drivers/net/pse-pd/pse_regulator.c

   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 <[email protected]>
   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
  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
  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
  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
  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
  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
  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 <[email protected]>");
 152 MODULE_DESCRIPTION("regulator based Ethernet Power Sourcing Equipment");
 153 MODULE_LICENSE("GPL v2");
 154 MODULE_ALIAS("platform:pse-regulator");