbbSNeil Armstrong 	regulator_bulk_disable(slot->num_supplies, slot->supplies);
57*ff124bbbSNeil Armstrong 	clk_disable_unprepare(slot->clk);
58*ff124bbbSNeil Armstrong 
59*ff124bbbSNeil Armstrong 	return 0;
60*ff124bbbSNeil Armstrong }
61*ff124bbbSNeil Armstrong 
62*ff124bbbSNeil Armstrong static void devm_slot_pwrctrl_release(void *data)
63*ff124bbbSNeil Armstrong {
64*ff124bbbSNeil Armstrong 	struct slot_pwrctrl *slot = data;
65*ff124bbbSNeil Armstrong 
66*ff124bbbSNeil Armstrong 	slot_pwrctrl_power_off(&slot->pwrctrl);
67*ff124bbbSNeil Armstrong 	regulator_bulk_free(slot->num_supplies, slot->supplies);
68*ff124bbbSNeil Armstrong }
69*ff124bbbSNeil Armstrong 
70*ff124bbbSNeil Armstrong static int slot_pwrctrl_probe(struct platform_device *pdev)
71*ff124bbbSNeil Armstrong {
72*ff124bbbSNeil Armstrong 	struct slot_pwrctrl *slot;
73*ff124bbbSNeil Armstrong 	struct device *dev = &pdev->dev;
74*ff124bbbSNeil Armstrong 	int ret;
75*ff124bbbSNeil Armstrong 
76*ff124bbbSNeil Armstrong 	slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
77*ff124bbbSNeil Armstrong 	if (!slot)
78*ff124bbbSNeil Armstrong 		return -ENOMEM;
79*ff124bbbSNeil Armstrong 
80*ff124bbbSNeil Armstrong 	if (of_graph_is_present(dev_of_node(dev))) {
81*ff124bbbSNeil Armstrong 		slot->pwrseq = devm_pwrseq_get(dev, "pcie");
82*ff124bbbSNeil Armstrong 		if (IS_ERR(slot->pwrseq))
83*ff124bbbSNeil Armstrong 			return dev_err_probe(dev, PTR_ERR(slot->pwrseq),
84*ff124bbbSNeil Armstrong 				     "Failed to get the power sequencer\n");
85*ff124bbbSNeil Armstrong 
86*ff124bbbSNeil Armstrong 		goto skip_resources;
87*ff124bbbSNeil Armstrong 	}
88*ff124bbbSNeil Armstrong 
89*ff124bbbSNeil Armstrong 	ret = of_regulator_bulk_get_all(dev, dev_of_node(dev),
90*ff124bbbSNeil Armstrong 					&slot->supplies);
91*ff124bbbSNeil Armstrong 	if (ret < 0) {
92*ff124bbbSNeil Armstrong 		dev_err_probe(dev, ret, "Failed to get slot regulators\n");
93*ff124bbbSNeil Armstrong 		return ret;
94*ff124bbbSNeil Armstrong 	}
95*ff124bbbSNeil Armstrong 
96*ff124bbbSNeil Armstrong 	slot->num_supplies = ret;
97*ff124bbbSNeil Armstrong 
98*ff124bbbSNeil Armstrong 	slot->clk = devm_clk_get_optional(dev, NULL);
99*ff124bbbSNeil Armstrong 	if (IS_ERR(slot->clk)) {
100*ff124bbbSNeil Armstrong 		return dev_err_probe(dev, PTR_ERR(slot->clk),
101*ff124bbbSNeil Armstrong 				     "Failed to enable slot clock\n");
102*ff124bbbSNeil Armstrong 	}
103*ff124bbbSNeil Armstrong 
104*ff124bbbSNeil Armstrong skip_resources:
105*ff124bbbSNeil Armstrong 	slot->pwrctrl.power_on = slot_pwrctrl_power_on;
106*ff124bbbSNeil Armstrong 	slot->pwrctrl.power_off = slot_pwrctrl_power_off;
107*ff124bbbSNeil Armstrong 
108*ff124bbbSNeil Armstrong 	ret = devm_add_action_or_reset(dev, devm_slot_pwrctrl_release, slot);
109*ff124bbbSNeil Armstrong 	if (ret)
110*ff124bbbSNeil Armstrong 		return ret;
111*ff124bbbSNeil Armstrong 
112*ff124bbbSNeil Armstrong 	pci_pwrctrl_init(&slot->pwrctrl, dev);
113*ff124bbbSNeil Armstrong 
114*ff124bbbSNeil Armstrong 	ret = devm_pci_pwrctrl_device_set_ready(dev, &slot->pwrctrl);
115*ff124bbbSNeil Armstrong 	if (ret)
116*ff124bbbSNeil Armstrong 		return dev_err_probe(dev, ret, "Failed to register pwrctrl driver\n");
117*ff124bbbSNeil Armstrong 
118*ff124bbbSNeil Armstrong 	return 0;
119*ff124bbbSNeil Armstrong }
120*ff124bbbSNeil Armstrong 
121*ff124bbbSNeil Armstrong static const struct of_device_id slot_pwrctrl_of_match[] = {
122*ff124bbbSNeil Armstrong 	{
123*ff124bbbSNeil Armstrong 		.compatible = "pciclass,0604",
124*ff124bbbSNeil Armstrong 	},
125*ff124bbbSNeil Armstrong 	{ }
126*ff124bbbSNeil Armstrong };
127*ff124bbbSNeil Armstrong MODULE_DEVICE_TABLE(of, slot_pwrctrl_of_match);
128*ff124bbbSNeil Armstrong 
129*ff124bbbSNeil Armstrong static struct platform_driver slot_pwrctrl_driver = {
130*ff124bbbSNeil Armstrong 	.driver = {
131*ff124bbbSNeil Armstrong 		.name = "pci-pwrctrl-slot",
132*ff124bbbSNeil Armstrong 		.of_match_table = slot_pwrctrl_of_match,
133*ff124bbbSNeil Armstrong 	},
134*ff124bbbSNeil Armstrong 	.probe = slot_pwrctrl_probe,
135*ff124bbbSNeil Armstrong };
136*ff124bbbSNeil Armstrong module_platform_driver(slot_pwrctrl_driver);
137*ff124bbbSNeil Armstrong 
138*ff124bbbSNeil Armstrong MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
139*ff124bbbSNeil Armstrong MODULE_DESCRIPTION("Generic PCI Power Control driver for PCI Slots");
140*ff124bbbSNeil Armstrong MODULE_LICENSE("GPL");
141