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_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
 40static int
 41pse_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
 54static int
 55pse_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
 62static int
 63pse_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
 85static 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
 92static int
 93pse_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
136static const __maybe_unused struct of_device_id pse_reg_of_match[] = {
137	{ .compatible = "podl-pse-regulator", },
138	{ },
139};
140MODULE_DEVICE_TABLE(of, pse_reg_of_match);
141
142static 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};
149module_platform_driver(pse_reg_driver);
150
151MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
152MODULE_DESCRIPTION("regulator based Ethernet Power Sourcing Equipment");
153MODULE_LICENSE("GPL v2");
154MODULE_ALIAS("platform:pse-regulator");