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
15 struct 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
to_pse_reg(struct pse_controller_dev * pcdev)21 static 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
26 static int
pse_reg_ethtool_set_config(struct pse_controller_dev * pcdev,unsigned long id,struct netlink_ext_ack * extack,const struct pse_control_config * config)27 pse_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
58 static int
pse_reg_ethtool_get_status(struct pse_controller_dev * pcdev,unsigned long id,struct netlink_ext_ack * extack,struct pse_control_status * status)59 pse_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
81 static 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
86 static int
pse_reg_probe(struct platform_device * pdev)87 pse_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
129 static const __maybe_unused struct of_device_id pse_reg_of_match[] = {
130 { .compatible = "podl-pse-regulator", },
131 { },
132 };
133 MODULE_DEVICE_TABLE(of, pse_reg_of_match);
134
135 static 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 };
142 module_platform_driver(pse_reg_driver);
143
144 MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
145 MODULE_DESCRIPTION("regulator based Ethernet Power Sourcing Equipment");
146 MODULE_LICENSE("GPL v2");
147 MODULE_ALIAS("platform:pse-regulator");
148