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_pi_enable(struct pse_controller_dev * pcdev,int id)27 pse_reg_pi_enable(struct pse_controller_dev *pcdev, int id)
28 {
29 struct pse_reg_priv *priv = to_pse_reg(pcdev);
30 int ret;
31
32 ret = regulator_enable(priv->ps);
33 if (ret)
34 return ret;
35
36 priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED;
37 return 0;
38 }
39
40 static int
pse_reg_pi_disable(struct pse_controller_dev * pcdev,int id)41 pse_reg_pi_disable(struct pse_controller_dev *pcdev, int id)
42 {
43 struct pse_reg_priv *priv = to_pse_reg(pcdev);
44 int ret;
45
46 ret = regulator_disable(priv->ps);
47 if (ret)
48 return ret;
49
50 priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED;
51 return 0;
52 }
53
54 static int
pse_reg_pi_is_enabled(struct pse_controller_dev * pcdev,int id)55 pse_reg_pi_is_enabled(struct pse_controller_dev *pcdev, int id)
56 {
57 struct pse_reg_priv *priv = to_pse_reg(pcdev);
58
59 return regulator_is_enabled(priv->ps);
60 }
61
62 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)63 pse_reg_ethtool_get_status(struct pse_controller_dev *pcdev, unsigned long id,
64 struct netlink_ext_ack *extack,
65 struct pse_control_status *status)
66 {
67 struct pse_reg_priv *priv = to_pse_reg(pcdev);
68 int ret;
69
70 ret = regulator_is_enabled(priv->ps);
71 if (ret < 0)
72 return ret;
73
74 if (!ret)
75 status->podl_pw_status = ETHTOOL_PODL_PSE_PW_D_STATUS_DISABLED;
76 else
77 status->podl_pw_status =
78 ETHTOOL_PODL_PSE_PW_D_STATUS_DELIVERING;
79
80 status->podl_admin_state = priv->admin_state;
81
82 return 0;
83 }
84
85 static const struct pse_controller_ops pse_reg_ops = {
86 .ethtool_get_status = pse_reg_ethtool_get_status,
87 .pi_enable = pse_reg_pi_enable,
88 .pi_is_enabled = pse_reg_pi_is_enabled,
89 .pi_disable = pse_reg_pi_disable,
90 };
91
92 static int
pse_reg_probe(struct platform_device * pdev)93 pse_reg_probe(struct platform_device *pdev)
94 {
95 struct device *dev = &pdev->dev;
96 struct pse_reg_priv *priv;
97 int ret;
98
99 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
100 if (!priv)
101 return -ENOMEM;
102
103 if (!pdev->dev.of_node)
104 return -ENOENT;
105
106 priv->ps = devm_regulator_get_exclusive(dev, "pse");
107 if (IS_ERR(priv->ps))
108 return dev_err_probe(dev, PTR_ERR(priv->ps),
109 "failed to get PSE regulator.\n");
110
111 platform_set_drvdata(pdev, priv);
112
113 ret = regulator_is_enabled(priv->ps);
114 if (ret < 0)
115 return ret;
116
117 if (ret)
118 priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED;
119 else
120 priv->admin_state = ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED;
121
122 priv->pcdev.owner = THIS_MODULE;
123 priv->pcdev.ops = &pse_reg_ops;
124 priv->pcdev.dev = dev;
125 priv->pcdev.types = ETHTOOL_PSE_PODL;
126 ret = devm_pse_controller_register(dev, &priv->pcdev);
127 if (ret) {
128 dev_err(dev, "failed to register PSE controller (%pe)\n",
129 ERR_PTR(ret));
130 return ret;
131 }
132
133 return 0;
134 }
135
136 static const __maybe_unused struct of_device_id pse_reg_of_match[] = {
137 { .compatible = "podl-pse-regulator", },
138 { },
139 };
140 MODULE_DEVICE_TABLE(of, pse_reg_of_match);
141
142 static struct platform_driver pse_reg_driver = {
143 .probe = pse_reg_probe,
144 .driver = {
145 .name = "PSE regulator",
146 .of_match_table = of_match_ptr(pse_reg_of_match),
147 },
148 };
149 module_platform_driver(pse_reg_driver);
150
151 MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
152 MODULE_DESCRIPTION("regulator based Ethernet Power Sourcing Equipment");
153 MODULE_LICENSE("GPL v2");
154 MODULE_ALIAS("platform:pse-regulator");
155