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 <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
  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_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
  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
  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");