1// SPDX-License-Identifier: GPL-2.0-only
2//
3// Driver for the regulator based Ethernet Power Sourcing Equipment, without
4// auto classification support.
5//
6// Copyright (c) 2022 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
7//
8
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/pse-pd/pse.h>
13#include <linux/regulator/consumer.h>
14
15struct pse_reg_priv {
16	struct pse_controller_dev pcdev;
17	struct regulator *ps; /*power source */
18	enum ethtool_podl_pse_admin_state admin_state;
19};
20
21static struct pse_reg_priv *to_pse_reg(struct pse_controller_dev *pcdev)
22{
23	return container_of(pcdev, struct pse_reg_priv, pcdev);
24}
25
26static int
27pse_reg_ethtool_set_config(struct pse_controller_dev *pcdev, unsigned long id,
28			   struct netlink_ext_ack *extack,
29			   const struct pse_control_config *config)
30{
31	struct pse_reg_priv *priv = to_pse_reg(pcdev);
32	int ret;
33
34	if (priv->admin_state == config->admin_cotrol)
35		return 0;
36
37	switch (config->admin_cotrol) {
38	case ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED:
39		ret = regulator_enable(priv->ps);
40		break;
41	case ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED:
42		ret = regulator_disable(priv->ps);
43		break;
44	default:
45		dev_err(pcdev->dev, "Unknown admin state %i\n",
46			config->admin_cotrol);
47		ret = -ENOTSUPP;
48	}
49
50	if (ret)
51		return ret;
52
53	priv->admin_state = config->admin_cotrol;
54
55	return 0;
56}
57
58static int
59pse_reg_ethtool_get_status(struct pse_controller_dev *pcdev, unsigned long id,
60			   struct netlink_ext_ack *extack,
61			   struct pse_control_status *status)
62{
63	struct pse_reg_priv *priv = to_pse_reg(pcdev);
64	int ret;
65
66	ret = regulator_is_enabled(priv->ps);
67	if (ret < 0)
68		return ret;
69
70	if (!ret)
71		status->podl_pw_status = ETHTOOL_PODL_PSE_PW_D_STATUS_DISABLED;
72	else
73		status->podl_pw_status =
74			ETHTOOL_PODL_PSE_PW_D_STATUS_DELIVERING;
75
76	status->podl_admin_state = priv->admin_state;
77
78	return 0;
79}
80
81static const struct pse_controller_ops pse_reg_ops = {
82	.ethtool_get_status = pse_reg_ethtool_get_status,
83	.ethtool_set_config = pse_reg_ethtool_set_config,
84};
85
86static int
87pse_reg_probe(struct platform_device *pdev)
88{
89	struct device *dev = &pdev->dev;
90	struct pse_reg_priv *priv;
91	int ret;
92
93	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
94	if (!priv)
95		return -ENOMEM;
96
97	if (!pdev->dev.of_node)
98		return -ENOENT;
99
100	priv->ps = devm_regulator_get_exclusive(dev, "pse");
101	if (IS_ERR(priv->ps))
102		return dev_err_probe(dev, PTR_ERR(priv->ps),
103				     "failed to get PSE regulator.\n");
104
105	platform_set_drvdata(pdev, priv);
106
107	ret = regulator_is_enabled(priv->ps);
108	if (ret < 0)
109		return ret;
110
111	if (ret)
112		priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED;
113	else
114		priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED;
115
116	priv->pcdev.owner = THIS_MODULE;
117	priv->pcdev.ops = &pse_reg_ops;
118	priv->pcdev.dev = dev;
119	ret = devm_pse_controller_register(dev, &priv->pcdev);
120	if (ret) {
121		dev_err(dev, "failed to register PSE controller (%pe)\n",
122			ERR_PTR(ret));
123		return ret;
124	}
125
126	return 0;
127}
128
129static const __maybe_unused struct of_device_id pse_reg_of_match[] = {
130	{ .compatible = "podl-pse-regulator", },
131	{ },
132};
133MODULE_DEVICE_TABLE(of, pse_reg_of_match);
134
135static struct platform_driver pse_reg_driver = {
136	.probe		= pse_reg_probe,
137	.driver		= {
138		.name		= "PSE regulator",
139		.of_match_table = of_match_ptr(pse_reg_of_match),
140	},
141};
142module_platform_driver(pse_reg_driver);
143
144MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
145MODULE_DESCRIPTION("regulator based Ethernet Power Sourcing Equipment");
146MODULE_LICENSE("GPL v2");
147MODULE_ALIAS("platform:pse-regulator");
148